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