LeOS-Genesis/external/badvpn/misc/BRefTarget.h

115 lines
3.6 KiB
C

/**
* @file BRefTarget.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef BADVPN_B_REF_TARGET_H
#define BADVPN_B_REF_TARGET_H
#include <limits.h>
#include <misc/debug.h>
#include <base/DebugObject.h>
/**
* Represents a reference-counted object.
*/
typedef struct BRefTarget_s BRefTarget;
/**
* Callback function called after the reference count of a {@link BRefTarget}
* reaches has reached zero. At this point the BRefTarget object has already
* been invalidated, i.e. {@link BRefTarget_Ref} must not be called on this
* object after this handler is called.
*/
typedef void (*BRefTarget_func_release) (BRefTarget *o);
struct BRefTarget_s {
BRefTarget_func_release func_release;
int refcnt;
DebugObject d_obj;
};
/**
* Initializes a reference target object. The initial reference count of the object
* is 1. The \a func_release argument specifies the function to be called from
* {@link BRefTarget_Deref} when the reference count reaches zero.
*/
static void BRefTarget_Init (BRefTarget *o, BRefTarget_func_release func_release);
/**
* Decrements the reference count of a reference target object. If the reference
* count has reached zero, the object's {@link BRefTarget_func_release} function
* is called, and the object is considered destroyed.
*/
static void BRefTarget_Deref (BRefTarget *o);
/**
* Increments the reference count of a reference target object.
* Returns 1 on success and 0 on failure.
*/
static int BRefTarget_Ref (BRefTarget *o) WARN_UNUSED;
static void BRefTarget_Init (BRefTarget *o, BRefTarget_func_release func_release)
{
ASSERT(func_release)
o->func_release = func_release;
o->refcnt = 1;
DebugObject_Init(&o->d_obj);
}
static void BRefTarget_Deref (BRefTarget *o)
{
DebugObject_Access(&o->d_obj);
ASSERT(o->refcnt > 0)
o->refcnt--;
if (o->refcnt == 0) {
DebugObject_Free(&o->d_obj);
o->func_release(o);
}
}
static int BRefTarget_Ref (BRefTarget *o)
{
DebugObject_Access(&o->d_obj);
ASSERT(o->refcnt > 0)
if (o->refcnt == INT_MAX) {
return 0;
}
o->refcnt++;
return 1;
}
#endif