/*
* Copyright (C) 2013 Martin Willi
* Copyright (C) 2013 revosec AG
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* 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.
*/
#include "thread.h"
#include <utils/debug.h>
#include <threading/rwlock.h>
#include <threading/rwlock_condvar.h>
#include <threading/thread_value.h>
typedef struct private_rwlock_t private_rwlock_t;
typedef struct private_rwlock_condvar_t private_rwlock_condvar_t;
/**
* private data of rwlock
*/
struct private_rwlock_t {
/**
* public functions
*/
rwlock_t public;
/**
* wrapped rwlock
*/
SRWLOCK srw;
/**
* Thread specific shared lock count
*/
thread_value_t *shared;
};
/**
* private data of condvar
*/
struct private_rwlock_condvar_t {
/**
* public interface
*/
rwlock_condvar_t public;
/**
* condition variable
*/
CONDITION_VARIABLE cv;
};
METHOD(rwlock_t, read_lock, void,
private_rwlock_t *this)
{
uintptr_t count;
/* Recursive read locks are not supported. Use a thread specific
* recursiveness counter. */
count = (uintptr_t)this->shared->get(this->shared);
if (count == 0)
{
AcquireSRWLockShared(&this->srw);
}
this->shared->set(this->shared, (void*)(count + 1));
}
METHOD(rwlock_t, write_lock, void,
private_rwlock_t *this)
{
AcquireSRWLockExclusive(&this->srw);
}
METHOD(rwlock_t, try_write_lock, bool,
private_rwlock_t *this)
{
return TryAcquireSRWLockExclusive(&this->srw);
}
METHOD(rwlock_t, unlock, void,
private_rwlock_t *this)
{
uintptr_t count;
count = (uintptr_t)this->shared->get(this->shared);
switch (count)
{
case 0:
ReleaseSRWLockExclusive(&this->srw);
break;
case 1:
ReleaseSRWLockShared(&this->srw);
/* fall */
default:
this->shared->set(this->shared, (void*)(count - 1));
break;
}
}
METHOD(rwlock_t, destroy, void,
private_rwlock_t *this)
{
this->shared->destroy(this->shared);
free(this);
}
/*
* see header file
*/
rwlock_t *rwlock_create(rwlock_type_t type)
{
private_rwlock_t *this;
INIT(this,
.public = {
.read_lock = _read_lock,
.write_lock = _write_lock,
.try_write_lock = _try_write_lock,
.unlock = _unlock,
.destroy = _destroy,
},
.shared = thread_value_create(NULL),
);
InitializeSRWLock(&this->srw);
return &this->public;
}
METHOD(rwlock_condvar_t, timed_wait, bool,
private_rwlock_condvar_t *this, rwlock_t *pubrwlock, u_int timeout)
{
private_rwlock_t *rwlock = (private_rwlock_t*)pubrwlock;
bool ret;
thread_set_active_condvar(&this->cv);
ret = SleepConditionVariableSRW(&this->cv, &rwlock->srw, timeout, 0);
thread_set_active_condvar(NULL);
return ret == 0;
}
METHOD(rwlock_condvar_t, wait_, void,
private_rwlock_condvar_t *this, rwlock_t *lock)
{
timed_wait(this, lock, INFINITE);
}
METHOD(rwlock_condvar_t, timed_wait_abs, bool,
private_rwlock_condvar_t *this, rwlock_t *lock, timeval_t tv)
{
DWORD timeout;
timeval_t now, diff;
time_monotonic(&now);
if (timercmp(&now, &tv, >))
{
return TRUE;
}
timersub(&tv, &now, &diff);
timeout = diff.tv_sec * 1000 + diff.tv_usec / 1000;
return timed_wait(this, lock, timeout);
}
METHOD(rwlock_condvar_t, signal_, void,
private_rwlock_condvar_t *this)
{
WakeConditionVariable(&this->cv);
}
METHOD(rwlock_condvar_t, broadcast, void,
private_rwlock_condvar_t *this)
{
WakeAllConditionVariable(&this->cv);
}
METHOD(rwlock_condvar_t, condvar_destroy, void,
private_rwlock_condvar_t *this)
{
free(this);
}
/*
* see header file
*/
rwlock_condvar_t *rwlock_condvar_create()
{
private_rwlock_condvar_t *this;
INIT(this,
.public = {
.wait = _wait_,
.timed_wait = _timed_wait,
.timed_wait_abs = _timed_wait_abs,
.signal = _signal_,
.broadcast = _broadcast,
.destroy = _condvar_destroy,
},
);
InitializeConditionVariable(&this->cv);
return &this->public;
}
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