diff options
Diffstat (limited to 'rts/Task.c')
| -rw-r--r-- | rts/Task.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/rts/Task.c b/rts/Task.c index 12c22c4b02..0421d8b785 100644 --- a/rts/Task.c +++ b/rts/Task.c @@ -39,7 +39,7 @@ static Task * allocTask (void); static Task * newTask (rtsBool); #if defined(THREADED_RTS) -static Mutex all_tasks_mutex; +Mutex all_tasks_mutex; #endif /* ----------------------------------------------------------------------------- @@ -350,6 +350,20 @@ discardTasksExcept (Task *keep) next = task->all_next; if (task != keep) { debugTrace(DEBUG_sched, "discarding task %" FMT_SizeT "", (size_t)TASK_ID(task)); +#if defined(THREADED_RTS) + // It is possible that some of these tasks are currently blocked + // (in the parent process) either on their condition variable + // `cond` or on their mutex `lock`. If they are we may deadlock + // when `freeTask` attempts to call `closeCondition` or + // `closeMutex` (the behaviour of these functions is documented to + // be undefined in the case that there are threads blocked on + // them). To avoid this, we re-initialize both the condition + // variable and the mutex before calling `freeTask` (we do + // precisely the same for all global locks in `forkProcess`). + initCondition(&task->cond); + initMutex(&task->lock); +#endif + // Note that we do not traceTaskDelete here because // we are not really deleting a task. // The OS threads for all these tasks do not exist in @@ -502,3 +516,11 @@ printAllTasks(void) #endif + +// Local Variables: +// mode: C +// fill-column: 80 +// indent-tabs-mode: nil +// c-basic-offset: 4 +// buffer-file-coding-system: utf-8-unix +// End: |