diff --git a/base/BUILD.gn b/base/BUILD.gn
index 5ad4e4869019..57d330c19ad0 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -103,7 +103,7 @@ if (is_apple) {
 
 # Determines whether libevent should be dep.
 dep_libevent = !is_fuchsia && !is_win && !is_mac && !is_nacl
-    && !use_cobalt_customizations
+    && (!use_cobalt_customizations || sb_api_version >= 16)
 
 # Determines whether message_pump_libevent should be used.
 use_libevent = dep_libevent && !is_ios
@@ -980,6 +980,26 @@ component("base") {
       "message_loop/message_pump_io_starboard.h",
       "message_loop/message_pump_ui_starboard.cc",
       "message_loop/message_pump_ui_starboard.h",
+
+      # added for posix - by zhangmax
+
+
+      "synchronization/condition_variable_posix.cc",
+      "time/time_conversion_posix.cc",
+
+      "files/file_posix.cc",
+      "files/file_util_posix.cc",
+      "files/file_descriptor_watcher_posix.cc",
+      "files/file_descriptor_watcher_posix.h",
+      "files/file_enumerator_posix.cc",
+
+      "memory/page_size_posix.cc",
+
+      "message_loop/watchable_io_message_pump_posix.cc",
+      "message_loop/watchable_io_message_pump_posix.h",
+
+      # end of adding - zhangmax
+
       "process/launch.cc",
       "process/launch.h",
       "process/launch_starboard.cc",
@@ -2345,7 +2365,7 @@ component("base") {
     ]
   }
 
-  if (!use_cobalt_customizations && is_posix && !is_apple) {
+  if (use_libevent) {
     sources += [
       "strings/sys_string_conversions_posix.cc",
       "synchronization/waitable_event_posix.cc",
diff --git a/base/allocator/partition_allocator/partition_alloc_base/time/time.h b/base/allocator/partition_allocator/partition_alloc_base/time/time.h
index 82a8d6b137f2..98f3f7389de5 100644
--- a/base/allocator/partition_allocator/partition_alloc_base/time/time.h
+++ b/base/allocator/partition_allocator/partition_alloc_base/time/time.h
@@ -93,7 +93,7 @@
 #include <jni.h>
 #endif
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include <sys/time.h>
 #include <unistd.h>
 #endif
@@ -126,14 +126,13 @@ class PlatformThreadHandle;
 class PA_COMPONENT_EXPORT(PARTITION_ALLOC) TimeDelta {
  public:
   constexpr TimeDelta() = default;
-
 #if BUILDFLAG(IS_WIN)
   static TimeDelta FromQPCValue(LONGLONG qpc_value);
   // TODO(crbug.com/989694): Avoid base::TimeDelta factory functions
   // based on absolute time
   static TimeDelta FromFileTime(FILETIME ft);
   static TimeDelta FromWinrtDateTime(ABI::Windows::Foundation::DateTime dt);
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   static TimeDelta FromTimeSpec(const timespec& ts);
 #endif
 #if BUILDFLAG(IS_FUCHSIA)
@@ -198,7 +197,7 @@ class PA_COMPONENT_EXPORT(PARTITION_ALLOC) TimeDelta {
   constexpr bool is_min() const { return *this == Min(); }
   constexpr bool is_inf() const { return is_min() || is_max(); }
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   struct timespec ToTimeSpec() const;
 #endif
 #if BUILDFLAG(IS_FUCHSIA)
@@ -586,7 +585,7 @@ class PA_COMPONENT_EXPORT(PARTITION_ALLOC) Time
   static Time FromDoubleT(double dt);
   double ToDoubleT() const;
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   // Converts the timespec structure to time. MacOS X 10.8.3 (and tentatively,
   // earlier versions) will have the |ts|'s tv_nsec component zeroed out,
   // having a 1 second resolution, which agrees with
@@ -612,7 +611,7 @@ class PA_COMPONENT_EXPORT(PARTITION_ALLOC) Time
   static Time FromJavaTime(int64_t ms_since_epoch);
   int64_t ToJavaTime() const;
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   static Time FromTimeVal(struct timeval t);
   struct timeval ToTimeVal() const;
 #endif
diff --git a/base/check.cc b/base/check.cc
index 89e7894f88a0..51b43dc161d8 100644
--- a/base/check.cc
+++ b/base/check.cc
@@ -83,7 +83,7 @@ class DCheckLogMessage : public LogMessage {
   const base::Location location_;
 };
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 class DCheckStarboardErrorLogMessage : public StarboardErrorLogMessage {
  public:
   DCheckStarboardErrorLogMessage(const base::Location& location,
@@ -123,7 +123,7 @@ class DCheckWin32ErrorLogMessage : public Win32ErrorLogMessage {
  private:
   const base::Location location_;
 };
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 class DCheckErrnoLogMessage : public ErrnoLogMessage {
  public:
   DCheckErrnoLogMessage(const base::Location& location,
@@ -166,13 +166,13 @@ CheckError CheckError::PCheck(const char* file,
                               int line,
                               const char* condition) {
   SystemErrorCode err_code = logging::GetLastSystemErrorCode();
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   auto* const log_message =
       new StarboardErrorLogMessage(file, line, LOGGING_FATAL, err_code);
 #elif BUILDFLAG(IS_WIN)
   auto* const log_message =
       new Win32ErrorLogMessage(file, line, LOGGING_FATAL, err_code);
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   auto* const log_message =
       new ErrnoLogMessage(file, line, LOGGING_FATAL, err_code);
 #endif
@@ -187,13 +187,13 @@ CheckError CheckError::PCheck(const char* file, int line) {
 CheckError CheckError::DPCheck(const char* condition,
                                const base::Location& location) {
   SystemErrorCode err_code = logging::GetLastSystemErrorCode();
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   auto* const log_message =
       new DCheckStarboardErrorLogMessage(location, LOGGING_DCHECK, err_code);
 #elif BUILDFLAG(IS_WIN)
   auto* const log_message =
       new DCheckWin32ErrorLogMessage(location, LOGGING_DCHECK, err_code);
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   auto* const log_message =
       new DCheckErrnoLogMessage(location, LOGGING_DCHECK, err_code);
 #endif
diff --git a/base/files/file.h b/base/files/file.h
index 855f763e8d9e..04bf0c26e73e 100644
--- a/base/files/file.h
+++ b/base/files/file.h
@@ -22,10 +22,13 @@ struct stat;
 
 namespace base {
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 using stat_wrapper_t = struct ::stat;
 #else
 using stat_wrapper_t = struct stat;
+#ifndef ftruncate64
+#define ftruncate64 ftruncate
+#endif
 #endif
 
 // Thin wrapper around an OS-level file.
@@ -357,11 +360,11 @@ class BASE_EXPORT File {
   bool DeleteOnClose(bool delete_on_close);
 #endif
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   static Error OSErrorToFileError(SbSystemError sb_system_error);
 #elif BUILDFLAG(IS_WIN)
   static Error OSErrorToFileError(DWORD last_error);
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   static Error OSErrorToFileError(int saved_errno);
 #endif
 
@@ -378,7 +381,7 @@ class BASE_EXPORT File {
   // Wrapper for stat() or stat64().
   static int Stat(const char* path, stat_wrapper_t* sb);
   static int Fstat(int fd, stat_wrapper_t* sb);
-# if !defined(STARBOARD)
+# if !defined(STARBOARD) || (defined(STARBOARD) && SB_API_VERSION >= 16)
   // Starboard does not support lstat yet.
   static int Lstat(const char* path, stat_wrapper_t* sb);
 #endif
diff --git a/base/files/file_descriptor_watcher_posix.cc b/base/files/file_descriptor_watcher_posix.cc
index cb520db19a39..402870f9fb51 100644
--- a/base/files/file_descriptor_watcher_posix.cc
+++ b/base/files/file_descriptor_watcher_posix.cc
@@ -21,6 +21,8 @@
 
 namespace base {
 
+#if SB_API_VERSION >= 16
+
 namespace {
 
 // Per-thread FileDescriptorWatcher registration.
@@ -272,4 +274,6 @@ void FileDescriptorWatcher::AssertAllowed() {
 }
 #endif
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/files/file_enumerator.h b/base/files/file_enumerator.h
index b970055bc8aa..fc01d7fd356a 100644
--- a/base/files/file_enumerator.h
+++ b/base/files/file_enumerator.h
@@ -17,13 +17,13 @@
 #include "base/time/time.h"
 #include "build/build_config.h"
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include <sys/stat.h>
 #include <unistd.h>
 #include "starboard/file.h"
 #elif BUILDFLAG(IS_WIN)
 #include "base/win/windows_types.h"
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include <sys/stat.h>
 #include <unistd.h>
 #include <unordered_set>
@@ -96,8 +96,8 @@ class BASE_EXPORT FileEnumerator {
     // called.
     NAMES_ONLY = 1 << 3,
 
-#if defined(STARBOARD)
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
     SHOW_SYM_LINKS = 1 << 4,
 #endif
   };
@@ -193,7 +193,7 @@ class BASE_EXPORT FileEnumerator {
 
   bool IsPatternMatched(const FilePath& src) const;
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   std::vector<FileInfo> ReadDirectory(const FilePath& source);
 
   // The files in the current directory
@@ -210,7 +210,7 @@ class BASE_EXPORT FileEnumerator {
   bool has_find_data_ = false;
   CHROME_WIN32_FIND_DATA find_data_;
   HANDLE find_handle_ = INVALID_HANDLE_VALUE;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   // The files in the current directory
   std::vector<FileInfo> directory_entries_;
 
diff --git a/base/files/file_enumerator_posix.cc b/base/files/file_enumerator_posix.cc
index e329b88a0d94..327b7f7a617c 100644
--- a/base/files/file_enumerator_posix.cc
+++ b/base/files/file_enumerator_posix.cc
@@ -15,6 +15,9 @@
 #include "build/build_config.h"
 
 namespace base {
+
+#if SB_API_VERSION >= 16
+
 namespace {
 
 void GetStat(const FilePath& path, bool show_links, stat_wrapper_t* st) {
@@ -258,4 +261,6 @@ bool FileEnumerator::IsPatternMatched(const FilePath& path) const {
          !fnmatch(pattern_.c_str(), path.value().c_str(), FNM_NOESCAPE);
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/files/file_enumerator_starboard.cc b/base/files/file_enumerator_starboard.cc
index a4ebb01e4f9a..34ae8bbb3531 100644
--- a/base/files/file_enumerator_starboard.cc
+++ b/base/files/file_enumerator_starboard.cc
@@ -28,6 +28,8 @@
 
 namespace base {
 
+#if SB_API_VERSION <= 15
+
 // FileEnumerator::FileInfo ----------------------------------------------------
 
 FileEnumerator::FileInfo::FileInfo() {
@@ -225,4 +227,6 @@ FileEnumerator::FileInfo FileEnumerator::GetInfo() const {
   return directory_entries_[current_directory_entry_];
 }
 
+#endif  // SB_API_VERSION <= 15
+
 }  // namespace base
diff --git a/base/files/file_posix.cc b/base/files/file_posix.cc
index 0808bb0e3ade..d45c84b0c910 100644
--- a/base/files/file_posix.cc
+++ b/base/files/file_posix.cc
@@ -33,6 +33,8 @@ static_assert(sizeof(base::stat_wrapper_t::st_size) >= 8);
 
 namespace base {
 
+#if SB_API_VERSION >= 16
+
 // Make sure our Whence mappings match the system headers.
 static_assert(File::FROM_BEGIN == SEEK_SET && File::FROM_CURRENT == SEEK_CUR &&
                   File::FROM_END == SEEK_END,
@@ -615,4 +617,6 @@ int File::Lstat(const char* path, stat_wrapper_t* sb) {
   return lstat(path, sb);
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/files/file_starboard.cc b/base/files/file_starboard.cc
index 17a4a4d308c1..9549be51d7f6 100644
--- a/base/files/file_starboard.cc
+++ b/base/files/file_starboard.cc
@@ -32,6 +32,8 @@
 
 namespace base {
 
+#if SB_API_VERSION <= 15
+
 namespace {
 SbFileError g_sb_file_error = kSbFileOk;
 }  // namespace
@@ -503,4 +505,6 @@ File File::Duplicate() const {
   return File();
 }
 
+#endif  // SB_API_VERSION <= 15
+
 }  // namespace base
diff --git a/base/files/file_util.h b/base/files/file_util.h
index c47f00265f41..033f64828be3 100644
--- a/base/files/file_util.h
+++ b/base/files/file_util.h
@@ -27,7 +27,7 @@
 
 #if BUILDFLAG(IS_WIN)
 #include "base/win/windows_types.h"
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include <sys/stat.h>
 #include <unistd.h>
 #include "base/posix/eintr_wrapper.h"
@@ -50,7 +50,7 @@ class Time;
 // 3) it removes "." and ".." directory components.
 BASE_EXPORT FilePath MakeAbsoluteFilePath(const FilePath& input);
 
-#if BUILDFLAG(IS_POSIX)
+#if BUILDFLAG(IS_POSIX) || SB_API_VERSION >= 16
 // Prepends the current working directory if `input` is not already absolute,
 // and removes "/./" and "/../" This is similar to MakeAbsoluteFilePath(), but
 // MakeAbsoluteFilePath() expands all symlinks in the path and this does not.
@@ -252,7 +252,7 @@ BASE_EXPORT bool ReadFileToStringWithMaxSize(const FilePath& path,
                                              std::string* contents,
                                              size_t max_size);
 
-#if !defined(STARBOARD)
+#if !defined(STARBOARD) || SB_API_VERSION >= 16
 // As ReadFileToString, but reading from an open stream after seeking to its
 // start (if supported by the stream). This can also be used to read the whole
 // file from a file descriptor by converting the file descriptor into a stream
@@ -266,7 +266,7 @@ BASE_EXPORT bool ReadStreamToStringWithMaxSize(FILE* stream,
                                                std::string* contents);
 #endif
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 
 // Read exactly |bytes| bytes from file descriptor |fd|, storing the result
 // in |buffer|. This function is protected against EINTR and partial reads.
@@ -281,9 +281,9 @@ BASE_EXPORT bool ReadFromFD(int fd, char* buffer, size_t bytes);
 BASE_EXPORT ScopedFD CreateAndOpenFdForTemporaryFileInDir(const FilePath& dir,
                                                           FilePath* path);
 
-#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 
-#if BUILDFLAG(IS_POSIX)
+#if BUILDFLAG(IS_POSIX) || SB_API_VERSION >= 16
 
 // ReadFileToStringNonBlocking is identical to ReadFileToString except it
 // guarantees that it will not block. This guarantee is provided on POSIX by
@@ -354,7 +354,7 @@ BASE_EXPORT bool ExecutableExistsInPath(Environment* env,
 BASE_EXPORT bool IsPathExecutable(const FilePath& path);
 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_AIX)
 
