/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Additional permissions under GNU GPL version 3 section 7

If you modify this Program, or any covered work, by linking or
combining it with any of RAD Game Tools Bink SDK, Autodesk 3ds Max SDK,
NVIDIA PhysX SDK, Microsoft DirectX SDK, OpenSSL library, Independent
JPEG Group JPEG library, Microsoft Windows Media SDK, or Apple QuickTime SDK
(or a modified version of those libraries),
containing parts covered by the terms of the Bink SDK EULA, 3ds Max EULA,
PhysX SDK EULA, DirectX SDK EULA, OpenSSL and SSLeay licenses, IJG
JPEG Library README, Windows Media SDK EULA, or QuickTime SDK EULA, the
licensors of this Program grant you additional
permission to convey the resulting work. Corresponding Source for a
non-source form of such a combination shall include the source code for
the parts of OpenSSL and IJG JPEG Library used as well as that of the covered
work.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
#include "hsThread.h"
#include "hsExceptions.h"
#include <sys/errno.h>
#include <string.h>

#define NO_POSIX_CLOCK 1

#if NO_POSIX_CLOCK
#include <sys/time.h>
#include <unistd.h>
#define CLOCK_REALTIME 0

//
// A linux hack b/c we're not quite POSIX
//
int clock_gettime(int clocktype, struct timespec* ts)
{
  struct timezone tz;
  struct timeval tv;

  int result = gettimeofday(&tv, &tz);
  ts->tv_sec = tv.tv_sec;
  ts->tv_nsec = tv.tv_usec * 1000 + 500;  // sice we're losing accuracy round up by 500 nanos

  return result;
}

#endif

extern "C" {
    static void* gEntryPoint(void* param)
    {
        pthread_mutex_lock(((hsThread*)param)->GetStartupMutex());
        void* ret = (void*)((hsThread*)param)->Run();
        pthread_mutex_unlock(((hsThread*)param)->GetStartupMutex());
        pthread_exit(ret);
        return ret;
    }
}

#define kInvalidStackSize   uint32_t(~0)

hsThread::hsThread(uint32_t stackSize) : fStackSize(stackSize), fQuit(false)
{
    fIsValid = false;
    pthread_mutex_init(&fMutex,nil);
}

hsThread::~hsThread()
{
    this->Stop();
}

void hsThread::Start()
{
    if (fIsValid == false)
    {
        pthread_mutex_lock(GetStartupMutex());

        int status = ::pthread_create(&fPThread, nil, gEntryPoint, this);
        pthread_mutex_unlock(GetStartupMutex());

        hsThrowIfOSErr(status);

        fIsValid = true;
    }
    else
        hsDebugMessage("Calling hsThread::Start() more than once", 0);
}

void hsThread::Stop()
{
    if (fIsValid)
    {   this->fQuit = true;

        int status = ::pthread_join(fPThread, nil);
        hsThrowIfOSErr(status);

        fIsValid = false;
    }
}

//////////////////////////////////////////////////////////////////////////////

void* hsThread::Alloc(size_t size)
{
    return ::malloc(size);
}

void hsThread::Free(void* p)
{
    if (p)
        ::free(p);
}

void hsThread::ThreadYield()
{
//  ::sched_yield();
}

//////////////////////////////////////////////////////////////////////////////

//#define MUTEX_TIMING
#ifdef MUTEX_TIMING

#include <time.h>
#include <stdio.h>
#include <unistd.h>
#include "hsWide.h"


static FILE * gMutexTimerFile = nil;
static void InitMutexTimerFile()
{
    if ( !gMutexTimerFile )
    {
        gMutexTimerFile = fopen( "log/MutexTimes.log", "wt" );
        if ( gMutexTimerFile )
            fprintf( gMutexTimerFile, "------------------------------------\n" );
    }
}

