blob: d0f732dd417a4c5338794f75e698950b3de808fd [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/threading/thread.h"
#include <stddef.h>
#include <stdint.h>
#include <vector>
#include "base/bind.h"
#include "base/debug/leak_annotations.h"
#include "base/macros.h"
#include "base/memory/ptr_util.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/waitable_event.h"
#include "base/test/gtest_util.h"
#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
#include "base/threading/platform_thread.h"
#include "base/time/time.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "testing/platform_test.h"
using base::Thread;
typedef PlatformTest ThreadTest;
namespace {
void ToggleValue(bool* value) {
ANNOTATE_BENIGN_RACE(value, "Test-only data race on boolean "
"in base/thread_unittest");
*value = !*value;
}
class SleepInsideInitThread : public Thread {
public:
SleepInsideInitThread() : Thread("none") {
init_called_ = false;
ANNOTATE_BENIGN_RACE(
this, "Benign test-only data race on vptr - http://crbug.com/98219");
}
~SleepInsideInitThread() override { Stop(); }
void Init() override {
base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(500));
init_called_ = true;
}
bool InitCalled() { return init_called_; }
private:
bool init_called_;
DISALLOW_COPY_AND_ASSIGN(SleepInsideInitThread);
};
enum ThreadEvent {
// Thread::Init() was called.
THREAD_EVENT_INIT = 0,
// The MessageLoop for the thread was deleted.
THREAD_EVENT_MESSAGE_LOOP_DESTROYED,
// Thread::CleanUp() was called.
THREAD_EVENT_CLEANUP,
// Keep at end of list.
THREAD_NUM_EVENTS
};
typedef std::vector<ThreadEvent> EventList;
class CaptureToEventList : public Thread {
public:
// This Thread pushes events into the vector |event_list| to show
// the order they occured in. |event_list| must remain valid for the
// lifetime of this thread.
explicit CaptureToEventList(EventList* event_list)
: Thread("none"),
event_list_(event_list) {
}
~CaptureToEventList() override { Stop(); }
void Init() override { event_list_->push_back(THREAD_EVENT_INIT); }
void CleanUp() override { event_list_->push_back(THREAD_EVENT_CLEANUP); }
private:
EventList* event_list_;
DISALLOW_COPY_AND_ASSIGN(CaptureToEventList);
};
// Observer that writes a value into |event_list| when a message loop has been
// destroyed.
class CapturingDestructionObserver
: public base::MessageLoop::DestructionObserver {
public:
// |event_list| must remain valid throughout the observer's lifetime.
explicit CapturingDestructionObserver(EventList* event_list)
: event_list_(event_list) {
}
// DestructionObserver implementation:
void WillDestroyCurrentMessageLoop() override {
event_list_->push_back(THREAD_EVENT_MESSAGE_LOOP_DESTROYED);
event_list_ = nullptr;
}
private:
EventList* event_list_;
DISALLOW_COPY_AND_ASSIGN(CapturingDestructionObserver);
};
// Task that adds a destruction observer to the current message loop.
void RegisterDestructionObserver(
base::MessageLoop::DestructionObserver* observer) {
base::MessageLoop::current()->AddDestructionObserver(observer);
}
// Task that calls GetThreadId() of |thread|, stores the result into |id|, then
// signal |event|.
void ReturnThreadId(base::Thread* thread,
base::PlatformThreadId* id,
base::WaitableEvent* event) {
*id = thread->GetThreadId();
event->Signal();
}
} // namespace
TEST_F(ThreadTest, StartWithOptions_StackSize) {
Thread a("StartWithStackSize");
// Ensure that the thread can work with only 12 kb and still process a
// message. At the same time, we should scale with the bitness of the system
// where 12 kb is definitely not enough.
// 12 kb = 3072 Slots on a 32-bit system, so we'll scale based off of that.