-#endif  // BUILDFLAG(IS_POSIX)
+#endif  // BUILDFLAG(IS_POSIX) || SB_API_VERSION >= 16
 
 // Returns true if the given directory is empty
 BASE_EXPORT bool IsDirectoryEmpty(const FilePath& dir_path);
@@ -549,7 +549,7 @@ BASE_EXPORT bool WriteFile(const FilePath& filename, span<const uint8_t> data);
 // do manual conversions from a char span to a uint8_t span.
 BASE_EXPORT bool WriteFile(const FilePath& filename, StringPiece data);
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 // Appends |data| to |fd|. Does not close |fd| when done.  Returns true iff all
 // of |data| were written to |fd|.
 BASE_EXPORT bool WriteFileDescriptor(int fd, span<const uint8_t> data);
@@ -627,7 +627,7 @@ BASE_EXPORT bool PreReadFile(
     bool is_executable,
     int64_t max_bytes = std::numeric_limits<int64_t>::max());
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 
 // Creates a pipe. Returns true on success, otherwise false.
 // On success, |read_fd| will be set to the fd of the read side, and
@@ -648,7 +648,7 @@ BASE_EXPORT bool CreateLocalNonBlockingPipe(int fds[2]);
 // Returns true if it was able to set it in the close-on-exec mode, otherwise
 // false.
 BASE_EXPORT bool SetCloseOnExec(int fd);
-#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 
 #if BUILDFLAG(IS_MAC)
 // Test that |path| can only be changed by a given user and members of
@@ -681,7 +681,7 @@ BASE_EXPORT bool VerifyPathControlledByAdmin(const base::FilePath& path);
 // the directory |path|, in the number of FilePath::CharType, or -1 on failure.
 BASE_EXPORT int GetMaximumPathComponentLength(const base::FilePath& path);
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 // Get a temporary directory for shared memory files. The directory may depend
 // on whether the destination is intended for executable files, which in turn
 // depends on how /dev/shmem was mounted. As a result, you must supply whether
diff --git a/base/files/file_util_posix.cc b/base/files/file_util_posix.cc
index da04b251ce91..bbb27d860979 100644
--- a/base/files/file_util_posix.cc
+++ b/base/files/file_util_posix.cc
@@ -75,6 +75,8 @@ extern "C" char* mkdtemp(char* path);
 
 namespace base {
 
+#if SB_API_VERSION >= 16
+
 namespace {
 
 #if BUILDFLAG(IS_MAC)
@@ -1363,4 +1365,6 @@ BASE_EXPORT bool IsPathExecutable(const FilePath& path) {
 }
 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_AIX)
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/files/file_util_starboard.cc b/base/files/file_util_starboard.cc
index bcec62a16edd..61318a5e0921 100644
--- a/base/files/file_util_starboard.cc
+++ b/base/files/file_util_starboard.cc
@@ -41,6 +41,8 @@
 
 namespace base {
 
+#if SB_API_VERSION <= 15
+
 namespace {
 
 // The list of portable filename characters as per POSIX. This should be the
@@ -477,6 +479,17 @@ FilePath MakeAbsoluteFilePath(const FilePath& input) {
   return input;
 }
 
+bool SetNonBlocking(int fd) {
+  const int flags = fcntl(fd, F_GETFL);
+  if (flags == -1)
+    return false;
+  if (flags & O_NONBLOCK)
+    return true;
+  if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
+    return false;
+  return true;
+}
+
 namespace internal {
 
 bool MoveUnsafe(const FilePath& from_path, const FilePath& to_path) {
@@ -488,4 +501,6 @@ bool MoveUnsafe(const FilePath& from_path, const FilePath& to_path) {
 
 }  // internal
 
+#endif  // SB_API_VERSION <= 15
+
 }  // namespace base
diff --git a/base/files/scoped_file.h b/base/files/scoped_file.h
index f0a57f283a44..753af9d42482 100644
--- a/base/files/scoped_file.h
+++ b/base/files/scoped_file.h
@@ -24,7 +24,7 @@ namespace base {
 
 namespace internal {
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 struct BASE_EXPORT ScopedFDCloseTraits {
   static int InvalidValue() { return -1; }
   static void Free(int file) { if (file >= 0) {close(file);} }
@@ -37,7 +37,7 @@ struct BASE_EXPORT ScopedFDCloseTraits : public ScopedGenericOwnershipTracking {
   static void Acquire(const ScopedGeneric<int, ScopedFDCloseTraits>&, int);
   static void Release(const ScopedGeneric<int, ScopedFDCloseTraits>&, int);
 };
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #if BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_LINUX)
 // On ChromeOS and Linux we guard FD lifetime with a global table and hook into
 // libc close() to perform checks.
@@ -56,7 +56,7 @@ struct BASE_EXPORT ScopedFDCloseTraits {
 };
 #endif
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 // Functor for |ScopedFILE| (below).
 struct ScopedFILECloser {
   inline void operator()(int* x) const {
@@ -127,7 +127,7 @@ typedef ScopedGeneric<int, internal::ScopedFDCloseTraits> ScopedFD;
 #endif
 
 // Automatically closes |FILE*|s.
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 typedef std::unique_ptr<starboard::ScopedFile> ScopedFILE;
 #else
 typedef std::unique_ptr<FILE, internal::ScopedFILECloser> ScopedFILE;
diff --git a/base/logging.cc b/base/logging.cc
index 5900a58e9e7f..318739f31762 100644
--- a/base/logging.cc
+++ b/base/logging.cc
@@ -38,7 +38,7 @@
 #include "base/debug/leak_annotations.h"
 #endif  // defined(LEAK_SANITIZER) && !BUILDFLAG(IS_NACL)
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include <fcntl.h>
 
 #include "base/files/file_starboard.h"
@@ -69,8 +69,8 @@ typedef HANDLE FileHandle;
 #include <mach/mach_time.h>
 #include <os/log.h>
 
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
-#if BUILDFLAG(IS_NACL)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
+#if BUILDFLAG(IS_NACL) || SB_API_VERSION >= 16
 #include <sys/time.h>  // timespec doesn't seem to be in <time.h>
 #endif
 #include <time.h>
@@ -84,7 +84,7 @@ typedef HANDLE FileHandle;
 #include <android/log.h>
 #endif
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include <errno.h>
 #include <paths.h>
 #include <stdio.h>
@@ -130,7 +130,7 @@ typedef FILE* FileHandle;
 #include "base/win/win_util.h"
 #endif
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include "base/posix/safe_strerror.h"
 #endif
 
@@ -293,7 +293,7 @@ base::stack<LogAssertHandlerFunction>& GetLogAssertHandlerStack() {
 LogMessageHandlerFunction g_log_message_handler = nullptr;
 
 uint64_t TickCount() {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   return starboard::CurrentMonotonicTime();
 #elif BUILDFLAG(IS_WIN)
   return GetTickCount();
@@ -307,7 +307,7 @@ uint64_t TickCount() {
   // NaCl sadly does not have _POSIX_TIMERS enabled in sys/features.h
   // So we have to use clock() for now.
   return clock();
-#elif BUILDFLAG(IS_POSIX)
+#elif BUILDFLAG(IS_POSIX) || SB_API_VERSION >= 16
   struct timespec ts;
   clock_gettime(CLOCK_MONOTONIC, &ts);
 
@@ -319,13 +319,13 @@ uint64_t TickCount() {
 }
 
 void DeleteFilePath(const PathString& log_name) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   unlink(log_name.c_str());
 #elif BUILDFLAG(IS_WIN)
   DeleteFile(log_name.c_str());
 #elif BUILDFLAG(IS_NACL)
   // Do nothing; unlink() isn't supported on NaCl.
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   unlink(log_name.c_str());
 #else
 #error Unsupported platform
@@ -333,7 +333,7 @@ void DeleteFilePath(const PathString& log_name) {
 }
 
 PathString GetDefaultLogFile() {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   // On Starboard, we politely ask for the log directory, like a civilized
   // platform.
   std::vector<char> path(kSbFileMaxPath + 1);
@@ -352,7 +352,7 @@ PathString GetDefaultLogFile() {
     log_name.erase(last_backslash + 1);
   log_name += FILE_PATH_LITERAL("debug.log");
   return log_name;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   // On other platforms we just use the current directory.
   return PathString("debug.log");
 #endif
@@ -360,7 +360,7 @@ PathString GetDefaultLogFile() {
 
 // We don't need locks on Windows for atomically appending to files. The OS
 // provides this functionality.
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 
 // Provides a lock to synchronize appending to the log file across
 // threads. This can be required to support NFS file systems even on OSes that
@@ -378,7 +378,7 @@ base::Lock& GetLoggingLock() {
   return *lock;
 }
 
-#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 
 // Called by logging functions to ensure that |g_log_file| is initialized
 // and can be used for writing. Returns false if the file could not be
@@ -393,7 +393,7 @@ bool InitializeLogFileHandle() {
     g_log_file_name = new PathString(GetDefaultLogFile());
   }
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   // This seems to get called a lot with an empty filename, at least in
   // base_unittests.
   if (g_log_file_name->empty()) {
@@ -404,7 +404,7 @@ bool InitializeLogFileHandle() {
   if ((g_logging_destination & LOG_TO_FILE) == 0)
     return true;
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   int g_log_file_descriptor =
     open(g_log_file_name->c_str(), O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);
   g_log_file = &g_log_file_descriptor;
@@ -447,7 +447,7 @@ bool InitializeLogFileHandle() {
       return false;
     }
   }
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   g_log_file = fopen(g_log_file_name->c_str(), "a");
   if (g_log_file == nullptr)
     return false;
@@ -459,13 +459,13 @@ bool InitializeLogFileHandle() {
 }
 
 void CloseFile(FileHandle log) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   if (*log >= 0) {
     close(*log);
   }
 #elif BUILDFLAG(IS_WIN)
   CloseHandle(log);
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   fclose(log);
 #else
 #error Unsupported platform
@@ -485,7 +485,7 @@ void CloseLogFileUnlocked() {
     g_logging_destination &= ~LOG_TO_FILE;
 }
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 SbLogPriority LogLevelToStarboardLogPriority(int level) {
   switch (level) {
     case LOG_INFO:
@@ -508,7 +508,7 @@ SbLogPriority LogLevelToStarboardLogPriority(int level) {
       return kSbLogPriorityInfo;
   }
 }
-#endif  // defined(STARBOARD)
+#endif  // defined(STARBOARD) && SB_API_VERSION <= 15
 
 #if BUILDFLAG(IS_FUCHSIA)
 inline FuchsiaLogSeverity LogSeverityToFuchsiaLogSeverity(
@@ -534,7 +534,7 @@ inline FuchsiaLogSeverity LogSeverityToFuchsiaLogSeverity(
 #endif  // BUILDFLAG(IS_FUCHSIA)
 
 void WriteToFd(int fd, const char* data, size_t length) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   if (length > 0) {
     SbLogRaw(data);
     if (data[length - 1] != '\n') {
@@ -552,7 +552,7 @@ void WriteToFd(int fd, const char* data, size_t length) {
     }
     bytes_written += static_cast<size_t>(rv);
   }
-#endif  // defined(STARBOARD)
+#endif  // defined(STARBOARD) && SB_API_VERSION <= 15
 }
 
 void SetLogFatalCrashKey(LogMessage* log_message) {
@@ -651,7 +651,7 @@ bool BaseInitLoggingImpl(const LoggingSettings& settings) {
   if ((g_logging_destination & LOG_TO_FILE) == 0)
     return true;
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   base::AutoLock guard(GetLoggingLock());
 #endif
 
@@ -700,7 +700,7 @@ bool ShouldCreateLogMessage(int severity) {
 // set, or only LOG_TO_FILE is set, since that is useful for local development
 // and debugging.
 bool ShouldLogToStderr(int severity) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   if ((g_logging_destination & LOG_TO_SYSTEM_DEBUG_LOG) != 0) {
     // Don't SbLog to stderr if already logging to system debug log.
     return false;
@@ -854,7 +854,7 @@ LogMessage::~LogMessage() {
   }
 
   if ((g_logging_destination & LOG_TO_SYSTEM_DEBUG_LOG) != 0) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
     SbLog(LogLevelToStarboardLogPriority(severity_), str_newline.c_str());
 #elif BUILDFLAG(IS_WIN)
     OutputDebugStringA(str_newline.c_str());
@@ -994,7 +994,7 @@ LogMessage::~LogMessage() {
     //   LOG(ERROR) << "Something went wrong";
     //   free_something();
     // }
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
     SbLog(LogLevelToStarboardLogPriority(severity_), str_newline.c_str());
 #else
     WriteToFd(STDERR_FILENO, str_newline.data(), str_newline.size());
@@ -1002,7 +1002,7 @@ LogMessage::~LogMessage() {
   }
 
   if ((g_logging_destination & LOG_TO_FILE) != 0) {
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
     // If the client app did not call InitLogging() and the lock has not
     // been created it will be done now on calling GetLoggingLock(). We do this
     // on demand, but if two threads try to do this at the same time, there will
@@ -1011,7 +1011,7 @@ LogMessage::~LogMessage() {
     base::AutoLock guard(GetLoggingLock());
 #endif
     if (InitializeLogFileHandle()) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
       lseek(*g_log_file, 0, SEEK_END);
       int written = 0;
       while (written < str_newline.length()) {
@@ -1031,7 +1031,7 @@ LogMessage::~LogMessage() {
                 static_cast<DWORD>(str_newline.length()),
                 &num_written,
                 nullptr);
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
       std::ignore =
           fwrite(str_newline.data(), str_newline.size(), 1, g_log_file);
       fflush(g_log_file);
@@ -1104,7 +1104,7 @@ void LogMessage::Init(const char* file, int line) {
     if (g_log_process_id)
       stream_ << base::GetUniqueIdForProcess() << ':';
     if (g_log_thread_id)
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
       // Logging the thread name is added for Starboard logs.
       stream_ << base::PlatformThread::GetName() << '/'
               << base::PlatformThread::CurrentId() << ":";
@@ -1112,7 +1112,7 @@ void LogMessage::Init(const char* file, int line) {
       stream_ << base::PlatformThread::CurrentId() << ':';
 #endif
     if (g_log_timestamp) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
     EzTimeValue time_value;
     EzTimeValueGetNow(&time_value, NULL);
     struct EzTimeExploded local_time = {0};
@@ -1140,7 +1140,7 @@ void LogMessage::Init(const char* file, int line) {
               << '.'
               << std::setw(3) << local_time.wMilliseconds
               << ':';
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
       timeval tv;
       gettimeofday(&tv, nullptr);
       time_t t = tv.tv_sec;
@@ -1181,17 +1181,17 @@ typedef DWORD SystemErrorCode;
 #endif
 
 SystemErrorCode GetLastSystemErrorCode() {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   return SbSystemGetLastError();
 #elif BUILDFLAG(IS_WIN)
   return ::GetLastError();
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   return errno;
 #endif
 }
 
 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   const int kErrorMessageBufferSize = 256;
   char msgbuf[kErrorMessageBufferSize];
 
