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/dalvik_system_VMStack.cc b/runtime/native/dalvik_system_VMStack.cc
index cf31064..5f718ba 100644
--- a/runtime/native/dalvik_system_VMStack.cc
+++ b/runtime/native/dalvik_system_VMStack.cc
@@ -35,7 +35,12 @@
// Suspend thread to build stack trace.
soa.Self()->TransitionFromRunnableToSuspended(kNative);
bool timed_out;
- Thread* thread = ThreadList::SuspendThreadByPeer(peer, true, false, &timed_out);
+ Thread* thread;
+ {
+ // Take suspend thread lock to avoid races with threads trying to suspend this one.
+ MutexLock mu(soa.Self(), *Locks::thread_list_suspend_thread_lock_);
+ thread = ThreadList::SuspendThreadByPeer(peer, true, false, &timed_out);
+ }
if (thread != nullptr) {
// Must be runnable to create returned array.
CHECK_EQ(soa.Self()->TransitionFromSuspendedToRunnable(), kNative);
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);
diff --git a/runtime/native/org_apache_harmony_dalvik_ddmc_DdmVmInternal.cc b/runtime/native/org_apache_harmony_dalvik_ddmc_DdmVmInternal.cc
index e17e60a..45ef9ae 100644
--- a/runtime/native/org_apache_harmony_dalvik_ddmc_DdmVmInternal.cc
+++ b/runtime/native/org_apache_harmony_dalvik_ddmc_DdmVmInternal.cc
@@ -61,7 +61,12 @@
}
// Suspend thread to build stack trace.
- Thread* thread = thread_list->SuspendThreadByThreadId(thin_lock_id, false, &timed_out);
+ Thread* thread;
+ {
+ // Take suspend thread lock to avoid races with threads trying to suspend this one.
+ MutexLock mu(self, *Locks::thread_list_suspend_thread_lock_);
+ thread = thread_list->SuspendThreadByThreadId(thin_lock_id, false, &timed_out);
+ }
if (thread != nullptr) {
{
ScopedObjectAccess soa(env);