我使用boost :: asio和SMFL音频库启动了语音聊天服务器项目。我认为我的互斥逻辑不正确，因为我收到了这个错误：
Unhandled exception at 0x00B7871D in TCPAudioReceiver.exe: 0xC0000005: Access violation reading location 0x00000000.
调试器在main中的if(mServer.samplesAvailable())行停止，我还注意到服务器中的if(mSamplesQueue.front().size() > 256) return true;行读取的大小为{???}。我认为锁定服务器的互斥锁足以防止出现这种问题，但我认为我仍然有一两个概念远离优秀的设计。
我没有特别使用recursive_mutex这一点，更多的是尝试在我的故障排除中获得更多。
你怎么建议我解决这个问题？
主
#include "TcpAsyncServer.h"
#include "TcpAsyncSession.h"
#include "AudioStream.h"
#include <thread>
int main()
{
io_service ioService;
deque<vector<Int16>> mSamplesQueue;
SoundBuffer mSoundBuffer;
AudioStream mAudioStream;
cout << "Starting server..." << endl;
Server mServer(ioService, PORT);
thread serviceThread([&](){ioService.run();});
cout << "Starting reception loop..." << endl;
for(;;) {
{
lock_guard<recursive_mutex> lock(mServer.mServerMutex);
// Look for new samples
if(mServer.samplesAvailable()) { // <-- debugger stops here
cout << "Samples available..." << endl;
vector<Int16> wSamples;
mServer.getNextSamples(wSamples);
mSamplesQueue.push_back(wSamples);
}
}
// Loading and playing samples
if((mAudioStream.getStatus() != AudioStream::Playing) && !mSamplesQueue.empty()) {
cout << "Loading and playing audio stream..." << endl;
if(mSoundBuffer.loadFromSamples(
reinterpret_cast<Int16*>(mSamplesQueue.front().data()),
mSamplesQueue.front().size(), 2, 48000)
)
{
cout << "SoundBuffer loaded successfully..." << endl;
mAudioStream.load(mSoundBuffer);
mAudioStream.play();
mSamplesQueue.pop_front();
}
else cout << "SoundBuffer failed to load..." << endl;
}
// Give it some room to play the sound
while (mAudioStream.getStatus() == AudioStream::Playing) {
sleep(milliseconds(50));
}
}
serviceThread.join();
}
服务器标头
#include <mutex>
#include <deque>
#include <vector>
#include <iostream>
#include <boost/asio.hpp>
#include <SFML/Audio.hpp>
using namespace sf;
using namespace boost::asio;
using namespace boost::asio::ip;
using namespace std;
#define PORT 2112
#define SAMPLE_BUFFER 512
class Server
{
public:
// Ctor
Server(io_service & iService, short iPort);
// Methods
bool samplesAvailable();
void getNextSamples(vector<Int16> oSamples);
void pushSamples(vector<Int16> iSamples);
// Variables
recursive_mutex mServerMutex;
private:
// Methods
void doAccept();
// Variables
tcp::acceptor mAcceptor;
tcp::socket mSocket;
deque<vector<Int16>> mSamplesQueue;
};
服务器类
#include "TcpAsyncServer.h"
#include "TcpAsyncSession.h"
Server::Server(io_service & service, short port)
: mAcceptor(service, tcp::endpoint(tcp::v4(), port)),
mSocket(service) {
doAccept();
}
void Server::doAccept()
{
mAcceptor.async_accept(mSocket,
[this]
(boost::system::error_code error) {
if(!error) make_shared<Session>(move(mSocket),this)->start();
doAccept();
}
);
}
bool Server::samplesAvailable() {
lock_guard<recursive_mutex> lock(mServerMutex);
if(mSamplesQueue.front().size() > 256) return true; // <-- mSamplesQueue.front() has undefined size
return false;
}
void Server::getNextSamples(vector<Int16> oSamples) {
lock_guard<recursive_mutex> lock(mServerMutex);
oSamples = mSamplesQueue.front();
mSamplesQueue.pop_front();
}
void Server::pushSamples(vector<Int16> iSamples) {
lock_guard<recursive_mutex> lock(mServerMutex);
mSamplesQueue.push_back(iSamples);
}
会话标题
#include <iostream>
#include <mutex>
#include <deque>
#include <vector>
#include <boost/asio.hpp>
#include <SFML/Audio.hpp>
using namespace std;
using namespace sf;
using namespace boost::asio;
using namespace boost::asio::ip;
#define BUFFER_SIZE 1024
class Server;
class Session : public enable_shared_from_this<Session>
