[compiler-rt] 519959a - [scudo] Fix deadlock in ScudoWrappersCTest.DisableForkEnable test.

[Evgenii Stepanov via llvm-commits]

Author: Evgenii Stepanov
Date: 2020-05-28T14:31:33-07:00
New Revision: 519959ad825bfad0b62a2012c064e582788d8f21

URL: https://github.com/llvm/llvm-project/commit/519959ad825bfad0b62a2012c064e582788d8f21
DIFF: https://github.com/llvm/llvm-project/commit/519959ad825bfad0b62a2012c064e582788d8f21.diff

LOG: [scudo] Fix deadlock in ScudoWrappersCTest.DisableForkEnable test.

pthread_cond_wait needs a loop around it to handle spurious wake ups,
as well as the case when signal runs before wait.

Added: 
    

Modified: 
    compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp b/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
index 8b2bc6ecbd5b..b41908cf4781 100644
--- a/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
@@ -372,6 +372,7 @@ TEST(ScudoWrappersCTest, Fork) {
 
 static pthread_mutex_t Mutex;
 static pthread_cond_t Conditional = PTHREAD_COND_INITIALIZER;
+static bool Ready;
 
 static void *enableMalloc(void *Unused) {
   // Initialize the allocator for this thread.
@@ -382,6 +383,7 @@ static void *enableMalloc(void *Unused) {
 
   // Signal the main thread we are ready.
   pthread_mutex_lock(&Mutex);
+  Ready = true;
   pthread_cond_signal(&Conditional);
   pthread_mutex_unlock(&Mutex);
 
@@ -398,7 +400,8 @@ TEST(ScudoWrappersCTest, DisableForkEnable) {
 
   // Wait for the thread to be warmed up.
   pthread_mutex_lock(&Mutex);
-  pthread_cond_wait(&Conditional, &Mutex);
+  while (!Ready)
+    pthread_cond_wait(&Conditional, &Mutex);
   pthread_mutex_unlock(&Mutex);
 
   // Disable the allocator and fork. fork should succeed after malloc_enable.