/*
 * Copyright 2008, Yahoo! Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <sys/types.h>
#include "ThreadingUtil.h"
#include "LibCSymTable.h"

#ifdef THREADED

// ****************************************************************************
// Mutex wrapper
struct Mutex::Impl{
    Impl(){
        LIBC_SYMBOLS.pthread_mutex_init(&mut_, 0);        
    }
    ~Impl(){
        LIBC_SYMBOLS.pthread_mutex_destroy(&mut_);        
    }
    pthread_mutex_t mut_;
};

Mutex::Mutex():impl_(new Impl) {}
Mutex::~Mutex() { delete impl_;}
void Mutex::acquire() {
    LIBC_SYMBOLS.pthread_mutex_lock(&impl_->mut_);
}
void Mutex::release() {
    LIBC_SYMBOLS.pthread_mutex_unlock(&impl_->mut_);
}

// ****************************************************************************
// Atomics
int32_t atomic_post_incr(volatile int32_t* operand, int32_t incr)
{
    int32_t result;
    __asm__ __volatile__(
         "lock xaddl %0,%1\n"
         : "=r"(result), "=m"(*operand)
         : "0"(incr)
         : "memory");
   return result;
}
int32_t atomic_fetch_store(volatile int32_t *ptr, int32_t value)
{
    int32_t result;
    __asm__ __volatile__("lock xchgl %0,%1\n"
                          : "=r"(result), "=m"(*ptr)
                          : "0"(value)
                          : "memory");
   return result; 
}
#else
int32_t atomic_post_incr(volatile int32_t* operand, int32_t incr){
    int32_t v=*operand;
    *operand+=incr;
    return v;
}
int32_t atomic_fetch_store(volatile int32_t *ptr, int32_t value)
{
    int32_t result=*ptr;
    *ptr=value;
    return result;
}
#endif // THREADED