* ------------------------------------------------------------------------- */
void
-shutdownCapability (Capability *cap, Task *task)
+shutdownCapability (Capability *cap, Task *task, rtsBool safe)
{
nat i;
yieldThread();
continue;
}
+
+ // If "safe", then busy-wait for any threads currently doing
+ // foreign calls. If we're about to unload this DLL, for
+ // example, we need to be sure that there are no OS threads
+ // that will try to return to code that has been unloaded.
+ // We can be a bit more relaxed when this is a standalone
+ // program that is about to terminate, and let safe=false.
+ if (cap->suspended_ccalling_tasks && safe) {
+ debugTrace(DEBUG_sched,
+ "thread(s) are involved in foreign calls, yielding");
+ cap->running_task = NULL;
+ RELEASE_LOCK(&cap->lock);
+ yieldThread();
+ continue;
+ }
+
debugTrace(DEBUG_sched, "capability %d is stopped.", cap->no);
- freeCapability(cap);
+ freeCapability(cap);
RELEASE_LOCK(&cap->lock);
break;
}
// Waits for a capability to drain of runnable threads and workers,
// and then acquires it. Used at shutdown time.
//
-void shutdownCapability (Capability *cap, Task *task);
+void shutdownCapability (Capability *cap, Task *task, rtsBool wait_foreign);
// Attempt to gain control of a Capability if it is free.
//
initProfiling2();
}
-/* -----------------------------------------------------------------------------
- Shutting down the RTS
- -------------------------------------------------------------------------- */
+/* ----------------------------------------------------------------------------
+ * Shutting down the RTS
+ *
+ * The wait_foreign parameter means:
+ * True ==> wait for any threads doing foreign calls now.
+ * False ==> threads doing foreign calls may return in the
+ * future, but will immediately block on a mutex.
+ * (capability->lock).
+ *
+ * If this RTS is a DLL that we're about to unload, then you want
+ * safe=True, otherwise the thread might return to code that has been
+ * unloaded. If this is a standalone program that is about to exit,
+ * then you can get away with safe=False, which is better because we
+ * won't hang on exit if there is a blocked foreign call outstanding.
+ *
+ ------------------------------------------------------------------------- */
-void
-hs_exit(void)
+static void
+hs_exit_(rtsBool wait_foreign)
{
if (hs_init_count <= 0) {
errorBelch("warning: too many hs_exit()s");
#endif
/* stop all running tasks */
- exitScheduler();
+ exitScheduler(wait_foreign);
#if defined(GRAN)
/* end_gr_simulation prints global stats if requested -- HWL */
}
+// The real hs_exit():
+void
+hs_exit(void)
+{
+ hs_exit_(rtsTrue);
+ // be safe; this might be a DLL
+}
+
// Compatibility interfaces
void
shutdownHaskell(void)
{
if (hs_init_count == 1) {
OnExitHook();
- hs_exit();
+ hs_exit_(rtsFalse);
+ // we're about to exit(), no need to wait for foreign calls to return.
#if defined(PAR)
/* really exit (stg_exit() would call shutdownParallelSystem() again) */
exit(n);
}
void
-exitScheduler( void )
+exitScheduler( rtsBool wait_foreign )
+ /* see Capability.c, shutdownCapability() */
{
Task *task = NULL;
nat i;
for (i = 0; i < n_capabilities; i++) {
- shutdownCapability(&capabilities[i], task);
+ shutdownCapability(&capabilities[i], task, wait_foreign);
}
boundTaskExiting(task);
stopTaskManager();
* Locks assumed : none
*/
void initScheduler (void);
-void exitScheduler (void);
+void exitScheduler (rtsBool wait_foreign);
void freeScheduler (void);
// Place a new thread on the run queue of the current Capability