X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2Fwin32%2FIOManager.c;h=96e5794031b94a9d3bc09fd168f1adeff4a2283a;hb=900ca61d2d1c61cb5a100dbcd67c265c89bbc8b5;hp=b8b79426522220bd20876965c2fffdad1e01c2d2;hpb=ce42f19f8c840fbe89844471a0d850d310a94556;p=ghc-hetmet.git

diff --git a/ghc/rts/win32/IOManager.c b/ghc/rts/win32/IOManager.c
index b8b7942..96e5794 100644
--- a/ghc/rts/win32/IOManager.c
+++ b/ghc/rts/win32/IOManager.c
@@ -42,7 +42,7 @@ IOWorkerProc(PVOID param)
     WorkQueue* pq = iom->workQueue;
     WorkItem*  work;
     int        len = 0, fd = 0;
-    DWORD      errCode;
+    DWORD      errCode = 0;
     void*      complData;
 
     hWaits[0] = (HANDLE)iom->hExitEvent;
@@ -70,6 +70,11 @@ IOWorkerProc(PVOID param)
 	 */
 	rc = WaitForMultipleObjects( 2, hWaits, FALSE, INFINITE );
 
+	if (rc == WAIT_OBJECT_0) {
+	    // we received the exit event
+	    return 0;
+	}
+
 	EnterCriticalSection(&iom->manLock);
 	/* Signal that the thread is 'non-idle' and about to consume 
 	 * a work item.
@@ -78,10 +83,7 @@ IOWorkerProc(PVOID param)
 	iom->queueSize--;
 	LeaveCriticalSection(&iom->manLock);
     
-	if ( WAIT_OBJECT_0 == rc ) {
-	    /* shutdown */
-	    return 0;
-	} else if ( (WAIT_OBJECT_0 + 1) == rc ) {
+	if ( rc == (WAIT_OBJECT_0 + 1) ) {
 	    /* work item available, fetch it. */
 	    if (FetchWork(pq,(void**)&work)) {
 		if ( work->workKind & WORKER_READ ) {
@@ -94,9 +96,40 @@ IOWorkerProc(PVOID param)
 			    errCode = WSAGetLastError();
 			}
 		    } else {
+			DWORD dw;
+
+			/* Do the read(), with extra-special handling for Ctrl+C */
 			len = read(work->workData.ioData.fd,
 				   work->workData.ioData.buf,
 				   work->workData.ioData.len);
+			if ( len == 0 && work->workData.ioData.len != 0 ) {
+			    /* Given the following scenario:
+			     *     - a console handler has been registered that handles Ctrl+C
+			     *       events.
+			     *     - we've not tweaked the 'console mode' settings to turn on
+			     *       ENABLE_PROCESSED_INPUT.
+			     *     - we're blocked waiting on input from standard input.
+			     *     - the user hits Ctrl+C.
+			     *
+			     * The OS will invoke the console handler (in a separate OS thread),
+			     * and the above read() (i.e., under the hood, a ReadFile() op) returns
+			     * 0, with the error set to ERROR_OPERATION_ABORTED. We don't
+			     * want to percolate this non-EOF condition too far back up, but ignore
+			     * it. However, we do want to give the RTS an opportunity to deliver the
+			     * console event.
+			     * 
+			     * Hence, we set 'errorCode' to (-2), which we then look out for in
+			     * GHC.Conc.asyncRead.
+			     */
+			    dw = GetLastError();
+			    if ( dw == ERROR_OPERATION_ABORTED ) {
+				/* Only do the retry when dealing with the standard input handle. */
+				HANDLE h  = (HANDLE)GetStdHandle(STD_INPUT_HANDLE);
+				if ( _get_osfhandle(work->workData.ioData.fd) == (long)h ) {
+				    errCode = (DWORD)-2;
+				}
+			    }
+			}
 			if (len == -1) { errCode = errno; }
 		    }
 		    complData = work->workData.ioData.buf;
@@ -363,9 +396,12 @@ AddProcRequest ( void* proc,
     return depositWorkItem(reqID, wItem);
 }
 
-void ShutdownIOManager()
+void ShutdownIOManager ( void )
 {
   SetEvent(ioMan->hExitEvent);
-  free(ioMan);
-  ioMan = NULL;
+  // ToDo: we can't free this now, because the worker thread(s)
+  // haven't necessarily finished with it yet.  Perhaps it should
+  // have a reference count or something.
+  // free(ioMan);
+  // ioMan = NULL;
 }