fix random crashes on pthread_detach() (#16137)

1 files changed, 8 insertions, 3 deletions

diff --git a/libnetdata/threads/threads.c b/libnetdata/threads/threads.c
index 09e08cd188..cc5690600d 100644
--- a/libnetdata/threads/threads.c
+++ b/libnetdata/threads/threads.c
@@ -9,8 +9,8 @@ static pthread_attr_t *netdata_threads_attr = NULL;
 
 typedef struct {
     void *arg;
-    pthread_t *thread;
     char tag[NETDATA_THREAD_NAME_MAX + 1];
+    SPINLOCK detach_lock;
     void *(*start_routine) (void *);
     NETDATA_THREAD_OPTIONS options;
 } NETDATA_THREAD;
@@ -185,6 +185,7 @@ static void thread_cleanup(void *ptr) {
         NETDATA_THREAD *info = (NETDATA_THREAD *)ptr;
         netdata_log_error("THREADS: internal error - thread local variable does not match the one passed to this function. Expected thread '%s', passed thread '%s'", netdata_thread->tag, info->tag);
     }
+    spinlock_lock(&netdata_thread->detach_lock);
 
     if(!(netdata_thread->options & NETDATA_THREAD_OPTION_DONT_LOG_CLEANUP))
         netdata_log_info("thread with task id %d finished", gettid());
@@ -199,6 +200,7 @@ static void thread_cleanup(void *ptr) {
 
     netdata_thread->tag[0] = '\0';
 
+    spinlock_unlock(&netdata_thread->detach_lock);
     freez(netdata_thread);
     netdata_thread = NULL;
 }
@@ -281,13 +283,15 @@ static void *netdata_thread_init(void *ptr) {
 }
 
 int netdata_thread_create(netdata_thread_t *thread, const char *tag, NETDATA_THREAD_OPTIONS options, void *(*start_routine) (void *), void *arg) {
-    NETDATA_THREAD *info = mallocz(sizeof(NETDATA_THREAD));
+    NETDATA_THREAD *info = callocz(1, sizeof(NETDATA_THREAD));
     info->arg = arg;
-    info->thread = thread;
     info->start_routine = start_routine;
     info->options = options;
     strncpyz(info->tag, tag, NETDATA_THREAD_NAME_MAX);
 
+    spinlock_init(&info->detach_lock);
+    spinlock_lock(&info->detach_lock);
+
     int ret = pthread_create(thread, netdata_threads_attr, netdata_thread_init, info);
     if(ret != 0)
         netdata_log_error("failed to create new thread for %s. pthread_create() failed with code %d", tag, ret);
@@ -300,6 +304,7 @@ int netdata_thread_create(netdata_thread_t *thread, const char *tag, NETDATA_THR
         }
     }
 
+    spinlock_unlock(&info->detach_lock);
     return ret;
 }