fixes #1236 Deadlock triggered on nng_close

fixes #1219 nng_close occasionally hang on Windows
nanomsg · May 18, 2020 · b7a11a0 · b7a11a0
1 parent 1a00f65
commit b7a11a0
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Showing 4 changed files with 24 additions and 3 deletions.
diff --git a/src/core/aio.c b/src/core/aio.c
@@ -328,6 +328,7 @@ nni_aio_schedule(nni_aio *aio, nni_aio_cancelfn cancelfn, void *data)
 		// Convert the relative timeout to an absolute timeout.
 		switch (aio->a_timeout) {
 		case NNG_DURATION_ZERO:
+			nni_task_abort(&aio->a_task);
 			return (NNG_ETIMEDOUT);
 		case NNG_DURATION_INFINITE:
 		case NNG_DURATION_DEFAULT:
@@ -341,6 +342,7 @@ nni_aio_schedule(nni_aio *aio, nni_aio_cancelfn cancelfn, void *data)
 
 	nni_mtx_lock(&nni_aio_lk);
 	if (aio->a_stop) {
+		nni_task_abort(&aio->a_task);
 		nni_mtx_unlock(&nni_aio_lk);
 		return (NNG_ECLOSED);
 	}

diff --git a/src/core/taskq.c b/src/core/taskq.c
@@ -183,6 +183,20 @@ nni_task_prep(nni_task *task)
 	nni_mtx_unlock(&task->task_mtx);
 }
 
+void
+nni_task_abort(nni_task *task)
+{
+	// This is called when unscheduling the task.
+	nni_mtx_lock(&task->task_mtx);
+	if (task->task_prep) {
+		task->task_prep = false;
+		task->task_busy--;
+		if (task->task_busy == 0) {
+			nni_cv_wake(&task->task_cv);
+		}
+	}
+	nni_mtx_unlock(&task->task_mtx);
+}
 void
 nni_task_wait(nni_task *task)
 {

diff --git a/src/core/taskq.h b/src/core/taskq.h
@@ -1,5 +1,5 @@
 //
-// Copyright 2018 Staysail Systems, Inc. <[email protected]>
+// Copyright 2020 Staysail Systems, Inc. <[email protected]>
 // Copyright 2018 Capitar IT Group BV <[email protected]>
 //
 // This software is supplied under the terms of the MIT License, a
@@ -38,6 +38,11 @@ extern void nni_task_exec(nni_task *);
 // nni_task_exec).
 extern void nni_task_prep(nni_task *);
 
+// nni_task_abort is called to undo the effect of nni_task_prep,
+// basically. The aio framework uses this when nni_aio_schedule()
+// returns an error.
+extern void nni_task_abort(nni_task *);
+
 extern void nni_task_wait(nni_task *);
 extern void  nni_task_init(nni_task *, nni_taskq *, nni_cb, void *);
 

diff --git a/src/transport/tcp/tcp.c b/src/transport/tcp/tcp.c
@@ -547,8 +547,8 @@ tcptran_pipe_recv_start(tcptran_pipe *p)
 
 	if (p->closed) {
 		nni_aio *aio;
-		while ((aio = nni_list_first(&p->sendq)) != NULL) {
-			nni_list_remove(&p->sendq, aio);
+		while ((aio = nni_list_first(&p->recvq)) != NULL) {
+			nni_list_remove(&p->recvq, aio);
 			nni_aio_finish_error(aio, NNG_ECLOSED);
 		}
 		return;