77 lines
1.1 KiB
C++
77 lines
1.1 KiB
C++
#include "stdafx.h"
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#include <assert.h>
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#include "SimpleLock.h"
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thread_local std::thread::id SimpleLock::_threadID = std::this_thread::get_id();
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SimpleLock::SimpleLock()
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{
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_lock.clear();
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_lockCount = 0;
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_holderThreadID = std::thread::id();
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}
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SimpleLock::~SimpleLock()
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{
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}
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LockHandler SimpleLock::AcquireSafe()
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{
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return LockHandler(this);
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}
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void SimpleLock::Acquire()
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{
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if (_lockCount == 0 || _holderThreadID != _threadID)
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{
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while (_lock.test_and_set());
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_holderThreadID = _threadID;
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_lockCount = 1;
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}
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else
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{
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//Same thread can acquire the same lock multiple times
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_lockCount++;
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}
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}
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bool SimpleLock::IsFree()
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{
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return _lockCount == 0;
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}
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void SimpleLock::WaitForRelease()
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{
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//Wait until we are able to grab a lock, and then release it again
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Acquire();
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Release();
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}
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void SimpleLock::Release()
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{
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if (_lockCount > 0 && _holderThreadID == _threadID)
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{
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_lockCount--;
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if (_lockCount == 0)
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{
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_holderThreadID = std::thread::id();
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_lock.clear();
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}
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}
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else
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{
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assert(false);
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}
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}
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LockHandler::LockHandler(SimpleLock* lock)
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{
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_lock = lock;
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_lock->Acquire();
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}
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LockHandler::~LockHandler()
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{
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_lock->Release();
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}
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