Merge pull request #3417 from Sonicadvance1/workaround_hang

ThreadManager: StealAndDropActiveLocks in the child forked process
FEX-Emu · Feb 12, 2024 · 930d265 · 930d265
2 parents 780b486 + 67143ed
commit 930d265
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Showing 4 changed files with 11 additions and 13 deletions.
diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/Syscalls.cpp b/Source/Tools/LinuxEmulation/LinuxSyscalls/Syscalls.cpp
@@ -580,7 +580,6 @@ uint64_t CloneHandler(FEXCore::Core::CpuStateFrame *Frame, FEX::HLE::clone3_args
     if (!AnyFlagsSet(flags, CLONE_THREAD)) {
       // Has an unsupported flag
       // Fall to a handler that can handle this case
-      auto Thread = Frame->Thread;
 
       args->SignalMask = ~0ULL;
       ::syscall(SYS_rt_sigprocmask, SIG_SETMASK, &args->SignalMask, &args->SignalMask, sizeof(args->SignalMask));
@@ -590,9 +589,7 @@ uint64_t CloneHandler(FEXCore::Core::CpuStateFrame *Frame, FEX::HLE::clone3_args
       args->StackSize = FEX::LinuxEmulation::Threads::STACK_SIZE;
       args->NewStack = FEX::LinuxEmulation::Threads::AllocateStackObject();
 
-      Thread->CTX->LockBeforeFork(Frame->Thread);
-
-      FEX::HLE::_SyscallHandler->LockBeforeFork();
+      FEX::HLE::_SyscallHandler->LockBeforeFork(Frame->Thread);
 
       uint64_t Result{};
       if (args->Type == TYPE_CLONE2) {
@@ -829,7 +826,8 @@ uint64_t UnimplementedSyscallSafe(FEXCore::Core::CpuStateFrame *Frame, uint64_t
   return -ENOSYS;
 }
 
-void SyscallHandler::LockBeforeFork() {
+void SyscallHandler::LockBeforeFork(FEXCore::Core::InternalThreadState *Thread) {
+  Thread->CTX->LockBeforeFork(Thread);
   VMATracking.Mutex.lock();
 }
 
@@ -841,6 +839,8 @@ void SyscallHandler::UnlockAfterFork(FEXCore::Core::InternalThreadState *LiveThr
     VMATracking.Mutex.unlock();
   }
 
+  CTX->UnlockAfterFork(LiveThread, Child);
+
   // Clear all the other threads that are being tracked
   TM.UnlockAfterFork(LiveThread, Child);
 }

diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/Syscalls.h b/Source/Tools/LinuxEmulation/LinuxSyscalls/Syscalls.h
@@ -165,7 +165,7 @@ class ThreadManager final {
     FEXCore::Context::Context *CTX;
     FEX::HLE::SignalDelegator *SignalDelegation;
 
-    std::mutex ThreadCreationMutex;
+    FEXCore::ForkableUniqueMutex ThreadCreationMutex;
     fextl::vector<FEXCore::Core::InternalThreadState *> Threads;
 
     // Thread idling support.
@@ -303,7 +303,7 @@ class SyscallHandler : public FEXCore::HLE::SyscallHandler, FEXCore::HLE::Source
   FEXCore::HLE::AOTIRCacheEntryLookupResult LookupAOTIRCacheEntry(FEXCore::Core::InternalThreadState *Thread, uint64_t GuestAddr) final override;
 
   ///// FORK tracking /////
-  void LockBeforeFork();
+  void LockBeforeFork(FEXCore::Core::InternalThreadState *Thread);
   void UnlockAfterFork(FEXCore::Core::InternalThreadState *LiveThread, bool Child);
 
   SourcecodeResolver *GetSourcecodeResolver() override { return this; }

diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/Syscalls/Thread.cpp b/Source/Tools/LinuxEmulation/LinuxSyscalls/Syscalls/Thread.cpp
@@ -233,9 +233,8 @@ namespace FEX::HLE {
 
     uint64_t Mask{~0ULL};
     ::syscall(SYS_rt_sigprocmask, SIG_SETMASK, &Mask, &Mask, sizeof(Mask));
-    Thread->CTX->LockBeforeFork(Frame->Thread);
 
-    FEX::HLE::_SyscallHandler->LockBeforeFork();
+    FEX::HLE::_SyscallHandler->LockBeforeFork(Frame->Thread);
 
     const bool IsVFork = flags & CLONE_VFORK;
     pid_t Result{};

diff --git a/Source/Tools/LinuxEmulation/LinuxSyscalls/ThreadManager.cpp b/Source/Tools/LinuxEmulation/LinuxSyscalls/ThreadManager.cpp
@@ -97,7 +97,7 @@ namespace FEX::HLE {
   void ThreadManager::WaitForThreadsToRun() {
     size_t NumThreads{};
     {
-      std::lock_guard<std::mutex> lk(ThreadCreationMutex);
+      std::lock_guard lk(ThreadCreationMutex);
       NumThreads = Threads.size();
     }
 
@@ -134,7 +134,7 @@ namespace FEX::HLE {
 
     // Tell all the threads that they should stop
     {
-      std::lock_guard<std::mutex> lk(ThreadCreationMutex);
+      std::lock_guard lk(ThreadCreationMutex);
       for (auto &Thread : Threads) {
         if (IgnoreCurrentThread &&
             Thread->ThreadManager.TID == tid) {
@@ -185,8 +185,6 @@ namespace FEX::HLE {
   }
 
   void ThreadManager::UnlockAfterFork(FEXCore::Core::InternalThreadState *LiveThread, bool Child) {
-    CTX->UnlockAfterFork(LiveThread, Child);
-
     if (!Child) return;
 
     // This function is called after fork
@@ -225,6 +223,7 @@ namespace FEX::HLE {
 
     // We now only have one thread.
     IdleWaitRefCount = 1;
+    ThreadCreationMutex.StealAndDropActiveLocks();
   }
 
   void ThreadManager::WaitForIdle() {