6395224: (so) SocketChannel writer blocked on large buffer is not preempted by close method (vista)

Reviewed-by: chegar

2 files changed, 36 insertions, 2 deletions

diff --git a/src/windows/native/sun/nio/ch/SocketDispatcher.c b/src/windows/native/sun/nio/ch/SocketDispatcher.c
index 78265a069..0fa7c35a9 100644
--- a/src/windows/native/sun/nio/ch/SocketDispatcher.c
+++ b/src/windows/native/sun/nio/ch/SocketDispatcher.c
@@ -50,6 +50,10 @@ Java_sun_nio_ch_SocketDispatcher_read0(JNIEnv *env, jclass clazz, jobject fdo,
     jint fd = fdval(env, fdo);
     WSABUF buf;
 
+    /* limit size */
+    if (len > MAX_BUFFER_SIZE)
+        len = MAX_BUFFER_SIZE;
+
     /* destination buffer and size */
     buf.buf = (char *)address;
     buf.len = (u_long)len;
@@ -86,6 +90,7 @@ Java_sun_nio_ch_SocketDispatcher_readv0(JNIEnv *env, jclass clazz, jobject fdo,
     jint fd = fdval(env, fdo);
     struct iovec *iovp = (struct iovec *)address;
     WSABUF *bufs = malloc(len * sizeof(WSABUF));
+    jint rem = MAX_BUFFER_SIZE;
 
     if (bufs == 0) {
         JNU_ThrowOutOfMemoryError(env, 0);
@@ -98,8 +103,16 @@ Java_sun_nio_ch_SocketDispatcher_readv0(JNIEnv *env, jclass clazz, jobject fdo,
 
     /* copy iovec into WSABUF */
     for(i=0; i<len; i++) {
+        jint iov_len = iovp[i].iov_len;
+        if (iov_len > rem)
+            iov_len = rem;
         bufs[i].buf = (char *)iovp[i].iov_base;
-        bufs[i].len = (u_long)iovp[i].iov_len;
+        bufs[i].len = (u_long)iov_len;
+        rem -= iov_len;
+        if (rem == 0) {
+            len = i+1;
+            break;
+        }
     }
 
     /* read into the buffers */
@@ -136,6 +149,10 @@ Java_sun_nio_ch_SocketDispatcher_write0(JNIEnv *env, jclass clazz, jobject fdo,
     jint fd = fdval(env, fdo);
     WSABUF buf;
 
+    /* limit size */
+    if (len > MAX_BUFFER_SIZE)
+        len = MAX_BUFFER_SIZE;
+
     /* copy iovec into WSABUF */
     buf.buf = (char *)address;
     buf.len = (u_long)len;
@@ -171,6 +188,7 @@ Java_sun_nio_ch_SocketDispatcher_writev0(JNIEnv *env, jclass clazz,
     jint fd = fdval(env, fdo);
     struct iovec *iovp = (struct iovec *)address;
     WSABUF *bufs = malloc(len * sizeof(WSABUF));
+    jint rem = MAX_BUFFER_SIZE;
 
     if (bufs == 0) {
         JNU_ThrowOutOfMemoryError(env, 0);
@@ -183,8 +201,16 @@ Java_sun_nio_ch_SocketDispatcher_writev0(JNIEnv *env, jclass clazz,
 
     /* copy iovec into WSABUF */
     for(i=0; i<len; i++) {
+        jint iov_len = iovp[i].iov_len;
+        if (iov_len > rem)
+            iov_len = rem;
         bufs[i].buf = (char *)iovp[i].iov_base;
-        bufs[i].len = (u_long)iovp[i].iov_len;
+        bufs[i].len = (u_long)iov_len;
+        rem -= iov_len;
+        if (rem == 0) {
+            len = i+1;
+            break;
+        }
     }
 
     /* read into the buffers */
diff --git a/src/windows/native/sun/nio/ch/nio_util.h b/src/windows/native/sun/nio/ch/nio_util.h
index 9c7a6d958..963e93ef0 100644
--- a/src/windows/native/sun/nio/ch/nio_util.h
+++ b/src/windows/native/sun/nio/ch/nio_util.h
@@ -25,6 +25,14 @@
 
 #include "jni.h"
 
+/**
+ * The maximum buffer size for WSASend/WSARecv. Microsoft recommendation for
+ * blocking operations is to use buffers no larger than 64k. We need the
+ * maximum to be less than 128k to support asynchronous close on Windows
+ * Server 2003 and newer editions of Windows.
+ */
+#define MAX_BUFFER_SIZE             ((128*1024)-1)
+
 jint fdval(JNIEnv *env, jobject fdo);
 jlong handleval(JNIEnv *env, jobject fdo);
 jboolean isNT();