From 6cd14bf5542b934b1b15131087e58f92da9f8a93 Mon Sep 17 00:00:00 2001
From: redman <redman>
Date: Wed, 26 May 1999 20:24:43 +0000
Subject: generic/tclThreadTest.c: Fix race condition in testthread code.

win/tclWinSock.c: Fixed hang in WinNT socket driver, now wakes up
the socket thread to check for events that didn't
trigger the WSAEvent.
---
 generic/tclThreadTest.c |  5 ++---
 win/tclWinSock.c        | 31 +++++++++++++++++++++----------
 2 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/generic/tclThreadTest.c b/generic/tclThreadTest.c
index 0acba19..c24b059 100644
--- a/generic/tclThreadTest.c
+++ b/generic/tclThreadTest.c
@@ -11,7 +11,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclThreadTest.c,v 1.2 1999/04/16 00:46:54 stanton Exp $
+ * RCS: @(#) $Id: tclThreadTest.c,v 1.3 1999/05/26 20:24:43 redman Exp $
  */
 
 #include "tclInt.h"
@@ -713,10 +713,10 @@ TclThreadSend(interp, id, script, wait)
     threadEventPtr->event.proc = ThreadEventProc;
     Tcl_ThreadQueueEvent(threadId, (Tcl_Event *)threadEventPtr, 
 	    TCL_QUEUE_TAIL);
-    Tcl_MutexUnlock(&threadMutex);
     Tcl_ThreadAlert(threadId);
 
     if (!wait) {
+	Tcl_MutexUnlock(&threadMutex);
 	return TCL_OK;
     }
 
@@ -725,7 +725,6 @@ TclThreadSend(interp, id, script, wait)
      */
 
     Tcl_ResetResult(interp);
-    Tcl_MutexLock(&threadMutex);
     while (resultPtr->result == NULL) {
         Tcl_ConditionWait(&resultPtr->done, &threadMutex, NULL);
     }
diff --git a/win/tclWinSock.c b/win/tclWinSock.c
index 969e2bb..03ded94 100644
--- a/win/tclWinSock.c
+++ b/win/tclWinSock.c
@@ -8,7 +8,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclWinSock.c,v 1.9 1999/04/22 20:28:02 redman Exp $
+ * RCS: @(#) $Id: tclWinSock.c,v 1.10 1999/05/26 20:24:43 redman Exp $
  */
 
 #include "tclWinInt.h"
@@ -111,6 +111,13 @@ static struct {
 #define SOCKET_MESSAGE	WM_USER+1
 
 /*
+ * The following defines the timeout value for the WSAWaitForMultipleEvents
+ * in milliseconds.
+ */
+
+#define TCL_SOCKET_EVENT_TIMEOUT 100
+
+/*
  * The following structure is used to store the data associated with
  * each socket.
  */
@@ -2337,6 +2344,15 @@ TcpGetHandleProc(instanceData, direction, handlePtr)
  *
  * SocketThread --
  *
+ *      Use a separate thread to check state for the sockets in each
+ *      thread.  Using a window isn't the best way, especially if the
+ *      WinSock2 API is available and working.  Also, creating N threads
+ *      per socket like the pipe, console, and serial drivers isn't
+ *      very efficient.  Currently, all sockets are tied to one event.
+ *      The overhead involved in creating an event for each socket is
+ *      a concern.  But, in order to avoid deadlocks, the call to
+ *      WSAWaitForMultipleEvents() needs to timeout to check for
+ *      status changes which haven't been handled (race condition).
  *
  * Results:
  *	0 on success.
@@ -2353,7 +2369,7 @@ SocketThread(LPVOID arg)
     WSAEVENT events[2];
     ThreadSpecificData *tsdPtr;
     DWORD result;
-    
+		
     /*
      * Find the specified socket on the socket list and update its
      * eventState flag.
@@ -2365,10 +2381,12 @@ SocketThread(LPVOID arg)
     while (1) {
 
 	result = (*winSock.WSAWaitForMultipleEvents)(2, events, FALSE,
-		WSA_INFINITE, FALSE);
+		TCL_SOCKET_EVENT_TIMEOUT, FALSE);
 
 	switch (result) {
+	    case WSA_WAIT_TIMEOUT:
 	    case (WSA_WAIT_EVENT_0 +1):
+
 		/*
 		 * A socket event has fired, determine which socket(s) it was
 		 * and which thread(s) it came from.
@@ -2384,13 +2402,6 @@ SocketThread(LPVOID arg)
 			if (GetSocketState(infoPtr) & infoPtr->watchEvents) {
 			    Tcl_ThreadAlert(tsdPtr->threadId);
 			    SetEvent(tsdPtr->wakeEvent);
-
-			    /*
-			     * Only process one at a time for a given thread,
-			     * so break here.
-			     */
-			    
-			    break;
 			}
 		    }
 		}
-- 
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