Miguel Sofer's patch (with small revisions) to make sure the bytecode engine

checks for async events fairly frequently. [Bug 746722]

2 files changed, 98 insertions, 2 deletions

diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index c642112..41f01fd 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.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: tclExecute.c,v 1.114 2003/11/14 20:44:44 dgp Exp $
+ * RCS: @(#) $Id: tclExecute.c,v 1.115 2003/11/16 00:49:20 dkf Exp $
  */
 
 #include "tclInt.h"
@@ -62,6 +62,16 @@ int errno;
 #endif /* !DBL_MAX */
 
 /*
+ * A mask (should be 2**n-1) that is used to work out when the
+ * bytecode engine should call Tcl_AsyncReady() to see whether there
+ * is a signal that needs handling.
+ */
+
+#ifndef ASYNC_CHECK_COUNT_MASK
+#   define ASYNC_CHECK_COUNT_MASK	15
+#endif /* !ASYNC_CHECK_COUNT_MASK */
+
+/*
  * Boolean flag indicating whether the Tcl bytecode interpreter has been
  * initialized.
  */
@@ -1088,6 +1098,7 @@ TclExecuteByteCode(interp, codePtr)
     int traceInstructions = (tclTraceExec == 3);
     char cmdNameBuf[21];
 #endif
+    int instructionCount = 0;
 
     /*
      * The execution uses a unified stack: first the catch stack, immediately
@@ -1202,6 +1213,21 @@ TclExecuteByteCode(interp, codePtr)
 #ifdef TCL_COMPILE_STATS    
     iPtr->stats.instructionCount[*pc]++;
 #endif
+
+    /*
+     * Check for asynchronous handlers [Bug 746722]; we
+     * do the check every 16th instruction.
+     */
+
+    if (!(instructionCount++ & ~ASYNC_CHECK_COUNT_MASK) && Tcl_AsyncReady()) {
+	DECACHE_STACK_INFO();
+	result = Tcl_AsyncInvoke(interp, result);
+	CACHE_STACK_INFO();
+	if (result == TCL_ERROR) {
+	    goto checkForCatch;
+	}
+    }
+
     switch (*pc) {
     case INST_RETURN:
 	if (iPtr->returnOpts != iPtr->defaultReturnOpts) {
@@ -1210,6 +1236,7 @@ TclExecuteByteCode(interp, codePtr)
 	    Tcl_IncrRefCount(iPtr->returnOpts);
 	}
 	result = TCL_RETURN;
+
     case INST_DONE:
 	if (tosPtr <= eePtr->stackPtr + initStackTop) {
 	    tosPtr--;
@@ -1493,6 +1520,14 @@ TclExecuteByteCode(interp, codePtr)
 	    ++*preservedStackRefCountPtr;
 
 	    /*
+	     * Reset the instructionCount variable, since we're about
+	     * to check for async stuff anyway while processing
+	     * TclEvalObjvInternal.
+	     */
+
+	    instructionCount = 0;
+
+	    /*
 	     * Finally, let TclEvalObjvInternal handle the command. 
 	     */
 
diff --git a/generic/tclTest.c b/generic/tclTest.c
index 794f7e3..69ead5b 100644
--- a/generic/tclTest.c
+++ b/generic/tclTest.c
@@ -14,7 +14,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclTest.c,v 1.72 2003/11/15 23:42:42 dkf Exp $
+ * RCS: @(#) $Id: tclTest.c,v 1.73 2003/11/16 00:49:20 dkf Exp $
  */
 
 #define TCL_TEST
@@ -129,6 +129,9 @@ typedef struct TestEvent {
 int			Tcltest_Init _ANSI_ARGS_((Tcl_Interp *interp));
 static int		AsyncHandlerProc _ANSI_ARGS_((ClientData clientData,
 			    Tcl_Interp *interp, int code));
+#ifdef TCL_THREADS
+static Tcl_ThreadCreateType AsyncThreadProc _ANSI_ARGS_((ClientData));
+#endif
 static void		CleanupTestSetassocdataTests _ANSI_ARGS_((
 			    ClientData clientData, Tcl_Interp *interp));
 static void		CmdDelProc1 _ANSI_ARGS_((ClientData clientData));
@@ -840,11 +843,39 @@ TestasyncCmd(dummy, interp, argc, argv)
 	}
 	Tcl_SetResult(interp, (char *)argv[3], TCL_VOLATILE);
 	return code;
+#ifdef TCL_THREADS
+    } else if (strcmp(argv[1], "marklater") == 0) {
+	if (argc != 3) {
+	    goto wrongNumArgs;
+	}
+	if (Tcl_GetInt(interp, argv[2], &id) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	for (asyncPtr = firstHandler; asyncPtr != NULL;
+		asyncPtr = asyncPtr->nextPtr) {
+	    if (asyncPtr->id == id) {
+		Tcl_ThreadId threadID;
+		if (Tcl_CreateThread(&threadID, AsyncThreadProc,
+			(ClientData) asyncPtr, TCL_THREAD_STACK_DEFAULT,
+			TCL_THREAD_NOFLAGS) != TCL_OK) {
+		    Tcl_SetResult(interp, "can't create thread", TCL_STATIC);
+		    return TCL_ERROR;
+		}
+		break;
+	    }
+	}
+    } else {
+	Tcl_AppendResult(interp, "bad option \"", argv[1],
+		"\": must be create, delete, int, mark, or marklater",
+		(char *) NULL);
+	return TCL_ERROR;
+#else /* !TCL_THREADS */
     } else {
 	Tcl_AppendResult(interp, "bad option \"", argv[1],
 		"\": must be create, delete, int, or mark",
 		(char *) NULL);
 	return TCL_ERROR;
+#endif
     }
     return TCL_OK;
 }
@@ -882,6 +913,36 @@ AsyncHandlerProc(clientData, interp, code)
 /*
  *----------------------------------------------------------------------
  *
+ * AsyncThreadProc --
+ *
+ *	Delivers an asynchronous event to a handler in another thread.
+ *
+ * Results:
+ *	None.
+ *
+ * Side effects:
+ *	Invokes Tcl_AsyncMark on the handler
+ *
+ *----------------------------------------------------------------------
+ */
+
+#ifdef TCL_THREADS
+static Tcl_ThreadCreateType
+AsyncThreadProc(clientData)
+    ClientData clientData;	/* Parameter is a pointer to a
+				 * TestAsyncHandler, defined above. */
+{
+    TestAsyncHandler* asyncPtr = clientData;
+    Tcl_Sleep(1);
+    Tcl_AsyncMark(asyncPtr->handler);
+    Tcl_ExitThread(TCL_OK);
+    TCL_THREAD_CREATE_RETURN;
+}
+#endif
+
+/*
+ *----------------------------------------------------------------------
+ *
  * TestcmdinfoCmd --
  *
  *	This procedure implements the "testcmdinfo" command.  It is used