| // RUN: %clangxx_tsan -O1 %s -o %t && %env_tsan_opts=atexit_sleep_ms=0 %run %t 2>&1 | FileCheck %s |
| |
| // This test models what happens on Mac when fork |
| // calls malloc/free inside of our atfork callbacks. |
| // and ensures that we don't deadlock on malloc/free calls. |
| |
| #include "../test.h" |
| #include "syscall.h" |
| #include <errno.h> |
| #include <string.h> |
| #include <sys/types.h> |
| #include <sys/wait.h> |
| |
| // disable_sanitizer_instrumentation on __tsan_test_only_on_fork is not |
| // transitive, so we must apply it here as well. |
| // Instrumenting alloc_free_blocks() will result in deadlocks in TSan. |
| __attribute__((disable_sanitizer_instrumentation)) void alloc_free_blocks() { |
| // Allocate a bunch of blocks to drain local allocator cache |
| // and provoke it to lock allocator global mutexes. |
| const int kBlocks = 1000; |
| void *blocks[kBlocks]; |
| for (int i = 0; i < kBlocks; i++) { |
| void *p = malloc(10); |
| *(volatile char *)p = 0; |
| blocks[i] = p; |
| } |
| for (int i = 0; i < kBlocks; i++) |
| free(blocks[i]); |
| } |
| |
| __attribute__((disable_sanitizer_instrumentation)) extern "C" void |
| __tsan_test_only_on_fork() { |
| const char *msg = "__tsan_test_only_on_fork\n"; |
| write(2, msg, strlen(msg)); |
| alloc_free_blocks(); |
| } |
| |
| static void *background(void *p) { |
| for (;;) |
| alloc_free_blocks(); |
| return 0; |
| } |
| |
| int main() { |
| pthread_t th; |
| pthread_create(&th, 0, background, 0); |
| pthread_detach(th); |
| for (int i = 0; i < 10; i++) { |
| int pid = myfork(); |
| if (pid < 0) { |
| fprintf(stderr, "failed to fork (%d)\n", errno); |
| exit(1); |
| } |
| if (pid == 0) { |
| // child |
| exit(0); |
| } |
| // parent |
| while (wait(0) < 0) { |
| } |
| } |
| fprintf(stderr, "DONE\n"); |
| } |
| |
| // CHECK: __tsan_test_only_on_fork |
| // CHECK: DONE |