Fixes for POSIX pollq structure.

It was possible for pollq arm to be called on a node that was removed
in some circumstances -- particularly and ep that was closed in the
callback.

While here, lets use normal booleans for closed state, and only call
the arm function (which is not free -- typicall it involves a mutex
and may even involve a system call) if we are going to arm some events.

We also initialize these things properly, and clean up a stale comment.

This work is done to faciliate the kqueue work by @liamstask.

3 files changed, 14 insertions, 13 deletions

diff --git a/src/platform/posix/posix_epdesc.c b/src/platform/posix/posix_epdesc.c
index 5b1d6a9c..3da36fa2 100644
--- a/src/platform/posix/posix_epdesc.c
+++ b/src/platform/posix/posix_epdesc.c
@@ -18,6 +18,7 @@
 #include <fcntl.h>
 #include <netdb.h>
 #include <poll.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
@@ -36,7 +37,7 @@ struct nni_posix_epdesc {
 	nni_posix_pollq_node    node;
 	nni_list                connectq;
 	nni_list                acceptq;
-	int                     closed;
+	bool                    closed;
 	struct sockaddr_storage locaddr;
 	struct sockaddr_storage remaddr;
 	socklen_t               loclen;
@@ -131,9 +132,6 @@ nni_posix_epdesc_doaccept(nni_posix_epdesc *ed)
 	int      newfd;
 
 	while ((aio = nni_list_first(&ed->acceptq)) != NULL) {
-// We could argue that knowing the remote peer address would
-// be nice.  But frankly if someone wants it, they can just
-// do getpeername().
 
 #ifdef NNG_USE_ACCEPT4
 		newfd = accept4(ed->node.fd, NULL, NULL, SOCK_CLOEXEC);
@@ -201,7 +199,7 @@ nni_posix_epdesc_doclose(nni_posix_epdesc *ed)
 	struct sockaddr_un *sun;
 	int                 fd;
 
-	ed->closed = 1;
+	ed->closed = true;
 	while ((aio = nni_list_first(&ed->acceptq)) != NULL) {
 		nni_posix_epdesc_finish(aio, NNG_ECLOSED, 0);
 	}
@@ -250,7 +248,9 @@ nni_posix_epdesc_cb(void *arg)
 	if (!nni_list_empty(&ed->acceptq)) {
 		events |= POLLIN;
 	}
-	nni_posix_pollq_arm(&ed->node, events);
+	if ((!ed->closed) && (events != 0)) {
+		nni_posix_pollq_arm(&ed->node, events);
+	}
 	nni_mtx_unlock(&ed->mtx);
 }
 
@@ -433,6 +433,8 @@ nni_posix_epdesc_init(nni_posix_epdesc **edp)
 	ed->node.index = 0;
 	ed->node.cb    = nni_posix_epdesc_cb;
 	ed->node.data  = ed;
+	ed->node.fd    = -1;
+	ed->closed     = false;
 
 	nni_aio_list_init(&ed->connectq);
 	nni_aio_list_init(&ed->acceptq);
diff --git a/src/platform/posix/posix_pipedesc.c b/src/platform/posix/posix_pipedesc.c
index 7cbf534b..05f3f13f 100644
--- a/src/platform/posix/posix_pipedesc.c
+++ b/src/platform/posix/posix_pipedesc.c
@@ -17,6 +17,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <poll.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
@@ -31,7 +32,7 @@ struct nni_posix_pipedesc {
 	nni_posix_pollq_node node;
 	nni_list             readq;
 	nni_list             writeq;
-	int                  closed;
+	bool                 closed;
 	nni_mtx              mtx;
 };
 
@@ -48,7 +49,7 @@ nni_posix_pipedesc_doclose(nni_posix_pipedesc *pd)
 	nni_aio *aio;
 	int      fd;
 
-	pd->closed = 1;
+	pd->closed = true;
 	while ((aio = nni_list_first(&pd->readq)) != NULL) {
 		nni_posix_pipedesc_finish(aio, NNG_ECLOSED);
 	}
@@ -213,7 +214,7 @@ nni_posix_pipedesc_cb(void *arg)
 		if (!nni_list_empty(&pd->readq)) {
 			events |= POLLIN;
 		}
-		if (events) {
+		if ((!pd->closed) && (events != 0)) {
 			nni_posix_pollq_arm(&pd->node, events);
 		}
 	}
@@ -341,7 +342,7 @@ nni_posix_pipedesc_init(nni_posix_pipedesc **pdp, int fd)
 	// one.  For now we just have a global pollq.  Note that by tying
 	// the pd to a single pollq we may get some kind of cache warmth.
 
-	pd->closed    = 0;
+	pd->closed    = false;
 	pd->node.fd   = fd;
 	pd->node.cb   = nni_posix_pipedesc_cb;
 	pd->node.data = pd;
diff --git a/src/platform/posix/posix_pollq_poll.c b/src/platform/posix/posix_pollq_poll.c
index 8b386ecd..8e3bc741 100644
--- a/src/platform/posix/posix_pollq_poll.c
+++ b/src/platform/posix/posix_pollq_poll.c
@@ -283,9 +283,7 @@ nni_posix_pollq_arm(nni_posix_pollq_node *node, int events)
 	nni_posix_pollq *pq = node->pq;
 	int              oevents;
 
-	if (pq == NULL) {
-		return;
-	}
+	NNI_ASSERT(pq != NULL);
 
 	nni_mtx_lock(&pq->mtx);
 	oevents = node->events;