From 8e4f6238558c28cd05bd580cc947d7178d2bac90 Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@meshlink.io>
Date: Wed, 10 Jun 2020 22:25:12 +0200
Subject: [PATCH] Properly initialize mutexes and condition variables.
On Linux, zeroing a pthread_mutex_t or pthread_cond_t variable ensures
the mutex/cond is properly initialized, however this is not the case om
some other platforms. Ensure we always call pthread_mutex/cond_init().
---
src/adns.c | 2 ++
src/discovery.c | 7 +++++--
src/meshlink.c | 7 ++++++-
3 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/src/adns.c b/src/adns.c
index 01989ac5..cb9611e1 100644
--- a/src/adns.c
+++ b/src/adns.c
@@ -184,6 +184,8 @@ struct addrinfo *adns_blocking_request(meshlink_handle_t *mesh, char *host, char
info->host = host;
info->serv = serv;
info->socktype = socktype;
+ pthread_mutex_init(&info->mutex, NULL);
+ pthread_cond_init(&info->cond, NULL);
struct timespec deadline;
clock_gettime(CLOCK_REALTIME, &deadline);
diff --git a/src/discovery.c b/src/discovery.c
index df88b179..d4790c43 100644
--- a/src/discovery.c
+++ b/src/discovery.c
@@ -343,6 +343,8 @@ static void *discovery_loop(void *userdata) {
meshlink_handle_t *mesh = userdata;
assert(mesh);
+ pthread_mutex_lock(&mesh->discovery_mutex);
+
// handle catta logs
catta_set_log_function(discovery_log_cb);
@@ -414,7 +416,6 @@ static void *discovery_loop(void *userdata) {
fail:
- pthread_mutex_lock(&mesh->discovery_mutex);
pthread_cond_broadcast(&mesh->discovery_cond);
pthread_mutex_unlock(&mesh->discovery_mutex);
@@ -461,14 +462,16 @@ bool discovery_start(meshlink_handle_t *mesh) {
assert(!mesh->discovery_threadstarted);
assert(!mesh->catta_servicetype);
+ pthread_mutex_lock(&mesh->discovery_mutex);
+
// Start the discovery thread
if(pthread_create(&mesh->discovery_thread, NULL, discovery_loop, mesh) != 0) {
+ pthread_mutex_unlock(&mesh->discovery_mutex);
logger(mesh, MESHLINK_ERROR, "Could not start discovery thread: %s\n", strerror(errno));
memset(&mesh->discovery_thread, 0, sizeof(mesh)->discovery_thread);
return false;
}
- pthread_mutex_lock(&mesh->discovery_mutex);
pthread_cond_wait(&mesh->discovery_cond, &mesh->discovery_mutex);
pthread_mutex_unlock(&mesh->discovery_mutex);
diff --git a/src/meshlink.c b/src/meshlink.c
index 9aca0677..8ad72c15 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -1456,12 +1456,17 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
}
}
- // initialize mutex
+ // initialize mutexes and conds
pthread_mutexattr_t attr;
pthread_mutexattr_init(&attr);
pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
pthread_mutex_init(&mesh->mutex, &attr);
+ pthread_mutex_init(&mesh->discovery_mutex, NULL);
+ pthread_cond_init(&mesh->discovery_cond, NULL);
+
+ pthread_cond_init(&mesh->adns_cond, NULL);
+
mesh->threadstarted = false;
event_loop_init(&mesh->loop);
mesh->loop.data = mesh;
--
2.39.5