{
public:
// Ctor
Session(tcp::socket & iSocket, Server* iServerPtr);
// Methods
void start();
private:
// Methods
void doRead();
// Variables
tcp::socket mSocket;
char mData[BUFFER_SIZE];
Server* mServerPtr;
deque<vector<Int16>> mSampleBufferQueue;
};
会话课
#include "TcpAsyncSession.h"
#include "TcpAsyncServer.h"
Session::Session(tcp::socket & iSocket, Server* iServerPtr)
: mSocket(move(iSocket)),
mServerPtr(iServerPtr)
{}
void Session::start() {
doRead();
}
void Session::doRead() {
shared_ptr<Session> self(shared_from_this());
mSocket.async_read_some(buffer(mData,BUFFER_SIZE),
[this,self]
(boost::system::error_code error, size_t iBytesReceived) {
if(!error) {
cout << "Receiving " << iBytesReceived << " bytes..." << endl;
vector<Int16> wSamples;
for(unsigned int i = 0; i < iBytesReceived; i+=2) {
wSamples.push_back(static_cast<Int16>( mData[i]<<8 | mData[i] ));
}
{
lock_guard<recursive_mutex> lock(mServerPtr->mServerMutex);
mServerPtr->pushSamples(move(wSamples));
}
doRead();
}
}
);
}
答案 0 :(得分：4)
你最明显的错误就在这里：
mSamplesQueue.empty()您应检查front()是否属实，否则使用bool Server::samplesAvailable() {
std::lock_guard<std::recursive_mutex> lock(mServerMutex);
if (mSamplesQueue.front().size() > 256)
return true;
return false;
}
为UB。
而不是
bool Server::samplesAvailable() {
std::lock_guard<std::recursive_mutex> lock(mServerMutex);
return mSamplesQueue.size() && mSamplesQueue.front().size()>256;
}
你可以简单地写
wSamples.push_back(static_cast<Int16>(mData[i] << 8 | mData[i]));
审阅：
中有UB
char你需要括号，并且在许多编译器using上签名，这导致UB左移。
永远不要在头文件中使用using namespace std; - 指令。 特别是而非char[]（Why is "using namespace std" considered bad practice?）
有一些不必要的缓冲区复制，为什么不重新解释在具有适当字节序的平台上强制转换std::move缓冲区，和/或为什么pushSamples() mSamplesQueue.push_back(std::move(iSamples));
{
std::lock_guard<std::recursive_mutex> lock(mServerPtr->mServerMutex);
mServerPtr->pushSamples(std::move(wSamples));
}
：
void Server::pushSamples(std::vector<sf::Int16> iSamples) {
std::lock_guard<std::recursive_mutex> lock(mServerMutex);
mSamplesQueue.push_back(std::move(iSamples));
}
是代码气味（Law of Demeter）。特别是，当你写作时，这是一个肯定的标志，你正在混合抽象层次：
Session::mSampleBufferQueue特别是因为你已经拥有
getNextSamples这意味着此时你需要一个递归互斥锁，否则就会出现死锁。
void getNextSamples(std::vector<sf::Int16>& oSamples);
未使用
std::vector<sf::Int16> getNextSamples();
的签名是错误的。您永远不会看到任何效果，因为参数是按值传递的。要么宣布它：
samplesAvailable()或
mutable考虑制作像//#include "AudioStream.h"
#include "TcpAsyncServer.h"
#include "TcpAsyncSession.h"
#include <thread>
struct AudioStream {
enum Status { Playing, Buffering };
Status getStatus() const { return Buffering; }
void load(sf::SoundBuffer const& buf) {
//
std::cout << __PRETTY_FUNCTION__
<< " rate=" << buf.getSampleRate()
<< " channels=" << buf.getChannelCount()
<< " duration=" << buf.getDuration().asSeconds() << "s "
<< " samples=" << buf.getSampleCount()
<< "\n";
}
void play() {}
};
int main() {
boost::asio::io_service ioService;
std::deque<std::vector<sf::Int16> > mSamplesQueue;
sf::SoundBuffer mSoundBuffer;
AudioStream mAudioStream;
std::cout << "Starting server..." << std::endl;
Server mServer(ioService, PORT); // start async accept loop
std::thread serviceThread([&]() { ioService.run(); });
std::cout << "Starting reception loop..." << std::endl;
for (;;) {
{
std::lock_guard<std::recursive_mutex> lock(mServer.mServerMutex);
// Look for new samples
if (mServer.samplesAvailable()) {
std::cout << "Samples available..." << std::endl;
std::vector<sf::Int16> wSamples;
mServer.getNextSamples(wSamples);
mSamplesQueue.push_back(wSamples);
}
}
// Loading and playing samples
if ((mAudioStream.getStatus() != AudioStream::Playing) && !mSamplesQueue.empty()) {
