/*
    Copyright (c) 2005-2019 Intel Corporation

    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 "tbb/recursive_mutex.h"
#include "itt_notify.h"

namespace tbb {

void recursive_mutex::scoped_lock::internal_acquire( recursive_mutex& m ) {
#if _WIN32||_WIN64
    switch( m.state ) {
      case INITIALIZED:
        // since we cannot look into the internal of the CriticalSection object
        // we won't know how many times the lock has been acquired, and thus
        // we won't know when we may safely set the state back to INITIALIZED
        // if we change the state to HELD as in mutex.cpp.  thus, we won't change
        // the state for recursive_mutex
        EnterCriticalSection( &m.impl );
        break;
      case DESTROYED:
        __TBB_ASSERT(false,"recursive_mutex::scoped_lock: mutex already destroyed");
        break;
      default:
        __TBB_ASSERT(false,"recursive_mutex::scoped_lock: illegal mutex state");
        break;
    }
#else
    int error_code = pthread_mutex_lock(&m.impl);
    if( error_code )
        tbb::internal::handle_perror(error_code,"recursive_mutex::scoped_lock: pthread_mutex_lock failed");
#endif /* _WIN32||_WIN64 */
    my_mutex = &m;
}

void recursive_mutex::scoped_lock::internal_release() {
    __TBB_ASSERT( my_mutex, "recursive_mutex::scoped_lock: not holding a mutex" );
#if _WIN32||_WIN64
    switch( my_mutex->state ) {
      case INITIALIZED:
        LeaveCriticalSection( &my_mutex->impl );
        break;
      case DESTROYED:
        __TBB_ASSERT(false,"recursive_mutex::scoped_lock: mutex already destroyed");
        break;
      default:
        __TBB_ASSERT(false,"recursive_mutex::scoped_lock: illegal mutex state");
        break;
    }
#else
     int error_code = pthread_mutex_unlock(&my_mutex->impl);
     __TBB_ASSERT_EX(!error_code, "recursive_mutex::scoped_lock: pthread_mutex_unlock failed");
#endif /* _WIN32||_WIN64 */
     my_mutex = NULL;
}

bool recursive_mutex::scoped_lock::internal_try_acquire( recursive_mutex& m ) {
#if _WIN32||_WIN64
    switch( m.state ) {
      case INITIALIZED:
        break;
      case DESTROYED:
        __TBB_ASSERT(false,"recursive_mutex::scoped_lock: mutex already destroyed");
        break;
      default:
        __TBB_ASSERT(false,"recursive_mutex::scoped_lock: illegal mutex state");
        break;
    }
#endif /* _WIN32||_WIN64 */
    bool result;
#if _WIN32||_WIN64
    result = TryEnterCriticalSection(&m.impl)!=0;
#else
    result = pthread_mutex_trylock(&m.impl)==0;
#endif /* _WIN32||_WIN64 */
    if( result )
        my_mutex = &m;
    return result;
}

void recursive_mutex::internal_construct() {
#if _WIN32||_WIN64
    InitializeCriticalSectionEx(&impl, 4000, 0);
    state = INITIALIZED;
#else
    pthread_mutexattr_t mtx_attr;
    int error_code = pthread_mutexattr_init( &mtx_attr );
    if( error_code )
        tbb::internal::handle_perror(error_code,"recursive_mutex: pthread_mutexattr_init failed");

    pthread_mutexattr_settype( &mtx_attr, PTHREAD_MUTEX_RECURSIVE );
    error_code = pthread_mutex_init( &impl, &mtx_attr );
    if( error_code )
        tbb::internal::handle_perror(error_code,"recursive_mutex: pthread_mutex_init failed");
    pthread_mutexattr_destroy( &mtx_attr );
#endif /* _WIN32||_WIN64*/
    ITT_SYNC_CREATE(&impl, _T("tbb::recursive_mutex"), _T(""));
}

void recursive_mutex::internal_destroy() {
#if _WIN32||_WIN64
    switch( state ) {
      case INITIALIZED:
        DeleteCriticalSection(&impl);
        break;
      case DESTROYED:
        __TBB_ASSERT(false,"recursive_mutex: already destroyed");
        break;
      default:
        __TBB_ASSERT(false,"recursive_mutex: illegal state for destruction");
        break;
    }
    state = DESTROYED;
#else
    int error_code = pthread_mutex_destroy(&impl);
    __TBB_ASSERT_EX(!error_code,"recursive_mutex: pthread_mutex_destroy failed");
#endif /* _WIN32||_WIN64 */
}

} // namespace tbb
