MagickCore/thread-private.h

/*
  Copyright 1999-2012 ImageMagick Studio LLC, a non-profit organization
  dedicated to making software imaging solutions freely available.

  You may not use this file except in compliance with the License.
  obtain a copy of the License at

    http://www.imagemagick.org/script/license.php

  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.

  MagickCore private methods for internal threading.
*/
#ifndef _MAGICKCORE_THREAD_PRIVATE_H
#define _MAGICKCORE_THREAD_PRIVATE_H

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

#include <MagickCore/cache.h>
#include <MagickCore/resource_.h>
#include <MagickCore/thread_.h>

/*
  Single threaded unless workload justifies the threading overhead.
*/
#define WorkloadThreshold()  (16*GetMagickResourceLimit(ThreadResource))
#define dynamic_number_threads(image,columns,rows,expression) \
  if (((((columns) > WorkloadThreshold()) || \
      ((rows) > WorkloadThreshold()))) && ((MagickSizeType) \
      ((columns)*(rows)) > (WorkloadThreshold()*WorkloadThreshold())) && \
      (expression)) \
    num_threads(GetMagickResourceLimit(ThreadResource)/ \
      (GetImagePixelCacheType(image) == DiskCache ? 2 : 1))

#if (__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ > 10))
#define MagickCachePrefetch(address,mode,locality) \
  __builtin_prefetch(address,mode,locality)
#else
#define MagickCachePrefetch(address,mode,locality)
#endif

#if defined(MAGICKCORE_THREAD_SUPPORT)
  typedef pthread_mutex_t MagickMutexType;
#elif defined(MAGICKCORE_WINDOWS_SUPPORT)
  typedef CRITICAL_SECTION MagickMutexType;
#else
  typedef size_t MagickMutexType;
#endif

static inline MagickThreadType GetMagickThreadId(void)
{
#if defined(MAGICKCORE_THREAD_SUPPORT)
  return(pthread_self());
#elif defined(MAGICKCORE_WINDOWS_SUPPORT)
  return(GetCurrentThreadId());
#else
  return(getpid());
#endif
}

static inline size_t GetMagickThreadSignature(void)
{
#if defined(MAGICKCORE_THREAD_SUPPORT)
  {
    union
    {
      pthread_t
        id;

      size_t
        signature;
    } magick_thread;

    magick_thread.signature=0UL;
    magick_thread.id=pthread_self();
    return(magick_thread.signature);
  }
#elif defined(MAGICKCORE_WINDOWS_SUPPORT)
  return((size_t) GetCurrentThreadId());
#else
  return((size_t) getpid());
#endif
}

static inline MagickBooleanType IsMagickThreadEqual(const MagickThreadType id)
{
#if defined(MAGICKCORE_THREAD_SUPPORT)
  if (pthread_equal(id,pthread_self()) != 0)
    return(MagickTrue);
#elif defined(MAGICKCORE_WINDOWS_SUPPORT)
  if (id == GetCurrentThreadId())
    return(MagickTrue);
#else
  if (id == getpid())
    return(MagickTrue);
#endif
  return(MagickFalse);
}

/*
  Lightweight OpenMP methods.
*/
static inline size_t GetOpenMPMaximumThreads(void)
{
#if defined(MAGICKCORE_OPENMP_SUPPORT)
  return(omp_get_max_threads());
#else
  return(1);
#endif
}

static inline int GetOpenMPThreadId(void)
{
#if defined(MAGICKCORE_OPENMP_SUPPORT)
  return(omp_get_thread_num());
#else
  return(0);
#endif
}

static inline void SetOpenMPMaximumThreads(const int threads)
{
#if defined(MAGICKCORE_OPENMP_SUPPORT)
  omp_set_num_threads(threads);
#else
  (void) threads;
#endif
}

static inline void SetOpenMPNested(const int value)
{
#if defined(MAGICKCORE_OPENMP_SUPPORT)
  omp_set_nested(value);
#else
  (void) value;
#endif
}

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

#endif