SkSpinlock.h File Reference

#include "include/private/base/SkAPI.h"
#include "include/private/base/SkThreadAnnotations.h"
#include <atomic>

Go to the source code of this file.

Classes
class	SkAutoSpinlock

Functions
class	SK_CAPABILITY ("mutex") SkSpinlock

Function Documentation

SK_CAPABILITY()

class SK_CAPABILITY

(

"mutex"

)

Definition at line 1 of file SkSpinlock.h.

                                        {
public:
    constexpr SkSpinlock() = default;
 
    void acquire() SK_ACQUIRE() {
        // To act as a mutex, we need an acquire barrier when we acquire the lock.
        if (fLocked.exchange(true, std::memory_order_acquire)) {
            // Lock was contended.  Fall back to an out-of-line spin loop.
            this->contendedAcquire();
        }
    }
 
    // Acquire the lock or fail (quickly). Lets the caller decide to do something other than wait.
    bool tryAcquire() SK_TRY_ACQUIRE(true) {
        // To act as a mutex, we need an acquire barrier when we acquire the lock.
        if (fLocked.exchange(true, std::memory_order_acquire)) {
            // Lock was contended. Let the caller decide what to do.
            return false;
        }
        return true;
    }
 
    void release() SK_RELEASE_CAPABILITY() {
        // To act as a mutex, we need a release barrier when we release the lock.
        fLocked.store(false, std::memory_order_release);
    }
 
private:
    SK_API void contendedAcquire();
 
    std::atomic<bool> fLocked{false};
};