std::cout << "Loading and playing audio stream..." << std::endl;
if (mSoundBuffer.loadFromSamples(reinterpret_cast<sf::Int16 *>(mSamplesQueue.front().data()),
mSamplesQueue.front().size(), 2, 48000)) {
std::cout << "SoundBuffer loaded successfully..." << std::endl;
mAudioStream.load(mSoundBuffer);
mAudioStream.play();
mSamplesQueue.pop_front();
} else
std::cout << "SoundBuffer failed to load..." << std::endl;
}
// Give it some room to play the sound
while (mAudioStream.getStatus() == AudioStream::Playing) {
sleep(sf::milliseconds(50));
}
}
serviceThread.join();
}
const这样的方法。为此，您需要标记互斥锁#include <SFML/Audio.hpp>
#include <boost/asio.hpp>
#include <deque>
#include <iostream>
#include <mutex>
#include <vector>
#define PORT 2113
#define SAMPLE_BUFFER 5120000
class Server {
using tcp = boost::asio::ip::tcp;
public:
// Ctor
Server(boost::asio::io_service &iService, short iPort);
// Methods
bool samplesAvailable() const;
void getNextSamples(std::vector<sf::Int16>& oSamples);
void pushSamples(std::vector<sf::Int16> iSamples);
// Variables
mutable std::recursive_mutex mServerMutex;
private:
// Methods
void doAccept();
// Variables
tcp::acceptor mAcceptor;
tcp::socket mSocket;
std::deque<std::vector<sf::Int16> > mSamplesQueue;
};
（Always declare std::mutex as mutable in C++11?）
从概念上讲，接受并发客户端存在问题。如果真的发生了，你最终会随机交错播放流。
的main.cpp
#include <boost/asio.hpp>
#define BUFFER_SIZE 10240000
class Server;
class Session : public std::enable_shared_from_this<Session> {
using tcp = boost::asio::ip::tcp;
public:
// Ctor
Session(tcp::socket &&iSocket, Server *iServerPtr);
// Methods
void start();
private:
// Methods
void doRead();
// Variables
tcp::socket mSocket;
uint8_t mData[BUFFER_SIZE];
Server *mServerPtr;
};
TcpAsyncServer.h
#include "TcpAsyncServer.h"
#include "TcpAsyncSession.h"
Server::Server(boost::asio::io_service &service, short port) : mAcceptor(service, tcp::endpoint(tcp::v4(), port)), mSocket(service) {
mAcceptor.set_option(tcp::acceptor::reuse_address());
doAccept();
}
void Server::doAccept() {
mAcceptor.async_accept(mSocket, [this](boost::system::error_code error) {
if (!error)
std::make_shared<Session>(std::move(mSocket), this)->start();
doAccept();
});
}
bool Server::samplesAvailable() const {
std::lock_guard<std::recursive_mutex> lock(mServerMutex);
return mSamplesQueue.size() && mSamplesQueue.front().size()>256;
}
void Server::getNextSamples(std::vector<sf::Int16>& oSamples) {
std::lock_guard<std::recursive_mutex> lock(mServerMutex);
oSamples = std::move(mSamplesQueue.front());
mSamplesQueue.pop_front();
}
void Server::pushSamples(std::vector<sf::Int16> iSamples) {
std::lock_guard<std::recursive_mutex> lock(mServerMutex);
mSamplesQueue.push_back(std::move(iSamples));
}
TcpAsyncSession.h
#include "TcpAsyncServer.h"
#include "TcpAsyncSession.h"
//#include <SFML/Audio.hpp>
#include <iostream>
Session::Session(tcp::socket &&iSocket, Server *iServerPtr) : mSocket(std::move(iSocket)), mServerPtr(iServerPtr) {}
void Session::start() { doRead(); }
void Session::doRead() {
std::shared_ptr<Session> self(shared_from_this());
mSocket.async_read_some(
boost::asio::buffer(mData, BUFFER_SIZE),
[this, self](boost::system::error_code error, size_t iBytesReceived) {
if (error)
return;
std::cout << "Receiving " << iBytesReceived << " bytes..." << std::endl;
std::vector<sf::Int16> wSamples;
for (unsigned int i = 0; i < iBytesReceived; i += 2) {
wSamples.push_back(static_cast<sf::Int16>((mData[i] << 8) | mData[i]));
}
mServerPtr->pushSamples(std::move(wSamples));
doRead();
});
}
TcpAsyncServer.cpp
Starting server...
Starting reception loop...