@@ -1216,13 +1216,13 @@ BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code) {
   }
   return base::StringPrintf("Error (0x%lX) while retrieving error. (0x%lX)",
                             GetLastError(), error_code);
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   return base::safe_strerror(error_code) +
          base::StringPrintf(" (%d)", error_code);
 #endif  // BUILDFLAG(IS_WIN)
 }
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 StarboardErrorLogMessage::StarboardErrorLogMessage(const char* file,
                                                    int line,
                                                    LogSeverity severity,
@@ -1250,7 +1250,7 @@ Win32ErrorLogMessage::~Win32ErrorLogMessage() {
   DWORD last_error = err_;
   base::debug::Alias(&last_error);
 }
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 ErrnoLogMessage::ErrnoLogMessage(const char* file,
                                  int line,
                                  LogSeverity severity,
@@ -1267,7 +1267,7 @@ ErrnoLogMessage::~ErrnoLogMessage() {
 #endif  // BUILDFLAG(IS_WIN)
 
 void CloseLogFile() {
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   base::AutoLock guard(GetLoggingLock());
 #endif
   CloseLogFileUnlocked();
@@ -1319,7 +1319,7 @@ ScopedLoggingSettings::ScopedLoggingSettings()
 ScopedLoggingSettings::~ScopedLoggingSettings() {
   // Re-initialize logging via the normal path. This will clean up old file
   // name and handle state, including re-initializing the VLOG internal state.
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   CHECK(InitLogging({
     logging_destination_,
     log_file_name_ ? log_file_name_->data() : nullptr,
@@ -1350,7 +1350,7 @@ void ScopedLoggingSettings::SetLogFormat(LogFormat log_format) const {
 
 void RawLog(int level, const char* message) {
   if (level >= g_min_log_level && message) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
     SbLogRaw(message);
     const size_t message_len = strlen(message);
     if (message_len > 0 && message[message_len - 1] != '\n') {
diff --git a/base/logging.h b/base/logging.h
index aeddb4c1de24..8d5668d16b49 100644
--- a/base/logging.h
+++ b/base/logging.h
@@ -217,11 +217,12 @@ enum : uint32_t {
 // On POSIX platforms, where it may not even be possible to locate the
 // executable on disk, use stderr.
 // On Fuchsia, use the Fuchsia logging service.
-#if BUILDFLAG(IS_FUCHSIA) || BUILDFLAG(IS_NACL) || defined(STARBOARD)
+#if BUILDFLAG(IS_FUCHSIA) || BUILDFLAG(IS_NACL) || \
+    (defined(STARBOARD) && SB_API_VERSION <= 15)
   LOG_DEFAULT = LOG_TO_SYSTEM_DEBUG_LOG,
 #elif BUILDFLAG(IS_WIN)
   LOG_DEFAULT = LOG_TO_FILE,
-#elif BUILDFLAG(IS_POSIX)
+#elif BUILDFLAG(IS_POSIX) || SB_API_VERSION >= 16
   LOG_DEFAULT = LOG_TO_SYSTEM_DEBUG_LOG | LOG_TO_STDERR,
 #endif
 };
@@ -530,7 +531,7 @@ BASE_EXPORT int GetDisableAllVLogLevel();
   LAZY_STREAM(VLOG_STREAM(verbose_level), \
       VLOG_IS_ON(verbose_level) && (condition))
 
-#if defined (STARBOARD)
+#if defined (STARBOARD) && SB_API_VERSION <= 15
 #define VPLOG_STREAM(verbose_level) \
   ::logging::StarboardErrorLogMessage(__FILE__, __LINE__, -verbose_level, \
     ::logging::GetLastSystemErrorCode()).stream()
@@ -538,7 +539,7 @@ BASE_EXPORT int GetDisableAllVLogLevel();
 #define VPLOG_STREAM(verbose_level) \
   ::logging::Win32ErrorLogMessage(__FILE__, __LINE__, -(verbose_level), \
     ::logging::GetLastSystemErrorCode()).stream()
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #define VPLOG_STREAM(verbose_level) \
   ::logging::ErrnoLogMessage(__FILE__, __LINE__, -(verbose_level), \
     ::logging::GetLastSystemErrorCode()).stream()
@@ -557,7 +558,7 @@ BASE_EXPORT int GetDisableAllVLogLevel();
   LOG_IF(FATAL, !(ANALYZER_ASSUME_TRUE(condition))) \
       << "Assert failed: " #condition ". "
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #define PLOG_STREAM(severity) \
   COMPACT_GOOGLE_LOG_EX_ ## severity(StarboardErrorLogMessage, \
       ::logging::GetLastSystemErrorCode()).stream()
@@ -565,7 +566,7 @@ BASE_EXPORT int GetDisableAllVLogLevel();
 #define PLOG_STREAM(severity) \
   COMPACT_GOOGLE_LOG_EX_ ## severity(Win32ErrorLogMessage, \
       ::logging::GetLastSystemErrorCode()).stream()
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #define PLOG_STREAM(severity) \
   COMPACT_GOOGLE_LOG_EX_ ## severity(ErrnoLogMessage, \
       ::logging::GetLastSystemErrorCode()).stream()
@@ -658,6 +659,7 @@ class BASE_EXPORT LogMessage {
 
   // Used for CHECK().  Implied severity = LOGGING_FATAL.
   LogMessage(const char* file, int line, const char* condition);
+
   LogMessage(const LogMessage&) = delete;
   LogMessage& operator=(const LogMessage&) = delete;
   virtual ~LogMessage();
@@ -712,11 +714,11 @@ class LogMessageVoidify {
   void operator&(std::ostream&) { }
 };
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 typedef SbSystemError SystemErrorCode;
 #elif BUILDFLAG(IS_WIN)
 typedef unsigned long SystemErrorCode;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 typedef int SystemErrorCode;
 #endif
 
@@ -725,7 +727,7 @@ typedef int SystemErrorCode;
 BASE_EXPORT SystemErrorCode GetLastSystemErrorCode();
 BASE_EXPORT std::string SystemErrorCodeToString(SystemErrorCode error_code);
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 // Appends a formatted system message of the GetLastError() type.
 class BASE_EXPORT StarboardErrorLogMessage : public LogMessage {
  public:
@@ -763,7 +765,7 @@ class BASE_EXPORT Win32ErrorLogMessage : public LogMessage {
  private:
   SystemErrorCode err_;
 };
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 // Appends a formatted system message of the errno type
 class BASE_EXPORT ErrnoLogMessage : public LogMessage {
  public:
@@ -771,6 +773,11 @@ class BASE_EXPORT ErrnoLogMessage : public LogMessage {
                   int line,
                   LogSeverity severity,
                   SystemErrorCode err);
+  ErrnoLogMessage(const char* function,
+                  const char* file,
+                  int line,
+                  LogSeverity severity,
+                  int err);
   ErrnoLogMessage(const ErrnoLogMessage&) = delete;
   ErrnoLogMessage& operator=(const ErrnoLogMessage&) = delete;
   // Appends the error message before destructing the encapsulated class.
diff --git a/base/memory/page_size_posix.cc b/base/memory/page_size_posix.cc
index 61189677efa1..612ce379a95c 100644
--- a/base/memory/page_size_posix.cc
+++ b/base/memory/page_size_posix.cc
@@ -8,6 +8,8 @@
 
 namespace base {
 
+#if SB_API_VERSION >= 16
+
 size_t GetPageSize() {
   static const size_t pagesize = []() -> size_t {
   // For more information see getpagesize(2). Portable applications should use
@@ -21,4 +23,6 @@ size_t GetPageSize() {
   return pagesize;
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/memory/page_size_starboard.cc b/base/memory/page_size_starboard.cc
index 65d6ed8dd57f..bc82df70b2bf 100644
--- a/base/memory/page_size_starboard.cc
+++ b/base/memory/page_size_starboard.cc
@@ -18,9 +18,13 @@
 
 namespace base {
 
+#if SB_API_VERSION <= 15
+
 size_t GetPageSize() {
   NOTREACHED();
   return 0;
 }
 
+#endif  // SB_API_VERSIO <= 15
+
 }
\ No newline at end of file
diff --git a/base/message_loop/fd_watch_controller_posix_unittest.cc b/base/message_loop/fd_watch_controller_posix_unittest.cc
index 87fdb1652d2a..3a33742d1ef8 100644
--- a/base/message_loop/fd_watch_controller_posix_unittest.cc
+++ b/base/message_loop/fd_watch_controller_posix_unittest.cc
@@ -209,7 +209,7 @@ class ReaderWriterHandler : public MessagePumpForIO::FdWatcher {
   ReaderWriterHandler& operator=(const ReaderWriterHandler&) = delete;
 
   // base::WatchableIOMessagePumpPosix::FdWatcher:
-  void OnFileCanReadWithoutBlocking(int fd) override {
+  void OnSocketReadyToRead(int fd) override {
     if (when_ == kOnReadEvent) {
       DoAction();
     } else {
diff --git a/base/message_loop/message_pump_for_io.h b/base/message_loop/message_pump_for_io.h
index 08bf51a39ec3..d09face7a1de 100644
--- a/base/message_loop/message_pump_for_io.h
+++ b/base/message_loop/message_pump_for_io.h
@@ -11,7 +11,7 @@
 #include "base/message_loop/ios_cronet_buildflags.h"
 #include "build/build_config.h"
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include "base/message_loop/message_pump_io_starboard.h"
 #elif BUILDFLAG(IS_WIN)
 #include "base/message_loop/message_pump_win.h"
@@ -23,13 +23,13 @@
 #include "base/message_loop/message_pump_default.h"
 #elif BUILDFLAG(IS_FUCHSIA)
 #include "base/message_loop/message_pump_fuchsia.h"
-#elif BUILDFLAG(IS_POSIX)
+#elif BUILDFLAG(IS_POSIX) || SB_API_VERSION >= 16
 #include "base/message_loop/message_pump_libevent.h"
 #endif
 
 namespace base {
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 using MessagePumpForIO = MessagePumpIOStarboard;
 #elif BUILDFLAG(IS_WIN)
 // Windows defines it as-is.
@@ -42,7 +42,7 @@ using MessagePumpForIO = MessagePumpKqueue;
 using MessagePumpForIO = MessagePumpDefault;
 #elif BUILDFLAG(IS_FUCHSIA)
 using MessagePumpForIO = MessagePumpFuchsia;
-#elif BUILDFLAG(IS_POSIX)
+#elif BUILDFLAG(IS_POSIX) || SB_API_VERSION >= 16
 using MessagePumpForIO = MessagePumpLibevent;
 #else
 #error Platform does not define MessagePumpForIO
diff --git a/base/message_loop/message_pump_for_ui.h b/base/message_loop/message_pump_for_ui.h
index 639a462946a9..0da9c874a766 100644
--- a/base/message_loop/message_pump_for_ui.h
+++ b/base/message_loop/message_pump_for_ui.h
@@ -10,7 +10,7 @@
 
 #include "build/build_config.h"
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include "base/message_loop/message_pump_ui_starboard.h"
 #elif BUILDFLAG(IS_WIN)
 #include "base/message_loop/message_pump_win.h"
@@ -22,7 +22,7 @@
 // No MessagePumpForUI, see below.
 #elif defined(USE_GLIB)
 #include "base/message_loop/message_pump_glib.h"
-#elif BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_BSD)
+#elif BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_BSD) || SB_API_VERSION >= 16
 #include "base/message_loop/message_pump_libevent.h"
 #elif BUILDFLAG(IS_FUCHSIA)
 #include "base/message_loop/message_pump_fuchsia.h"
@@ -30,7 +30,7 @@
 
 namespace base {
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 using MessagePumpForUI = MessagePumpUIStarboard;
 #elif BUILDFLAG(IS_WIN)
 // Windows defines it as-is.
@@ -48,7 +48,7 @@ using MessagePumpForUI = MessagePump;
 // TODO(abarth): Figure out if we need this.
 #elif defined(USE_GLIB)
 using MessagePumpForUI = MessagePumpGlib;
-#elif BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_BSD)
+#elif BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_BSD) || SB_API_VERSION >= 16
 using MessagePumpForUI = MessagePumpLibevent;
 #elif BUILDFLAG(IS_FUCHSIA)
 using MessagePumpForUI = MessagePumpFuchsia;
diff --git a/base/message_loop/message_pump_glib_unittest.cc b/base/message_loop/message_pump_glib_unittest.cc
index 77b5ca425024..a47f8dc9c3e2 100644
--- a/base/message_loop/message_pump_glib_unittest.cc
+++ b/base/message_loop/message_pump_glib_unittest.cc
@@ -717,14 +717,14 @@ class NestedPumpWatcher : public MessagePumpGlib::FdWatcher {
   NestedPumpWatcher() = default;
   ~NestedPumpWatcher() override = default;
 
-  void OnFileCanReadWithoutBlocking(int /* fd */) override {
+  void OnFileCanWriteWithoutBlocking(int /* fd */) override {
     RunLoop runloop;
     SingleThreadTaskRunner::GetCurrentDefault()->PostTask(
         FROM_HERE, BindOnce(&QuitMessageLoopAndStart, runloop.QuitClosure()));
     runloop.Run();
   }
 
-  void OnFileCanWriteWithoutBlocking(int /* fd */) override {}
+  void OnSocketReadyToWrite(int /* fd */) override {}
 };
 
 class QuitWatcher : public DeleteWatcher {
diff --git a/base/message_loop/message_pump_libevent.cc b/base/message_loop/message_pump_libevent.cc
index 72f67b836c6f..be507b9dcd92 100644
--- a/base/message_loop/message_pump_libevent.cc
+++ b/base/message_loop/message_pump_libevent.cc
@@ -39,6 +39,8 @@
 
 namespace base {
 
+#if SB_API_VERSION >= 16
+
 namespace {
 
 #if BUILDFLAG(ENABLE_MESSAGE_PUMP_EPOLL)
@@ -485,4 +487,6 @@ MessagePumpLibevent::EpollInterest::EpollInterest(
 
 MessagePumpLibevent::EpollInterest::~EpollInterest() = default;
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/message_loop/message_pump_libevent.h b/base/message_loop/message_pump_libevent.h
index 0389de964599..f6644747d069 100644
--- a/base/message_loop/message_pump_libevent.h
+++ b/base/message_loop/message_pump_libevent.h
@@ -263,6 +263,8 @@ class BASE_EXPORT MessagePumpLibevent : public MessagePump,
   ThreadChecker watch_file_descriptor_caller_checker_;
 };
 
+using MessagePumpForUI = MessagePumpLibevent;
+
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_LIBEVENT_H_
diff --git a/base/strings/sys_string_conversions_starboard.cc b/base/strings/sys_string_conversions_starboard.cc
index 3e7cfda9eecc..d98a1df56482 100644
--- a/base/strings/sys_string_conversions_starboard.cc
+++ b/base/strings/sys_string_conversions_starboard.cc
@@ -13,4 +13,6 @@
 // limitations under the License.
 
