subthread signal handling

Since multiple threads responding simultaneously to a signal leading to race condition, this is used to ensure that only the main thread handles the signal.
esnet · Aug 30, 2024 · da21dc2 · da21dc2
1 parent d312ddc
commit da21dc2
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Showing 2 changed files with 22 additions and 24 deletions.
diff --git a/src/iperf_client_api.c b/src/iperf_client_api.c
@@ -57,6 +57,17 @@ iperf_client_worker_run(void *s) {
     struct iperf_stream *sp = (struct iperf_stream *) s;
     struct iperf_test *test = sp->test;
 
+    /* Blocking signal to make sure that signal will be handled by main thread */
+    sigset_t set;
+    sigemptyset(&set);
+    sigaddset(&set, SIGTERM);
+    sigaddset(&set, SIGHUP);
+    sigaddset(&set, SIGINT);
+    if (pthread_sigmask(SIG_BLOCK, &set, NULL) != 0) {
+	    i_errno = IEPTHREADSIGMASK;
+	    goto cleanup_and_fail;
+    }
+
     /* Allow this thread to be cancelled even if it's in a syscall */
     pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
     pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
@@ -688,18 +699,6 @@ iperf_run_client(struct iperf_test * test)
                     goto cleanup_and_fail;
                 }
 
-		/* Block signals that handled by main thread, sub thread(s) will
-		 * inherit a copy of the signal mask */
-		sigset_t set;
-		sigemptyset(&set);
-		sigaddset(&set, SIGTERM);
-		sigaddset(&set, SIGHUP);
-		sigaddset(&set, SIGINT);
-		if (pthread_sigmask(SIG_BLOCK, &set, NULL) != 0) {
-                    i_errno = IEPTHREADSIGMASK;
-                    goto cleanup_and_fail;
-		}
-
                 SLIST_FOREACH(sp, &test->streams, streams) {
                     if (pthread_create(&(sp->thr), &attr, &iperf_client_worker_run, sp) != 0) {
                         i_errno = IEPTHREADCREATE;

diff --git a/src/iperf_server_api.c b/src/iperf_server_api.c
@@ -70,6 +70,17 @@ iperf_server_worker_run(void *s) {
     struct iperf_stream *sp = (struct iperf_stream *) s;
     struct iperf_test *test = sp->test;
 
+    /* Blocking signal to make sure that signal will be handled by main thread */
+    sigset_t set;
+    sigemptyset(&set);
+    sigaddset(&set, SIGTERM);
+    sigaddset(&set, SIGHUP);
+    sigaddset(&set, SIGINT);
+    if (pthread_sigmask(SIG_BLOCK, &set, NULL) != 0) {
+	    i_errno = IEPTHREADSIGMASK;
+	    goto cleanup_and_fail;
+    }
+
     /* Allow this thread to be cancelled even if it's in a syscall */
     pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
     pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
@@ -886,18 +897,6 @@ iperf_run_server(struct iperf_test *test)
                         cleanup_server(test);
                     };
 
-                    /* Block signals that handled by main thread, sub thread(s) will
-                     * inherit a copy of the signal mask */
-                    sigset_t set;
-                    sigemptyset(&set);
-                    sigaddset(&set, SIGTERM);
-                    sigaddset(&set, SIGHUP);
-                    sigaddset(&set, SIGINT);
-                    if (pthread_sigmask(SIG_BLOCK, &set, NULL) != 0) {
-			i_errno = IEPTHREADSIGMASK;
-                        cleanup_server(test);
-		    }
-
                     SLIST_FOREACH(sp, &test->streams, streams) {
                         if (pthread_create(&(sp->thr), &attr, &iperf_server_worker_run, sp) != 0) {
                             i_errno = IEPTHREADCREATE;