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// 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.
#pragma once
#include "android/base/Compiler.h"
#include "android/base/threads/AndroidThreadTypes.h"
#include "android/base/synchronization/AndroidLock.h"
#ifdef _WIN32
#include <windows.h>
#else
#include <pthread.h>
#endif
#include <inttypes.h>
namespace android {
namespace base {
namespace guest {
// Wrapper class for platform-specific threads.
// To create your own thread, define a sub-class of emugl::Thread
// and override its main() method.
//
// For example:
//
// class MyThread : public emugl::Thread {
// public:
// MyThread() : Thread() {}
//
// virtual intptr_t main() {
// ... main thread loop implementation
// return 0;
// }
// };
//
// ...
//
// // Create new instance, but does not start it.
// MyThread* thread = new MyThread();
//
// // Start the thread.
// thread->start();
//
// // Wait for thread completion, and gets result into |exitStatus|.
// int exitStatus;
// thread->wait(&exitStatus);
//
class Thread {
DISALLOW_COPY_ASSIGN_AND_MOVE(Thread);
public:
// Public constructor.
Thread(ThreadFlags flags = ThreadFlags::MaskSignals, int stackSize = 0);
// Virtual destructor.
virtual ~Thread();
// Override this method in your own thread sub-classes. This will
// be called when start() is invoked on the Thread instance.
virtual intptr_t main() = 0;
// Override this if you need to execute some code after thread has
// exited main() and is guaranteed not to access any of its members.
// E.g. if you need to delete a thread object from the same thread
// it has created
virtual void onExit() {}
// Start a thread instance. Return true on success, false otherwise
// (e.g. if the thread was already started or terminated).
bool start();
// Wait for thread termination and retrieve exist status into
// |*exitStatus|. Return true on success, false otherwise.
// NOTE: |exitStatus| can be NULL.
virtual bool wait(intptr_t *exitStatus = nullptr);
// Check whether a thread has terminated. On success, return true
// and sets |*exitStatus|. On failure, return false.
// NOTE: |exitStatus| can be NULL.
bool tryWait(intptr_t *exitStatus);
// Mask all signals for the current thread
// This is needed for the qemu guest to run properly
// NB: noop for Win32
static void maskAllSignals();
// Sleep for |n| milliseconds
static void sleepMs(unsigned n);
// Sleep for |n| microseconds
static void sleepUs(unsigned n);
// Yield the remaining part of current thread's CPU time slice to another
// thread that's ready to run.
static void yield();
private:
#ifdef _WIN32
static DWORD WINAPI thread_main(void* arg);
HANDLE mThread = nullptr;
#else // !WIN32
static void* thread_main(void* arg);
pthread_t mThread;
#endif
Lock mLock;
// Access guarded by |mLock|.
intptr_t mExitStatus = 0;
int mStackSize;
const ThreadFlags mFlags;
bool mStarted = false;
// Access guarded by |mLock|.
bool mFinished = false;
#ifndef _WIN32
// Posix-only, remember if we've joined our non-detached thread already.
bool mJoined = false;
#endif
};
// Helper function to obtain a printable id for the current thread.
unsigned long getCurrentThreadId();
// Subclass of Thread covering interruptible threads.
class InterruptibleThread : public Thread {
DISALLOW_COPY_ASSIGN_AND_MOVE(InterruptibleThread);
public:
// Public constructor.
InterruptibleThread(ThreadFlags flags = ThreadFlags::MaskSignals, int stackSize = 0) :
Thread(flags, stackSize) { }
virtual void interrupt() = 0;
};
} // namespace guest
} // namespace base
} // namespace android