/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "monitor.h"
#include <memory>
#include <string>
#include "base/atomic.h"
#include "barrier.h"
#include "base/time_utils.h"
#include "class_linker-inl.h"
#include "common_runtime_test.h"
#include "handle_scope-inl.h"
#include "mirror/class-inl.h"
#include "mirror/string-inl.h" // Strings are easiest to allocate
#include "object_lock.h"
#include "scoped_thread_state_change-inl.h"
#include "thread_pool.h"
namespace art {
class MonitorTest : public CommonRuntimeTest {
protected:
void SetUpRuntimeOptions(RuntimeOptions *options) override {
// Use a smaller heap
SetUpRuntimeOptionsForFillHeap(options);
options->push_back(std::make_pair("-Xint", nullptr));
}
public:
std::unique_ptr<Monitor> monitor_;
Handle<mirror::String> object_;
Handle<mirror::String> second_object_;
Handle<mirror::String> watchdog_object_;
// One exception test is for waiting on another Thread's lock. This is used to race-free &
// loop-free pass
Thread* thread_;
std::unique_ptr<Barrier> barrier_;
std::unique_ptr<Barrier> complete_barrier_;
bool completed_;
};
// Check that an exception can be thrown correctly.
// This test is potentially racy, but the timeout is long enough that it should work.
class CreateTask : public Task {
public:
CreateTask(MonitorTest* monitor_test, uint64_t initial_sleep, int64_t millis, bool expected) :
monitor_test_(monitor_test), initial_sleep_(initial_sleep), millis_(millis),
expected_(expected) {}
void Run(Thread* self) override {
{
ScopedObjectAccess soa(self);
monitor_test_->thread_ = self; // Pass the Thread.
monitor_test_->object_.Get()->MonitorEnter(self); // Lock the object. This should transition
LockWord lock_after = monitor_test_->object_.Get()->GetLockWord(false); // it to thinLocked.
LockWord::LockState new_state = lock_after.GetState();
// Cannot use ASSERT only, as analysis thinks we'll keep holding the mutex.
if (LockWord::LockState::kThinLocked != new_state) {
monitor_test_->object_.Get()->MonitorExit(self); // To appease analysis.
ASSERT_EQ(LockWord::LockState::kThinLocked, new_state); // To fail the test.
return;
}
// Force a fat lock by running identity hashcode to fill up lock word.
monitor_test_->object_.Get()->IdentityHashCode();
LockWord lock_after2 = monitor_test_->object_.Get()->GetLockWord(false);
LockWord::LockState new_state2 = lock_after2.GetState();
// Cannot use ASSERT only, as analysis thinks we'll keep holding the mutex.
if (LockWord::LockState::kFatLocked != new_state2) {
monitor_test_->object_.Get()->MonitorExit(self); // To appease analysis.
ASSERT_EQ(LockWord::LockState::kFatLocked, new_state2); // To fail the test.
return;
}
} // Need to drop the mutator lock to use the barrier.
monitor_test_->barrier_->Wait(self); // Let the other thread know we're done.
{
ScopedObjectAccess soa(self);
// Give the other task a chance to do its thing.
NanoSleep(initial_sleep_ * 1000 * 1000);
// Now try to Wait on the Monitor.
Monitor::Wait(self, monitor_test_->object_.Get(), millis_, 0, true,
ThreadState::kTimedWaiting);
// Check the exception status against what we expect.
EXPECT_EQ(expected_, self->IsExceptionPending());
if (expected_) {
self->ClearException();
}
}
monitor_test_->complete_barrier_->Wait(self); // Wait for test completion.
{
ScopedObjectAccess soa(self);
monitor_test_->object_.Get()->MonitorExit(self); // Release the object. Appeases analysis.
}
}
void Finalize() override {
delete this;
}
private:
MonitorTest* monitor_test_;
uint64_t initial_sleep_;
int64_t millis_;
bool expected_;
};
class UseTask : public Task {
public:
UseTask(MonitorTest* monitor_test, uint64_t initial_sleep, int64_t millis, bool expected) :
monitor_test_(monitor_test), initial_sleep_(initial_sleep), millis_(millis),
expected_(expected) {}
void Run(Thread* self) override {
monitor_test_->barrier_->Wait(self); // Wait for the other thread to set up the monitor.