Receiving 8192 bytes...
Samples available...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=0.042666s samples=4096
Receiving 562829 bytes...
Samples available...
Receiving 745525 bytes...
Loading and playing audio stream...
An internal OpenAL call failed in SoundBuffer.cpp(265).
Expression:
alBufferData(m_buffer, format, &m_samples[0], size, sampleRate)
Error description:
AL_INVALID_VALUE
A numeric argument is out of range.
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=2.93141s samples=281415
Samples available...
Loading and playing audio stream...
Receiving 2815769 bytes...
An internal OpenAL call failed in SoundBuffer.cpp(265).
Expression:
alBufferData(m_buffer, format, &m_samples[0], size, sampleRate)
Error description:
AL_INVALID_VALUE
A numeric argument is out of range.
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=3.88295s samples=372763
Samples available...
Receiving 4978211 bytes...
Loading and playing audio stream...
An internal OpenAL call failed in SoundBuffer.cpp(265).
Expression:
alBufferData(m_buffer, format, &m_samples[0], size, sampleRate)
Error description:
AL_INVALID_VALUE
A numeric argument is out of range.
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=14.6655s samples=1407885
Samples available...
Receiving 5632954 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=25.9282s samples=2489106
Samples available...
Receiving 5893470 bytes...
Loading and playing audio stream...
An internal OpenAL call failed in SoundBuffer.cpp(265).
Expression:
alBufferData(m_buffer, format, &m_samples[0], size, sampleRate)
Error description:
AL_INVALID_VALUE
A numeric argument is out of range.
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=29.3383s samples=2816477
Samples available...
Receiving 5895401 bytes...
Loading and playing audio stream...
An internal OpenAL call failed in SoundBuffer.cpp(265).
Expression:
alBufferData(m_buffer, format, &m_samples[0], size, sampleRate)
Error description:
AL_INVALID_VALUE
A numeric argument is out of range.
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=30.6952s samples=2946735
Samples available...
Receiving 5894091 bytes...
Loading and playing audio stream...
An internal OpenAL call failed in SoundBuffer.cpp(265).
Expression:
alBufferData(m_buffer, format, &m_samples[0], size, sampleRate)
Error description:
AL_INVALID_VALUE
A numeric argument is out of range.
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=30.7052s samples=2947701
Samples available...
Receiving 5894197 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=30.6984s samples=2947046
Samples available...
Receiving 5894303 bytes...
Loading and playing audio stream...
An internal OpenAL call failed in SoundBuffer.cpp(265).
Expression:
alBufferData(m_buffer, format, &m_samples[0], size, sampleRate)
Error description:
AL_INVALID_VALUE
A numeric argument is out of range.
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=30.6989s samples=2947099
Samples available...
Receiving 5894144 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=30.6995s samples=2947152
Samples available...
Receiving 5896192 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=30.6987s samples=2947072
Samples available...
Receiving 5961675 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=30.7093s samples=2948096
Samples available...
Receiving 5961728 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0504s samples=2980838
Samples available...
Receiving 5960615 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0507s samples=2980864
Samples available...
Receiving 5960793 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0449s samples=2980308
Samples available...
Receiving 5960668 bytes...
Loading and playing audio stream...
An internal OpenAL call failed in SoundBuffer.cpp(265).
Expression:
alBufferData(m_buffer, format, &m_samples[0], size, sampleRate)
Error description:
AL_INVALID_VALUE
A numeric argument is out of range.
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0458s samples=2980397
Samples available...
Receiving 5960740 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0451s samples=2980334
Samples available...
Receiving 5960668 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0455s samples=2980370
Samples available...
Receiving 5960740 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0451s samples=2980334
Samples available...
Receiving 5960668 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0455s samples=2980370
Samples available...
Receiving 5960740 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0451s samples=2980334
Samples available...
Receiving 5960668 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0455s samples=2980370
Samples available...
Receiving 5960740 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0451s samples=2980334
Samples available...
Receiving 5960668 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0455s samples=2980370
Samples available...
Receiving 5960740 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0451s samples=2980334
Samples available...
Receiving 4770135 bytes...
Loading and playing audio stream...
SoundBuffer loaded successfully...
void AudioStream::load(const sf::SoundBuffer &) rate=48000 channels=2 duration=31.0455s samples=2980370
Samples available...
Loading and playing audio stream...
SoundBuffer loaded successfully...
TcpAsyncSession.cpp
AudioStream给它一个138M的mp3：
{{1}}
除了我的模拟{{1}}没有正确初始化音频库这一事实，这对我来说很好。
请注意，我增加了缓冲区大小，因此日志不会太大。