/*==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/>.

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(~0)

hsThread::hsThread(UInt32 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 millis)
{
    UInt32 secs = millis / 1000;
    if (secs > 0)
    {
        millis %= 1000;
        ::sleep(secs);
    }
    usleep(millis*1000);
}