{
ScopedObjectAccess soa(self);
// Give the other task a chance to do its thing.
NanoSleep(initial_sleep_ * 1000 * 1000);
Monitor::Wait(self, monitor_test_->object_.Get(), millis_, 0, true,
ThreadState::kTimedWaiting);
// Check the exception status against what we expect.
EXPECT_EQ(expected_, self->IsExceptionPending());
if (expected_) {
self->ClearException();
}
}
monitor_test_->complete_barrier_->Wait(self); // Wait for test completion.
}
void Finalize() override {
delete this;
}
private:
MonitorTest* monitor_test_;
uint64_t initial_sleep_;
int64_t millis_;
bool expected_;
};
class InterruptTask : public Task {
public:
InterruptTask(MonitorTest* monitor_test, uint64_t initial_sleep, uint64_t millis) :
monitor_test_(monitor_test), initial_sleep_(initial_sleep), millis_(millis) {}
void Run(Thread* self) override {
monitor_test_->barrier_->Wait(self); // Wait for the other thread to set up the monitor.
{
ScopedObjectAccess soa(self);
// Give the other task a chance to do its thing.
NanoSleep(initial_sleep_ * 1000 * 1000);
// Interrupt the other thread.
monitor_test_->thread_->Interrupt(self);
// Give it some more time to get to the exception code.
NanoSleep(millis_ * 1000 * 1000);
// Now try to Wait.
Monitor::Wait(self, monitor_test_->object_.Get(), 10, 0, true,
ThreadState::kTimedWaiting);
// No check here, as depending on scheduling we may or may not fail.
if (self->IsExceptionPending()) {
self->ClearException();
}
}
monitor_test_->complete_barrier_->Wait(self); // Wait for test completion.
}
void Finalize() override {
delete this;
}
private:
MonitorTest* monitor_test_;
uint64_t initial_sleep_;
uint64_t millis_;
};
class WatchdogTask : public Task {
public:
explicit WatchdogTask(MonitorTest* monitor_test) : monitor_test_(monitor_test) {}
void Run(Thread* self) override {
ScopedObjectAccess soa(self);
monitor_test_->watchdog_object_.Get()->MonitorEnter(self); // Lock the object.
monitor_test_->watchdog_object_.Get()->Wait(self, 30 * 1000, 0); // Wait for 30s, or being
// woken up.
monitor_test_->watchdog_object_.Get()->MonitorExit(self); // Release the lock.
if (!monitor_test_->completed_) {
LOG(FATAL) << "Watchdog timeout!";
}
}
void Finalize() override {
delete this;
}
private:
MonitorTest* monitor_test_;
};
static void CommonWaitSetup(MonitorTest* test, ClassLinker* class_linker, uint64_t create_sleep,
int64_t c_millis, bool c_expected, bool interrupt, uint64_t use_sleep,
int64_t u_millis, bool u_expected, const char* pool_name) {
Thread* const self = Thread::Current();
ScopedObjectAccess soa(self);
// First create the object we lock. String is easiest.
StackHandleScope<3> hs(soa.Self());
test->object_ = hs.NewHandle(mirror::String::AllocFromModifiedUtf8(self, "hello, world!"));
test->watchdog_object_ = hs.NewHandle(mirror::String::AllocFromModifiedUtf8(self,
"hello, world!"));
// Create the barrier used to synchronize.
test->barrier_ = std::make_unique<Barrier>(2);
test->complete_barrier_ = std::make_unique<Barrier>(3);
test->completed_ = false;
// Our job: Fill the heap, then try Wait.
{
VariableSizedHandleScope vhs(soa.Self());
test->FillHeap(soa.Self(), class_linker, &vhs);
// Now release everything.
}
// Need to drop the mutator lock to allow barriers.
