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实现一个限定的队列落实界缓冲区(读者中读写器,模块之间的非块,作家之中块)
阅读:
如果队列为空,等到它可以随着时间的推移返回一个值了
如果另一个线程从队列中读取,然后等到该线程完成
从队列中取出第一个元素,并将其返回
不要阻塞如果一个线程被写入队列
写:
如果队列已满,等到如果另一个线程写入队列中的一个值读取超时
,等到线程完成
在队列
不要阻塞,如果年底写的元素一个线程从队列
阅读我不知道如果我的实现是正确
using namespace std;
template <typename T, int N>
class BoundedBuffer {
private:
std::array<T, N> buffer;
int read_pos;
int write_pos;
std::mutex reader_mutex; //mutex for between readers
std::mutex writer_mutex; //mutex for between writers
std::mutex shared_mutex;
std::condition_variable reader_queue;
std::condition_variable writer_queue;
int timeout; //timeout in millisecond
public:
BoundedBuffer(const BoundedBuffer&) = delete;
BoundedBuffer& operator=(const BoundedBuffer&) = delete;
BoundedBuffer(int t) :
read_pos(0),
write_pos(0),
timeout(t) {
}
inline bool empty() {
return read_pos == write_pos;
}
inline bool full() {
return write_pos >= read_pos + N;
}
bool put(const T& data) {
unique_lock<mutex> writer_lock(writer_mutex);
{
unique_lock<mutex> shared_lock(shared_mutex);
if (full()) { //buffer full
if (writer_queue.wait_for(shared_lock, std::chrono::milliseconds(timeout)) ==
std::cv_status::timeout)
return false;
}
}
buffer[write_pos%N] = data;
write_pos++;
reader_queue.notify_one();
return true;
}
pair<T, bool> get() {
unique_lock<mutex> reader_lock(reader_mutex);
{
unique_lock<mutex> shared_lock(shared_mutex);
if (empty()) { //buffer empty
if (reader_queue.wait_for(shared_lock, std::chrono::milliseconds(timeout)) ==
std::cv_status::timeout) {
T t;
return make_pair(t, false);
}
}
}
pair<T, bool> result = make_pair(buffer[read_pos%N], true);
read_pos++;
writer_queue.notify_one();
return result;
}
};