tsan: add another fork deadlock test
The test tries to provoke internal allocator to be locked during fork
and then force the child process to use the internal allocator.
This test sometimes deadlocks with the new tsan runtime.
Depends on D114514.
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D114515
GitOrigin-RevId: a68b52e0a33382f241a250c1d67bed1141727447
diff --git a/test/tsan/Linux/fork_multithreaded4.cpp b/test/tsan/Linux/fork_multithreaded4.cpp
new file mode 100644
index 0000000..927f5a6
--- /dev/null
+++ b/test/tsan/Linux/fork_multithreaded4.cpp
@@ -0,0 +1,46 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+
+// The test tries to provoke internal allocator to be locked during fork
+// and then force the child process to use the internal allocator.
+
+#include "../test.h"
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+static void *forker(void *arg) {
+ void *p = calloc(1, 16);
+ static_cast<volatile int *>(p)[0]++;
+ __atomic_fetch_add(static_cast<int *>(p), 1, __ATOMIC_SEQ_CST);
+ int pid = fork();
+ if (pid < 0) {
+ fprintf(stderr, "failed to fork (%d)\n", errno);
+ exit(1);
+ }
+ if (pid == 0) {
+ __atomic_fetch_add(&static_cast<int *>(p)[1], 1, __ATOMIC_SEQ_CST);
+ exit(0);
+ }
+ int status = 0;
+ while (waitpid(pid, &status, 0) != pid) {
+ }
+ if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+ fprintf(stderr, "subprocess failed (%d)\n", status);
+ exit(1);
+ }
+ free(p);
+ return 0;
+}
+
+int main() {
+ for (int i = 0; i < 10; i++) {
+ pthread_t threads[100];
+ for (auto &th : threads)
+ pthread_create(&th, 0, forker, 0);
+ for (auto th : threads)
+ pthread_join(th, 0);
+ }
+ fprintf(stderr, "DONE\n");
+}
+
+// CHECK: DONE
