Works on Windows, but only with single pass of 8k

mkarg · Mar 10, 2024 · e8010f1 · e8010f1
1 parent 375a9c3
commit e8010f1
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Showing 2 changed files with 41 additions and 22 deletions.
diff --git a/src/java.base/share/classes/sun/nio/ch/SocketChannelImpl.java b/src/java.base/share/classes/sun/nio/ch/SocketChannelImpl.java
@@ -1662,12 +1662,11 @@ public long skip(long n) throws IOException {
     }
 
     private long implSkip(long nt) throws IOException {
-        var buf = ByteBuffer.allocateDirect(Math.toIntExact(nt));
         readLock.lock();
         try {
             ensureOpenAndConnected();
             boolean blocking = isBlocking();
-            int n = 0;
+            long n = 0;
             try {
                 beginRead(blocking);
 
@@ -1680,11 +1679,11 @@ private long implSkip(long nt) throws IOException {
                     return IOStatus.EOF;
 
                 configureSocketNonBlockingIfVirtualThread();
-                n = IOUtil.read(fd, buf, -1, nd);
+                n = IOUtil.drainN(fdVal, nt);
                 if (blocking) {
                     while (IOStatus.okayToRetry(n) && isOpen()) {
                         park(Net.POLLIN);
-                        n = IOUtil.read(fd, buf, -1, nd);
+                        n = IOUtil.drainN(fdVal, nt);
                     }
                 }
             } catch (ConnectionResetException e) {

diff --git a/src/java.base/windows/native/libnio/ch/IOUtil.c b/src/java.base/windows/native/libnio/ch/IOUtil.c
@@ -179,29 +179,49 @@ Java_sun_nio_ch_IOUtil_drain(JNIEnv *env, jclass cl, jint fd)
 }
 
 JNIEXPORT jlong JNICALL
-Java_sun_nio_ch_IOUtil_drainN(JNIEnv *env, jclass cl, jint fd, jlong nt)
+Java_sun_nio_ch_IOUtil_drainN(JNIEnv *env, jclass cl, jint fd, jlong len)
 {
-    if (nt < 1)
+    if (len < 1)
         return 0;
 
-    char buf[4096];
-    jlong readBytes = 0;
-    for (;;) {
-        const jlong remaining = nt - readBytes;
-        const int count = remaining < sizeof(buf) ? (int) remaining : sizeof(buf);
-        int n = recv((SOCKET) fd, buf, count, 0);
-        if (n == SOCKET_ERROR) {
-            if (WSAGetLastError() != WSAEWOULDBLOCK) {
-                JNU_ThrowIOExceptionWithLastError(env, "recv failed");
-            }
-            return readBytes;
+    /* set up */
+    int i = 0;
+    DWORD read = 0;
+    DWORD flags = 0;
+    WSABUF buf;
+
+    /* limit size */
+    if (len > 8192)
+        len = 8192;
+
+    /* destination buffer and size */
+    char cb[8192];
+    buf.buf = cb;
+    buf.len = (u_long) len;
+
+    /* read into the buffers */
+    i = WSARecv((SOCKET) fd, /* Socket */
+            &buf,            /* pointers to the buffers */
+            (DWORD) 1,       /* number of buffers to process */
+            &read,           /* receives number of bytes read */
+            &flags,          /* no flags */
+            0,               /* no overlapped sockets */
+            0);              /* no completion routine */
+
+    if (i == SOCKET_ERROR) {
+        int theErr = (jint) WSAGetLastError();
+        if (theErr == WSAEWOULDBLOCK) {
+            return IOS_UNAVAILABLE;
         }
-        if (n <= 0)
-            return readBytes;
-        readBytes += n;
-        if (n < (int)sizeof(buf))
-            return readBytes;
+        if (theErr == WSAECONNRESET) {
+            JNU_ThrowByName(env, "sun/net/ConnectionResetException", "Connection reset");
+        } else {
+            JNU_ThrowIOExceptionWithLastError(env, "Read failed");
+        }
+        return IOS_THROWN;
     }
+
+    return convertReturnVal(env, (jint) read, JNI_TRUE);
 }
 
 JNIEXPORT jint JNICALL