#endif

//#define EVENT_LOGGING
#ifdef EVENT_LOGGING

#include <time.h>
#include <stdio.h>
#include <unistd.h>
#include "NucleusLib/inc/hsTimer.h"


static FILE * gEventLoggingFile = nil;
static void InitEventLoggingFile()
{
    if ( !gEventLoggingFile )
    {
        char fname[256];
        sprintf(fname,"log/Events-%u.log",getpid());
        gEventLoggingFile = fopen( fname, "wt" );
        if ( gEventLoggingFile )
            fprintf( gEventLoggingFile, "------------------------------------\n" );
    }
}

#endif

hsMutex::hsMutex()
{

#ifdef MUTEX_TIMING
    InitMutexTimerFile();
#endif

    // create mutex attributes
    pthread_mutexattr_t attr;
    int status = ::pthread_mutexattr_init(&attr);
    hsThrowIfOSErr(status);

    // make the mutex attributes recursive
    status = ::pthread_mutexattr_settype(&attr,PTHREAD_MUTEX_RECURSIVE);
    hsThrowIfOSErr(status);

    //init the mutex
    status = ::pthread_mutex_init(&fPMutex, &attr);
    hsThrowIfOSErr(status);

    // destroy the attributes
    status = ::pthread_mutexattr_destroy(&attr);
    hsThrowIfOSErr(status);
}

hsMutex::~hsMutex()
{
    int status = ::pthread_mutex_destroy(&fPMutex);
    hsThrowIfOSErr(status);
}

void hsMutex::Lock()
{
#ifdef MUTEX_TIMING
# ifndef HS_DEBUGGING
    timeval tv;
    hsWide start;
    gettimeofday( &tv, nil );
    start.Mul( tv.tv_sec, 1000000 )->Add( tv.tv_usec );
# endif
#endif

    int status = ::pthread_mutex_lock(&fPMutex);
    hsThrowIfOSErr(status);

#ifdef MUTEX_TIMING
# ifndef HS_DEBUGGING
    hsWide diff;
    gettimeofday( &tv, nil );
    diff.Mul( tv.tv_sec, 1000000 )->Add( tv.tv_usec )->Sub( &start )->Div( 1000000 );
    double duration = diff.AsDouble();
    if ( gMutexTimerFile && duration>0.005 )
    {
        time_t t;
        time( &t );
        struct tm *now = localtime( &t );
        char tmp[30];
        strftime( tmp, 30, "%c", now );
        fprintf( gMutexTimerFile, "[%s] [%lu:%lu] %f\n", tmp, getpid(), hsThread::GetMyThreadId(), duration );
    }
# endif
#endif
}

hsBool hsMutex::TryLock()
{
    int status = ::pthread_mutex_trylock(&fPMutex);
    hsThrowIfOSErr(status);
    return status==EBUSY?false:true;
}

void hsMutex::Unlock()
{
    int status = ::pthread_mutex_unlock(&fPMutex);
    hsThrowIfOSErr(status);
}

/////////////////////////////////////////////////////////////////////////////

hsSemaphore::hsSemaphore(int initialValue)
{
#ifdef USE_SEMA
    int shared = 0; // 1 if sharing between processes
    int status = ::sem_init(&fPSema, shared, initialValue);
    hsThrowIfOSErr(status);
#else
    int status = ::pthread_mutex_init(&fPMutex, nil);
    hsThrowIfOSErr(status);

    status = ::pthread_cond_init(&fPCond, nil);
    hsThrowIfOSErr(status);

    fCounter = initialValue;
#endif
}

hsSemaphore::~hsSemaphore()
{
#ifdef USE_SEMA
    int status = ::sem_destroy(&fPSema);
    hsThrowIfOSErr(status);
#else
    int status = ::pthread_cond_destroy(&fPCond);
    hsThrowIfOSErr(status);

