ZeroTierOne/windows/TapDriver/lock.h

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/*
* TAP-Windows -- A kernel driver to provide virtual tap
* device functionality on Windows.
*
* This code was inspired by the CIPE-Win32 driver by Damion K. Wilson.
*
* This source code is Copyright (C) 2002-2010 OpenVPN Technologies, Inc.,
* and is released under the GPL version 2 (see below).
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
typedef struct
{
volatile long count;
} MUTEX;
#define MUTEX_SLEEP_TIME 10000 // microseconds
#define INIT_MUTEX(m) { (m)->count = 0; }
#define ACQUIRE_MUTEX_BLOCKING(m) \
{ \
while (NdisInterlockedIncrement (&((m)->count)) != 1) \
{ \
NdisInterlockedDecrement(&((m)->count)); \
NdisMSleep(MUTEX_SLEEP_TIME); \
} \
}
#define RELEASE_MUTEX(m) \
{ \
NdisInterlockedDecrement(&((m)->count)); \
}
#define ACQUIRE_MUTEX_NONBLOCKING(m, result) \
{ \
if (NdisInterlockedIncrement (&((m)->count)) != 1) \
{ \
NdisInterlockedDecrement(&((m)->count)); \
result = FALSE; \
} \
else \
{ \
result = TRUE; \
} \
}
#define ACQUIRE_MUTEX_ADAPTIVE(m, result) \
{ \
result = TRUE; \
while (NdisInterlockedIncrement (&((m)->count)) != 1) \
{ \
NdisInterlockedDecrement(&((m)->count)); \
if (KeGetCurrentIrql () < DISPATCH_LEVEL) \
NdisMSleep(MUTEX_SLEEP_TIME); \
else \
{ \
result = FALSE; \
break; \
} \
} \
}