 // We use the same code as the POSIX version.
+#if SB_API_VERSION <= 15
 #include "sys_string_conversions_posix.cc"
+#endif  // SB_API_VERSIO <= 15
diff --git a/base/synchronization/condition_variable.h b/base/synchronization/condition_variable.h
index 4c84bc200b25..c6598bb549e5 100644
--- a/base/synchronization/condition_variable.h
+++ b/base/synchronization/condition_variable.h
@@ -69,14 +69,10 @@
 #include "base/base_export.h"
 #include "base/synchronization/lock.h"
 
-#if defined(STARBOARD)
-#if SB_API_VERSION < 16
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include "starboard/condition_variable.h"
 #else
-#include <pthread.h>
-#endif  // SB_API_VERSION < 16
-#else
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include <pthread.h>
 #endif
 
@@ -121,18 +117,13 @@ class BASE_EXPORT ConditionVariable {
   void declare_only_used_while_idle() { waiting_is_blocking_ = false; }
 
  private:
-#if defined(STARBOARD)
-#if SB_API_VERSION < 16
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   SbConditionVariable condition_;
   SbMutex* user_mutex_;
-#else
-  pthread_cond_t condition_;
-  pthread_mutex_t* user_mutex_;
-#endif  // SB_API_VERSION < 16
 #elif BUILDFLAG(IS_WIN)
   CHROME_CONDITION_VARIABLE cv_;
   const raw_ptr<CHROME_SRWLOCK> srwlock_;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   pthread_cond_t condition_;
   raw_ptr<pthread_mutex_t> user_mutex_;
 #endif
diff --git a/base/synchronization/condition_variable_posix.cc b/base/synchronization/condition_variable_posix.cc
index 0b7ccc9bdba7..dde24d122d35 100644
--- a/base/synchronization/condition_variable_posix.cc
+++ b/base/synchronization/condition_variable_posix.cc
@@ -21,6 +21,8 @@
 
 namespace base {
 
+#if SB_API_VERSION >= 16
+
 ConditionVariable::ConditionVariable(Lock* user_lock)
     : user_mutex_(user_lock->lock_.native_handle())
 #if DCHECK_IS_ON()
@@ -151,4 +153,6 @@ void ConditionVariable::Signal() {
   DCHECK_EQ(0, rv);
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/synchronization/condition_variable_starboard.cc b/base/synchronization/condition_variable_starboard.cc
index c46217e0490d..f29716c0b124 100644
--- a/base/synchronization/condition_variable_starboard.cc
+++ b/base/synchronization/condition_variable_starboard.cc
@@ -23,6 +23,8 @@
 
 namespace base {
 
+#if SB_API_VERSION <= 15
+
 ConditionVariable::ConditionVariable(Lock* user_lock)
     : user_mutex_(user_lock->lock_.native_handle())
 #if DCHECK_IS_ON()
@@ -136,4 +138,6 @@ void ConditionVariable::Signal() {
 #endif  // SB_API_VERSION < 16
 }
 
+#endif  // SB_API_VERSION <= 15
+
 }  // namespace base
diff --git a/base/synchronization/waitable_event_starboard.cc b/base/synchronization/waitable_event_starboard.cc
index 43010d671fc6..1cb65a4ac437 100644
--- a/base/synchronization/waitable_event_starboard.cc
+++ b/base/synchronization/waitable_event_starboard.cc
@@ -13,4 +13,6 @@
 // limitations under the License.
 
 // We use the same code as the POSIX version.
+#if SB_API_VERSION <= 15
 #include "base/synchronization/waitable_event_posix.cc"
+#endif  // SB_API_VERSIO <= 15
\ No newline at end of file
diff --git a/base/synchronization/waitable_event_watcher_starboard.cc b/base/synchronization/waitable_event_watcher_starboard.cc
index 518f92966332..8b3339487c49 100644
--- a/base/synchronization/waitable_event_watcher_starboard.cc
+++ b/base/synchronization/waitable_event_watcher_starboard.cc
@@ -13,4 +13,6 @@
 // limitations under the License.
 
 // We use the same code as the POSIX version.
+#if SB_API_VERSION <= 15
 #include "base/synchronization/waitable_event_watcher_posix.cc"
+#endif  // SB_API_VERSIO <= 15
\ No newline at end of file
diff --git a/base/task/current_thread.cc b/base/task/current_thread.cc
index 673e2028d4a2..fbb1fae1c6bf 100644
--- a/base/task/current_thread.cc
+++ b/base/task/current_thread.cc
@@ -211,12 +211,13 @@ MessagePumpForIO* CurrentIOThread::GetMessagePumpForIO() const {
 
 #if !BUILDFLAG(IS_NACL)
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 bool CurrentIOThread::Watch(SbSocket socket,
                             bool persistent,
                             int mode,
                             SocketWatcher* controller,
                             Watcher* delegate) {
+
   return static_cast<MessagePumpIOStarboard*>(GetMessagePumpForIO())
       ->Watch(socket, persistent, mode, controller, delegate);
 }
@@ -234,7 +235,7 @@ bool CurrentIOThread::RegisterJobObject(HANDLE job,
   return GetMessagePumpForIO()->RegisterJobObject(job, handler);
 }
 
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 bool CurrentIOThread::WatchFileDescriptor(
     int fd,
     bool persistent,
diff --git a/base/task/current_thread.h b/base/task/current_thread.h
index 5106c5e9fd71..822ea0fab11f 100644
--- a/base/task/current_thread.h
+++ b/base/task/current_thread.h
@@ -270,7 +270,7 @@ class BASE_EXPORT CurrentIOThread : public CurrentThread {
 
 #if !BUILDFLAG(IS_NACL)
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   typedef base::MessagePumpIOStarboard::Watcher Watcher;
   typedef base::MessagePumpIOStarboard::SocketWatcher SocketWatcher;
   typedef base::MessagePumpIOStarboard::IOObserver IOObserver;
@@ -284,11 +284,12 @@ class BASE_EXPORT CurrentIOThread : public CurrentThread {
              int mode,
              SocketWatcher* controller,
              Watcher* delegate);
+
 #elif BUILDFLAG(IS_WIN)
   // Please see MessagePumpWin for definitions of these methods.
   HRESULT RegisterIOHandler(HANDLE file, MessagePumpForIO::IOHandler* handler);
   bool RegisterJobObject(HANDLE job, MessagePumpForIO::IOHandler* handler);
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   // Please see WatchableIOMessagePumpPosix for definition.
   // Prefer base::FileDescriptorWatcher for non-critical IO.
   bool WatchFileDescriptor(int fd,
diff --git a/base/task/sequence_manager/sequence_manager_impl.cc b/base/task/sequence_manager/sequence_manager_impl.cc
index 15b96bde3bcc..e61d4f7e7bad 100644
--- a/base/task/sequence_manager/sequence_manager_impl.cc
+++ b/base/task/sequence_manager/sequence_manager_impl.cc
@@ -368,7 +368,7 @@ void SequenceManagerImpl::BindToMessagePump(std::unique_ptr<MessagePump> pump) {
 #endif
 
   // On iOS attach to the native loop when there is one.
-#if BUILDFLAG(IS_IOS) || defined(STARBOARD)
+#if BUILDFLAG(IS_IOS) || (defined(STARBOARD) && SB_API_VERSION <= 15)
   if (settings_.message_loop_type == MessagePumpType::UI) {
     controller_->AttachToMessagePump();
   }
@@ -1159,7 +1159,7 @@ bool SequenceManagerImpl::IsTaskExecutionAllowed() const {
   return controller_->IsTaskExecutionAllowed();
 }
 
-#if BUILDFLAG(IS_IOS) || defined(STARBOARD)
+#if BUILDFLAG(IS_IOS) || (defined(STARBOARD) && SB_API_VERSION <= 15)
 void SequenceManagerImpl::AttachToMessagePump() {
   return controller_->AttachToMessagePump();
 }
diff --git a/base/task/sequence_manager/sequence_manager_impl.h b/base/task/sequence_manager/sequence_manager_impl.h
index a0a0c169dd9f..5d9c9775fc1f 100644
--- a/base/task/sequence_manager/sequence_manager_impl.h
+++ b/base/task/sequence_manager/sequence_manager_impl.h
@@ -172,7 +172,7 @@ class BASE_EXPORT SequenceManagerImpl
   void SetAddQueueTimeToTasks(bool enable);
   void SetTaskExecutionAllowed(bool allowed);
   bool IsTaskExecutionAllowed() const;
-#if BUILDFLAG(IS_IOS) || defined(STARBOARD)
+#if BUILDFLAG(IS_IOS) || (defined(STARBOARD) && SB_API_VERSION <= 15)
   void AttachToMessagePump();
 #endif
   bool IsIdleForTesting() override;
diff --git a/base/task/sequence_manager/thread_controller.h b/base/task/sequence_manager/thread_controller.h
index 2db10ba82ea8..446d4dee3747 100644
--- a/base/task/sequence_manager/thread_controller.h
+++ b/base/task/sequence_manager/thread_controller.h
@@ -132,7 +132,7 @@ class BASE_EXPORT ThreadController {
   // Returns true if the current run loop should quit when idle.
   virtual bool ShouldQuitRunLoopWhenIdle() = 0;
 
-#if BUILDFLAG(IS_IOS) || BUILDFLAG(IS_ANDROID) || defined(STARBOARD)
+#if BUILDFLAG(IS_IOS) || BUILDFLAG(IS_ANDROID) || (defined(STARBOARD) && SB_API_VERSION <= 15)
   // On iOS, the main message loop cannot be Run().  Instead call
   // AttachToMessagePump(), which connects this ThreadController to the
   // UI thread's CFRunLoop and allows PostTask() to work.
diff --git a/base/task/sequence_manager/thread_controller_impl.cc b/base/task/sequence_manager/thread_controller_impl.cc
index ce77f88be9d4..446a56f0b6fd 100644
--- a/base/task/sequence_manager/thread_controller_impl.cc
+++ b/base/task/sequence_manager/thread_controller_impl.cc
@@ -363,7 +363,7 @@ MessagePump* ThreadControllerImpl::GetBoundMessagePump() const {
   return nullptr;
 }
 
-#if BUILDFLAG(IS_IOS) || BUILDFLAG(IS_ANDROID) || defined(STARBOARD)
+#if BUILDFLAG(IS_IOS) || BUILDFLAG(IS_ANDROID) || (defined(STARBOARD) && SB_API_VERSION <= 15)
 void ThreadControllerImpl::AttachToMessagePump() {
   NOTREACHED();
 }
diff --git a/base/task/sequence_manager/thread_controller_impl.h b/base/task/sequence_manager/thread_controller_impl.h
index 262a4bdd6c57..f21287a6a9c4 100644
--- a/base/task/sequence_manager/thread_controller_impl.h
+++ b/base/task/sequence_manager/thread_controller_impl.h
@@ -61,7 +61,7 @@ class BASE_EXPORT ThreadControllerImpl : public ThreadController,
   void SetTaskExecutionAllowed(bool allowed) override;
   bool IsTaskExecutionAllowed() const override;
   MessagePump* GetBoundMessagePump() const override;
-#if BUILDFLAG(IS_IOS) || BUILDFLAG(IS_ANDROID) || defined(STARBOARD)
+#if BUILDFLAG(IS_IOS) || BUILDFLAG(IS_ANDROID) || (defined(STARBOARD) && SB_API_VERSION <= 15)
   void AttachToMessagePump() override;
 #endif
 #if BUILDFLAG(IS_IOS)
diff --git a/base/task/sequence_manager/thread_controller_with_message_pump_impl.cc b/base/task/sequence_manager/thread_controller_with_message_pump_impl.cc
index e2eb0fd38864..8d4ffe0a38c7 100644
--- a/base/task/sequence_manager/thread_controller_with_message_pump_impl.cc
+++ b/base/task/sequence_manager/thread_controller_with_message_pump_impl.cc
@@ -731,7 +731,7 @@ void ThreadControllerWithMessagePumpImpl::AttachToMessagePump() {
 void ThreadControllerWithMessagePumpImpl::DetachFromMessagePump() {
   static_cast<MessagePumpCFRunLoopBase*>(pump_.get())->Detach();
 }
-#elif BUILDFLAG(IS_ANDROID) || defined(STARBOARD)
+#elif BUILDFLAG(IS_ANDROID) || (defined(STARBOARD) && SB_API_VERSION <= 15)
 void ThreadControllerWithMessagePumpImpl::AttachToMessagePump() {
   CHECK(main_thread_only().work_batch_size == 1);
   // Aborting the message pump currently relies on the batch size being 1.
diff --git a/base/task/sequence_manager/thread_controller_with_message_pump_impl.h b/base/task/sequence_manager/thread_controller_with_message_pump_impl.h
index e3c6c97863c3..1f9c7b4eeaeb 100644
--- a/base/task/sequence_manager/thread_controller_with_message_pump_impl.h
+++ b/base/task/sequence_manager/thread_controller_with_message_pump_impl.h
@@ -74,7 +74,7 @@ class BASE_EXPORT ThreadControllerWithMessagePumpImpl
   bool IsTaskExecutionAllowed() const override;
   MessagePump* GetBoundMessagePump() const override;
   void PrioritizeYieldingToNative(base::TimeTicks prioritize_until) override;
-#if BUILDFLAG(IS_IOS) || BUILDFLAG(IS_ANDROID) || defined(STARBOARD)
+#if BUILDFLAG(IS_IOS) || BUILDFLAG(IS_ANDROID) || (defined(STARBOARD) && SB_API_VERSION <= 15)
   void AttachToMessagePump() override;
 #endif
 #if BUILDFLAG(IS_IOS)
diff --git a/base/time/time.h b/base/time/time.h
index d84b2f69d01a..676683874e10 100644
--- a/base/time/time.h
+++ b/base/time/time.h
@@ -77,7 +77,7 @@
 #include "build/build_config.h"
 #include "build/chromeos_buildflags.h"
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include "starboard/common/time.h"
 #else
 #if BUILDFLAG(IS_APPLE)
@@ -99,7 +99,7 @@
 #include <jni.h>
 #endif
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include <unistd.h>
 #include <sys/time.h>
 #endif
@@ -206,6 +206,11 @@ class BASE_EXPORT TimeDelta {
                                             MakeClampedNum(n))
             : TimeDelta::Max();
   }
+
+#if SB_API_VERSION >= 16
+  static TimeDelta FromTimeSpec(const timespec& ts);
+#endif
+
 #elif BUILDFLAG(IS_WIN)
   static TimeDelta FromQPCValue(LONGLONG qpc_value);
   // TODO(crbug.com/989694): Avoid base::TimeDelta factory functions
@@ -278,7 +283,7 @@ class BASE_EXPORT TimeDelta {
   constexpr bool is_min() const { return *this == Min(); }
   constexpr bool is_inf() const { return is_min() || is_max(); }
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   struct timespec ToTimeSpec() const;
 #endif
 #if BUILDFLAG(IS_FUCHSIA)
@@ -740,6 +745,9 @@ class BASE_EXPORT Time : public time_internal::TimeBase<Time> {
   double ToDoubleT() const;
 
 #if defined(STARBOARD)
+#if SB_API_VERSION >= 16
+  static Time FromTimeSpec(const timespec& ts);
+#endif
 #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
   // Converts the timespec structure to time. MacOS X 10.8.3 (and tentatively,
   // earlier versions) will have the |ts|'s tv_nsec component zeroed out,
@@ -766,7 +774,7 @@ class BASE_EXPORT Time : public time_internal::TimeBase<Time> {
   static Time FromJavaTime(int64_t ms_since_epoch);
   int64_t ToJavaTime() const;
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   static Time FromTimeVal(struct timeval t);
   struct timeval ToTimeVal() const;
 #endif
@@ -1243,7 +1251,7 @@ class BASE_EXPORT ThreadTicks : public time_internal::TimeBase<ThreadTicks> {
 