Thread::Options options;
#if defined(ADDRESS_SANITIZER) || !defined(NDEBUG)
// ASan bloats the stack variables and overflows the 3072 slot stack. Some
// debug builds also grow the stack too much.
options.stack_size = 2 * 3072 * sizeof(uintptr_t);
#else
options.stack_size = 3072 * sizeof(uintptr_t);
#endif
EXPECT_TRUE(a.StartWithOptions(options));
EXPECT_TRUE(a.message_loop());
EXPECT_TRUE(a.IsRunning());
base::WaitableEvent event(base::WaitableEvent::ResetPolicy::AUTOMATIC,
base::WaitableEvent::InitialState::NOT_SIGNALED);
a.task_runner()->PostTask(
FROM_HERE,
base::BindOnce(&base::WaitableEvent::Signal, base::Unretained(&event)));
event.Wait();
}
// Intentional test-only race for otherwise untestable code, won't fix.
// https://crbug.com/634383
#if !defined(THREAD_SANITIZER)
TEST_F(ThreadTest, StartWithOptions_NonJoinable) {
Thread* a = new Thread("StartNonJoinable");
// Non-joinable threads have to be leaked for now (see
// Thread::Options::joinable for details).
ANNOTATE_LEAKING_OBJECT_PTR(a);
Thread::Options options;
options.joinable = false;
EXPECT_TRUE(a->StartWithOptions(options));
EXPECT_TRUE(a->message_loop());
EXPECT_TRUE(a->IsRunning());
// Without this call this test is racy. The above IsRunning() succeeds because
// of an early-return condition while between Start() and StopSoon(), after
// invoking StopSoon() below this early-return condition is no longer
// satisfied and the real |is_running_| bit has to be checked. It could still
// be false if the message loop hasn't started for real in practice. This is
// only a requirement for this test because the non-joinable property forces
// it to use StopSoon() and not wait for a complete Stop().
EXPECT_TRUE(a->WaitUntilThreadStarted());
// Make the thread block until |block_event| is signaled.
base::WaitableEvent block_event(
base::WaitableEvent::ResetPolicy::AUTOMATIC,
base::WaitableEvent::InitialState::NOT_SIGNALED);
a->task_runner()->PostTask(FROM_HERE,
base::BindOnce(&base::WaitableEvent::Wait,
base::Unretained(&block_event)));
a->StopSoon();
EXPECT_TRUE(a->IsRunning());
// Unblock the task and give a bit of extra time to unwind QuitWhenIdle().
block_event.Signal();
base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(20));
// The thread should now have stopped on its own.
EXPECT_FALSE(a->IsRunning());
}
#endif
TEST_F(ThreadTest, TwoTasksOnJoinableThread) {
bool was_invoked = false;
{
Thread a("TwoTasksOnJoinableThread");
EXPECT_TRUE(a.Start());
EXPECT_TRUE(a.message_loop());
// Test that all events are dispatched before the Thread object is
// destroyed. We do this by dispatching a sleep event before the
// event that will toggle our sentinel value.
a.task_runner()->PostTask(
FROM_HERE, base::BindOnce(static_cast<void (*)(base::TimeDelta)>(
&base::PlatformThread::Sleep),
base::TimeDelta::FromMilliseconds(20)));
a.task_runner()->PostTask(FROM_HERE,
base::BindOnce(&ToggleValue, &was_invoked));
}
EXPECT_TRUE(was_invoked);
}
TEST_F(ThreadTest, DestroyWhileRunningIsSafe) {
Thread a("DestroyWhileRunningIsSafe");
EXPECT_TRUE(a.Start());
EXPECT_TRUE(a.WaitUntilThreadStarted());
}
// TODO(gab): Enable this test when destroying a non-joinable Thread instance
// is supported (proposal @ https://crbug.com/629139#c14).
