Move some misc thread-related stuff from base to base/thread and into the bas...

base/worker_pool_posix_unittest.cc

-// Copyright (c) 2009 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/worker_pool_posix.h"
-
-#include <set>
-
-#include "base/condition_variable.h"
-#include "base/lock.h"
-#include "base/platform_thread.h"
-#include "base/task.h"
-#include "base/waitable_event.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace base {
-
-// Peer class to provide passthrough access to PosixDynamicThreadPool internals.
-class PosixDynamicThreadPool::PosixDynamicThreadPoolPeer {
- public:
-  explicit PosixDynamicThreadPoolPeer(PosixDynamicThreadPool* pool)
-      : pool_(pool) {}
-
-  Lock* lock() { return &pool_->lock_; }
-  ConditionVariable* tasks_available_cv() {
-    return &pool_->tasks_available_cv_;
-  }
-  const std::queue<Task*>& tasks() const { return pool_->tasks_; }
-  int num_idle_threads() const { return pool_->num_idle_threads_; }
-  ConditionVariable* num_idle_threads_cv() {
-    return pool_->num_idle_threads_cv_.get();
-  }
-  void set_num_idle_threads_cv(ConditionVariable* cv) {
-    pool_->num_idle_threads_cv_.reset(cv);
-  }
-
- private:
-  PosixDynamicThreadPool* pool_;
-
-  DISALLOW_COPY_AND_ASSIGN(PosixDynamicThreadPoolPeer);
-};
-
-}  // namespace base
-
-namespace {
-
-// IncrementingTask's main purpose is to increment a counter.  It also updates a
-// set of unique thread ids, and signals a ConditionVariable on completion.
-// Note that since it does not block, there is no way to control the number of
-// threads used if more than one IncrementingTask is consecutively posted to the
-// thread pool, since the first one might finish executing before the subsequent
-// PostTask() calls get invoked.
-class IncrementingTask : public Task {
- public:
-  IncrementingTask(Lock* counter_lock,
-                   int* counter,
-                   Lock* unique_threads_lock,
-                   std::set<PlatformThreadId>* unique_threads)
-      : counter_lock_(counter_lock),
-        unique_threads_lock_(unique_threads_lock),
-        unique_threads_(unique_threads),
-        counter_(counter) {}
-
-  virtual void Run() {
-    AddSelfToUniqueThreadSet();
-    AutoLock locked(*counter_lock_);
-    (*counter_)++;
-  }
-
-  void AddSelfToUniqueThreadSet() {
-    AutoLock locked(*unique_threads_lock_);
-    unique_threads_->insert(PlatformThread::CurrentId());
-  }
-
- private:
-  Lock* counter_lock_;
-  Lock* unique_threads_lock_;
-  std::set<PlatformThreadId>* unique_threads_;
-  int* counter_;
-
-  DISALLOW_COPY_AND_ASSIGN(IncrementingTask);
-};
-
-// BlockingIncrementingTask is a simple wrapper around IncrementingTask that
-// allows for waiting at the start of Run() for a WaitableEvent to be signalled.
-class BlockingIncrementingTask : public Task {
- public:
-  BlockingIncrementingTask(Lock* counter_lock,
-                           int* counter,
-                           Lock* unique_threads_lock,
-                           std::set<PlatformThreadId>* unique_threads,
-                           Lock* num_waiting_to_start_lock,
-                           int* num_waiting_to_start,
-                           ConditionVariable* num_waiting_to_start_cv,
-                           base::WaitableEvent* start)
-      : incrementer_(
-          counter_lock, counter, unique_threads_lock, unique_threads),
-        num_waiting_to_start_lock_(num_waiting_to_start_lock),
-        num_waiting_to_start_(num_waiting_to_start),
-        num_waiting_to_start_cv_(num_waiting_to_start_cv),
-        start_(start) {}
-
-  virtual void Run() {
-    {
-      AutoLock num_waiting_to_start_locked(*num_waiting_to_start_lock_);
-      (*num_waiting_to_start_)++;
-    }
-    num_waiting_to_start_cv_->Signal();
-    CHECK(start_->Wait());
-    incrementer_.Run();
-  }
-
- private:
-  IncrementingTask incrementer_;
-  Lock* num_waiting_to_start_lock_;
-  int* num_waiting_to_start_;
-  ConditionVariable* num_waiting_to_start_cv_;
-  base::WaitableEvent* start_;
-
-  DISALLOW_COPY_AND_ASSIGN(BlockingIncrementingTask);
-};
-
-class PosixDynamicThreadPoolTest : public testing::Test {
- protected:
-  PosixDynamicThreadPoolTest()
-      : pool_(new base::PosixDynamicThreadPool("dynamic_pool", 60*60)),
-        peer_(pool_.get()),
-        counter_(0),
-        num_waiting_to_start_(0),
-        num_waiting_to_start_cv_(&num_waiting_to_start_lock_),
-        start_(true, false) {}
-
-  virtual void SetUp() {
-    peer_.set_num_idle_threads_cv(new ConditionVariable(peer_.lock()));
-  }
-
-  virtual void TearDown() {
-    // Wake up the idle threads so they can terminate.
