/* Copyright (c) 2001, Stanford University
 * All rights reserved.
 *
 * See the file LICENSE.txt for information on redistributing this software.
 */
    
#include <stdio.h>
#include "cr_threads.h"
#include "cr_error.h"

/* perror() messages */
#define INIT_TSD_ERROR "InitTSD: failed to allocate key"
#define FREE_TSD_ERROR "FreeTSD: failed to destroy key"
#define SET_TSD_ERROR "InitTSD: thread failed to set thread specific data"
#define GET_TSD_ERROR "InitTSD: failed to get thread specific data"

/* Magic number to determine if a CRtsd has been initialized */
#define INIT_MAGIC 0xff8adc98


/* Initialize a CRtsd */
void crInitTSDF(CRtsd *tsd, void (*destructor)(void *))
{
#ifdef WINDOWS
    tsd->key = TlsAlloc();
    if (tsd->key == 0xffffffff) {
        crError("crInitTSD failed!");
    }
    (void) destructor;
#else
    if (pthread_key_create(&tsd->key, destructor) != 0) {
        perror(INIT_TSD_ERROR);
        crError("crInitTSD failed!");
    }
#endif
    tsd->initMagic = INIT_MAGIC;
}


void crInitTSD(CRtsd *tsd)
{
    crInitTSDF(tsd, NULL);
}


void crFreeTSD(CRtsd *tsd)
{
#ifdef WINDOWS
    /* Windows returns true on success, 0 on failure */
    if (TlsFree(tsd->key) == 0) {
        crError("crFreeTSD failed!");
    }
#else
    if (pthread_key_delete(tsd->key) != 0) {
        perror(FREE_TSD_ERROR);
        crError("crFreeTSD failed!");
    }
#endif
    tsd->initMagic = 0x0;
}


/* Set thread-specific data */
void crSetTSD(CRtsd *tsd, void *ptr)
{
    if (tsd->initMagic != (int) INIT_MAGIC) {
        /* initialize this CRtsd */
        crInitTSD(tsd);
    }
#ifdef WINDOWS
    if (TlsSetValue(tsd->key, ptr) == 0) {
        crError("crSetTSD failed!");
    }
#else
    if (pthread_setspecific(tsd->key, ptr) != 0) {
        crError("crSetTSD failed!");
    }
#endif
}


/* Get thread-specific data */
void *crGetTSD(CRtsd *tsd)
{
#ifdef WINDOWS
    void * value;
    DWORD  err;
    LPVOID lpMsgBuf;
#endif
    if (tsd->initMagic != (int) INIT_MAGIC) {
        crInitTSD(tsd);
    }
#ifdef WINDOWS
    value = TlsGetValue(tsd->key);
    if (!value) {
        err = GetLastError();
        if ( err != ERROR_SUCCESS ) {
            FormatMessage(
                FORMAT_MESSAGE_ALLOCATE_BUFFER | 
                FORMAT_MESSAGE_FROM_SYSTEM |
                FORMAT_MESSAGE_IGNORE_INSERTS,
                NULL,
                err,
                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                (LPTSTR) &lpMsgBuf,
                0, NULL );
            crError("crGetTSD failed with %d: %s", err, lpMsgBuf);
            LocalFree(lpMsgBuf);
        }
    }
    return value;
#else
    return pthread_getspecific(tsd->key);
#endif
}



/* Return ID of calling thread */
unsigned long crThreadID(void)
{
#ifdef WINDOWS
    return (unsigned long) GetCurrentThreadId();
#else
    return (unsigned long) pthread_self();
#endif
}



void crInitMutex(CRmutex *mutex)
{
#ifdef WINDOWS
    InitializeCriticalSection(mutex);
#else
    pthread_mutexattr_t mta;
    int rc;

    rc = pthread_mutexattr_init(&mta);
    CRASSERT(!rc);
    rc = pthread_mutexattr_settype(&mta, PTHREAD_MUTEX_RECURSIVE);
    CRASSERT(!rc);
    rc = pthread_mutex_init(mutex, &mta);
    CRASSERT(!rc);
    pthread_mutexattr_destroy(&mta);
#endif
}


void crFreeMutex(CRmutex *mutex)
{
#ifdef WINDOWS
    DeleteCriticalSection(mutex);
#else
    pthread_mutex_destroy(mutex);
#endif
}


void crLockMutex(CRmutex *mutex)
{
#ifdef WINDOWS
    EnterCriticalSection(mutex);
#else
    pthread_mutex_lock(mutex);
#endif
}


void crUnlockMutex(CRmutex *mutex)
{
#ifdef WINDOWS
    LeaveCriticalSection(mutex);
#else
    pthread_mutex_unlock(mutex);
#endif
}


void crInitCondition(CRcondition *cond)
{
#ifdef WINDOWS
    /* XXX fix me */
    (void) cond;
#else
    int err = pthread_cond_init(cond, NULL);
    if (err) {
        crError("crInitCondition failed");
    }
#endif
}


void crFreeCondition(CRcondition *cond)
{
#ifdef WINDOWS
    /* XXX fix me */
    (void) cond;
#else
    int err = pthread_cond_destroy(cond);
    if (err) {
        crError("crFreeCondition error (threads waiting on the condition?)");
    }
#endif
}

/**
 * We're basically just wrapping the pthread condition var interface.
 * See the man page for pthread_cond_wait to learn about the mutex parameter.
 */
void crWaitCondition(CRcondition *cond, CRmutex *mutex)
{
#ifdef WINDOWS
    /* XXX fix me */
    (void) cond;
    (void) mutex;
#else
    pthread_cond_wait(cond, mutex);
#endif
}


void crSignalCondition(CRcondition *cond)
{
#ifdef WINDOWS
    /* XXX fix me */
    (void) cond;
#else
    pthread_cond_signal(cond);
#endif
}


void crInitBarrier(CRbarrier *b, unsigned int count)
{
#ifdef WINDOWS
    unsigned int i;
    for (i = 0; i < count; i++)
        b->hEvents[i] = CreateEvent(NULL, FALSE, FALSE, NULL);
#else
    b->count = count;
    b->waiting = 0;
    pthread_cond_init( &(b->cond), NULL );
    pthread_mutex_init( &(b->mutex), NULL );
#endif
}


void crFreeBarrier(CRbarrier *b)
{
    /* XXX anything to do? */
}


void crWaitBarrier(CRbarrier *b)
{
#ifdef WINDOWS
    DWORD dwEvent
        = WaitForMultipleObjects( b->count, b->hEvents, FALSE, INFINITE );
#else
    pthread_mutex_lock( &(b->mutex) );
    b->waiting++;
    if (b->waiting < b->count) {
        pthread_cond_wait( &(b->cond), &(b->mutex) );
    }
    else {
        pthread_cond_broadcast( &(b->cond) );
        b->waiting = 0;
    }
    pthread_mutex_unlock( &(b->mutex) );
#endif
}


void crInitSemaphore(CRsemaphore *s, unsigned int count)
{
#ifdef WINDOWS
    crWarning("CRsemaphore functions not implemented on Windows");
#else
    sem_init(s, 0, count);
#endif
}


void crWaitSemaphore(CRsemaphore *s)
{
#ifdef WINDOWS
    /* to do */
#else
    sem_wait(s);
#endif
}


void crSignalSemaphore(CRsemaphore *s)
{
#ifdef WINDOWS
    /* to do */
#else
    sem_post(s);
#endif
}