    status = ::pthread_mutex_destroy(&fPMutex);
    hsThrowIfOSErr(status);
#endif
}

hsBool hsSemaphore::Wait(hsMilliseconds timeToWait)
{
#ifdef USE_SEMA  // SHOULDN'T THIS USE timeToWait??!?!? -rje
    hsAssert( timeToWait==kPosInfinity32, "sem_t does not support wait with timeout. #undef USE_SEMA and recompile." );
    int status = ::sem_wait(&fPSema);
    hsThrowIfOSErr(status);
    return true;
#else
    hsBool  retVal = true;
    int status = ::pthread_mutex_lock(&fPMutex);
    hsThrowIfOSErr(status);

    if (timeToWait == kPosInfinity32)
    {   while (fCounter == 0)
        {   status = ::pthread_cond_wait(&fPCond, &fPMutex);
            hsThrowIfOSErr(status);
        }
    }
    else
    {   timespec spec;
        int  result;

        result = ::clock_gettime(CLOCK_REALTIME, &spec);
        hsThrowIfFalse(result == 0);

        spec.tv_sec += timeToWait / 1000;
        spec.tv_nsec += (timeToWait % 1000) * 1000 * 1000;
        while (spec.tv_nsec >= 1000 * 1000 * 1000)
        {   spec.tv_sec += 1;
            spec.tv_nsec -= 1000 * 1000 * 1000;
        }

        while (fCounter == 0)
        {   status = ::pthread_cond_timedwait(&fPCond, &fPMutex, &spec);
            if (status == ETIMEDOUT)
            {   retVal = false;
                goto EXIT;
            }
            hsThrowIfOSErr(status);
        }
    }

    hsAssert(fCounter > 0, "oops");
    fCounter -= 1;
EXIT:
    status = ::pthread_mutex_unlock(&fPMutex);
    hsThrowIfOSErr(status);
    return retVal;
#endif
}

void hsSemaphore::Signal()
{
#ifdef USE_SEMA
    int status = ::sem_post(&fPSema);
    hsThrowIfOSErr(status);
#else
    int status = ::pthread_mutex_lock(&fPMutex);
    hsThrowIfOSErr(status);

    fCounter += 1;

    status = ::pthread_mutex_unlock(&fPMutex);
    hsThrowIfOSErr(status);

    status = ::pthread_cond_signal(&fPCond);
    hsThrowIfOSErr(status);
#endif
}


///////////////////////////////////////////////////////////////

#ifndef PSEUDO_EVENT

hsEvent::hsEvent() : fTriggered(false)
{
#ifdef EVENT_LOGGING
    InitEventLoggingFile();
#endif
    int status = ::pthread_mutex_init(&fMutex, nil);
    hsAssert(status == 0, "hsEvent Mutex Init");
    hsThrowIfOSErr(status);

    //  fCond = PTHREAD_COND_INITIALIZER;
    status = ::pthread_cond_init(&fCond, nil);
    hsAssert(status == 0, "hsEvent Cond Init");
    hsThrowIfOSErr(status);
}

hsEvent::~hsEvent()
{
    int status = ::pthread_cond_destroy(&fCond);
    hsAssert(status == 0, "hsEvent Cond De-Init");
    hsThrowIfOSErr(status);

    status = ::pthread_mutex_destroy(&fMutex);
    hsAssert(status == 0, "hsEvent Mutex De-Init");
    hsThrowIfOSErr(status);
}

hsBool hsEvent::Wait(hsMilliseconds timeToWait)
{
    hsBool  retVal = true;
    int status = ::pthread_mutex_lock(&fMutex);
    hsAssert(status == 0, "hsEvent Mutex Lock");
    hsThrowIfOSErr(status);

#ifdef EVENT_LOGGING
    fprintf(gEventLoggingFile,"Event: %p - In Wait (pre trig check), Triggered: %d, t=%f\n",this,fTriggered,hsTimer::GetSeconds());
#endif

    if ( !fTriggered )
    {
        if (timeToWait == kPosInfinity32)
        {
            status = ::pthread_cond_wait(&fCond, &fMutex);
            hsAssert(status == 0, "hsEvent Cond Wait");
            hsThrowIfOSErr(status);
        }
        else
        {   timespec spec;
            int  result;

            result = ::clock_gettime(CLOCK_REALTIME, &spec);
            hsThrowIfFalse(result == 0);

