test/tsan/memcpy_race.cc

   1 // RUN: %clangxx_tsan -O1 %s -o %t && not %t 2>&1 | FileCheck %s
   2 #include <pthread.h>
   3 #include <stddef.h>
   4 #include <stdio.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7
   8 char *data = new char[10];
   9 char *data1 = new char[10];
  10 char *data2 = new char[10];
  11
  12 void *Thread1(void *x) {
  13   static volatile int size = 1;
  14   memcpy(data+5, data1, size);
  15   return NULL;
  16 }
  17
  18 void *Thread2(void *x) {
  19   static volatile int size = 4;
  20   sleep(1);
  21   memcpy(data+3, data2, size);
  22   return NULL;
  23 }
  24
  25 int main() {
  26   fprintf(stderr, "addr=%p\n", &data[5]);
  27   pthread_t t[2];
  28   pthread_create(&t[0], NULL, Thread1, NULL);
  29   pthread_create(&t[1], NULL, Thread2, NULL);
  30   pthread_join(t[0], NULL);
  31   pthread_join(t[1], NULL);
  32   return 0;
  33 }
  34
  35 // CHECK: addr=[[ADDR:0x[0-9,a-f]+]]
  36 // CHECK: WARNING: ThreadSanitizer: data race
  37 // CHECK:   Write of size 1 at [[ADDR]] by thread T2:
  38 // CHECK:     #0 memcpy
  39 // CHECK:     #1 Thread2
  40 // CHECK:   Previous write of size 1 at [[ADDR]] by thread T1:
  41 // CHECK:     #0 memcpy
  42 // CHECK:     #1 Thread1