Provide versions of mutex, condvar, and aio init that never fail.

If the underlying platform fails (FreeBSD is the only one I'm aware
of that does this!), we use a global lock or condition variable instead.
This means that our lock initializers never ever fail.

Probably we could eliminate most of this for Linux and Darwin, since
on those platforms, mutex and condvar initialization reasonably never
fails.  Initial benchmarks show little difference either way -- so we
can revisit (optimize) later.

This removes a lot of otherwise untested code in error cases and so forth,
improving coverage and resilience in the face of allocation failures.

Platforms other than POSIX should follow a similar pattern if they need
this.  (VxWorks, I'm thinking of you.)  Most sane platforms won't have
an issue here, since normally these initializations do not need to allocate
memory. (Reportedly, even FreeBSD has plans to "fix" this in libthr2.)

While here, some bugs were fixed in initialization & teardown.

The fallback code is properly tested with dedicated test cases.

1 files changed, 8 insertions, 34 deletions

diff --git a/src/protocol/reqrep/req.c b/src/protocol/reqrep/req.c
index fdf29fd9..bab81331 100644
--- a/src/protocol/reqrep/req.c
+++ b/src/protocol/reqrep/req.c
@@ -75,19 +75,12 @@ static int
 nni_req_sock_init(void **reqp, nni_sock *sock)
 {
 	nni_req_sock *req;
-	int           rv;
 
 	if ((req = NNI_ALLOC_STRUCT(req)) == NULL) {
 		return (NNG_ENOMEM);
 	}
-	if ((rv = nni_mtx_init(&req->mtx)) != 0) {
-		NNI_FREE_STRUCT(req);
-		return (rv);
-	}
-	if ((rv = nni_cv_init(&req->cv, &req->mtx)) != 0) {
-		nni_mtx_fini(&req->mtx);
-		NNI_FREE_STRUCT(req);
-	}
+	nni_mtx_init(&req->mtx);
+	nni_cv_init(&req->cv, &req->mtx);
 
 	NNI_LIST_INIT(&req->readypipes, nni_req_pipe, node);
 	NNI_LIST_INIT(&req->busypipes, nni_req_pipe, node);
@@ -152,41 +145,22 @@ static int
 nni_req_pipe_init(void **rpp, nni_pipe *pipe, void *rsock)
 {
 	nni_req_pipe *rp;
-	int           rv;
 
 	if ((rp = NNI_ALLOC_STRUCT(rp)) == NULL) {
 		return (NNG_ENOMEM);
 	}
-	if ((rv = nni_mtx_init(&rp->mtx)) != 0) {
-		goto failed;
-	}
-	if ((rv = nni_aio_init(&rp->aio_getq, nni_req_getq_cb, rp)) != 0) {
-		goto failed;
-	}
-	if ((rv = nni_aio_init(&rp->aio_putq, nni_req_putq_cb, rp)) != 0) {
-		goto failed;
-	}
-	if ((rv = nni_aio_init(&rp->aio_recv, nni_req_recv_cb, rp)) != 0) {
-		goto failed;
-	}
-	rv = nni_aio_init(&rp->aio_sendraw, nni_req_sendraw_cb, rp);
-	if (rv != 0) {
-		goto failed;
-	}
-	rv = nni_aio_init(&rp->aio_sendcooked, nni_req_sendcooked_cb, rp);
-	if (rv != 0) {
-		goto failed;
-	}
+	nni_mtx_init(&rp->mtx);
+	nni_aio_init(&rp->aio_getq, nni_req_getq_cb, rp);
+	nni_aio_init(&rp->aio_putq, nni_req_putq_cb, rp);
+	nni_aio_init(&rp->aio_recv, nni_req_recv_cb, rp);
+	nni_aio_init(&rp->aio_sendraw, nni_req_sendraw_cb, rp);
+	nni_aio_init(&rp->aio_sendcooked, nni_req_sendcooked_cb, rp);
 
 	NNI_LIST_NODE_INIT(&rp->node);
 	rp->pipe = pipe;
 	rp->req  = rsock;
 	*rpp     = rp;
 	return (0);
-
-failed:
-	nni_req_pipe_fini(rp);
-	return (rv);
 }
 
 static void