ScopedThreadSuspension sts(soa.Self(), kNative);
ThreadPool thread_pool(pool_name, 3);
thread_pool.AddTask(self, new CreateTask(test, create_sleep, c_millis, c_expected));
if (interrupt) {
thread_pool.AddTask(self, new InterruptTask(test, use_sleep, static_cast<uint64_t>(u_millis)));
} else {
thread_pool.AddTask(self, new UseTask(test, use_sleep, u_millis, u_expected));
}
thread_pool.AddTask(self, new WatchdogTask(test));
thread_pool.StartWorkers(self);
// Wait on completion barrier.
test->complete_barrier_->Wait(self);
test->completed_ = true;
// Wake the watchdog.
{
ScopedObjectAccess soa2(self);
test->watchdog_object_.Get()->MonitorEnter(self); // Lock the object.
test->watchdog_object_.Get()->NotifyAll(self); // Wake up waiting parties.
test->watchdog_object_.Get()->MonitorExit(self); // Release the lock.
}
thread_pool.StopWorkers(self);
}
// First test: throwing an exception when trying to wait in Monitor with another thread.
TEST_F(MonitorTest, CheckExceptionsWait1) {
// Make the CreateTask wait 10ms, the UseTask wait 10ms.
// => The use task will get the lock first and get to self == owner check.
// This will lead to OOM and monitor error messages in the log.
ScopedLogSeverity sls(LogSeverity::FATAL);
CommonWaitSetup(this, class_linker_, 10, 50, false, false, 2, 50, true,
"Monitor test thread pool 1");
}
// Second test: throwing an exception for invalid wait time.
TEST_F(MonitorTest, CheckExceptionsWait2) {
// Make the CreateTask wait 0ms, the UseTask wait 10ms.
// => The create task will get the lock first and get to ms >= 0
// This will lead to OOM and monitor error messages in the log.
ScopedLogSeverity sls(LogSeverity::FATAL);
CommonWaitSetup(this, class_linker_, 0, -1, true, false, 10, 50, true,
"Monitor test thread pool 2");
}
// Third test: throwing an interrupted-exception.
TEST_F(MonitorTest, CheckExceptionsWait3) {
// Make the CreateTask wait 0ms, then Wait for a long time. Make the InterruptTask wait 10ms,
// after which it will interrupt the create task and then wait another 10ms.
// => The create task will get to the interrupted-exception throw.
// This will lead to OOM and monitor error messages in the log.
ScopedLogSeverity sls(LogSeverity::FATAL);
CommonWaitSetup(this, class_linker_, 0, 500, true, true, 10, 50, true,
"Monitor test thread pool 3");
}
class TryLockTask : public Task {
public:
explicit TryLockTask(Handle<mirror::Object> obj) : obj_(obj) {}
void Run(Thread* self) override {
ScopedObjectAccess soa(self);
// Lock is held by other thread, try lock should fail.
ObjectTryLock<mirror::Object> lock(self, obj_);
EXPECT_FALSE(lock.Acquired());
}
void Finalize() override {
delete this;
}
private:
Handle<mirror::Object> obj_;
};
// Test trylock in deadlock scenarios.
TEST_F(MonitorTest, TestTryLock) {
ScopedLogSeverity sls(LogSeverity::FATAL);
Thread* const self = Thread::Current();
ThreadPool thread_pool("the pool", 2);
ScopedObjectAccess soa(self);
StackHandleScope<1> hs(self);
Handle<mirror::Object> obj1(
hs.NewHandle<mirror::Object>(mirror::String::AllocFromModifiedUtf8(self, "hello, world!")));
{
ObjectLock<mirror::Object> lock1(self, obj1);
{
ObjectTryLock<mirror::Object> trylock(self, obj1);
EXPECT_TRUE(trylock.Acquired());
}
// Test failure case.
thread_pool.AddTask(self, new TryLockTask(obj1));
thread_pool.StartWorkers(self);
ScopedThreadSuspension sts(self, kSuspended);
thread_pool.Wait(Thread::Current(), /*do_work=*/false, /*may_hold_locks=*/false);
}
// Test that the trylock actually locks the object.
{
ObjectTryLock<mirror::Object> trylock(self, obj1);
EXPECT_TRUE(trylock.Acquired());
obj1->Notify(self);
// Since we hold the lock there should be no monitor state exeception.
self->AssertNoPendingException();
}
thread_pool.StopWorkers(self);
}
} // namespace art