//C-  -*- C++ -*-

//C- -------------------------------------------------------------------

//C- DjVuLibre-3.5

//C- Copyright (c) 2002  Leon Bottou and Yann Le Cun.

//C- Copyright (c) 2001  AT&T

//C-

//C- This software is subject to, and may be distributed under, the

//C- GNU General Public License, either Version 2 of the license,

//C- or (at your option) any later version. The license should have

//C- accompanied the software or you may obtain a copy of the license

//C- from the Free Software Foundation at http://www.fsf.org .

//C-

//C- This program is distributed in the hope that it will be useful,

//C- but WITHOUT ANY WARRANTY; without even the implied warranty of

//C- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

//C- GNU General Public License for more details.

//C- 

//C- DjVuLibre-3.5 is derived from the DjVu(r) Reference Library from

//C- Lizardtech Software.  Lizardtech Software has authorized us to

//C- replace the original DjVu(r) Reference Library notice by the following

//C- text (see doc/lizard2002.djvu and doc/lizardtech2007.djvu):

//C-

//C-  ------------------------------------------------------------------

//C- | DjVu (r) Reference Library (v. 3.5)

//C- | Copyright (c) 1999-2001 LizardTech, Inc. All Rights Reserved.

//C- | The DjVu Reference Library is protected by U.S. Pat. No.

//C- | 6,058,214 and patents pending.

//C- |

//C- | This software is subject to, and may be distributed under, the

//C- | GNU General Public License, either Version 2 of the license,

//C- | or (at your option) any later version. The license should have

//C- | accompanied the software or you may obtain a copy of the license

//C- | from the Free Software Foundation at http://www.fsf.org .

//C- |

//C- | The computer code originally released by LizardTech under this

//C- | license and unmodified by other parties is deemed "the LIZARDTECH

//C- | ORIGINAL CODE."  Subject to any third party intellectual property

//C- | claims, LizardTech grants recipient a worldwide, royalty-free, 

//C- | non-exclusive license to make, use, sell, or otherwise dispose of 

//C- | the LIZARDTECH ORIGINAL CODE or of programs derived from the 

//C- | LIZARDTECH ORIGINAL CODE in compliance with the terms of the GNU 

//C- | General Public License.   This grant only confers the right to 

//C- | infringe patent claims underlying the LIZARDTECH ORIGINAL CODE to 

//C- | the extent such infringement is reasonably necessary to enable 

//C- | recipient to make, have made, practice, sell, or otherwise dispose 

//C- | of the LIZARDTECH ORIGINAL CODE (or portions thereof) and not to 

//C- | any greater extent that may be necessary to utilize further 

//C- | modifications or combinations.

//C- |

//C- | The LIZARDTECH ORIGINAL CODE is provided "AS IS" WITHOUT WARRANTY

//C- | OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED

//C- | TO ANY WARRANTY OF NON-INFRINGEMENT, OR ANY IMPLIED WARRANTY OF

//C- | MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

//C- +------------------------------------------------------------------

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#if NEED_GNUG_PRAGMAS

# pragma implementation

#endif

// This file defines machine independent classes

// for running and synchronizing threads.

// - Author: Leon Bottou, 01/1998

// From: Leon Bottou, 1/31/2002

// Almost unchanged by Lizardtech.

// GSafeFlags should go because it not as safe as it claims.

#include "GThreads.h"

#include "GException.h"

#include "DjVuMessageLite.h"

#include <stddef.h>

#include <stdlib.h>

#include <stdio.h>

// ----------------------------------------

// Consistency check

#ifdef USE_EXCEPTION_EMULATION

# if defined(WINTHREADS) || defined(POSIXTHREADS)

#  warning "Compiler must support thread safe exceptions"

# endif

#endif

#ifndef _DEBUG

# if defined(DEBUG) 

#  define _DEBUG /* */

# elif DEBUGLVL >= 1

#  define _DEBUG /* */

# endif

#endif

#if WINTHREADS

# include <process.h>

#endif

#ifdef HAVE_NAMESPACES

namespace DJVU {

# ifdef NOT_DEFINED // Just to fool emacs c++ mode

}

#endif

#endif

// ----------------------------------------

// WIN32 IMPLEMENTATION

// ----------------------------------------

#if WINTHREADS

static unsigned __stdcall 

start(void *arg)

{

  GThread *gt = (GThread*)arg;

  try 

    {

      G_TRY

        {

          gt->xentry( gt->xarg );

        }

      G_CATCH(ex)

        {

          ex.perror();

          DjVuMessageLite::perror( ERR_MSG("GThreads.uncaught") );

          abort();

        }

      G_ENDCATCH;

    }

  catch(...)