            spec.tv_sec += timeToWait / 1000;
            spec.tv_nsec += (timeToWait % 1000) * 1000 * 1000;
            while (spec.tv_nsec >= 1000 * 1000 * 1000)
            {   spec.tv_sec += 1;
                spec.tv_nsec -= 1000 * 1000 * 1000;
            }

            status = ::pthread_cond_timedwait(&fCond, &fMutex, &spec);

            if (status == ETIMEDOUT)
            {
                // It's a conditional paired with a variable!
                //   Pthread docs all use a variable in conjunction with the conditional
                retVal = fTriggered;
                status = 0;
#ifdef EVENT_LOGGING
                fprintf(gEventLoggingFile,"Event: %p - In Wait (wait timed out), Triggered: %d, t=%f\n",this,fTriggered,hsTimer::GetSeconds());
#endif
            }
            else
            {
#ifdef EVENT_LOGGING
                fprintf(gEventLoggingFile,"Event: %p - In Wait (wait recvd signal), Triggered: %d, t=%f\n",this,fTriggered,hsTimer::GetSeconds());
#endif
            }

            hsAssert(status == 0, "hsEvent Cond Wait");
            hsThrowIfOSErr(status);
        }
    }
    else
    {
#ifdef EVENT_LOGGING
        fprintf(gEventLoggingFile,"Event: %p - In Wait (post triggerd), Triggered: %d, t=%f\n",this,fTriggered,hsTimer::GetSeconds());
#endif
    }

    fTriggered = false;
    status = ::pthread_mutex_unlock(&fMutex);
    hsAssert(status == 0, "hsEvent Mutex Unlock");
    hsThrowIfOSErr(status);
    return retVal;
}

void hsEvent::Signal()
{
    int status = ::pthread_mutex_lock(&fMutex);
    hsAssert(status == 0, "hsEvent Mutex Lock");
    hsThrowIfOSErr(status);
#ifdef EVENT_LOGGING
    fprintf(gEventLoggingFile,"Event: %p - In Signal, Triggered: %d, t=%f\n",this,fTriggered,hsTimer::GetSeconds());
#endif
    fTriggered = true;
    status = ::pthread_cond_broadcast(&fCond);
    hsAssert(status == 0, "hsEvent Cond Broadcast");
    hsThrowIfOSErr(status);
    status = ::pthread_mutex_unlock(&fMutex);
    hsAssert(status == 0, "hsEvent Mutex Unlock");
    hsThrowIfOSErr(status);
}

#else

hsEvent::hsEvent()
{
    pipe( fFds );
}

hsEvent::~hsEvent()
{
    close( fFds[kRead] );
    close( fFds[kWrite] );
}

hsBool hsEvent::Wait( hsMilliseconds timeToWait )
{
    hsTempMutexLock lock( fWaitLock );

    fd_set  fdset;
    FD_ZERO( &fdset );
    FD_SET( fFds[kRead], &fdset );

    int ans;
    if( timeToWait==kPosInfinity32 )                
    {
        ans = select( fFds[kRead]+1, &fdset, nil, nil, nil );
    }
    else
    {
        struct timeval tv;
        tv.tv_sec = timeToWait / 1000;
        tv.tv_usec = ( timeToWait % 1000 ) * 1000;
        
        ans = select( fFds[kRead]+1, &fdset, nil, nil, &tv );
    }

    bool signaled = false;

    if ( ans>0 )
    {
        char buf[2];
        int n = read( fFds[kRead], buf, 1 );
        signaled = ( n==1 );
    }

    return signaled;
}

void hsEvent::Signal()
{
    hsTempMutexLock lock( fSignalLock );
    write( fFds[kWrite], "*", 1 );
}


#endif

void hsSleep::Sleep(uint32_t millis)
{
    uint32_t secs = millis / 1000;
    if (secs > 0)
    {
        millis %= 1000;
        ::sleep(secs);
    }
    usleep(millis*1000);
}