   // Returns true if ThreadTicks::Now() is supported on this system.
   [[nodiscard]] static bool IsSupported() {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
     return starboard::CurrentMonotonicThreadTime() != 0;
 #elif (defined(_POSIX_THREAD_CPUTIME) && (_POSIX_THREAD_CPUTIME >= 0)) || \
     BUILDFLAG(IS_APPLE) || BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_FUCHSIA)
diff --git a/base/time/time_conversion_posix.cc b/base/time/time_conversion_posix.cc
index 47e1e10312f2..c923c6d565dc 100644
--- a/base/time/time_conversion_posix.cc
+++ b/base/time/time_conversion_posix.cc
@@ -14,6 +14,8 @@
 
 namespace base {
 
+#if SB_API_VERSION >= 16
+
 // static
 TimeDelta TimeDelta::FromTimeSpec(const timespec& ts) {
   return TimeDelta(ts.tv_sec * Time::kMicrosecondsPerSecond +
@@ -64,4 +66,6 @@ struct timeval Time::ToTimeVal() const {
   return result;
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/time/time_exploded_posix.cc b/base/time/time_exploded_posix.cc
index 8cc737611aaa..5e8f1ca5110a 100644
--- a/base/time/time_exploded_posix.cc
+++ b/base/time/time_exploded_posix.cc
@@ -120,6 +120,8 @@ void SysTimeToTimeStruct(SysTime t, struct tm* timestruct, bool is_local) {
 
 namespace base {
 
+#if SB_API_VERSION >= 16
+
 void Time::Explode(bool is_local, Exploded* exploded) const {
   const int64_t millis_since_unix_epoch =
       ToRoundedDownMillisecondsSinceUnixEpoch();
@@ -288,4 +290,6 @@ bool Time::FromExploded(bool is_local, const Exploded& exploded, Time* time) {
   return false;
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/time/time_now_posix.cc b/base/time/time_now_posix.cc
index b0ecb39fe23c..c4079ec39340 100644
--- a/base/time/time_now_posix.cc
+++ b/base/time/time_now_posix.cc
@@ -28,6 +28,8 @@
 
 namespace {
 
+#if SB_API_VERSION >= 16
+
 int64_t ConvertTimespecToMicros(const struct timespec& ts) {
   // On 32-bit systems, the calculation cannot overflow int64_t.
   // 2**32 * 1000000 + 2**64 / 1000 < 2**63
@@ -47,9 +49,10 @@ int64_t ConvertTimespecToMicros(const struct timespec& ts) {
 // microsecond timebase. Minimum requirement is MONOTONIC_CLOCK to be supported
 // on the system. FreeBSD 6 has CLOCK_MONOTONIC but defines
 // _POSIX_MONOTONIC_CLOCK to -1.
-#if (BUILDFLAG(IS_POSIX) && defined(_POSIX_MONOTONIC_CLOCK) && \
-     _POSIX_MONOTONIC_CLOCK >= 0) ||                           \
-    BUILDFLAG(IS_BSD) || BUILDFLAG(IS_ANDROID)
+#if ((BUILDFLAG(IS_POSIX) || SB_API_VERSION >= 16) && \
+     defined(_POSIX_MONOTONIC_CLOCK) && \
+     _POSIX_MONOTONIC_CLOCK >= 0) || \
+     BUILDFLAG(IS_BSD) || BUILDFLAG(IS_ANDROID)
 int64_t ClockNow(clockid_t clk_id) {
   struct timespec ts;
   CHECK(clock_gettime(clk_id, &ts) == 0);
@@ -137,4 +140,6 @@ ThreadTicks ThreadTicksNowIgnoringOverride() {
 }
 }  // namespace subtle
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace base
diff --git a/base/time/time_now_starboard.cc b/base/time/time_now_starboard.cc
index 6c6fd1023c59..7f905fec079a 100644
--- a/base/time/time_now_starboard.cc
+++ b/base/time/time_now_starboard.cc
@@ -24,6 +24,8 @@
 
 namespace base {
 
+#if SB_API_VERSION <= 15
+
 // Time -----------------------------------------------------------------------
 
 namespace subtle {
@@ -67,4 +69,6 @@ ThreadTicks ThreadTicksNowIgnoringOverride() {
 }
 }  // namespace subtle
 
+#endif  // SB_API_VERSIO <= 15
+
 }  // namespace base
diff --git a/base/time/time_starboard.cc b/base/time/time_starboard.cc
index 62b2f4e3a694..7cf2113018cf 100644
--- a/base/time/time_starboard.cc
+++ b/base/time/time_starboard.cc
@@ -19,6 +19,8 @@
 
 namespace base {
 
+#if SB_API_VERSION <= 15
+
 namespace {
 EzTimeZone GetTz(bool is_local) {
   return is_local ? kEzTimeZoneLocal : kEzTimeZoneUTC;
@@ -86,4 +88,6 @@ bool TimeTicks::IsHighResolution() {
   return true;
 }
 
+#endif  // SB_API_VERSION <= 15
+
 }  // namespace base
diff --git a/cobalt/base/c_val.h b/cobalt/base/c_val.h
index 99a90dbc8f5c..8479cecee443 100644
--- a/cobalt/base/c_val.h
+++ b/cobalt/base/c_val.h
@@ -99,6 +99,7 @@ class CValImpl;
 // a CVal of type SizeInBytes, this can be made explicit, and allows the CVal
 // system to use KB/MB suffixes instead of K/M.
 namespace cval {
+
 class SizeInBytes {
  public:
   SizeInBytes(uint64 size_in_bytes)  // NOLINT(runtime/explicit)
diff --git a/cobalt/base/task_runner_util.cc b/cobalt/base/task_runner_util.cc
index 990d88f5d890..37675f5904d6 100644
--- a/cobalt/base/task_runner_util.cc
+++ b/cobalt/base/task_runner_util.cc
@@ -27,6 +27,7 @@
 #include "starboard/system.h"
 
 namespace base {
+
 namespace task_runner_util {
 
 namespace {
@@ -87,4 +88,5 @@ void PostBlockingTask(base::SequencedTaskRunner *task_runner,
 }
 
 }  // namespace task_runner_util
+
 }  // namespace base
diff --git a/cobalt/renderer/rasterizer/skia/skia/src/ports/SkOSFile_cobalt.cc b/cobalt/renderer/rasterizer/skia/skia/src/ports/SkOSFile_cobalt.cc
index a8054f90e262..3d298e50683b 100644
--- a/cobalt/renderer/rasterizer/skia/skia/src/ports/SkOSFile_cobalt.cc
+++ b/cobalt/renderer/rasterizer/skia/skia/src/ports/SkOSFile_cobalt.cc
@@ -93,7 +93,9 @@ size_t sk_fwrite(const void* buffer, size_t byteCount, FILE* sk_file) {
   FilePtr file = ToFilePtr(sk_file);
   int result =
       write(file->fd, reinterpret_cast<const char*>(buffer), byteCount);
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   base::RecordFileWriteStat(result);
+#endif
   return result;
 }
 
diff --git a/cobalt/renderer/test/png_utils/png_encode.cc b/cobalt/renderer/test/png_utils/png_encode.cc
index 853c59940f71..56af108ca39f 100644
--- a/cobalt/renderer/test/png_utils/png_encode.cc
+++ b/cobalt/renderer/test/png_utils/png_encode.cc
@@ -61,7 +61,9 @@ void EncodeRGBAToPNG(const base::FilePath& png_file_path,
   DCHECK_NE(file.GetPlatformFile(), -1);
   int bytes_written =
       file.WriteAtCurrentPos(reinterpret_cast<char*>(buffer.get()), size);
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   base::RecordFileWriteStat(bytes_written);
+#endif
   DLOG_IF(ERROR, bytes_written != size) << "Error writing PNG to file.";
 }
 
diff --git a/cobalt/trace_event/json_file_outputter.cc b/cobalt/trace_event/json_file_outputter.cc
index f3d10e329d8d..424ace50ba28 100644
--- a/cobalt/trace_event/json_file_outputter.cc
+++ b/cobalt/trace_event/json_file_outputter.cc
@@ -138,7 +138,9 @@ void JSONFileOutputter::Write(const char* buffer, int length) {
   }
 
   int count = file_.WriteAtCurrentPos(buffer, length);
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   base::RecordFileWriteStat(count);
+#endif
   if (count < 0) {
     Close();
   }
diff --git a/net/BUILD.gn b/net/BUILD.gn
index ec5057e993fc..f53c3e597b38 100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -1175,6 +1175,17 @@ component("net") {
       "socket/tcp_socket_starboard.h",
       "socket/udp_socket_starboard.cc",
       "socket/udp_socket_starboard.h",
+      # Use POSIX socket for SB16 - zhangmax
+      "base/file_stream_context_posix.cc",
+      "base/net_errors_posix.cc",
+      "base/sockaddr_util_posix.cc",
+      "base/sockaddr_util_posix.h",
+      "socket/socket_posix.cc",
+      "socket/socket_posix.h",
+      "socket/tcp_socket_posix.cc",
+      "socket/tcp_socket_posix.h",
+      "socket/udp_socket_posix.cc",
+      "socket/udp_socket_posix.h",
     ]
     deps += [ "//starboard:starboard_group" ]
   }
diff --git a/net/base/address_family.cc b/net/base/address_family.cc
index d6db1ffc3087..54e9dd0b3d5a 100644
--- a/net/base/address_family.cc
+++ b/net/base/address_family.cc
@@ -20,7 +20,7 @@ AddressFamily GetAddressFamily(const IPAddress& address) {
   }
 }
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 SbSocketAddressType ConvertAddressFamily(AddressFamily address_family) {
   switch (address_family) {
     case ADDRESS_FAMILY_IPV4:
diff --git a/net/base/address_family.h b/net/base/address_family.h
index 90f2be5181ff..0de19b7e277c 100644
--- a/net/base/address_family.h
+++ b/net/base/address_family.h
@@ -42,7 +42,7 @@ typedef int HostResolverFlags;
 // Returns AddressFamily for |address|.
 NET_EXPORT AddressFamily GetAddressFamily(const IPAddress& address);
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 NET_EXPORT SbSocketAddressType ConvertAddressFamily(
     AddressFamily address_family);
 #else
diff --git a/net/base/features.cc b/net/base/features.cc
index f554886495be..1f1e5baf2e04 100644
--- a/net/base/features.cc
+++ b/net/base/features.cc
@@ -212,7 +212,7 @@ BASE_FEATURE(kDocumentReporting,
              base::FEATURE_ENABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(ENABLE_REPORTING)
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 BASE_FEATURE(kUdpSocketPosixAlwaysUpdateBytesReceived,
              "UdpSocketPosixAlwaysUpdateBytesReceived",
              base::FEATURE_ENABLED_BY_DEFAULT);
diff --git a/net/base/features.h b/net/base/features.h
index 2c235b37f768..dd6a84f0c8ef 100644
--- a/net/base/features.h
+++ b/net/base/features.h
@@ -261,14 +261,14 @@ NET_EXPORT extern const base::FeatureParam<base::TimeDelta>
 NET_EXPORT BASE_DECLARE_FEATURE(kDocumentReporting);
 #endif  // BUILDFLAG(ENABLE_REPORTING)
 
-#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 // When enabled, UDPSocketPosix increments the global counter of bytes received
 // every time bytes are received, instead of using a timer to batch updates.
 // This should reduce the number of wake ups and improve battery consumption.
 // TODO(https://crbug.com/1189805): Cleanup the feature after verifying that it
 // doesn't negatively affect performance.
 NET_EXPORT BASE_DECLARE_FEATURE(kUdpSocketPosixAlwaysUpdateBytesReceived);
-#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 
 // When this feature is enabled, redirected requests will be considered
 // cross-site for the purpose of SameSite cookies if any redirect hop was
diff --git a/net/base/net_errors_posix.cc b/net/base/net_errors_posix.cc
index df49829735bd..d8b88bee0a24 100644
--- a/net/base/net_errors_posix.cc
+++ b/net/base/net_errors_posix.cc
@@ -15,6 +15,8 @@
 
 namespace net {
 
+#if SB_API_VERSION >= 16
+
 Error MapSystemError(logging::SystemErrorCode os_error) {
   if (os_error != 0)
     DVLOG(2) << "Error " << os_error << ": "
@@ -124,10 +126,12 @@ Error MapSystemError(logging::SystemErrorCode os_error) {
     case 0:
       return OK;
     default:
-      LOG(WARNING) << "Unknown error " << base::safe_strerror(os_error) << " ("
+      LOG(WARNING) << "Unknown error " << " ("
                    << os_error << ") mapped to net::ERR_FAILED";
       return ERR_FAILED;
   }
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace net
diff --git a/net/base/net_errors_starboard.cc b/net/base/net_errors_starboard.cc
index 7ed4aa304caa..329ec117d82a 100644
--- a/net/base/net_errors_starboard.cc
+++ b/net/base/net_errors_starboard.cc
@@ -24,6 +24,8 @@
 
 namespace net {
 
+#if SB_API_VERSION <= 15
+
 Error MapSystemError(logging::SystemErrorCode error) {
   if (error != 0) {
     char error_string[256];
@@ -58,4 +60,6 @@ Error MapSocketError(SbSocketError error) {
   }
 }
 
+#endif  // SB_API_VERSION <= 15
+
 }  // namespace net
diff --git a/net/socket/socket_descriptor.cc b/net/socket/socket_descriptor.cc
index 4880f0ee1b57..649bd77e373a 100644
--- a/net/socket/socket_descriptor.cc
+++ b/net/socket/socket_descriptor.cc
@@ -6,13 +6,13 @@
 
 #include "build/build_config.h"
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include "starboard/socket.h"
 #include "base/notreached.h"
 #elif BUILDFLAG(IS_WIN)
 #include <ws2tcpip.h>
 #include "net/base/winsock_init.h"
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include <sys/socket.h>
 #include <sys/types.h>
 #endif
@@ -24,7 +24,7 @@
 namespace net {
 