    {

      DjVuMessageLite::perror( ERR_MSG("GThreads.unrecognized") );

      abort();

    }

  return 0;

}

GThread::GThread(int stacksize)

  : hthr(0), thrid(0), xentry(0), xarg(0)

{

}

GThread::~GThread()

{

  if (hthr)

    CloseHandle(hthr);

  hthr = 0;

  thrid = 0;

}

int  

GThread::create(void (*entry)(void*), void *arg)

{

  if (hthr)

    return -1;

  xentry = entry;

  xarg = arg;

  unsigned uthread = 0;

  hthr = (HANDLE)_beginthreadex(NULL, 0, start, (void*)this, 0, &uthread);

  thrid = (DWORD) uthread;

  if (hthr)

    return 0;

  return -1;

}

void 

GThread::terminate()

{

  OutputDebugString("Terminating thread.\n");

  if (hthr)

    TerminateThread(hthr,0);

}

int

GThread::yield()

{

  Sleep(0);

  return 0;

}

void *

GThread::current()

{

  return (void*) GetCurrentThreadId();

}

struct thr_waiting {

  struct thr_waiting *next;

  struct thr_waiting *prev;

  BOOL   waiting;

  HANDLE gwait;

};

GMonitor::GMonitor()

  : ok(0), count(1), head(0), tail(0)

{

  InitializeCriticalSection(&cs);

  locker = GetCurrentThreadId();

  ok = 1;

}

GMonitor::~GMonitor()

{

  ok = 0;

  EnterCriticalSection(&cs);

  for (struct thr_waiting *w=head; w; w=w->next)

    SetEvent(w->gwait);

  LeaveCriticalSection(&cs);

  DeleteCriticalSection(&cs); 

}

void 

GMonitor::enter()

{

  DWORD self = GetCurrentThreadId();

  if (count>0 || self!=locker)

    {

      if (ok)

        EnterCriticalSection(&cs);

      locker = self;

      count = 1;

    }

  count -= 1;

}

void 

GMonitor::leave()

{

  DWORD self = GetCurrentThreadId();

  if (ok && (count>0 || self!=locker))

    G_THROW( ERR_MSG("GThreads.not_acq_broad") );

  count += 1;

  if (count > 0)

    {

      count = 1;

      if (ok)

        LeaveCriticalSection(&cs);

    }

}

void

GMonitor::signal()

{

  if (ok)

    {

      DWORD self = GetCurrentThreadId();

      if (count>0 || self!=locker)

        G_THROW( ERR_MSG("GThreads.not_acq_signal") );

      for (struct thr_waiting *w=head; w; w=w->next)

        if (w->waiting) 

          {

            SetEvent(w->gwait);

            w->waiting = FALSE;

            break; // Only one thread is allowed to run!

          }

    }

}

void

GMonitor::broadcast()

{

  if (ok)

    {

      DWORD self = GetCurrentThreadId();

      if (count>0 || self!=locker)

        G_THROW( ERR_MSG("GThreads.not_acq_broad") );

      for (struct thr_waiting *w=head; w; w=w->next)

        if (w->waiting)

            {

              SetEvent(w->gwait);

              w->waiting = FALSE;

            }

    }

}

void

GMonitor::wait()

{

  // Check state

  DWORD self = GetCurrentThreadId();

  if (count>0 || self!=locker)

    G_THROW( ERR_MSG("GThreads.not_acq_wait") );

  // Wait

  if (ok)

    {

      // Prepare wait record

      struct thr_waiting waitrec;

      waitrec.waiting = TRUE;

      waitrec.gwait = CreateEvent(NULL,FALSE,FALSE,NULL);

      waitrec.next = 0;

      waitrec.prev = tail;

      // Link wait record (protected by critical section)

      *(waitrec.next ? &waitrec.next->prev : &tail) = &waitrec; 

      *(waitrec.prev ? &waitrec.prev->next : &head) = &waitrec;

      // Start wait

      int sav_count = count;

      count = 1;

      LeaveCriticalSection(&cs);

      WaitForSingleObject(waitrec.gwait,INFINITE);

      // Re-acquire

      EnterCriticalSection(&cs);

      count = sav_count;

      locker = self;

      // Unlink wait record

      *(waitrec.next ? &waitrec.next->prev : &tail) = waitrec.prev;

      *(waitrec.prev ? &waitrec.prev->next : &head) = waitrec.next;

      CloseHandle(waitrec.gwait);

    }

}

void

GMonitor::wait(unsigned long timeout) 

{

  // Check state

  DWORD self = GetCurrentThreadId();

  if (count>0 || self!=locker)

