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- #pragma once
- #include "../C/Baselib_HighCapacitySemaphore.h"
- #include "Time.h"
- namespace baselib
- {
- BASELIB_CPP_INTERFACE
- {
- // baselib::HighCapacitySemaphore is similar to baselib::Semaphore but allows for far greater token count.
- // It is suitable to be used as resource counting semaphore.
- class HighCapacitySemaphore
- {
- public:
- // non-copyable
- HighCapacitySemaphore(const HighCapacitySemaphore& other) = delete;
- HighCapacitySemaphore& operator=(const HighCapacitySemaphore& other) = delete;
- // non-movable (strictly speaking not needed but listed to signal intent)
- HighCapacitySemaphore(HighCapacitySemaphore&& other) = delete;
- HighCapacitySemaphore& operator=(HighCapacitySemaphore&& other) = delete;
- // This is the max number of tokens guaranteed to be held by the semaphore at
- // any given point in time. Tokens submitted that exceed this value may silently
- // be discarded.
- enum : int64_t { MaxGuaranteedCount = Baselib_HighCapacitySemaphore_MaxGuaranteedCount };
- // Creates a counting semaphore synchronization primitive.
- // If there are not enough system resources to create a semaphore, process abort is triggered.
- HighCapacitySemaphore()
- {
- Baselib_HighCapacitySemaphore_CreateInplace(&m_SemaphoreData);
- }
- // Reclaim resources and memory held by the semaphore.
- //
- // If threads are waiting on the semaphore, destructor will trigger an assert and may cause process abort.
- ~HighCapacitySemaphore()
- {
- Baselib_HighCapacitySemaphore_FreeInplace(&m_SemaphoreData);
- }
- // Wait for semaphore token to become available
- //
- // This function is guaranteed to emit an acquire barrier.
- inline void Acquire()
- {
- return Baselib_HighCapacitySemaphore_Acquire(&m_SemaphoreData);
- }
- // Try to consume a token and return immediately.
- //
- // When successful this function is guaranteed to emit an acquire barrier.
- //
- // Return: true if token was consumed. false if not.
- inline bool TryAcquire()
- {
- return Baselib_HighCapacitySemaphore_TryAcquire(&m_SemaphoreData);
- }
- // Wait for semaphore token to become available
- //
- // When successful this function is guaranteed to emit an acquire barrier.
- //
- // TryAcquire with a zero timeout differs from TryAcquire() in that TryAcquire() is guaranteed to be a user space operation
- // while Acquire with a zero timeout may enter the kernel and cause a context switch.
- //
- // Timeout passed to this function may be subject to system clock resolution.
- // If the system clock has a resolution of e.g. 16ms that means this function may exit with a timeout error 16ms earlier than originally scheduled.
- //
- // Arguments:
- // - timeout: Time to wait for token to become available.
- //
- // Return: true if token was consumed. false if timeout was reached.
- inline bool TryTimedAcquire(const timeout_ms timeoutInMilliseconds)
- {
- return Baselib_HighCapacitySemaphore_TryTimedAcquire(&m_SemaphoreData, timeoutInMilliseconds.count());
- }
- // Submit tokens to the semaphore.
- //
- // When successful this function is guaranteed to emit a release barrier.
- //
- // Increase the number of available tokens on the semaphore by `count`. Any waiting threads will be notified there are new tokens available.
- // If count reach `Baselib_HighCapacitySemaphore_MaxGuaranteedCount` this function may silently discard any overflow.
- inline void Release(uint32_t count)
- {
- return Baselib_HighCapacitySemaphore_Release(&m_SemaphoreData, count);
- }
- // Sets the semaphore token count to zero and release all waiting threads.
- //
- // When successful this function is guaranteed to emit a release barrier.
- //
- // Return: number of released threads.
- inline uint64_t ResetAndReleaseWaitingThreads()
- {
- return Baselib_HighCapacitySemaphore_ResetAndReleaseWaitingThreads(&m_SemaphoreData);
- }
- private:
- Baselib_HighCapacitySemaphore m_SemaphoreData;
- };
- }
- }
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