1 files changed, 60 insertions, 0 deletions
diff --git a/test/tsan/signal_block.cc b/test/tsan/signal_block.cc
new file mode 100644
index 0000000000000..dfd4259c43c9b
--- /dev/null
+++ b/test/tsan/signal_block.cc
@@ -0,0 +1,60 @@
+// RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+
+// Test that a signal is not delivered when it is blocked.
+
+#include "test.h"
+#include <semaphore.h>
+#include <signal.h>
+#include <errno.h>
+
+int stop;
+sig_atomic_t signal_blocked;
+
+void handler(int signum) {
+  if (signal_blocked) {
+    fprintf(stderr, "signal arrived when blocked\n");
+    exit(1);
+  }
+}
+
+void *thread(void *arg) {
+  sigset_t myset;
+  sigemptyset(&myset);
+  sigaddset(&myset, SIGUSR1);
+  while (!__atomic_load_n(&stop, __ATOMIC_RELAXED)) {
+    usleep(1);
+    if (pthread_sigmask(SIG_BLOCK, &myset, 0)) {
+      fprintf(stderr, "pthread_sigmask failed %d\n", errno);
+      exit(1);
+    }
+    signal_blocked = 1;
+    usleep(1);
+    signal_blocked = 0;
+    if (pthread_sigmask(SIG_UNBLOCK, &myset, 0)) {
+      fprintf(stderr, "pthread_sigmask failed %d\n", errno);
+      exit(1);
+    }
+  }
+  return 0;
+}
+
+int main(int argc, char** argv) {
+  struct sigaction act = {};
+  act.sa_handler = &handler;
+  if (sigaction(SIGUSR1, &act, 0)) {
+    fprintf(stderr, "sigaction failed %d\n", errno);
+    return 1;
+  }
+  pthread_t th;
+  pthread_create(&th, 0, thread, 0);
+  for (int i = 0; i < 100000; i++)
+    pthread_kill(th, SIGUSR1);
+  __atomic_store_n(&stop, 1, __ATOMIC_RELAXED);
+  pthread_join(th, 0);
+  fprintf(stderr, "DONE\n");
+  return 0;
+}
+
+// CHECK-NOT: ThreadSanitizer CHECK
+// CHECK-NOT: WARNING: ThreadSanitizer:
+// CHECK: DONE