    G_THROW( ERR_MSG("GThreads.not_acq_wait") );

  // Wait

  if (ok)

    {

      // Prepare wait record

      struct thr_waiting waitrec;

      waitrec.waiting = TRUE;

      waitrec.gwait = CreateEvent(NULL,FALSE,FALSE,NULL);

      waitrec.next = 0;

      waitrec.prev = tail;

      // Link wait record (protected by critical section)

      *(waitrec.prev ? &waitrec.prev->next : &head) = &waitrec;

      *(waitrec.next ? &waitrec.next->prev : &tail) = &waitrec; 

      // Start wait

      int sav_count = count;

      count = 1;

      LeaveCriticalSection(&cs);

      WaitForSingleObject(waitrec.gwait,timeout);

      // Re-acquire

      EnterCriticalSection(&cs);

      count = sav_count;

      locker = self;

      // Unlink wait record

      *(waitrec.next ? &waitrec.next->prev : &tail) = waitrec.prev;

      *(waitrec.prev ? &waitrec.prev->next : &head) = waitrec.next;

      CloseHandle(waitrec.gwait);

    }

}

#endif

// ----------------------------------------

// POSIXTHREADS IMPLEMENTATION

// ----------------------------------------

#if POSIXTHREADS

#if defined(CMA_INCLUDE)

# define DCETHREADS 1

# define pthread_key_create pthread_keycreate

#else

# define pthread_mutexattr_default  NULL

# define pthread_condattr_default   NULL

#endif

static pthread_t pthread_null; // portable zero initialization!

void *

GThread::start(void *arg)

{

  GThread *gt = (GThread*)arg;

#if DCETHREADS

# ifdef CANCEL_ON

  pthread_setcancel(CANCEL_ON);

  pthread_setasynccancel(CANCEL_ON);

# endif

#else // !DCETHREADS

# ifdef PTHREAD_CANCEL_ENABLE

  pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, 0);

# endif

# ifdef PTHREAD_CANCEL_ASYNCHRONOUS

  pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, 0);

# endif

#endif

  // Catch exceptions

#ifdef __EXCEPTIONS

  try 

    {

#endif 

      G_TRY

        {

          (gt->xentry)(gt->xarg);

        }

      G_CATCH(ex)

        {

          ex.perror();

          DjVuMessageLite::perror( ERR_MSG("GThreads.uncaught") );

          abort();

        }

      G_ENDCATCH;

#ifdef __EXCEPTIONS

    }

  catch(...)

    {

      DjVuMessageLite::perror( ERR_MSG("GThreads.unrecognized") );

      abort();

    }

#endif

  return 0;

}

// GThread

GThread::GThread(int stacksize) : 

  hthr(pthread_null), xentry(0), xarg(0)

{

}

GThread::~GThread()

{

  hthr = pthread_null;

}

int  

GThread::create(void (*entry)(void*), void *arg)

{

  if (xentry || xarg)

    return -1;

  xentry = entry;

  xarg = arg;

#if DCETHREADS

  int ret = pthread_create(&hthr, pthread_attr_default, GThread::start, (void*)this);

  if (ret >= 0)

    pthread_detach(hthr);

#else

  pthread_attr_t attr;

  pthread_attr_init(&attr);

  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

  int ret = pthread_create(&hthr, &attr, start, (void*)this);

  pthread_attr_destroy(&attr);

#endif

  return ret;

}

void 

GThread::terminate()

{

  if (xentry || xarg)

    pthread_cancel(hthr);

}

int

GThread::yield()

{

#if DCETHREADS

  pthread_yield();

#else

  // should use sched_yield() when available.

  static struct timeval timeout = { 0, 0 };

  ::select(0, 0,0,0, &timeout);

#endif

  return 0;

}

void*

GThread::current()

{

  pthread_t self = pthread_self();

#if defined(pthread_getunique_np)

  return (void*) pthread_getunique_np( & self );

#elif defined(cma_thread_get_unique)

  return (void*) cma_thread_get_unique( & self );  

#else

  return (void*) self;

#endif

}

// -- GMonitor

GMonitor::GMonitor()

  : ok(0), count(1), locker(pthread_null)

{

  // none of this should be necessary ... in theory.

