add a refcount to library init/cleanup

Add a refcount around mosquitto_lib_init and mosquitto_lib_cleanup so
that multiple calls to init/cleanup don't trigger memory leaks or
double-frees.

Signed-off-by: Martin Kelly <[email protected]>

lib/mosquitto.c

@@ -34,6 +34,7 @@ and the Eclipse Distribution License is available at
 #include "packet_mosq.h"
 #include "will_mosq.h"
 
+static unsigned int init_refcount = 0;
 
 void mosquitto__destroy(struct mosquitto *mosq);
 
@@ -47,31 +48,47 @@ int mosquitto_lib_version(int *major, int *minor, int *revision)
 
 int mosquitto_lib_init(void)
 {
+ int rc;
+
+ if (init_refcount == 0) {
 #ifdef WIN32
- srand(GetTickCount64());
+  srand(GetTickCount64());
 #elif _POSIX_TIMERS>0 && defined(_POSIX_MONOTONIC_CLOCK)
- struct timespec tp;
+  struct timespec tp;
 
- clock_gettime(CLOCK_MONOTONIC, &tp);
- srand(tp.tv_nsec);
+  clock_gettime(CLOCK_MONOTONIC, &tp);
+  srand(tp.tv_nsec);
 #elif defined(__APPLE__)
- uint64_t ticks;
+  uint64_t ticks;
 
- ticks = mach_absolute_time();
- srand((unsigned int)ticks);
+  ticks = mach_absolute_time();
+  srand((unsigned int)ticks);
 #else
- struct timeval tv;
+  struct timeval tv;
 
- gettimeofday(&tv, NULL);
- srand(tv.tv_sec*1000 + tv.tv_usec/1000);
+  gettimeofday(&tv, NULL);
+  srand(tv.tv_sec*1000 + tv.tv_usec/1000);
 #endif
 
- return net__init();
+ rc = net__init();
+ if (rc != MOSQ_ERR_SUCCESS) {
+ return rc;
+ }
+ }
+
+ init_refcount++;
+ return MOSQ_ERR_SUCCESS;
 }
 
 int mosquitto_lib_cleanup(void)
 {
- net__cleanup();
+ if (init_refcount == 1) {
+ net__cleanup();
+ }
+
+ if (init_refcount > 0) {
+ --init_refcount;
+ }
 
  return MOSQ_ERR_SUCCESS;
 }