[PATCH] D43548: Fix racy msan test

[Maxim Kuvyrkov via Phabricator via llvm-commits]

maxim-kuvyrkov created this revision.
Herald added subscribers: Sanitizers, llvm-commits.

Child thread may finish before pthread_setname_np() and/or
pthread_getname_np() had a chance to run, which causes these functions
to fail with ENOENT (meaning /proc/self/task/[tid]/comm doesn't exist).

Fix by stalling child thread on a mutex.


Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D43548

Files:
  test/msan/pthread_getname_np.cc


Index: test/msan/pthread_getname_np.cc
===================================================================
--- test/msan/pthread_getname_np.cc
+++ test/msan/pthread_getname_np.cc
@@ -10,12 +10,22 @@
 
 #include <stdio.h>
 
+// Stall child thread on this lock to make sure it doesn't finish
+// before the end of the pthread_getname_np() / pthread_setname_np() tests.
+static pthread_mutex_t lock;
+
 void *ThreadFn(void *) {
+  pthread_mutex_lock (&lock);
+  pthread_mutex_unlock (&lock);
   return nullptr;
 }
 
 int main(void) {
   pthread_t t;
+
+  pthread_mutex_init (&lock, NULL);
+  pthread_mutex_lock (&lock);
+
   int res = pthread_create(&t, 0, ThreadFn, 0);
   assert(!res);
 
@@ -28,6 +38,8 @@
   assert(!res);
   assert(strcmp(buf, kMyThreadName) == 0);
 
+  pthread_mutex_unlock (&lock);
+
   res = pthread_join(t, 0);
   assert(!res);
   return 0;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D43548.135204.patch
Type: text/x-patch
Size: 862 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20180221/70402168/attachment.bin>