 SocketDescriptor CreatePlatformSocket(int family, int type, int protocol) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   NOTREACHED();
   return kSbSocketInvalid;
 #elif BUILDFLAG(IS_WIN)
@@ -40,7 +40,7 @@ SocketDescriptor CreatePlatformSocket(int family, int type, int protocol) {
     }
   }
   return result;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   SocketDescriptor result = ::socket(family, type, protocol);
 #if BUILDFLAG(IS_APPLE)
   // Disable SIGPIPE on this socket. Although Chromium globally disables
diff --git a/net/socket/socket_descriptor.h b/net/socket/socket_descriptor.h
index 032cb73d5cb1..5e96cbdd8ea6 100644
--- a/net/socket/socket_descriptor.h
+++ b/net/socket/socket_descriptor.h
@@ -17,12 +17,12 @@
 
 namespace net {
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 typedef SbSocket SocketDescriptor;
 #elif BUILDFLAG(IS_WIN)
 typedef UINT_PTR SocketDescriptor;
 const SocketDescriptor kInvalidSocket = (SocketDescriptor)(~0);
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 typedef int SocketDescriptor;
 const SocketDescriptor kInvalidSocket = -1;
 #endif
diff --git a/net/socket/socket_options.cc b/net/socket/socket_options.cc
index 7f23a600a2da..42cc6c25aba9 100644
--- a/net/socket/socket_options.cc
+++ b/net/socket/socket_options.cc
@@ -9,12 +9,12 @@
 #include "build/build_config.h"
 #include "net/base/net_errors.h"
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include "base/notreached.h"
 #elif BUILDFLAG(IS_WIN)
 #include <winsock2.h>
 #include <ws2tcpip.h>
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <sys/socket.h>
@@ -23,12 +23,13 @@
 namespace net {
 
 int SetTCPNoDelay(SocketDescriptor fd, bool no_delay) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   return SbSocketSetTcpNoDelay(fd, no_delay) ? OK : ERR_FAILED;
 #else
+
 #if BUILDFLAG(IS_WIN)
   BOOL on = no_delay ? TRUE : FALSE;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   int on = no_delay ? 1 : 0;
 #endif
   int rv = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY,
@@ -38,7 +39,7 @@ int SetTCPNoDelay(SocketDescriptor fd, bool no_delay) {
 }
 
 int SetReuseAddr(SocketDescriptor fd, bool reuse) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   return SbSocketSetReuseAddress(fd, reuse) ? OK : ERR_FAILED;
 #else
 // SO_REUSEADDR is useful for server sockets to bind to a recently unbound
@@ -56,7 +57,7 @@ int SetReuseAddr(SocketDescriptor fd, bool reuse) {
 // SO_REUSEPORT is provided in MacOS X and iOS.
 #if BUILDFLAG(IS_WIN)
   BOOL boolean_value = reuse ? TRUE : FALSE;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   int boolean_value = reuse ? 1 : 0;
 #endif
   int rv = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
@@ -67,14 +68,14 @@ int SetReuseAddr(SocketDescriptor fd, bool reuse) {
 }
 
 int SetSocketReceiveBufferSize(SocketDescriptor fd, int32_t size) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   return SbSocketSetReceiveBufferSize(fd, size) ? OK : ERR_FAILED;
 #else
   int rv = setsockopt(fd, SOL_SOCKET, SO_RCVBUF,
                       reinterpret_cast<const char*>(&size), sizeof(size));
 #if BUILDFLAG(IS_WIN)
   int os_error = WSAGetLastError();
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   int os_error = errno;
 #endif
   int net_error = (rv == -1) ? MapSystemError(os_error) : OK;
@@ -86,14 +87,14 @@ int SetSocketReceiveBufferSize(SocketDescriptor fd, int32_t size) {
 }
 
 int SetSocketSendBufferSize(SocketDescriptor fd, int32_t size) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   return SbSocketSetSendBufferSize(fd, size) ? OK : ERR_FAILED;
 #else
   int rv = setsockopt(fd, SOL_SOCKET, SO_SNDBUF,
                       reinterpret_cast<const char*>(&size), sizeof(size));
 #if BUILDFLAG(IS_WIN)
   int os_error = WSAGetLastError();
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   int os_error = errno;
 #endif
   int net_error = (rv == -1) ? MapSystemError(os_error) : OK;
@@ -105,13 +106,13 @@ int SetSocketSendBufferSize(SocketDescriptor fd, int32_t size) {
 }
 
 int SetIPv6Only(SocketDescriptor fd, bool ipv6_only) {
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
   NOTREACHED();
   return -1;
 #else
 #if BUILDFLAG(IS_WIN)
   DWORD on = ipv6_only ? 1 : 0;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
   int on = ipv6_only ? 1 : 0;
 #endif
   int rv = setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
diff --git a/net/socket/socket_posix.cc b/net/socket/socket_posix.cc
index ea3d794d9858..177a26007bc4 100644
--- a/net/socket/socket_posix.cc
+++ b/net/socket/socket_posix.cc
@@ -33,6 +33,8 @@
 
 namespace net {
 
+#if SB_API_VERSION >= 16
+
 namespace {
 
 int MapAcceptError(int os_error) {
@@ -523,8 +525,19 @@ int SocketPosix::DoWrite(IOBuffer* buf, int buf_len) {
   // socket creation.
   int rv = HANDLE_EINTR(send(socket_fd_, buf->data(), buf_len, MSG_NOSIGNAL));
 #else
+
+#if SB_API_VERSION >= 16
+#if defined(MSG_NOSIGNAL)
+  const int kSendFlags = MSG_NOSIGNAL;
+#else
+  const int kSendFlags = 0;
+#endif  // defined(MSG_NOSIGNAL)
+  int rv = HANDLE_EINTR(send(socket_fd_, buf->data(), buf_len, kSendFlags));
+#else
   int rv = HANDLE_EINTR(write(socket_fd_, buf->data(), buf_len));
-#endif
+#endif  //SB_API_VERSION >= 16
+
+#endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID)
   return rv >= 0 ? rv : MapSystemError(errno);
 }
 
@@ -581,4 +594,6 @@ void SocketPosix::StopWatchingAndCleanUp(bool close_socket) {
   peer_address_.reset();
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace net
diff --git a/net/socket/socket_posix.h b/net/socket/socket_posix.h
index f7155cab06ec..7b6bdfcf19ae 100644
--- a/net/socket/socket_posix.h
+++ b/net/socket/socket_posix.h
@@ -19,6 +19,8 @@
 
 namespace net {
 
+#if SB_API_VERSION >= 16
+
 class IOBuffer;
 struct SockaddrStorage;
 
@@ -158,6 +160,8 @@ class NET_EXPORT_PRIVATE SocketPosix
   base::ThreadChecker thread_checker_;
 };
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace net
 
 #endif  // NET_SOCKET_SOCKET_POSIX_H_
diff --git a/net/socket/tcp_socket.h b/net/socket/tcp_socket.h
index 19cfc74ea910..708df595e0f1 100644
--- a/net/socket/tcp_socket.h
+++ b/net/socket/tcp_socket.h
@@ -9,11 +9,11 @@
 #include "net/base/net_export.h"
 #include "net/socket/socket_descriptor.h"
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include "net/socket/tcp_socket_starboard.h"
 #elif BUILDFLAG(IS_WIN)
 #include "net/socket/tcp_socket_win.h"
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include "net/socket/tcp_socket_posix.h"
 #endif
 
@@ -25,11 +25,11 @@ namespace net {
 // class, unless a clear separation of client and server socket functionality is
 // not suitable for your use case (e.g., a socket needs to be created and bound
 // before you know whether it is a client or server socket).
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 typedef TCPSocketStarboard TCPSocket;
 #elif BUILDFLAG(IS_WIN)
 typedef TCPSocketWin TCPSocket;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 typedef TCPSocketPosix TCPSocket;
 #endif
 
diff --git a/net/socket/tcp_socket_posix.cc b/net/socket/tcp_socket_posix.cc
index 73d002d44281..a7b8ffb07f8c 100644
--- a/net/socket/tcp_socket_posix.cc
+++ b/net/socket/tcp_socket_posix.cc
@@ -62,6 +62,8 @@
 
 namespace net {
 
+#if SB_API_VERSION >= 16
+
 namespace {
 
 // SetTCPKeepAlive sets SO_KEEPALIVE.
@@ -711,4 +713,6 @@ bool TCPSocketPosix::GetEstimatedRoundTripTime(base::TimeDelta* out_rtt) const {
 #endif  // defined(TCP_INFO)
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace net
diff --git a/net/socket/tcp_socket_posix.h b/net/socket/tcp_socket_posix.h
index b1798a0494d2..a84cf61eb469 100644
--- a/net/socket/tcp_socket_posix.h
+++ b/net/socket/tcp_socket_posix.h
@@ -26,6 +26,8 @@ class TimeDelta;
 
 namespace net {
 
+#if SB_API_VERSION >= 16
+
 class AddressList;
 class IOBuffer;
 class IPEndPoint;
@@ -227,6 +229,8 @@ class NET_EXPORT TCPSocketPosix {
   SocketTag tag_;
 };
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace net
 
 #endif  // NET_SOCKET_TCP_SOCKET_POSIX_H_
diff --git a/net/socket/tcp_socket_starboard.cc b/net/socket/tcp_socket_starboard.cc
index e87f81520d6a..f8458be61aad 100644
--- a/net/socket/tcp_socket_starboard.cc
+++ b/net/socket/tcp_socket_starboard.cc
@@ -28,6 +28,8 @@
 
 namespace net {
 
+#if SB_API_VERSION <= 15
+
 TCPSocketStarboard::TCPSocketStarboard(
     std::unique_ptr<SocketPerformanceWatcher> socket_performance_watcher,
     NetLog* net_log,
@@ -683,4 +685,6 @@ int TCPSocketStarboard::SetIPv6Only(bool ipv6_only) {
     return 0;
 }
 
+#endif  // SB_API_VERSION <= 15
+
 }  // namespace net
diff --git a/net/socket/tcp_socket_starboard.h b/net/socket/tcp_socket_starboard.h
index 876dac02d8a5..5e77b3640fb5 100644
--- a/net/socket/tcp_socket_starboard.h
+++ b/net/socket/tcp_socket_starboard.h
@@ -15,6 +15,8 @@
 #ifndef NET_SOCKET_TCP_SOCKET_STARBOARD_H_
 #define NET_SOCKET_TCP_SOCKET_STARBOARD_H_
 
+#if SB_API_VERSION <= 15
+
 #include "base/bind.h"
 #include "base/task/sequenced_task_runner.h"
 #include "base/message_loop/message_pump_io_starboard.h"
@@ -215,4 +217,6 @@ class NET_EXPORT TCPSocketStarboard : public base::MessagePumpIOStarboard::Watch
 
 }  // namespace net
 
+#endif  // SB_API_VERSION <= 15
+
 #endif  // NET_SOCKET_TCP_SOCKET_STARBOARD_H_
diff --git a/net/socket/udp_socket.h b/net/socket/udp_socket.h
index e7b897f09ec2..f57366dab4e5 100644
--- a/net/socket/udp_socket.h
+++ b/net/socket/udp_socket.h
@@ -7,11 +7,11 @@
 
 #include "build/build_config.h"
 
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 #include "net/socket/udp_socket_starboard.h"
 #elif BUILDFLAG(IS_WIN)
 #include "net/socket/udp_socket_win.h"
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 #include "net/socket/udp_socket_posix.h"
 #endif
 
@@ -37,11 +37,11 @@ namespace net {
 //       RecvFrom/SendTo       // Each read can come from a different client
 //                             // Writes need to be directed to a specific
 //                             // address.
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
 typedef UDPSocketStarboard UDPSocket;
 #elif BUILDFLAG(IS_WIN)
 typedef UDPSocketWin UDPSocket;
-#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
+#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) || SB_API_VERSION >= 16
 typedef UDPSocketPosix UDPSocket;
 #endif
 
diff --git a/net/socket/udp_socket_posix.cc b/net/socket/udp_socket_posix.cc
index d7fe60ca6b77..c23ab0d10d56 100644
--- a/net/socket/udp_socket_posix.cc
+++ b/net/socket/udp_socket_posix.cc
@@ -66,6 +66,8 @@
 
 namespace net {
 
+#if SB_API_VERSION >= 16
+
 namespace {
 
 const int kBindRetries = 10;
@@ -1096,4 +1098,6 @@ int UDPSocketPosix::SetIOSNetworkServiceType(int ios_network_service_type) {
   return OK;
 }
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace net
diff --git a/net/socket/udp_socket_posix.h b/net/socket/udp_socket_posix.h
index ed9c7549c1fc..03ea42b3348a 100644
--- a/net/socket/udp_socket_posix.h
+++ b/net/socket/udp_socket_posix.h
@@ -33,6 +33,8 @@
 
 namespace net {
 
+#if SB_API_VERSION >= 16
+
 class IPAddress;
 class NetLog;
 struct NetLogSource;
@@ -465,6 +467,8 @@ class NET_EXPORT UDPSocketPosix {
   THREAD_CHECKER(thread_checker_);
 };
 
+#endif  // SB_API_VERSION >= 16
+
 }  // namespace net
 
 #endif  // NET_SOCKET_UDP_SOCKET_POSIX_H_
diff --git a/net/socket/udp_socket_starboard.cc b/net/socket/udp_socket_starboard.cc
index 7e51b873276a..89218e62b0bc 100644
--- a/net/socket/udp_socket_starboard.cc
+++ b/net/socket/udp_socket_starboard.cc
@@ -35,6 +35,8 @@
 
 namespace net {
 
+#if SB_API_VERSION <= 15
+
 UDPSocketStarboard::UDPSocketStarboard(DatagramSocket::BindType bind_type,
                                        net::NetLog* net_log,
                                        const net::NetLogSource& source)
@@ -900,4 +902,6 @@ int UDPSocketStarboard::ResetWrittenBytes() {
   return bytes;
 }
 
+#endif  // SB_API_VERSION <= 15
+
 }  // namespace net
diff --git a/net/socket/udp_socket_starboard.h b/net/socket/udp_socket_starboard.h
index 905964eccc67..73b7e5916a2b 100644
--- a/net/socket/udp_socket_starboard.h
+++ b/net/socket/udp_socket_starboard.h
@@ -17,6 +17,8 @@
 #ifndef NET_SOCKET_UDP_SOCKET_STARBOARD_H_
 #define NET_SOCKET_UDP_SOCKET_STARBOARD_H_
 
+#if SB_API_VERSION <= 15
+
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_pump_io_starboard.h"
 #include "base/message_loop/message_pump_for_io.h"
@@ -493,4 +495,6 @@ class NET_EXPORT UDPSocketStarboard
 
 }  // namespace net
 
+#endif  // SB_API_VERSION <= 15
+
 #endif  // NET_SOCKET_UDP_SOCKET_STARBOARD_H_
diff --git a/net/ssl/ssl_key_logger_impl.cc b/net/ssl/ssl_key_logger_impl.cc
index aaca04940ac8..6e56f70b7350 100644
--- a/net/ssl/ssl_key_logger_impl.cc
+++ b/net/ssl/ssl_key_logger_impl.cc
@@ -109,7 +109,7 @@ class SSLKeyLoggerImpl::Core
 
     if (file_) {
       
-#if defined(STARBOARD)
+#if defined(STARBOARD) && SB_API_VERSION <= 15
       for (const auto& line : buffer) {
         file_->WriteAll(line.c_str(), line.length());
       }
diff --git a/starboard/elf_loader/exported_symbols.cc b/starboard/elf_loader/exported_symbols.cc
index 48f816a36374..1081ab9b9d39 100644
--- a/starboard/elf_loader/exported_symbols.cc
+++ b/starboard/elf_loader/exported_symbols.cc
@@ -468,7 +468,9 @@ ExportedSymbols::ExportedSymbols() {
   REGISTER_SYMBOL(ftruncate);
   REGISTER_SYMBOL(getaddrinfo);
   REGISTER_SYMBOL(getifaddrs);
+  REGISTER_SYMBOL(getpeername);
   REGISTER_SYMBOL(getsockname);
+  REGISTER_SYMBOL(getsockopt);
   REGISTER_SYMBOL(listen);
   REGISTER_SYMBOL(lseek);
   REGISTER_SYMBOL(malloc);
@@ -483,10 +485,11 @@ ExportedSymbols::ExportedSymbols() {
   REGISTER_SYMBOL(readdir_r);
   REGISTER_SYMBOL(realloc);
   REGISTER_SYMBOL(recv);
-  REGISTER_SYMBOL(send);
+  REGISTER_SYMBOL(recvmsg);
   REGISTER_SYMBOL(recvfrom);
   REGISTER_SYMBOL(rmdir);
   REGISTER_SYMBOL(sched_yield);
+  REGISTER_SYMBOL(send);
   REGISTER_SYMBOL(sendto);
   REGISTER_SYMBOL(setsockopt);
   REGISTER_SYMBOL(socket);
diff --git a/starboard/shared/win32/posix_emu/socket.cc b/starboard/shared/win32/posix_emu/socket.cc
index c8a8dba2ed81..aeb39f6e91c6 100644
--- a/starboard/shared/win32/posix_emu/socket.cc
+++ b/starboard/shared/win32/posix_emu/socket.cc
@@ -241,7 +241,7 @@ static void set_errno() {
       sockError = NO_DATA;
       break;
     default:
-      SB_DLOG(WARNING) << "Unknown socket error.";
+      SB_DLOG(WARNING) << "Unknown socket error - " << winsockError;
       break;
   }
 
