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authorJunjie Hu <junjie.hu@mediatek.com>2015-11-11 12:52:25 +0800
committerJunjie Hu <junjie.hu@mediatek.com>2015-11-11 04:54:52 +0000
commit4f8010293506d4e08d184e66bf4af44ef3483611 (patch)
treed1c073a2a0207b48af767f78592155ffe9768692
parent93a91f0cf4f015762ac1ed57395c4c0de8ba7db3 (diff)
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Fix potential race condition on CTS TC pthread_gettid_np
Root cause: If start_routine thread exits before pthread_gettid_np is invokded, the "tid" field will be cleared so that pthread_gettid_np will get "0" (which is cleared by kernel, due to the flag "CLONE_CHILD_CLEARTID" is set while calling clone system call inside pthread_create). Proposed patch: Use a mutex to guarantee pthread_gettid_np will be invoked and returned before the start_routine exits Signed-off-by: Junjie Hu <junjie.hu@mediatek.com> Change-Id: I22411f1b0f7446d76a0373cef4ccec858fac7018
-rwxr-xr-x[-rw-r--r--]tests/pthread_test.cpp7
1 files changed, 7 insertions, 0 deletions
diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index 8ae28d8..f15cdab 100644..100755
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -1244,8 +1244,11 @@ TEST(pthread, pthread_attr_getstack_18908062) {
}
#if defined(__BIONIC__)
+static pthread_mutex_t gettid_mutex;
static void* pthread_gettid_np_helper(void* arg) {
+ pthread_mutex_lock(&gettid_mutex);
*reinterpret_cast<pid_t*>(arg) = gettid();
+ pthread_mutex_unlock(&gettid_mutex);
return NULL;
}
#endif
@@ -1256,11 +1259,15 @@ TEST(pthread, pthread_gettid_np) {
pid_t t_gettid_result;
pthread_t t;
+ pthread_mutex_init(&gettid_mutex, NULL);
+ pthread_mutex_lock(&gettid_mutex);
pthread_create(&t, NULL, pthread_gettid_np_helper, &t_gettid_result);
pid_t t_pthread_gettid_np_result = pthread_gettid_np(t);
+ pthread_mutex_unlock(&gettid_mutex);
pthread_join(t, NULL);
+ pthread_mutex_destroy(&gettid_mutex);
ASSERT_EQ(t_gettid_result, t_pthread_gettid_np_result);
#else