TEST_F(ThreadTest, DISABLED_DestroyWhileRunningNonJoinableIsSafe) {
{
Thread a("DestroyWhileRunningNonJoinableIsSafe");
Thread::Options options;
options.joinable = false;
EXPECT_TRUE(a.StartWithOptions(options));
EXPECT_TRUE(a.WaitUntilThreadStarted());
}
// Attempt to catch use-after-frees from the non-joinable thread in the
// scope of this test if any.
base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(20));
}
TEST_F(ThreadTest, StopSoon) {
Thread a("StopSoon");
EXPECT_TRUE(a.Start());
EXPECT_TRUE(a.message_loop());
EXPECT_TRUE(a.IsRunning());
a.StopSoon();
a.Stop();
EXPECT_FALSE(a.message_loop());
EXPECT_FALSE(a.IsRunning());
}
TEST_F(ThreadTest, StopTwiceNop) {
Thread a("StopTwiceNop");
EXPECT_TRUE(a.Start());
EXPECT_TRUE(a.message_loop());
EXPECT_TRUE(a.IsRunning());
a.StopSoon();
// Calling StopSoon() a second time should be a nop.
a.StopSoon();
a.Stop();
// Same with Stop().
a.Stop();
EXPECT_FALSE(a.message_loop());
EXPECT_FALSE(a.IsRunning());
// Calling them when not running should also nop.
a.StopSoon();
a.Stop();
}
// TODO(gab): Enable this test in conjunction with re-enabling the sequence
// check in Thread::Stop() as part of http://crbug.com/629139.
TEST_F(ThreadTest, DISABLED_StopOnNonOwningThreadIsDeath) {
Thread a("StopOnNonOwningThreadDeath");
EXPECT_TRUE(a.StartAndWaitForTesting());
Thread b("NonOwningThread");
b.Start();
EXPECT_DCHECK_DEATH({
// Stopping |a| on |b| isn't allowed.
b.task_runner()->PostTask(
FROM_HERE, base::BindOnce(&Thread::Stop, base::Unretained(&a)));
// Block here so the DCHECK on |b| always happens in this scope.
base::PlatformThread::Sleep(base::TimeDelta::Max());
});
}
TEST_F(ThreadTest, TransferOwnershipAndStop) {
std::unique_ptr<Thread> a =
std::make_unique<Thread>("TransferOwnershipAndStop");
EXPECT_TRUE(a->StartAndWaitForTesting());
EXPECT_TRUE(a->IsRunning());
Thread b("TakingOwnershipThread");
b.Start();
base::WaitableEvent event(base::WaitableEvent::ResetPolicy::MANUAL,
base::WaitableEvent::InitialState::NOT_SIGNALED);
// a->DetachFromSequence() should allow |b| to use |a|'s Thread API.
a->DetachFromSequence();
b.task_runner()->PostTask(
FROM_HERE, base::BindOnce(
[](std::unique_ptr<Thread> thread_to_stop,
base::WaitableEvent* event_to_signal) -> void {
thread_to_stop->Stop();
event_to_signal->Signal();
},
base::Passed(&a), base::Unretained(&event)));
event.Wait();
}
TEST_F(ThreadTest, StartTwice) {
Thread a("StartTwice");
EXPECT_FALSE(a.message_loop());
EXPECT_FALSE(a.IsRunning());
EXPECT_TRUE(a.Start());
EXPECT_TRUE(a.message_loop());
EXPECT_TRUE(a.IsRunning());
a.Stop();
EXPECT_FALSE(a.message_loop());
EXPECT_FALSE(a.IsRunning());
EXPECT_TRUE(a.Start());
EXPECT_TRUE(a.message_loop());
EXPECT_TRUE(a.IsRunning());
a.Stop();
EXPECT_FALSE(a.message_loop());
EXPECT_FALSE(a.IsRunning());
}
// Intentional test-only race for otherwise untestable code, won't fix.
// https://crbug.com/634383
#if !defined(THREAD_SANITIZER)
TEST_F(ThreadTest, StartTwiceNonJoinableNotAllowed) {
LOG(ERROR) << __FUNCTION__;
Thread* a = new Thread("StartTwiceNonJoinable");
// Non-joinable threads have to be leaked for now (see
// Thread::Options::joinable for details).
