Avoid race in single thread suspension.
Don't allow more than one concurrent single thread suspension to avoid
potential cycles and deadlocks where threads try to suspend each other.
Bug: 16364458, 16354227
Change-Id: I907f1d5591a6aa5c241d37d6b4a34f968f98df77
diff --git a/runtime/native/java_lang_Thread.cc b/runtime/native/java_lang_Thread.cc
index bae67f2..8f83f96 100644
--- a/runtime/native/java_lang_Thread.cc
+++ b/runtime/native/java_lang_Thread.cc
@@ -116,18 +116,25 @@
static void Thread_nativeSetName(JNIEnv* env, jobject peer, jstring java_name) {
ScopedUtfChars name(env, java_name);
+ Thread* self;
{
ScopedObjectAccess soa(env);
if (soa.Decode<mirror::Object*>(peer) == soa.Self()->GetPeer()) {
soa.Self()->SetThreadName(name.c_str());
return;
}
+ self = soa.Self();
}
// Suspend thread to avoid it from killing itself while we set its name. We don't just hold the
// thread list lock to avoid this, as setting the thread name causes mutator to lock/unlock
// in the DDMS send code.
bool timed_out;
- Thread* thread = ThreadList::SuspendThreadByPeer(peer, true, false, &timed_out);
+ // Take suspend thread lock to avoid races with threads trying to suspend this one.
+ Thread* thread;
+ {
+ MutexLock mu(self, *Locks::thread_list_suspend_thread_lock_);
+ thread = ThreadList::SuspendThreadByPeer(peer, true, false, &timed_out);
+ }
if (thread != NULL) {
{
ScopedObjectAccess soa(env);