Inflate contended lock word by suspending owner.
Bug 6961405.
Don't inflate monitors for Notify and NotifyAll.
Tidy lock word, handle recursive lock case alongside unlocked case and move
assembly out of line (except for ARM quick). Also handle null in out-of-line
assembly as the test is quick and the enter/exit code is already a safepoint.
To gain ownership of a monitor on behalf of another thread, monitor contenders
must not hold the monitor_lock_, so they wait on a condition variable.
Reduce size of per mutex contention log.
Be consistent in calling thin lock thread ids just thread ids.
Fix potential thread death races caused by the use of FindThreadByThreadId,
make it invariant that returned threads are either self or suspended now.
Code size reduction on ARM boot.oat 0.2%.
Old nexus 7 speedup 0.25%, new nexus 7 speedup 1.4%, nexus 10 speedup 2.24%,
nexus 4 speedup 2.09% on DeltaBlue.
Change-Id: Id52558b914f160d9c8578fdd7fc8199a9598576a
diff --git a/runtime/base/mutex.cc b/runtime/base/mutex.cc
index b048bbb..249f031 100644
--- a/runtime/base/mutex.cc
+++ b/runtime/base/mutex.cc
@@ -54,17 +54,17 @@
std::set<BaseMutex*>* all_mutexes;
AllMutexData() : all_mutexes(NULL) {}
};
-static struct AllMutexData all_mutex_data[kAllMutexDataSize];
+static struct AllMutexData gAllMutexData[kAllMutexDataSize];
class ScopedAllMutexesLock {
public:
explicit ScopedAllMutexesLock(const BaseMutex* mutex) : mutex_(mutex) {
- while (!all_mutex_data->all_mutexes_guard.compare_and_swap(0, reinterpret_cast<int32_t>(mutex))) {
+ while (!gAllMutexData->all_mutexes_guard.compare_and_swap(0, reinterpret_cast<int32_t>(mutex))) {
NanoSleep(100);
}
}
~ScopedAllMutexesLock() {
- while (!all_mutex_data->all_mutexes_guard.compare_and_swap(reinterpret_cast<int32_t>(mutex_), 0)) {
+ while (!gAllMutexData->all_mutexes_guard.compare_and_swap(reinterpret_cast<int32_t>(mutex_), 0)) {
NanoSleep(100);
}
}
@@ -75,7 +75,7 @@
BaseMutex::BaseMutex(const char* name, LockLevel level) : level_(level), name_(name) {
if (kLogLockContentions) {
ScopedAllMutexesLock mu(this);
- std::set<BaseMutex*>** all_mutexes_ptr = &all_mutex_data->all_mutexes;
+ std::set<BaseMutex*>** all_mutexes_ptr = &gAllMutexData->all_mutexes;
if (*all_mutexes_ptr == NULL) {
// We leak the global set of all mutexes to avoid ordering issues in global variable
// construction/destruction.
@@ -88,7 +88,7 @@
BaseMutex::~BaseMutex() {
if (kLogLockContentions) {
ScopedAllMutexesLock mu(this);
- all_mutex_data->all_mutexes->erase(this);
+ gAllMutexData->all_mutexes->erase(this);
}
}
@@ -96,13 +96,13 @@
if (kLogLockContentions) {
os << "Mutex logging:\n";
ScopedAllMutexesLock mu(reinterpret_cast<const BaseMutex*>(-1));
- std::set<BaseMutex*>* all_mutexes = all_mutex_data->all_mutexes;
+ std::set<BaseMutex*>* all_mutexes = gAllMutexData->all_mutexes;
if (all_mutexes == NULL) {
// No mutexes have been created yet during at startup.
return;
}
typedef std::set<BaseMutex*>::const_iterator It;
- os << "(Contented)\n";
+ os << "(Contended)\n";
for (It it = all_mutexes->begin(); it != all_mutexes->end(); ++it) {
BaseMutex* mutex = *it;
if (mutex->HasEverContended()) {
@@ -127,7 +127,8 @@
return;
}
if (kDebugLocking) {
- CHECK(self->GetHeldMutex(level_) == this) << "Waiting on unacquired mutex: " << name_;
+ CHECK(self->GetHeldMutex(level_) == this || level_ == kMonitorLock)
+ << "Waiting on unacquired mutex: " << name_;
bool bad_mutexes_held = false;
for (int i = kLockLevelCount - 1; i >= 0; --i) {
if (i != level_) {