ANNOTATE_LEAKING_OBJECT_PTR(a);
Thread::Options options;
options.joinable = false;
EXPECT_TRUE(a->StartWithOptions(options));
EXPECT_TRUE(a->message_loop());
EXPECT_TRUE(a->IsRunning());
// Signaled when last task on |a| is processed.
base::WaitableEvent last_task_event(
base::WaitableEvent::ResetPolicy::AUTOMATIC,
base::WaitableEvent::InitialState::NOT_SIGNALED);
a->task_runner()->PostTask(
FROM_HERE, base::BindOnce(&base::WaitableEvent::Signal,
base::Unretained(&last_task_event)));
// StopSoon() is non-blocking, Yield() to |a|, wait for last task to be
// processed and a little more for QuitWhenIdle() to unwind before considering
// the thread "stopped".
a->StopSoon();
base::PlatformThread::YieldCurrentThread();
last_task_event.Wait();
base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(20));
// This test assumes that the above was sufficient to let the thread fully
// stop.
ASSERT_FALSE(a->IsRunning());
// Restarting it should not be allowed.
EXPECT_DCHECK_DEATH(a->Start());
}
#endif
TEST_F(ThreadTest, ThreadName) {
Thread a("ThreadName");
EXPECT_TRUE(a.Start());
EXPECT_EQ("ThreadName", a.thread_name());
}
TEST_F(ThreadTest, ThreadId) {
Thread a("ThreadId0");
Thread b("ThreadId1");
a.Start();
b.Start();
// Post a task that calls GetThreadId() on the created thread.
base::WaitableEvent event(base::WaitableEvent::ResetPolicy::AUTOMATIC,
base::WaitableEvent::InitialState::NOT_SIGNALED);
base::PlatformThreadId id_from_new_thread;
a.task_runner()->PostTask(
FROM_HERE,
base::BindOnce(ReturnThreadId, &a, &id_from_new_thread, &event));
// Call GetThreadId() on the current thread before calling event.Wait() so
// that this test can find a race issue with TSAN.
base::PlatformThreadId id_from_current_thread = a.GetThreadId();
// Check if GetThreadId() returns consistent value in both threads.
event.Wait();
EXPECT_EQ(id_from_current_thread, id_from_new_thread);
// A started thread should have a valid ID.
EXPECT_NE(base::kInvalidThreadId, a.GetThreadId());
EXPECT_NE(base::kInvalidThreadId, b.GetThreadId());
// Each thread should have a different thread ID.
EXPECT_NE(a.GetThreadId(), b.GetThreadId());
}
TEST_F(ThreadTest, ThreadIdWithRestart) {
Thread a("ThreadIdWithRestart");
base::PlatformThreadId previous_id = base::kInvalidThreadId;
for (size_t i = 0; i < 16; ++i) {
EXPECT_TRUE(a.Start());
base::PlatformThreadId current_id = a.GetThreadId();
EXPECT_NE(previous_id, current_id);
previous_id = current_id;
a.Stop();
}
}
// Make sure Init() is called after Start() and before
// WaitUntilThreadInitialized() returns.
TEST_F(ThreadTest, SleepInsideInit) {
SleepInsideInitThread t;
EXPECT_FALSE(t.InitCalled());
t.StartAndWaitForTesting();
EXPECT_TRUE(t.InitCalled());
}
// Make sure that the destruction sequence is:
//
// (1) Thread::CleanUp()
// (2) MessageLoop::~MessageLoop()
// MessageLoop::DestructionObservers called.
TEST_F(ThreadTest, CleanUp) {
EventList captured_events;
CapturingDestructionObserver loop_destruction_observer(&captured_events);
{
// Start a thread which writes its event into |captured_events|.
CaptureToEventList t(&captured_events);
EXPECT_TRUE(t.Start());
EXPECT_TRUE(t.message_loop());
EXPECT_TRUE(t.IsRunning());
// Register an observer that writes into |captured_events| once the
// thread's message loop is destroyed.
t.task_runner()->PostTask(
FROM_HERE,
base::BindOnce(&RegisterDestructionObserver,
base::Unretained(&loop_destruction_observer)));
// Upon leaving this scope, the thread is deleted.
