1 //===-- sanitizer_stoptheworld_testlib.cc ---------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // Dynamic library to test StopTheWorld functionality.
10 // When loaded with LD_PRELOAD, it will periodically suspend all threads.
11 //===----------------------------------------------------------------------===//
12 /* Usage:
13 clang++ -fno-exceptions -g -fPIC -I. \
14  sanitizer_common/tests/sanitizer_stoptheworld_testlib.cc \
15  sanitizer_common/sanitizer_*.cc -shared -lpthread -o teststoptheworld.so
16 LD_PRELOAD=`pwd`/teststoptheworld.so /your/app
17 */
18 
19 #include "sanitizer_common/sanitizer_platform.h"
20 #if SANITIZER_LINUX
21 
22 #include <dlfcn.h>
23 #include <stddef.h>
24 #include <stdio.h>
25 #include <pthread.h>
26 #include <unistd.h>
27 
28 #include "sanitizer_common/sanitizer_stoptheworld.h"
29 
30 namespace {
31 const uptr kSuspendDuration = 3;
32 const uptr kRunDuration = 3;
33 
Callback(const SuspendedThreadsList & suspended_threads_list,void * argument)34 void Callback(const SuspendedThreadsList &suspended_threads_list,
35               void *argument) {
36   sleep(kSuspendDuration);
37 }
38 
SuspenderThread(void * argument)39 void *SuspenderThread(void *argument) {
40   while (true) {
41     sleep(kRunDuration);
42     StopTheWorld(Callback, NULL);
43   }
44   return NULL;
45 }
46 
StopTheWorldTestLibConstructor(void)47 __attribute__((constructor)) void StopTheWorldTestLibConstructor(void) {
48   pthread_t thread_id;
49   pthread_create(&thread_id, NULL, SuspenderThread, NULL);
50 }
51 }  // namespace
52 
53 #endif  // SANITIZER_LINUX
54