#ifdef PTHREAD_MUTEX_INITIALIZER

  static pthread_mutex_t tmutex=PTHREAD_MUTEX_INITIALIZER;

  memcpy(&mutex,&tmutex,sizeof(mutex));

#endif

#ifdef PTHREAD_COND_INITIALIZER

  static pthread_cond_t tcond=PTHREAD_COND_INITIALIZER;

  memcpy(&cond,&tcond,sizeof(cond));

#endif

  // standard

  pthread_mutex_init(&mutex, pthread_mutexattr_default);

  pthread_cond_init(&cond, pthread_condattr_default); 

  locker = pthread_self();

  ok = 1;

}

GMonitor::~GMonitor()

{

  ok = 0;

  pthread_cond_destroy(&cond;;

  pthread_mutex_destroy(&mutex); 

}

void 

GMonitor::enter()

{

  pthread_t self = pthread_self();

  if (count>0 || !pthread_equal(locker, self))

    {

      if (ok)

        pthread_mutex_lock(&mutex);

      locker = self;

      count = 1;

    }

  count -= 1;

}

void 

GMonitor::leave()

{

  pthread_t self = pthread_self();

  if (ok && (count>0 || !pthread_equal(locker, self)))

    G_THROW( ERR_MSG("GThreads.not_acq_broad") );

  count += 1;

  if (count > 0)

    {

      count = 1;

      locker = pthread_null;

      if (ok)

        pthread_mutex_unlock(&mutex);

    }

}

void

GMonitor::signal()

{

  if (ok)

    {

      pthread_t self = pthread_self();

      if (count>0 || !pthread_equal(locker, self))

        G_THROW( ERR_MSG("GThreads.not_acq_signal") );

      pthread_cond_signal(&cond;;

    }

}

void

GMonitor::broadcast()

{

  if (ok)

    {

      pthread_t self = pthread_self();

      if (count>0 || !pthread_equal(locker, self))

        G_THROW( ERR_MSG("GThreads.not_acq_broad") );

      pthread_cond_broadcast(&cond;;

    }

}

void

GMonitor::wait()

{

  // Check

  pthread_t self = pthread_self();

  if (count>0 || !pthread_equal(locker, self))

    G_THROW( ERR_MSG("GThreads.not_acq_wait") );

  // Wait

  if (ok)

    {

      // Release

      int sav_count = count;

      count = 1;

      // Wait

      pthread_cond_wait(&cond, &mutex);

      // Re-acquire

      count = sav_count;

      locker = self;

    }      

}

void

GMonitor::wait(unsigned long timeout) 

{

  // Check

  pthread_t self = pthread_self();

  if (count>0 || !pthread_equal(locker, self))

    G_THROW( ERR_MSG("GThreads.not_acq_wait") );

  // Wait

  if (ok)

    {

      // Release

      int sav_count = count;

      count = 1;

      // Wait

      struct timeval  abstv;

      struct timespec absts;

      gettimeofday(&abstv, NULL); // grrr

      absts.tv_sec = abstv.tv_sec + timeout/1000;

      absts.tv_nsec = abstv.tv_usec*1000  + (timeout%1000)*1000000;

      if (absts.tv_nsec > 1000000000) {

        absts.tv_nsec -= 1000000000;

        absts.tv_sec += 1;

      }

      pthread_cond_timedwait(&cond, &mutex, &absts);

      // Re-acquire

      count = sav_count;

      locker = self;

    }      

}

#endif

// ----------------------------------------

// GSAFEFLAGS 

// ----------------------------------------

GSafeFlags &

GSafeFlags::operator=(long xflags)

{

   enter();

   if (flags!=xflags)

   {

      flags=xflags;

      broadcast();

   }

   leave();

   return *this;

}

GSafeFlags::operator long(void) const

{

   long f;

   ((GSafeFlags *) this)->enter();

   f=flags;

   ((GSafeFlags *) this)->leave();

   return f;

}

bool

GSafeFlags::test_and_modify(long set_mask, long clr_mask,

			    long set_mask1, long clr_mask1)

{

   enter();

   if ((flags & set_mask)==set_mask &&

       (~flags & clr_mask)==clr_mask)

   {

      long new_flags=flags;

      new_flags|=set_mask1;

      new_flags&=~clr_mask1;

      if (new_flags!=flags)

      {

	 flags=new_flags;

	 broadcast();

      }

      leave();

      return true;

   }

   leave();

   return false;

}

void

GSafeFlags::wait_and_modify(long set_mask, long clr_mask,

			    long set_mask1, long clr_mask1)

{

   enter();

   while((flags & set_mask)!=set_mask ||

	 (~flags & clr_mask)!=clr_mask) wait();

   long new_flags=flags;

   new_flags|=set_mask1;

   new_flags&=~clr_mask1;

   if (flags!=new_flags)

   {

      flags=new_flags;

      broadcast();

   }

   leave();

}

#ifdef HAVE_NAMESPACES

}

# ifndef NOT_USING_DJVU_NAMESPACE

using namespace DJVU;

# endif

#endif