}
// Check the order of events during shutdown.
ASSERT_EQ(static_cast<size_t>(THREAD_NUM_EVENTS), captured_events.size());
EXPECT_EQ(THREAD_EVENT_INIT, captured_events[0]);
EXPECT_EQ(THREAD_EVENT_CLEANUP, captured_events[1]);
EXPECT_EQ(THREAD_EVENT_MESSAGE_LOOP_DESTROYED, captured_events[2]);
}
TEST_F(ThreadTest, ThreadNotStarted) {
Thread a("Inert");
EXPECT_FALSE(a.task_runner());
}
TEST_F(ThreadTest, MultipleWaitUntilThreadStarted) {
Thread a("MultipleWaitUntilThreadStarted");
EXPECT_TRUE(a.Start());
// It's OK to call WaitUntilThreadStarted() multiple times.
EXPECT_TRUE(a.WaitUntilThreadStarted());
EXPECT_TRUE(a.WaitUntilThreadStarted());
}
TEST_F(ThreadTest, FlushForTesting) {
Thread a("FlushForTesting");
// Flushing a non-running thread should be a no-op.
a.FlushForTesting();
ASSERT_TRUE(a.Start());
// Flushing a thread with no tasks shouldn't block.
a.FlushForTesting();
constexpr base::TimeDelta kSleepPerTestTask =
base::TimeDelta::FromMilliseconds(50);
constexpr size_t kNumSleepTasks = 5;
const base::TimeTicks ticks_before_post = base::TimeTicks::Now();
for (size_t i = 0; i < kNumSleepTasks; ++i) {
a.task_runner()->PostTask(
FROM_HERE,
base::BindOnce(&base::PlatformThread::Sleep, kSleepPerTestTask));
}
// All tasks should have executed, as reflected by the elapsed time.
a.FlushForTesting();
EXPECT_GE(base::TimeTicks::Now() - ticks_before_post,
kNumSleepTasks * kSleepPerTestTask);
a.Stop();
// Flushing a stopped thread should be a no-op.
a.FlushForTesting();
}
namespace {
// A Thread which uses a MessageLoop on the stack. It won't start a real
// underlying thread (instead its messages can be processed by a RunLoop on the
// stack).
class ExternalMessageLoopThread : public Thread {
public:
ExternalMessageLoopThread() : Thread("ExternalMessageLoopThread") {}
~ExternalMessageLoopThread() override { Stop(); }
void InstallMessageLoop() { SetMessageLoop(&external_message_loop_); }
void VerifyUsingExternalMessageLoop(
bool expected_using_external_message_loop) {
EXPECT_EQ(expected_using_external_message_loop,
using_external_message_loop());
}
private:
base::MessageLoop external_message_loop_;
DISALLOW_COPY_AND_ASSIGN(ExternalMessageLoopThread);
};
} // namespace
TEST_F(ThreadTest, ExternalMessageLoop) {
ExternalMessageLoopThread a;
EXPECT_FALSE(a.message_loop());
EXPECT_FALSE(a.IsRunning());
a.VerifyUsingExternalMessageLoop(false);
a.InstallMessageLoop();
EXPECT_TRUE(a.message_loop());
EXPECT_TRUE(a.IsRunning());
a.VerifyUsingExternalMessageLoop(true);
bool ran = false;
a.task_runner()->PostTask(
FROM_HERE, base::BindOnce([](bool* toggled) { *toggled = true; }, &ran));
base::RunLoop().RunUntilIdle();
EXPECT_TRUE(ran);
a.Stop();
EXPECT_FALSE(a.message_loop());
EXPECT_FALSE(a.IsRunning());
a.VerifyUsingExternalMessageLoop(true);
// Confirm that running any remaining tasks posted from Stop() goes smoothly
// (e.g. https://codereview.chromium.org/2135413003/#ps300001 crashed if
// StopSoon() posted Thread::ThreadQuitHelper() while |run_loop_| was null).
base::RunLoop().RunUntilIdle();
}