-    if (pool_.get()) pool_->Terminate();
-  }
-
-  void WaitForTasksToStart(int num_tasks) {
-    AutoLock num_waiting_to_start_locked(num_waiting_to_start_lock_);
-    while (num_waiting_to_start_ < num_tasks) {
-      num_waiting_to_start_cv_.Wait();
-    }
-  }
-
-  void WaitForIdleThreads(int num_idle_threads) {
-    AutoLock pool_locked(*peer_.lock());
-    while (peer_.num_idle_threads() < num_idle_threads) {
-      peer_.num_idle_threads_cv()->Wait();
-    }
-  }
-
-  Task* CreateNewIncrementingTask() {
-    return new IncrementingTask(&counter_lock_, &counter_,
-                                &unique_threads_lock_, &unique_threads_);
-  }
-
-  Task* CreateNewBlockingIncrementingTask() {
-    return new BlockingIncrementingTask(
-        &counter_lock_, &counter_, &unique_threads_lock_, &unique_threads_,
-        &num_waiting_to_start_lock_, &num_waiting_to_start_,
-        &num_waiting_to_start_cv_, &start_);
-  }
-
-  scoped_refptr<base::PosixDynamicThreadPool> pool_;
-  base::PosixDynamicThreadPool::PosixDynamicThreadPoolPeer peer_;
-  Lock counter_lock_;
-  int counter_;
-  Lock unique_threads_lock_;
-  std::set<PlatformThreadId> unique_threads_;
-  Lock num_waiting_to_start_lock_;
-  int num_waiting_to_start_;
-  ConditionVariable num_waiting_to_start_cv_;
-  base::WaitableEvent start_;
-};
-
-TEST_F(PosixDynamicThreadPoolTest, Basic) {
-  EXPECT_EQ(0, peer_.num_idle_threads());
-  EXPECT_EQ(0U, unique_threads_.size());
-  EXPECT_EQ(0U, peer_.tasks().size());
-
-  // Add one task and wait for it to be completed.
-  pool_->PostTask(CreateNewIncrementingTask());
-
-  WaitForIdleThreads(1);
-
-  EXPECT_EQ(1U, unique_threads_.size()) <<
-      "There should be only one thread allocated for one task.";
-  EXPECT_EQ(1, peer_.num_idle_threads());
-  EXPECT_EQ(1, counter_);
-}
-
-TEST_F(PosixDynamicThreadPoolTest, ReuseIdle) {
-  // Add one task and wait for it to be completed.
-  pool_->PostTask(CreateNewIncrementingTask());
-
-  WaitForIdleThreads(1);
-
-  // Add another 2 tasks.  One should reuse the existing worker thread.
-  pool_->PostTask(CreateNewBlockingIncrementingTask());
-  pool_->PostTask(CreateNewBlockingIncrementingTask());
-
-  WaitForTasksToStart(2);
-  start_.Signal();
-  WaitForIdleThreads(2);
-
-  EXPECT_EQ(2U, unique_threads_.size());
-  EXPECT_EQ(2, peer_.num_idle_threads());
-  EXPECT_EQ(3, counter_);
-}
-
-TEST_F(PosixDynamicThreadPoolTest, TwoActiveTasks) {
-  // Add two blocking tasks.
-  pool_->PostTask(CreateNewBlockingIncrementingTask());
-  pool_->PostTask(CreateNewBlockingIncrementingTask());
-
-  EXPECT_EQ(0, counter_) << "Blocking tasks should not have started yet.";
-
-  WaitForTasksToStart(2);
-  start_.Signal();
-  WaitForIdleThreads(2);
-
-  EXPECT_EQ(2U, unique_threads_.size());
-  EXPECT_EQ(2, peer_.num_idle_threads()) << "Existing threads are now idle.";
-  EXPECT_EQ(2, counter_);
-}
-
-TEST_F(PosixDynamicThreadPoolTest, Complex) {
-  // Add two non blocking tasks and wait for them to finish.
-  pool_->PostTask(CreateNewIncrementingTask());
-
-  WaitForIdleThreads(1);
-
-  // Add two blocking tasks, start them simultaneously, and wait for them to
-  // finish.
-  pool_->PostTask(CreateNewBlockingIncrementingTask());
-  pool_->PostTask(CreateNewBlockingIncrementingTask());
-
-  WaitForTasksToStart(2);
-  start_.Signal();
-  WaitForIdleThreads(2);
-
-  EXPECT_EQ(3, counter_);
-  EXPECT_EQ(2, peer_.num_idle_threads());
-  EXPECT_EQ(2U, unique_threads_.size());
-
-  // Wake up all idle threads so they can exit.
-  {
-    AutoLock locked(*peer_.lock());
-    while (peer_.num_idle_threads() > 0) {
-      peer_.tasks_available_cv()->Signal();
-      peer_.num_idle_threads_cv()->Wait();
-    }
-  }
-
-  // Add another non blocking task.  There are no threads to reuse.
-  pool_->PostTask(CreateNewIncrementingTask());
-  WaitForIdleThreads(1);
-
-  EXPECT_EQ(3U, unique_threads_.size());
-  EXPECT_EQ(1, peer_.num_idle_threads());
-  EXPECT_EQ(4, counter_);
-}
-
-}  // namespace