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