You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
51 lines
978 B
51 lines
978 B
//
|
|
// Created by 马也驰 on 2024/12/28.
|
|
//
|
|
|
|
#ifndef LEVELDB_SHARED_LOCK_H
|
|
#define LEVELDB_SHARED_LOCK_H
|
|
|
|
#include <mutex>
|
|
|
|
class SharedLock {
|
|
public:
|
|
SharedLock() : read_count_(0) {}
|
|
|
|
public:
|
|
void soft_lock() {
|
|
write_latch_.lock();
|
|
|
|
read_count_latch_.lock();
|
|
if (!read_count_) {
|
|
read_latch_.lock();
|
|
}
|
|
read_count_ ++;
|
|
read_count_latch_.unlock();
|
|
|
|
write_latch_.unlock();
|
|
}
|
|
void soft_unlock() {
|
|
read_count_latch_.lock();
|
|
read_count_ --;
|
|
if (!read_count_) {
|
|
read_latch_.unlock();
|
|
}
|
|
read_count_latch_.unlock();
|
|
}
|
|
void hard_lock() {
|
|
read_latch_.lock();
|
|
write_latch_.lock();
|
|
read_latch_.unlock();
|
|
}
|
|
void hard_unlock() {
|
|
write_latch_.unlock();
|
|
}
|
|
|
|
private:
|
|
std::mutex read_latch_; // indicate if any read is proceeding
|
|
std::mutex read_count_latch_;
|
|
volatile size_t read_count_;
|
|
std::mutex write_latch_; // indicate if any write is proceeding
|
|
};
|
|
|
|
#endif // LEVELDB_SHARED_LOCK_H
|