Added synchronization to socket transport APIs... Added access methods for getting the PRCList from a transport...

netwerk/base/src/nsSocketTransport.cpp

@@ -103,11 +103,12 @@ nsSocketTransport::nsSocketTransport()
 {
   NS_INIT_REFCNT();
 
-  PR_INIT_CLIST(this);
+  PR_INIT_CLIST(&mListLink);
 
   mHostName     = nsnull;
   mPort         = 0;
   mSocketFD     = nsnull;
+  mLock         = nsnull;
 
   mCurrentState = eSocketState_Created;
   mOperation    = eSocketOperation_None;
@@ -160,6 +161,11 @@ nsSocketTransport::~nsSocketTransport()
     PR_Close(mSocketFD);
     mSocketFD = nsnull;
   }
+
+  if (mLock) {
+    PR_DestroyLock(mLock);
+    mLock = nsnull;
+  }
 }
 
 
@@ -184,6 +190,16 @@ nsresult nsSocketTransport::Init(nsSocketTransportService* aService,
     rv = NS_ERROR_NULL_POINTER;
   }
 
+  //
+  // Create the lock used for synchronizing access to the transport instance.
+  //
+  if (NS_SUCCEEDED(rv)) {
+    mLock = PR_NewLock();
+    if (!mLock) {
+      rv = NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+
   return rv;
 }
 
@@ -193,6 +209,12 @@ nsresult nsSocketTransport::Process(PRInt16 aSelectFlags)
   nsresult rv = NS_OK;
   PRBool done = PR_FALSE;
 
+  //
+  // Enter the socket transport lock...  
+  // This lock protects access to socket transport member data...
+  //
+  Lock();
+
   while (!done)
   {
     switch (mCurrentState) {
@@ -300,16 +322,22 @@ nsresult nsSocketTransport::Process(PRInt16 aSelectFlags)
     // 
     aSelectFlags = 0;
   }
-  
+
+  // Leave the socket transport lock...
+  Unlock();
+
   return rv;
 }
 
 
 //-----
 //
-// doResolveHost:
+//  doResolveHost:
 //
-// Return Codes:
+//  This method is called while holding the SocketTransport lock.  It is
+//  always called on the socket transport thread...
+//
+//  Return Codes:
 //    NS_OK
 //    NS_ERROR_HOST_NOT_FOUND
 //    NS_ERROR_FAILURE
@@ -355,9 +383,12 @@ nsresult nsSocketTransport::doResolveHost(void)
 
 //-----
 //
-// doConnection:
+//  doConnection:
 //
-// Return values:
+//  This method is called while holding the SocketTransport lock.  It is
+//  always called on the socket transport thread...
+//
+//  Return values:
 //    NS_OK
 //    NS_BASE_STREAM_WOULD_BLOCK
 //
@@ -448,7 +479,10 @@ nsresult nsSocketTransport::doConnection(PRInt16 aSelectFlags)
       rv = NS_ERROR_CONNECTION_REFUSED;
     }
     //
-    // The connection was successful...
+    // The connection was successful...  
+    //
+    // PR_Poll(...) returns PR_POLL_WRITE to indicate that the connection is
+    // established...
     //
     else if (PR_POLL_WRITE & aSelectFlags) {
       rv = NS_OK;
@@ -461,9 +495,12 @@ nsresult nsSocketTransport::doConnection(PRInt16 aSelectFlags)
 
 //-----
 //
-// doRead:
+//  doRead:
 //
-// Return values:
+//  This method is called while holding the SocketTransport lock.  It is
+//  always called on the socket transport thread...
+//
+//  Return values:
 //    NS_OK
 //    NS_BASE_STREAM_WOULD_BLOCK
 //
@@ -564,9 +601,12 @@ nsresult nsSocketTransport::doRead(PRInt16 aSelectFlags)
 
 //-----
 //
-// doWrite:
+//  doWrite:
 //
-// Return values:
+//  This method is called while holding the SocketTransport lock.  It is
+//  always called on the socket transport thread...
+//
+//  Return values:
 //    NS_OK
 //    NS_BASE_STREAM_WOULD_BLOCK
 //
@@ -696,20 +736,27 @@ nsSocketTransport::AsyncRead(nsISupports* aContext,
 {
   nsresult rv = NS_OK;
 
+  // Enter the socket transport lock...
+  Lock();
+
+  // If a read is already in progress then fail...
   if (mReadListener) {
     rv = NS_ERROR_IN_PROGRESS;
   }
 
+  // Create a new input stream for reading data into...
   if (NS_SUCCEEDED(rv) && !mReadStream) {
     rv = NS_NewByteBufferInputStream(&mReadStream, PR_FALSE, 
                                      MAX_IO_BUFFER_SIZE);
   }
 
   if (NS_SUCCEEDED(rv)) {
+    // Store the context used for this read...
     NS_IF_RELEASE(mReadContext);
     mReadContext = aContext;
     NS_IF_ADDREF(mReadContext);
 
