historical/toontown-classic.git/panda/include/mutexWin32Impl.h
2024-01-16 11:20:27 -06:00

103 lines
2.7 KiB
C++

/**
* PANDA 3D SOFTWARE
* Copyright (c) Carnegie Mellon University. All rights reserved.
*
* All use of this software is subject to the terms of the revised BSD
* license. You should have received a copy of this license along
* with this source code in a file named "LICENSE."
*
* @file mutexWin32Impl.h
* @author drose
* @date 2006-02-07
*/
#ifndef MUTEXWIN32IMPL_H
#define MUTEXWIN32IMPL_H
#include "dtoolbase.h"
#include "selectThreadImpl.h"
#ifdef WIN32_VC
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN 1
#endif
#include <windows.h>
/**
* Uses SRWLock on Vista and above to implement a mutex. Older versions of
* Windows fall back to a combination of a spinlock and an Event object.
*/
class EXPCL_DTOOL_DTOOLBASE MutexWin32Impl {
public:
constexpr MutexWin32Impl() = default;
MutexWin32Impl(const MutexWin32Impl &copy) = delete;
INLINE ~MutexWin32Impl();
MutexWin32Impl &operator = (const MutexWin32Impl &copy) = delete;
public:
INLINE void lock();
INLINE bool try_lock();
INLINE void unlock();
static void init_lock_funcs();
private:
#ifndef CPPPARSER
// Store function pointers; these point directly to the SRWLock Win32 API
// functions on Vista and above, or to our own implementation on Windows XP.
typedef void (__stdcall *LockFunc)(volatile PVOID *lock);
typedef BOOL (__stdcall *TryLockFunc)(volatile PVOID *lock);
typedef BOOL (__stdcall *CondWaitFunc)(volatile PVOID *cvar, volatile PVOID *lock, DWORD, ULONG);
struct LockFunctions {
LockFunc _lock;
TryLockFunc _try_lock;
LockFunc _unlock;
CondWaitFunc _cvar_wait;
LockFunc _cvar_notify_one;
LockFunc _cvar_notify_all;
};
static LockFunctions _funcs;
static void __stdcall lock_initially(volatile PVOID *lock);
static BOOL __stdcall try_lock_initially(volatile PVOID *lock);
static void __stdcall unlock_initially(volatile PVOID *lock);
#endif
private:
// In the SRWLock implementation, only the first field is used. On Windows
// XP, the first field contains a waiter count and lock bit, and the second
// field contains an Event handle if contention has occurred.
volatile PVOID _lock[2] = {nullptr, nullptr};
friend class ConditionVarWin32Impl;
};
/**
* Uses CRITICAL_SECTION to implement a recursive mutex.
*/
class EXPCL_DTOOL_DTOOLBASE ReMutexWin32Impl {
public:
ReMutexWin32Impl();
ReMutexWin32Impl(const ReMutexWin32Impl &copy) = delete;
INLINE ~ReMutexWin32Impl();
ReMutexWin32Impl &operator = (const ReMutexWin32Impl &copy) = delete;
public:
INLINE void lock();
INLINE bool try_lock();
INLINE void unlock();
private:
CRITICAL_SECTION _lock;
};
#include "mutexWin32Impl.I"
#endif // WIN32_VC
#endif