// 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/compiler_specific.h"
#include "base/threading/platform_thread.h"

#include "testing/gtest/include/gtest/gtest.h"

namespace base {

// Trivial tests that thread runs and doesn't crash on create and join ---------

class TrivialThread : public PlatformThread::Delegate {
 public:
  TrivialThread() : did_run_(false) {}

  virtual void ThreadMain() override {
    did_run_ = true;
  }

  bool did_run() const { return did_run_; }

 private:
  bool did_run_;

  DISALLOW_COPY_AND_ASSIGN(TrivialThread);
};

TEST(PlatformThreadTest, Trivial) {
  TrivialThread thread;
  PlatformThreadHandle handle = kNullThreadHandle;

  ASSERT_FALSE(thread.did_run());
  ASSERT_TRUE(PlatformThread::Create(0, &thread, &handle));
  PlatformThread::Join(handle);
  ASSERT_TRUE(thread.did_run());
}

TEST(PlatformThreadTest, TrivialTimesTen) {
  TrivialThread thread[10];
  PlatformThreadHandle handle[arraysize(thread)];

  for (size_t n = 0; n < arraysize(thread); n++)
    ASSERT_FALSE(thread[n].did_run());
  for (size_t n = 0; n < arraysize(thread); n++)
    ASSERT_TRUE(PlatformThread::Create(0, &thread[n], &handle[n]));
  for (size_t n = 0; n < arraysize(thread); n++)
    PlatformThread::Join(handle[n]);
  for (size_t n = 0; n < arraysize(thread); n++)
    ASSERT_TRUE(thread[n].did_run());
}

// Tests of basic thread functions ---------------------------------------------

class FunctionTestThread : public TrivialThread {
 public:
  FunctionTestThread() : thread_id_(0) {}

  virtual void ThreadMain() override {
    thread_id_ = PlatformThread::CurrentId();
    PlatformThread::YieldCurrentThread();
    PlatformThread::Sleep(TimeDelta::FromMilliseconds(50));

    // Make sure that the thread ID is the same across calls.
    EXPECT_EQ(thread_id_, PlatformThread::CurrentId());

    TrivialThread::ThreadMain();
  }

  PlatformThreadId thread_id() const { return thread_id_; }

 private:
  PlatformThreadId thread_id_;

  DISALLOW_COPY_AND_ASSIGN(FunctionTestThread);
};

TEST(PlatformThreadTest, Function) {
  PlatformThreadId main_thread_id = PlatformThread::CurrentId();

  FunctionTestThread thread;
  PlatformThreadHandle handle = kNullThreadHandle;

  ASSERT_FALSE(thread.did_run());
  ASSERT_TRUE(PlatformThread::Create(0, &thread, &handle));
  PlatformThread::Join(handle);
  ASSERT_TRUE(thread.did_run());
  EXPECT_NE(thread.thread_id(), main_thread_id);

  // Make sure that the thread ID is the same across calls.
  EXPECT_EQ(main_thread_id, PlatformThread::CurrentId());
}

TEST(PlatformThreadTest, FunctionTimesTen) {
  PlatformThreadId main_thread_id = PlatformThread::CurrentId();

  FunctionTestThread thread[10];
  PlatformThreadHandle handle[arraysize(thread)];

  for (size_t n = 0; n < arraysize(thread); n++)
    ASSERT_FALSE(thread[n].did_run());
  for (size_t n = 0; n < arraysize(thread); n++)
    ASSERT_TRUE(PlatformThread::Create(0, &thread[n], &handle[n]));
  for (size_t n = 0; n < arraysize(thread); n++)
    PlatformThread::Join(handle[n]);
  for (size_t n = 0; n < arraysize(thread); n++) {
    ASSERT_TRUE(thread[n].did_run());
    EXPECT_NE(thread[n].thread_id(), main_thread_id);

    // Make sure no two threads get the same ID.
    for (size_t i = 0; i < n; ++i) {
      EXPECT_NE(thread[i].thread_id(), thread[n].thread_id());
    }
  }

  // Make sure that the thread ID is the same across calls.
  EXPECT_EQ(main_thread_id, PlatformThread::CurrentId());
}

}  // namespace base