diff --git a/starboard/tools/api_leak_detector/api_leak_detector.py b/starboard/tools/api_leak_detector/api_leak_detector.py
index cdfe27f99752..17ee0b71a9d6 100755
--- a/starboard/tools/api_leak_detector/api_leak_detector.py
+++ b/starboard/tools/api_leak_detector/api_leak_detector.py
@@ -94,6 +94,7 @@
     'connect',
     'clock_gettime',
     'close',
+    'fcntl',
     'free',
     'freeifaddrs',
     'freeaddrinfo',
@@ -103,14 +104,23 @@
     'gettimeofday',
     'getifaddrs',
     'getaddrinfo',
+    'getpeername',
+    'getsockname',
+    'getsockopt',
     'gmtime_r',
     'inet_ntop',
     'listen',
     'lseek',
     'malloc',
     'posix_memalign',
+    'posixSocketGetFdFromSb',
+    'posixSocketGetSbFromFd',
+    'SbPosixSocketWaiterAdd',
+    'SbPosixSocketWaiterRemove',
+    'puts',
     'recv',
     'recvfrom',
+    'recvmsg',
     'realloc',
     'rmdir',
     'setsockopt',
diff --git a/third_party/crashpad/crashpad/snapshot/elf/elf_image_reader_fuzzer.cc b/third_party/crashpad/crashpad/snapshot/elf/elf_image_reader_fuzzer.cc
index b780af4e1321..a915117c3a00 100644
--- a/third_party/crashpad/crashpad/snapshot/elf/elf_image_reader_fuzzer.cc
+++ b/third_party/crashpad/crashpad/snapshot/elf/elf_image_reader_fuzzer.cc
@@ -45,8 +45,8 @@ class FakeProcessMemory : public ProcessMemory {
 
 extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
   // Swallow all logs to avoid spam.
-  logging::SetLogMessageHandler(
-      [](logging::LogSeverity, const char*, int, size_t, const std::string&) {
+  mini_chromium_base_logging::SetLogMessageHandler(
+      [](mini_chromium_base_logging::LogSeverity, const char*, int, size_t, const std::string&) {
         return true;
       });
   return 0;
diff --git a/third_party/crashpad/crashpad/test/errors.cc b/third_party/crashpad/crashpad/test/errors.cc
index 14845062566a..0694c29d4106 100644
--- a/third_party/crashpad/crashpad/test/errors.cc
+++ b/third_party/crashpad/crashpad/test/errors.cc
@@ -55,7 +55,7 @@ std::string ErrorMessage(const std::string& base) {
       "%s%s%s",
       base.c_str(),
       base.empty() ? "" : ": ",
-      logging::SystemErrorCodeToString(GetLastError()).c_str());
+      mini_chromium_base_logging::SystemErrorCodeToString(GetLastError()).c_str());
 }
 #endif
 
diff --git a/third_party/crashpad/crashpad/test/filesystem.cc b/third_party/crashpad/crashpad/test/filesystem.cc
index c1a912d35f71..79cfbe56c6a3 100644
--- a/third_party/crashpad/crashpad/test/filesystem.cc
+++ b/third_party/crashpad/crashpad/test/filesystem.cc
@@ -74,7 +74,7 @@ bool SymbolicLinkFlags(DWORD* flags) {
     // Don’t use ErrorMessage() here because the second CreateSymbolicLink() may
     // have scrambled it. Use the saved |error| value instead.
     EXPECT_EQ(error, static_cast<DWORD>(ERROR_PRIVILEGE_NOT_HELD))
-        << "CreateSymbolicLink: " << logging::SystemErrorCodeToString(error);
+        << "CreateSymbolicLink: " << mini_chromium_base_logging::SystemErrorCodeToString(error);
     return -1;
   }();
 
diff --git a/third_party/crashpad/crashpad/util/thread/thread_log_messages.cc b/third_party/crashpad/crashpad/util/thread/thread_log_messages.cc
index 60c824834ac0..5f5a51f1a0bd 100644
--- a/third_party/crashpad/crashpad/util/thread/thread_log_messages.cc
+++ b/third_party/crashpad/crashpad/util/thread/thread_log_messages.cc
@@ -34,7 +34,7 @@ namespace {
 class ThreadLogMessagesMaster {
  public:
   void SetThreadMessageList(std::vector<std::string>* message_list) {
-    DCHECK_EQ(logging::GetLogMessageHandler(), &LogMessageHandler);
+    DCHECK_EQ(mini_chromium_base_logging::GetLogMessageHandler(), &LogMessageHandler);
     DCHECK_NE(tls_.Get() != nullptr, message_list != nullptr);
     tls_.Set(message_list);
   }
@@ -46,13 +46,13 @@ class ThreadLogMessagesMaster {
 
  private:
   ThreadLogMessagesMaster() {
-    DCHECK(!logging::GetLogMessageHandler());
-    logging::SetLogMessageHandler(LogMessageHandler);
+    DCHECK(!mini_chromium_base_logging::GetLogMessageHandler());
+    mini_chromium_base_logging::SetLogMessageHandler(LogMessageHandler);
   }
 
   ~ThreadLogMessagesMaster() = delete;
 
-  static bool LogMessageHandler(logging::LogSeverity severity,
+  static bool LogMessageHandler(mini_chromium_base_logging::LogSeverity severity,
                                 const char* file_path,
                                 int line,
                                 size_t message_start,
diff --git a/third_party/crashpad/crashpad/util/thread/thread_log_messages.h b/third_party/crashpad/crashpad/util/thread/thread_log_messages.h
index e8eef358b6df..fa7e54d80312 100644
--- a/third_party/crashpad/crashpad/util/thread/thread_log_messages.h
+++ b/third_party/crashpad/crashpad/util/thread/thread_log_messages.h
@@ -27,7 +27,7 @@ namespace crashpad {
 //!
 //! At most one object of this class type may exist on a single thread at a
 //! time. When using this class, no other part of the program may call
-//! `logging::SetLogMessageHandler()` at any time.
+//! `mini_chromium_base_logging::SetLogMessageHandler()` at any time.
 class ThreadLogMessages {
  public:
   ThreadLogMessages();
diff --git a/third_party/crashpad/crashpad/util/win/ntstatus_logging.cc b/third_party/crashpad/crashpad/util/win/ntstatus_logging.cc
index e9a9b61a5a93..81bab850dd5a 100644
--- a/third_party/crashpad/crashpad/util/win/ntstatus_logging.cc
+++ b/third_party/crashpad/crashpad/util/win/ntstatus_logging.cc
@@ -47,7 +47,7 @@ std::string FormatNtstatus(DWORD ntstatus) {
 
 }  // namespace
 
-namespace logging {
+namespace mini_chromium_base_logging {
 
 NtstatusLogMessage::NtstatusLogMessage(
 #if defined(MINI_CHROMIUM_BASE_LOGGING_H_)
@@ -72,4 +72,4 @@ NtstatusLogMessage::~NtstatusLogMessage() {
            << base::StringPrintf(" (0x%08lx)", ntstatus_);
 }
 
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
diff --git a/third_party/crashpad/crashpad/util/win/ntstatus_logging.h b/third_party/crashpad/crashpad/util/win/ntstatus_logging.h
index 7eececc95bf7..e678cda5775c 100644
--- a/third_party/crashpad/crashpad/util/win/ntstatus_logging.h
+++ b/third_party/crashpad/crashpad/util/win/ntstatus_logging.h
@@ -20,9 +20,9 @@
 #include "base/logging.h"
 #include "base/macros.h"
 
-namespace logging {
+namespace mini_chromium_base_logging {
 
-class NtstatusLogMessage : public logging::LogMessage {
+class NtstatusLogMessage : public mini_chromium_base_logging::LogMessage {
  public:
   NtstatusLogMessage(
 #if defined(MINI_CHROMIUM_BASE_LOGGING_H_)
@@ -40,7 +40,7 @@ class NtstatusLogMessage : public logging::LogMessage {
   DISALLOW_COPY_AND_ASSIGN(NtstatusLogMessage);
 };
 
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
 
 #define NTSTATUS_LOG_STREAM(severity, ntstatus) \
   COMPACT_GOOGLE_LOG_EX_##severity(NtstatusLogMessage, ntstatus).stream()
@@ -48,14 +48,14 @@ class NtstatusLogMessage : public logging::LogMessage {
 #if defined(MINI_CHROMIUM_BASE_LOGGING_H_)
 
 #define NTSTATUS_VLOG_STREAM(verbose_level, ntstatus)                    \
-  logging::NtstatusLogMessage(                                           \
+  mini_chromium_base_logging::NtstatusLogMessage(                                           \
       __PRETTY_FUNCTION__, __FILE__, __LINE__, -verbose_level, ntstatus) \
       .stream()
 
 #else
 
 #define NTSTATUS_VLOG_STREAM(verbose_level, ntstatus)                       \
-  logging::NtstatusLogMessage(__FILE__, __LINE__, -verbose_level, ntstatus) \
+  mini_chromium_base_logging::NtstatusLogMessage(__FILE__, __LINE__, -verbose_level, ntstatus) \
       .stream()
 
 #endif  // MINI_CHROMIUM_BASE_LOGGING_H_
diff --git a/third_party/mini_chromium/base/files/file_util.h b/third_party/mini_chromium/base/files/file_util.h
index 312525176b44..5eb97806025b 100644
--- a/third_party/mini_chromium/base/files/file_util.h
+++ b/third_party/mini_chromium/base/files/file_util.h
@@ -11,11 +11,11 @@
 
 #include <sys/types.h>
 
-namespace base {
+namespace mini_chromium_base {
 
 bool ReadFromFD(int fd, char* buffer, size_t bytes);
 
-}  // namespace base
+}  // namespace mini_chromium_base
 
 #endif  // OS_POSIX
 
diff --git a/third_party/mini_chromium/base/files/file_util_posix.cc b/third_party/mini_chromium/base/files/file_util_posix.cc
index 6d3c096c8861..dd9eb6ae21e2 100644
--- a/third_party/mini_chromium/base/files/file_util_posix.cc
+++ b/third_party/mini_chromium/base/files/file_util_posix.cc
@@ -8,7 +8,7 @@
 
 #include "base/posix/eintr_wrapper.h"
 
-namespace base {
+namespace mini_chromium_base {
 
 bool ReadFromFD(int fd, char* buffer, size_t bytes) {
   size_t total_read = 0;
@@ -23,4 +23,4 @@ bool ReadFromFD(int fd, char* buffer, size_t bytes) {
   return total_read == bytes;
 }
 
-}  // namespace base
+}  // namespace mini_chromium_base
diff --git a/third_party/mini_chromium/base/fuchsia/fuchsia_logging.cc b/third_party/mini_chromium/base/fuchsia/fuchsia_logging.cc
index de30a3043c84..833122900dbf 100644
--- a/third_party/mini_chromium/base/fuchsia/fuchsia_logging.cc
+++ b/third_party/mini_chromium/base/fuchsia/fuchsia_logging.cc
@@ -8,7 +8,7 @@
 
 #include <iomanip>
 
-namespace logging {
+namespace mini_chromium_base_logging {
 
 ZxLogMessage::ZxLogMessage(const char* function,
                            const char* file_path,
@@ -24,4 +24,4 @@ ZxLogMessage::~ZxLogMessage() {
   stream() << ": " << zx_status_get_string(zx_err_) << " (" << zx_err_ << ")";
 }
 
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
diff --git a/third_party/mini_chromium/base/fuchsia/fuchsia_logging.h b/third_party/mini_chromium/base/fuchsia/fuchsia_logging.h
index 778a24b9cd64..b55e08a8708a 100644
--- a/third_party/mini_chromium/base/fuchsia/fuchsia_logging.h
+++ b/third_party/mini_chromium/base/fuchsia/fuchsia_logging.h
@@ -14,9 +14,9 @@
 // error. The error value will be decoded so that logged messages explain the
 // error.
 
-namespace logging {
+namespace mini_chromium_base_logging {
 
-class ZxLogMessage : public logging::LogMessage {
+class ZxLogMessage : public mini_chromium_base_logging::LogMessage {
  public:
   ZxLogMessage(const char* function,
                const char* file_path,
@@ -31,7 +31,7 @@ class ZxLogMessage : public logging::LogMessage {
   DISALLOW_COPY_AND_ASSIGN(ZxLogMessage);
 };
 
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
 
 #define ZX_LOG_STREAM(severity, zx_err) \
   COMPACT_GOOGLE_LOG_EX_##severity(ZxLogMessage, zx_err).stream()
diff --git a/third_party/mini_chromium/base/logging.cc b/third_party/mini_chromium/base/logging.cc
index 49f0fbe6539b..f07339b3ac7c 100644
--- a/third_party/mini_chromium/base/logging.cc
+++ b/third_party/mini_chromium/base/logging.cc
@@ -61,7 +61,7 @@
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 
-namespace logging {
+namespace mini_chromium_base_logging {
 
 namespace {
 
@@ -490,4 +490,4 @@ ErrnoLogMessage::~ErrnoLogMessage() {
 
 #endif  // OS_POSIX
 
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
diff --git a/third_party/mini_chromium/base/logging.h b/third_party/mini_chromium/base/logging.h
index 0270090e5bbc..b687c441e220 100644
--- a/third_party/mini_chromium/base/logging.h
+++ b/third_party/mini_chromium/base/logging.h
@@ -5,6 +5,9 @@
 #ifndef MINI_CHROMIUM_BASE_LOGGING_H_
 #define MINI_CHROMIUM_BASE_LOGGING_H_
 
+//#ifndef BASE_LOGGING_H_
+//#define BASE_LOGGING_H_
+
 #include <assert.h>
 #include <errno.h>
 
@@ -16,7 +19,7 @@
 #include "base/macros.h"
 #include "build/build_config.h"
 
-namespace logging {
+namespace mini_chromium_base_logging {
 
 typedef int LogSeverity;
 const LogSeverity LOG_VERBOSE = -1;
@@ -162,7 +165,7 @@ class ErrnoLogMessage : public LogMessage {
 };
 #endif
 
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
 
 #if defined(COMPILER_MSVC)
 #define FUNCTION_SIGNATURE __FUNCSIG__
@@ -171,23 +174,23 @@ class ErrnoLogMessage : public LogMessage {
 #endif
 
 #define COMPACT_GOOGLE_LOG_EX_INFO(ClassName, ...) \
-    logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
-                       logging::LOG_INFO, ## __VA_ARGS__)
+    mini_chromium_base_logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+                       mini_chromium_base_logging::LOG_INFO, ## __VA_ARGS__)
 #define COMPACT_GOOGLE_LOG_EX_WARNING(ClassName, ...) \
-    logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
-                       logging::LOG_WARNING, ## __VA_ARGS__)
+    mini_chromium_base_logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+                       mini_chromium_base_logging::LOG_WARNING, ## __VA_ARGS__)
 #define COMPACT_GOOGLE_LOG_EX_ERROR(ClassName, ...) \
-    logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
-                       logging::LOG_ERROR, ## __VA_ARGS__)
+    mini_chromium_base_logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+                       mini_chromium_base_logging::LOG_ERROR, ## __VA_ARGS__)
 #define COMPACT_GOOGLE_LOG_EX_ERROR_REPORT(ClassName, ...) \
-    logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
-                       logging::LOG_ERROR_REPORT, ## __VA_ARGS__)
+    mini_chromium_base_logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+                       mini_chromium_base_logging::LOG_ERROR_REPORT, ## __VA_ARGS__)
 #define COMPACT_GOOGLE_LOG_EX_FATAL(ClassName, ...) \
-    logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
-                       logging::LOG_FATAL, ## __VA_ARGS__)
+    mini_chromium_base_logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+                       mini_chromium_base_logging::LOG_FATAL, ## __VA_ARGS__)
 #define COMPACT_GOOGLE_LOG_EX_DFATAL(ClassName, ...) \
-    logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
-                       logging::LOG_DFATAL, ## __VA_ARGS__)
+    mini_chromium_base_logging::ClassName(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+                       mini_chromium_base_logging::LOG_DFATAL, ## __VA_ARGS__)
 
