Subsystem initialize is idempotent; simplify cleanup.

1 files changed, 13 insertions, 15 deletions

diff --git a/src/core/taskq.c b/src/core/taskq.c
index 14b04085..e32983e9 100644
--- a/src/core/taskq.c
+++ b/src/core/taskq.c
@@ -23,7 +23,7 @@ struct nni_taskq {
 	nni_cv         tq_cv;
 	nni_taskq_thr *tq_threads;
 	int            tq_nthreads;
-	int            tq_close;
+	int            tq_run;
 	int            tq_waiting;
 };
 
@@ -61,7 +61,7 @@ nni_taskq_thread(void *self)
 			tq->tq_waiting = 0;
 			nni_cv_wake(&tq->tq_cv);
 		}
-		if (tq->tq_close) {
+		if (!tq->tq_run) {
 			break;
 		}
 		nni_cv_wait(&tq->tq_cv);
@@ -88,7 +88,6 @@ nni_taskq_init(nni_taskq **tqp, int nthr)
 		NNI_FREE_STRUCT(tq);
 		return (rv);
 	}
-	tq->tq_close = 0;
 	NNI_LIST_INIT(&tq->tq_tasks, nni_task, task_node);
 
 	tq->tq_threads = nni_alloc(sizeof(nni_taskq_thr) * nthr);
@@ -109,6 +108,7 @@ nni_taskq_init(nni_taskq **tqp, int nthr)
 		}
 	}
 	tq->tq_nthreads = nthr;
+	tq->tq_run      = 1;
 	for (i = 0; i < tq->tq_nthreads; i++) {
 		nni_thr_run(&tq->tq_threads[i].tqt_thread);
 	}
@@ -157,19 +157,19 @@ nni_taskq_drain(nni_taskq *tq)
 void
 nni_taskq_fini(nni_taskq *tq)
 {
-	int i;
-
 	// First drain the taskq completely.  This is necessary since some
 	// tasks that are presently running may need to schedule additional
 	// tasks, and we don't want those to block.
 
-	nni_mtx_lock(&tq->tq_mtx);
-	nni_taskq_drain_locked(tq);
+	if (tq->tq_run) {
+		nni_mtx_lock(&tq->tq_mtx);
+		nni_taskq_drain_locked(tq);
 
-	tq->tq_close = 1;
-	nni_cv_wake(&tq->tq_cv);
-	nni_mtx_unlock(&tq->tq_mtx);
-	for (i = 0; i < tq->tq_nthreads; i++) {
+		tq->tq_run = 0;
+		nni_cv_wake(&tq->tq_cv);
+		nni_mtx_unlock(&tq->tq_mtx);
+	}
+	for (int i = 0; i < tq->tq_nthreads; i++) {
 		nni_thr_fini(&tq->tq_threads[i].tqt_thread);
 	}
 	nni_free(tq->tq_threads, tq->tq_nthreads * sizeof(nni_taskq_thr));
@@ -201,7 +201,6 @@ void
 nni_task_wait(nni_task *task)
 {
 	nni_taskq *tq = task->task_tq;
-	int        i;
 	int        running;
 
 	nni_mtx_lock(&tq->tq_mtx);
@@ -210,7 +209,7 @@ nni_task_wait(nni_task *task)
 		if (nni_list_active(&tq->tq_tasks, task)) {
 			running = 1;
 		} else {
-			for (i = 0; i < tq->tq_nthreads; i++) {
+			for (int i = 0; i < tq->tq_nthreads; i++) {
 				if (tq->tq_threads[i].tqt_running == task) {
 					running = 1;
 					break;
@@ -231,14 +230,13 @@ int
 nni_task_cancel(nni_task *task)
 {
 	nni_taskq *tq = task->task_tq;
-	int        i;
 	int        running;
 
 	nni_mtx_lock(&tq->tq_mtx);
 	running = 1;
 	for (;;) {
 		running = 0;
-		for (i = 0; i < tq->tq_nthreads; i++) {
+		for (int i = 0; i < tq->tq_nthreads; i++) {
 			if (tq->tq_threads[i].tqt_running == task) {
 				running = 1;
 				break;