Start of event framework.

This compiles correctly, but doesn't actually deliver events yet.
As part of this, I've made most of the initializables in nng
safe to tear-down if uninitialized (or set to zero e.g. via calloc).

This makes it loads easier to write the teardown on error code, since
I can deinit everything, without worrying about which things have been
initialized and which have not.

1 files changed, 103 insertions, 0 deletions

diff --git a/src/core/event.c b/src/core/event.c
new file mode 100644
index 00000000..3f7d1143
--- /dev/null
+++ b/src/core/event.c
@@ -0,0 +1,103 @@
+//
+// Copyright 2017 Garrett D'Amore <garrett@damore.org>
+//
+// This software is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+#include "core/nng_impl.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+int
+nni_event_init(nni_event *event, int type, nni_sock *sock)
+{
+	int rv;
+
+	memset(event, 0, sizeof (*event));
+	if ((rv = nni_cv_init(&event->e_cv, &sock->s_mx)) != 0) {
+		return (rv);
+	}
+	NNI_LIST_NODE_INIT(&event->e_node);
+	event->e_type = type;
+	event->e_sock = sock;
+	return (0);
+}
+
+
+void
+nni_event_fini(nni_event *event)
+{
+	nni_cv_fini(&event->e_cv);
+}
+
+
+void
+nni_event_submit(nni_sock *sock, nni_event *event)
+{
+	// Call with socket mutex owned!
+	if (event->e_pending == 0) {
+		event->e_pending = 1;
+		event->e_done = 0;
+		nni_list_append(&sock->s_events, event);
+		nni_cv_wake(&sock->s_notify_cv);
+	}
+}
+
+
+void
+nni_event_wait(nni_sock *sock, nni_event *event)
+{
+	// Call with socket mutex owned!
+	// Note that the socket mutex is dropped during the call.
+	while ((event->e_pending) && (!event->e_done)) {
+		nni_cv_wait(&event->e_cv);
+	}
+}
+
+
+void
+nni_event_notifier(void *arg)
+{
+	nni_sock *sock = arg;
+	nni_event *event;
+	nni_notify *notify;
+
+	nni_mtx_lock(&sock->s_mx);
+	for (;;) {
+		if (sock->s_closing) {
+			break;
+		}
+
+		if ((event = nni_list_first(&sock->s_events)) != NULL) {
+			event->e_pending = 0;
+			nni_list_remove(&sock->s_events, event);
+			nni_mtx_unlock(&sock->s_mx);
+
+			// Lock the notify list, it must not change.
+			nni_mtx_lock(&sock->s_notify_mx);
+			NNI_LIST_FOREACH (&sock->s_notify, notify) {
+				if ((notify->n_mask & event->e_type) == 0) {
+					// No interest.
+					continue;
+				}
+				notify->n_func(event, &notify->n_arg);
+			}
+			nni_mtx_unlock(&sock->s_notify_mx);
+
+			nni_mtx_lock(&sock->s_mx);
+			// Let the event submitter know we are done, unless
+			// they have resubmitted.  Submitters can wait on this
+			// lock.
+			event->e_done = 1;
+			nni_cv_wake(&event->e_cv);
+			continue;
+		}
+
+		nni_cv_wait(&sock->s_notify_cv);
+	}
+	nni_mtx_unlock(&sock->s_mx);
+}