dep/src/zthread/linux/AtomicCount.cxx

   1 /*
   2  * Copyright (c) 2005, Eric Crahen
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is furnished
   9  * to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in all
  12  * copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  18  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  19  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  20  *
  21  */
  22
  23 #ifndef __ZTATOMICCOUNTIMPL_H__
  24 #define __ZTATOMICCOUNTIMPL_H__
  25
  26 #include <asm/atomic.h>
  27 #include <assert.h>
  28
  29 namespace ZThread {
  30
  31 typedef struct atomic_count_t {
  32
  33   atomic_t count;
  34
  35   atomic_count_t() {
  36     atomic_t init = ATOMIC_INIT(0);
  37     count = init;
  38   }
  39
  40   ~atomic_count_t() {
  41     assert(atomic_read(&count) == 0);
  42   }
  43
  44 } ATOMIC_COUNT;
  45
  46
  47 AtomicCount::AtomicCount() {
  48
  49   _value = reinterpret_cast<void*>(new ATOMIC_COUNT);
  50
  51 }
  52
  53 AtomicCount::~AtomicCount() {
  54
  55   delete reinterpret_cast<ATOMIC_COUNT*>(_value);
  56
  57 }
  58
  59 void AtomicCount::increment() {
  60
  61   atomic_inc(&reinterpret_cast<ATOMIC_COUNT*>(_value)->count);
  62
  63 }
  64
  65 bool AtomicCount::decrement() {
  66
  67   return atomic_dec_and_test(&reinterpret_cast<ATOMIC_COUNT*>(_value)->count);
  68
  69 }
  70
  71 };
  72
  73 #endif // __ZTATOMICCOUNTIMPL_H__