Encapsulate semaphore handling

src/fastd.c

@@ -537,8 +537,7 @@ static inline void init(int argc, char *argv[]) {
 	VECTOR_ALLOC(ctx.async_pids, 0);
 
 #ifdef WITH_VERIFY
-	if (sem_init(&ctx.verify_limit, 0, VERIFY_LIMIT))
+	fastd_sem_init(&ctx.verify_limit, VERIFY_LIMIT);
-		exit_errno("sem_init");
 #endif
 
 	if (pthread_attr_init(&ctx.detached_thread))

src/fastd.h

@@ -36,6 +36,7 @@
 #include "dlist.h"
 #include "buffer.h"
 #include "log.h"
+#include "sem.h"
 #include "shell.h"
 #include "vector.h"
 
@@ -244,7 +245,7 @@ struct fastd_context {
 	uint64_t next_peer_id;			/**< An monotonously increasing ID peers are identified with in some components */
 	VECTOR(fastd_peer_t*) peers;		/**< The currectly active peers */
 #ifdef WITH_VERIFY
-	sem_t verify_limit;			/**< Keeps track of the number of verifier threads */
+	fastd_sem_t verify_limit;		/**< Keeps track of the number of verifier threads */
 #endif
 
 #ifdef USE_EPOLL

src/sem.h

@@ -0,0 +1,59 @@
+/*
+  Copyright (c) 2012-2014, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+/**
+   \file
+
+   Portable semapores
+*/
+
+
+#pragma once
+
+#include "log.h"
+
+#include <semaphore.h>
+
+
+/** Generic semaphore type */
+typedef sem_t fastd_sem_t;
+
+
+/** Initializes a semaphore with a given value */
+static inline void fastd_sem_init(fastd_sem_t *sem, unsigned value) {
+	if (sem_init(sem, 0, value))
+		exit_errno("sem_init");
+}
+
+/** Increments the semaphore */
+static inline void fastd_sem_post(fastd_sem_t *sem) {
+	if (sem_post(sem))
+		exit_errno("sem_post");
+}
+
+/** Tries to decrement the semaphore */
+static inline bool fastd_sem_trywait(fastd_sem_t *sem) {
+	return !sem_trywait(sem);
+}

src/verify.c

@@ -82,8 +82,7 @@ static void * do_verify_thread(void *p) {
 
 	free(arg);
 
-	if (sem_post(&ctx.verify_limit))
+	fastd_sem_post(&ctx.verify_limit);
-		exit_errno("sem_post");
 
 	return NULL;
 }
@@ -110,7 +109,7 @@ fastd_tristate_t fastd_verify_peer(fastd_peer_t *peer, fastd_socket_t *sock, con
 		return ret ? fastd_tristate_true : fastd_tristate_false;
 	}
 	else {
-		if (sem_trywait(&ctx.verify_limit)) {
+		if (!fastd_sem_trywait(&ctx.verify_limit)) {
 			pr_debug("maximum number of verification processes reached");
 			return fastd_tristate_false;
 		}
@@ -131,8 +130,7 @@ fastd_tristate_t fastd_verify_peer(fastd_peer_t *peer, fastd_socket_t *sock, con
 		if ((errno = pthread_create(&thread, &ctx.detached_thread, do_verify_thread, arg)) != 0) {
 			pr_error_errno("unable to create verify thread");
 
-			if (sem_post(&ctx.verify_limit))
+			fastd_sem_post(&ctx.verify_limit);
-				exit_errno("sem_post");
 
 			fastd_shell_env_free(env);
 			free(arg);