 #define COMPACT_GOOGLE_LOG_INFO \
     COMPACT_GOOGLE_LOG_EX_INFO(LogMessage)
@@ -214,39 +217,39 @@ class ErrnoLogMessage : public LogMessage {
 #define COMPACT_GOOGLE_LOG_EX_0(ClassName, ...) \
   COMPACT_GOOGLE_LOG_EX_ERROR(ClassName , ##__VA_ARGS__)
 #define COMPACT_GOOGLE_LOG_0 COMPACT_GOOGLE_LOG_ERROR
-namespace logging {
+namespace mini_chromium_base_logging {
 const LogSeverity LOG_0 = LOG_ERROR;
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
 
 #endif  // OS_WIN
 
 #define LAZY_STREAM(stream, condition) \
-    !(condition) ? (void) 0 : ::logging::LogMessageVoidify() & (stream)
+    !(condition) ? (void) 0 : ::mini_chromium_base_logging::LogMessageVoidify() & (stream)
 
 #define LOG_IS_ON(severity) \
-    ((::logging::LOG_ ## severity) >= ::logging::GetMinLogLevel())
+    ((::mini_chromium_base_logging::LOG_ ## severity) >= ::mini_chromium_base_logging::GetMinLogLevel())
 #define VLOG_IS_ON(verbose_level) \
-    ((verbose_level) <= ::logging::GetVlogLevel(__FILE__))
+    ((verbose_level) <= ::mini_chromium_base_logging::GetVlogLevel(__FILE__))
 
 #define LOG_STREAM(severity) COMPACT_GOOGLE_LOG_ ## severity.stream()
 #define VLOG_STREAM(verbose_level) \
-    logging::LogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+    mini_chromium_base_logging::LogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
                         -verbose_level).stream()
 
 #if defined(OS_WIN)
 #define PLOG_STREAM(severity) COMPACT_GOOGLE_LOG_EX_ ## severity( \
-    Win32ErrorLogMessage, ::logging::GetLastSystemErrorCode()).stream()
+    Win32ErrorLogMessage, ::mini_chromium_base_logging::GetLastSystemErrorCode()).stream()
 #define VPLOG_STREAM(verbose_level)                                       \
-    logging::Win32ErrorLogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+    mini_chromium_base_logging::Win32ErrorLogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
                                   -verbose_level,                         \
-                                  ::logging::GetLastSystemErrorCode()).stream()
+                                  ::mini_chromium_base_logging::GetLastSystemErrorCode()).stream()
 #elif defined(OS_POSIX)
 #define PLOG_STREAM(severity) COMPACT_GOOGLE_LOG_EX_ ## severity( \
-    ErrnoLogMessage, ::logging::GetLastSystemErrorCode()).stream()
+    ErrnoLogMessage, ::mini_chromium_base_logging::GetLastSystemErrorCode()).stream()
 #define VPLOG_STREAM(verbose_level) \
-    logging::ErrnoLogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+    mini_chromium_base_logging::ErrnoLogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
                              -verbose_level, \
-                             ::logging::GetLastSystemErrorCode()).stream()
+                             ::mini_chromium_base_logging::GetLastSystemErrorCode()).stream()
 #endif
 
 #define LOG(severity) LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity))
@@ -280,9 +283,9 @@ const LogSeverity LOG_0 = LOG_ERROR;
 
 #define CHECK_OP(name, op, val1, val2) \
     if (std::string* _result = \
-          logging::Check ## name ## Impl((val1), (val2), \
+          mini_chromium_base_logging::Check ## name ## Impl((val1), (val2), \
                                          # val1 " " # op " " # val2)) \
-      logging::LogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+      mini_chromium_base_logging::LogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
                           _result).stream()
 
 #define CHECK_EQ(val1, val2) CHECK_OP(EQ, ==, val1, val2)
@@ -334,9 +337,9 @@ const LogSeverity LOG_0 = LOG_ERROR;
 #define DCHECK_OP(name, op, val1, val2) \
     if (DCHECK_IS_ON()) \
       if (std::string* _result = \
-          logging::Check ## name ## Impl((val1), (val2), \
+          mini_chromium_base_logging::Check ## name ## Impl((val1), (val2), \
                                          # val1 " " # op " " # val2)) \
-        logging::LogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
+        mini_chromium_base_logging::LogMessage(FUNCTION_SIGNATURE, __FILE__, __LINE__, \
                             _result).stream()
 
 #define DCHECK_EQ(val1, val2) DCHECK_OP(EQ, ==, val1, val2)
@@ -352,3 +355,4 @@ const LogSeverity LOG_0 = LOG_ERROR;
 #define assert(condition) DLOG_ASSERT(condition)
 
 #endif  // MINI_CHROMIUM_BASE_LOGGING_H_
+//#endif  // BASE_LOGGING_H_
\ No newline at end of file
diff --git a/third_party/mini_chromium/base/mac/mach_logging.cc b/third_party/mini_chromium/base/mac/mach_logging.cc
index 0411e30700f2..c97ff8e5673a 100644
--- a/third_party/mini_chromium/base/mac/mach_logging.cc
+++ b/third_party/mini_chromium/base/mac/mach_logging.cc
@@ -27,7 +27,7 @@ std::string FormatMachErrorNumber(mach_error_t mach_err) {
 
 }  // namespace
 
-namespace logging {
+namespace mini_chromium_base_logging {
 
 MachLogMessage::MachLogMessage(const char* function,
                                const char* file_path,
@@ -86,4 +86,4 @@ BootstrapLogMessage::~BootstrapLogMessage() {
 
 #endif  // !OS_IOS
 
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
diff --git a/third_party/mini_chromium/base/mac/mach_logging.h b/third_party/mini_chromium/base/mac/mach_logging.h
index 8cefc19e0e8f..46559f9ea3a0 100644
--- a/third_party/mini_chromium/base/mac/mach_logging.h
+++ b/third_party/mini_chromium/base/mac/mach_logging.h
@@ -30,9 +30,9 @@
 //   kr = vm_deallocate(task, address, size);
 //   MACH_DCHECK(kr == KERN_SUCCESS, kr) << "vm_deallocate";
 
-namespace logging {
+namespace mini_chromium_base_logging {
 
-class MachLogMessage : public logging::LogMessage {
+class MachLogMessage : public mini_chromium_base_logging::LogMessage {
  public:
   MachLogMessage(const char* function,
                  const char* file_path,
@@ -47,12 +47,12 @@ class MachLogMessage : public logging::LogMessage {
   DISALLOW_COPY_AND_ASSIGN(MachLogMessage);
 };
 
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
 
 #define MACH_LOG_STREAM(severity, mach_err) \
     COMPACT_GOOGLE_LOG_EX_ ## severity(MachLogMessage, mach_err).stream()
 #define MACH_VLOG_STREAM(verbose_level, mach_err) \
-    logging::MachLogMessage(__PRETTY_FUNCTION__, __FILE__, __LINE__, \
+    mini_chromium_base_logging::MachLogMessage(__PRETTY_FUNCTION__, __FILE__, __LINE__, \
                             -verbose_level, mach_err).stream()
 
 #define MACH_LOG(severity, mach_err) \
@@ -92,9 +92,9 @@ class MachLogMessage : public logging::LogMessage {
 
 #if !defined(OS_IOS)
 
-namespace logging {
+namespace mini_chromium_base_logging {
 
-class BootstrapLogMessage : public logging::LogMessage {
+class BootstrapLogMessage : public mini_chromium_base_logging::LogMessage {
  public:
   BootstrapLogMessage(const char* function,
                       const char* file_path,
@@ -109,13 +109,13 @@ class BootstrapLogMessage : public logging::LogMessage {
   DISALLOW_COPY_AND_ASSIGN(BootstrapLogMessage);
 };
 
-}  // namespace logging
+}  // namespace mini_chromium_base_logging
 
 #define BOOTSTRAP_LOG_STREAM(severity, bootstrap_err) \
     COMPACT_GOOGLE_LOG_EX_ ## severity(BootstrapLogMessage, \
                                        bootstrap_err).stream()
 #define BOOTSTRAP_VLOG_STREAM(verbose_level, bootstrap_err) \
-    logging::BootstrapLogMessage(__PRETTY_FUNCTION__, __FILE__, __LINE__, \
+    mini_chromium_base_logging::BootstrapLogMessage(__PRETTY_FUNCTION__, __FILE__, __LINE__, \
                             -verbose_level, bootstrap_err).stream()
 
 #define BOOTSTRAP_LOG(severity, bootstrap_err) \
diff --git a/third_party/mini_chromium/base/rand_util.cc b/third_party/mini_chromium/base/rand_util.cc
index ae5cdbfb19f5..5a0739062387 100644
--- a/third_party/mini_chromium/base/rand_util.cc
+++ b/third_party/mini_chromium/base/rand_util.cc
@@ -113,7 +113,7 @@ void RandBytes(void* output, size_t output_length) {
   zx_cprng_draw(output, output_length);
 #elif defined(OS_POSIX)
   int fd = GetUrandomFD();
-  bool success = ReadFromFD(fd, static_cast<char*>(output), output_length);
+  bool success = mini_chromium_base::ReadFromFD(fd, static_cast<char*>(output), output_length);
   CHECK(success);
 #elif defined(OS_WIN)
   char* output_ptr = static_cast<char*>(output);
diff --git a/third_party/musl/src/starboard/network/posix_socket.h b/third_party/musl/src/starboard/network/posix_socket.h
new file mode 100644
index 000000000000..3f15b832d6a9
--- /dev/null
+++ b/third_party/musl/src/starboard/network/posix_socket.h
@@ -0,0 +1,35 @@
+// Copyright 2024 The Cobalt Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef THIRD_PARTY_MUSL_SRC_STARBOARD_POSIX_SOCKET_H_
+#define THIRD_PARTY_MUSL_SRC_STARBOARD_POSIX_SOCKET_H_
+
+#include <stdint.h>
+#include "starboard/socket.h"
+
+#define PTHREAD_CREATE_JOINABLE 0
+#define PTHREAD_CREATE_DETACHED 1
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int posixSocketGetFdFromSb(SbSocket socket);
+SbSocket posixSocketGetSbFromFd(int socket);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // THIRD_PARTY_MUSL_SRC_STARBOARD_POSIX_SOCKET_H_
diff --git a/third_party/musl/src/starboard/network/socket.c b/third_party/musl/src/starboard/network/socket.c
index a14e0cc0835e..0a15658e663a 100644
--- a/third_party/musl/src/starboard/network/socket.c
+++ b/third_party/musl/src/starboard/network/socket.c
@@ -152,6 +152,40 @@ static int get(int key, bool take, FileOrSocket** valuePtr) {
   return status;
 }
 
+/******************************************************
+* This function looks for the sbSocket in the database.
+* Return
+*   -1 - not found
+*   positive value - the file descriptor/key of sbSocket
+******************************************************/
+static int getBySocket(SbSocket sbSocket) {
+  int index = 0;
+  int key = -1;
+  if (map == NULL) {
+    return -1;
+  }
+
+  pthread_mutex_lock(&lock);
+
+  while (index < mapSize){
+    Node* node = map->array[index];
+    if (node != NULL){
+      FileOrSocket* pValue = node->value;
+      if (pValue != NULL) {
+        if ((pValue->is_file == false) && (pValue->socket == sbSocket)){
+          key = node->key;
+          break;
+        }
+      }
+    }
+    index++;
+  }
+
+  pthread_mutex_unlock(&lock);
+
+  return key;
+}
+
 static SB_C_FORCE_INLINE time_t WindowsUsecToTimeT(int64_t time) {
   int64_t posix_time = time - 11644473600000000ULL;
   posix_time = posix_time / 1000000;
@@ -761,13 +795,6 @@ int getsockname(int sockfd, struct sockaddr *restrict addr, socklen_t *restrict
   }
   SbSocketAddress out_address = {0};
   int result = SbSocketGetLocalAddress(fileOrSock->socket, &out_address)? 0: -1;
-
-  struct sockaddr_in* addr_in = (struct sockaddr_in*)addr;
-  addr_in->sin_family = AF_INET;
-  addr_in->sin_addr.s_addr = out_address.address;
-  addr_in->sin_port = out_address.port;
-  *addrlen = sizeof(struct sockaddr_in);
-
   return result;
 }
 
@@ -787,7 +814,8 @@ int setsockopt (int sockfd, int level, int optname, const void* optval,
     return -1;
   }
 
-  if (level == SOL_SOCKET || level == SOL_TCP || level == IPPROTO_TCP || level == IPPROTO_IP) {
+  if (level == SOL_SOCKET || level == SOL_TCP || level == IPPROTO_TCP) {
+
     int* operation = (int*)optval;
     switch (optname){
       case SO_BROADCAST:{
@@ -829,18 +857,12 @@ int setsockopt (int sockfd, int level, int optname, const void* optval,
         return 0;
       }
       case TCP_NODELAY: {
+        int* operation = (int*)optval;
         bool bool_value = *operation == 1? true:false;
         return SbSocketSetTcpNoDelay(fileOrSock->socket, bool_value) == true? 0:-1;
       }
       case IP_ADD_MEMBERSHIP: {
-        if (optval == NULL) {
-          errno = EFAULT;
-          return -1;
-        }
-        const struct ip_mreq* imreq = (const struct ip_mreq*)optval;
-        SbSocketAddress* addr = (SbSocketAddress*)malloc(sizeof(SbSocketAddress));
-        memcpy(addr->address, &(imreq->imr_multiaddr.s_addr), sizeof(imreq->imr_multiaddr.s_addr));
-
+        SbSocketAddress* addr = (SbSocketAddress*)optval;
         return SbSocketJoinMulticastGroup(fileOrSock->socket, addr) == true? 0:-1;
       }
       default:
@@ -956,4 +978,26 @@ int getifaddrs(struct ifaddrs** ifap) {
   return 0;
 }
 
+
+int posixSocketGetFdFromSb(SbSocket socket){
+  return getBySocket(socket);
+}
+
+SbSocket posixSocketGetSbFromFd(int socket){
+  if (socket <= 0){
+    return NULL;
+  }
+  FileOrSocket *fileOrSock = NULL;
+  if (get(socket, false, &fileOrSock) != 0){
+    errno = EBADF;
+    return NULL;
+  }
+  if (fileOrSock == NULL || fileOrSock->is_file == true) {
+    errno = EBADF;
+    return NULL;
+  }
+
+  return fileOrSock->socket;
+}
+
 #endif  // SB_API_VERSION < 16