Condition variable implementation.

3 files changed, 71 insertions, 10 deletions

diff --git a/src/nng.h b/src/nng.h
index 1075b95a..16596fa6 100644
--- a/src/nng.h
+++ b/src/nng.h
@@ -415,9 +415,11 @@ NNG_DECL int nng_device(nng_socket_t, nng_socket_t);
  * Error codes.  These may happen to align to errnos used on your platform,
  * but do not count on this.
  */
-#define	NNG_ENOMEM	(-2)
-#define	NNG_EINVAL	(-3)
-#define	NNG_EBUSY	(-4)
+#define	NNG_ENOMEM		(-2)
+#define	NNG_EINVAL		(-3)
+#define	NNG_EBUSY		(-4)
+#define	NNG_ETIMEDOUT		(-5)
+#define	NNG_ECONNREFUSED	(-6)
 
 #ifdef __cplusplus
 }
diff --git a/src/platform/platform.h b/src/platform/platform.h
index 05f55be9..36ec207c 100644
--- a/src/platform/platform.h
+++ b/src/platform/platform.h
@@ -26,6 +26,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <stdarg.h>
+#include <string.h>
 
 /*
  * These are the APIs that a platform must implement to support nng.
@@ -95,22 +96,19 @@ void nni_cond_destroy(nni_cond_t);
  * nni_cond_broadcast wakes all waiters on the condition.  This should be
  * called with the lock held.
  */
-int nni_cond_broadcast(nni_cond_t);
+void nni_cond_broadcast(nni_cond_t);
 
 /*
  * nni_cond_signal wakes a signal waiter.
  */
-int nni_cond_signal(nni_cond_t);
+void nni_cond_signal(nni_cond_t);
 
 /*
  * nni_condwait waits for a wake up on the condition variable.  The
  * associated lock is atomically released and reacquired upon wake up.
- * Callers can be spuriously woken. The return value is 0 on success,
- * or an error code.  (Most implementations should never return an error.)
- * Most callers will ignore the return value.  The associated lock must
- * be held.
+ * Callers can be spuriously woken.  The associated lock must be held.
  */
-int nni_cond_wait(nni_cond_t);
+void nni_cond_wait(nni_cond_t);
 
 /*
  * nni_cond_timedwait waits for a wakeup on the condition variable, just
diff --git a/src/platform/posix/posix_synch.h b/src/platform/posix/posix_synch.h
index 4a3a152d..0eae133e 100644
--- a/src/platform/posix/posix_synch.h
+++ b/src/platform/posix/posix_synch.h
@@ -32,6 +32,7 @@
  */
 
 #include <pthread.h>
+#include <time.h>
 
 struct nni_mutex {
 	pthread_mutex_t	mx;
@@ -141,3 +142,63 @@ nni_cond_destroy(nni_cond_t c)
 	}
 	nni_free(c, sizeof (*c));
 }
+
+void
+nni_cond_signal(nni_cond_t c)
+{
+	if (pthread_cond_signal(&c->cv) != 0) {
+		nni_panic("pthread_cond_signal failed");
+	}
+}
+
+void
+nni_cond_broadcast(nni_cond_t c)
+{
+	if (pthread_cond_broadcast(&c->cv) != 0) {
+		nni_panic("pthread_cond_broadcast failed");
+	}
+}
+
+void
+nni_cond_wait(nni_cond_t c)
+{
+	if (pthread_cond_wait(&c->cv, c->mx) != 0) {
+		nni_panic("pthread_cond_wait failed");
+	}
+}
+
+int
+nni_cond_timedwait(nni_cond_t c, int msec)
+{
+	struct timespec ts;
+	int rv;
+	/* POSIX says clock_gettime exists since SUSv2 at least. */
+
+	rv = clock_gettime(CLOCK_REALTIME, &ts);
+	if (rv != 0) {
+		/*
+		 * If the clock_gettime() is not working, its a problem with
+		 * the platform. Arguably we could use gettimeofday instead,
+		 * but for now we just panic().  We can fix this when someone
+		 * finds a platform that returns ENOSYS here.
+		 */
+		nni_panic("clock_gettime failed: %s", strerror(errno));
+	}
+
+	ts.tv_nsec += (msec * 1000000);
+
+	/* Normalize -- its not clear if this is strictly necessary. */
+	while (ts.tv_nsec > 1000000000) {
+		ts.tv_nsec -= 1000000000;
+		ts.tv_sec++;
+	}
+
+	if ((rv = pthread_cond_timedwait(&c->cv, c->mx, &ts)) != 0) {
+		if (rv == ETIMEDOUT) {
+			return (NNG_ETIMEDOUT);
+		} else {
+			nni_panic("pthread_cond_timedwait returned %d", rv);
+		}
+	}
+	return (0);
+}