140 lines
3.9 KiB
C++
140 lines
3.9 KiB
C++
#ifndef QUTEX_H
|
|
#define QUTEX_H
|
|
|
|
#include <list>
|
|
#include <atomic>
|
|
#include <memory>
|
|
#include <spinLock.h>
|
|
|
|
namespace smo {
|
|
|
|
// Forward declarations
|
|
class LockerAndInvoker;
|
|
|
|
/**
|
|
* @brief Qutex - Queue-based mutex for asynchronous lock management
|
|
*
|
|
* A Qutex combines a spinlock, an ownership flag, and a queue of waiting
|
|
* lockvokers to provide efficient asynchronous lock management with
|
|
* priority-based acquisition for LockSets.
|
|
*/
|
|
class Qutex
|
|
{
|
|
public:
|
|
typedef std::list<std::shared_ptr<LockerAndInvoker>> LockerAndInvokerList;
|
|
|
|
/**
|
|
* @brief Constructor
|
|
*/
|
|
Qutex()
|
|
{
|
|
// TODO: Initialize member variables
|
|
}
|
|
|
|
/**
|
|
* @brief Register a lockvoker in the queue
|
|
* @param lockvoker The lockvoker to register
|
|
* @return Iterator pointing to the registered lockvoker in the queue
|
|
*/
|
|
LockerAndInvokerList::iterator registerInQueue(
|
|
const std::shared_ptr<LockerAndInvoker> &lockvoker
|
|
)
|
|
{
|
|
// TODO: Implement registration logic
|
|
// - Acquire the spinlock
|
|
// - Insert lockvoker at the rear of the queue
|
|
// - Return iterator to the inserted element
|
|
// - Release the spinlock
|
|
lock.acquire();
|
|
auto it = queue.insert(queue.end(), lockvoker);
|
|
lock.release();
|
|
return it;
|
|
}
|
|
|
|
/**
|
|
* @brief Unregister a lockvoker from the queue
|
|
* @param it Iterator pointing to the lockvoker to unregister
|
|
*/
|
|
void unregisterFromQueue(LockerAndInvokerList::iterator it)
|
|
{
|
|
// TODO: Implement unregistration logic
|
|
// - Acquire the spinlock
|
|
// - Erase the element at the given iterator
|
|
// - Release the spinlock
|
|
(void)it; // Suppress unused parameter warning
|
|
}
|
|
|
|
/**
|
|
* @brief Try to acquire the lock for a lockvoker
|
|
* @param tryingLockvoker The lockvoker attempting to acquire the lock
|
|
* @param nRequiredLocks Number of locks required by the lockvoker's LockSet
|
|
* @return true if the lock was successfully acquired, false otherwise
|
|
*/
|
|
bool tryAcquire(LockerAndInvoker &tryingLockvoker, int nRequiredLocks)
|
|
{
|
|
// TODO: Implement acquisition logic
|
|
// - Acquire the spinlock
|
|
// - Check if lock is already owned
|
|
// - For single-lock requests, grant immediately if available
|
|
// - For multi-lock requests, check if in top X% of queue
|
|
// - Set isOwned flag if successful
|
|
// - Release the spinlock
|
|
// - Return success/failure
|
|
(void)tryingLockvoker; // Suppress unused parameter warning
|
|
(void)nRequiredLocks; // Suppress unused parameter warning
|
|
return false; // Placeholder return value
|
|
}
|
|
|
|
/**
|
|
* @brief Handle backoff when a lockvoker fails to acquire all required locks
|
|
* @param failedAcquirer The lockvoker that failed to acquire all locks
|
|
*/
|
|
void backoff(LockerAndInvoker &failedAcquirer)
|
|
{
|
|
// TODO: Implement backoff logic
|
|
// - Acquire the spinlock
|
|
// - If failedAcquirer is at front, rotate queue items
|
|
// - Move failedAcquirer to appropriate position in queue
|
|
// - Release the spinlock
|
|
// - Wake up the new front item
|
|
(void)failedAcquirer; // Suppress unused parameter warning
|
|
}
|
|
|
|
/**
|
|
* @brief Release the lock and wake up the next waiting lockvoker
|
|
* @param prevOwner The lockvoker that previously owned the lock
|
|
*/
|
|
void release(LockerAndInvoker &prevOwner)
|
|
{
|
|
// TODO: Implement release logic
|
|
// - Acquire the spinlock
|
|
// - Unregister the previous owner from the queue
|
|
// - Clear the isOwned flag
|
|
// - Get the new front item
|
|
// - Release the spinlock
|
|
// - Wake up the new front item (conditionally)
|
|
(void)prevOwner; // Suppress unused parameter warning
|
|
}
|
|
|
|
/**
|
|
* @brief Wake up a specific lockvoker
|
|
* @param lockvoker The lockvoker to wake up
|
|
*/
|
|
void wakeUp(LockerAndInvoker &lockvoker)
|
|
{
|
|
// TODO: Implement wake-up logic
|
|
// - Post the lockvoker's invocation to its io_service
|
|
// - This will cause the lockvoker to retry acquisition
|
|
(void)lockvoker; // Suppress unused parameter warning
|
|
}
|
|
|
|
public:
|
|
SpinLock lock;
|
|
std::atomic<bool> isOwned;
|
|
LockerAndInvokerList queue;
|
|
};
|
|
|
|
} // namespace smo
|
|
|
|
#endif // QUTEX_H
|