+    // Create a marshalling stream listener to receive notifications...
     rv = NS_NewAsyncStreamListener(&mReadListener, aAppEventQueue, aListener);
   }
 
@@ -719,6 +766,9 @@ nsSocketTransport::AsyncRead(nsISupports* aContext,
     rv = mService->AddToWorkQ(this);
   }
 
+  // Leave the socket transport lock...
+  Unlock();
+
   return rv;
 }
 
@@ -731,6 +781,10 @@ nsSocketTransport::AsyncWrite(nsIInputStream* aFromStream,
 {
   nsresult rv = NS_OK;
 
+  // Enter the socket transport lock...
+  Lock();
+
+  // If a write is already in progress then fail...
   if (mWriteStream) {
     rv = NS_ERROR_IN_PROGRESS;
   }
@@ -743,8 +797,11 @@ nsSocketTransport::AsyncWrite(nsIInputStream* aFromStream,
     mWriteContext = aContext;
     NS_IF_ADDREF(mWriteContext);
 
+    // Create a marshalling stream observer to receive notifications...
     NS_IF_RELEASE(mWriteObserver);
-    rv = NS_NewAsyncStreamObserver(&mWriteObserver, aAppEventQueue, aObserver);
+    if (aObserver) {
+      rv = NS_NewAsyncStreamObserver(&mWriteObserver, aAppEventQueue, aObserver);
+    }
   }
 
   if (NS_SUCCEEDED(rv)) {
@@ -752,6 +809,9 @@ nsSocketTransport::AsyncWrite(nsIInputStream* aFromStream,
     rv = mService->AddToWorkQ(this);
   }
 
+  // Leave the socket transport lock...
+  Unlock();
+
   return rv;
 }
 

netwerk/base/src/nsSocketTransport.h

@@ -52,8 +52,7 @@ enum nsSocketOperation {
 
 class nsSocketTransportService;
 
-class nsSocketTransport : public PRCList,
-                          public nsITransport
+class nsSocketTransport : public nsITransport
 {
 public:
   // nsISupports methods:
@@ -95,7 +94,18 @@ public:
   PRFileDesc* GetSocket(void)      { return mSocketFD;    }
   PRInt16     GetSelectFlags(void) { return mSelectFlags; }
 
+  PRCList*    GetListNode(void) { return &mListLink; }
+  static nsSocketTransport* GetInstance(PRCList* qp) { return (nsSocketTransport*)((char*)qp - offsetof(nsSocketTransport, mListLink)); }
+
 protected:
+  // Inline helpers...
+  void Lock  (void) { NS_ASSERTION(mLock, "Lock null."); PR_Lock(mLock);   }
+  void Unlock(void) { NS_ASSERTION(mLock, "Lock null."); PR_Unlock(mLock); }
+
+protected:
+  PRCList           mListLink;
+
+  PRLock*           mLock;
   nsSocketState     mCurrentState;
   nsSocketOperation mOperation;
 

netwerk/base/src/nsSocketTransportService.cpp

@@ -147,15 +147,17 @@ nsresult nsSocketTransportService::AddToWorkQ(nsSocketTransport* aTransport)
   PRStatus status;
   PRBool bFireEvent = PR_FALSE;
   nsresult rv = NS_OK;
+  PRCList* qp;
 
   Lock();
   //
   // Only add the transport if it is *not* already on the list...
   //
-  if (PR_CLIST_IS_EMPTY(aTransport)) {
+  qp = aTransport->GetListNode();
+  if (PR_CLIST_IS_EMPTY(qp)) {
     NS_ADDREF(aTransport);
     bFireEvent = PR_CLIST_IS_EMPTY(&mWorkQ);
-    PR_APPEND_LINK(aTransport, &mWorkQ);
+    PR_APPEND_LINK(qp, &mWorkQ);
   }
   Unlock();
   //
@@ -176,6 +178,7 @@ nsresult nsSocketTransportService::AddToWorkQ(nsSocketTransport* aTransport)
 nsresult nsSocketTransportService::ProcessWorkQ(void)
 {
   nsresult rv = NS_OK;
+  PRCList* qp;
 
   //
   // Only process pending operations while there is space available in the
@@ -190,8 +193,10 @@ nsresult nsSocketTransportService::ProcessWorkQ(void)
     nsSocketTransport* transport;
 
     // Get the next item off of the workQ...
-    transport = (nsSocketTransport*)PR_LIST_HEAD(&mWorkQ);
-    PR_REMOVE_AND_INIT_LINK(transport);
+    qp = PR_LIST_HEAD(&mWorkQ);
+
+    transport = nsSocketTransport::GetInstance(qp);
+    PR_REMOVE_AND_INIT_LINK(qp);
 
     // Try to perform the operation...
     //