/edk2/AppPkg/Applications/Python/Python-2.7.2/Python/thread_pthread.h

/* Posix threads interface */



#include <stdlib.h>

#include <string.h>

#if defined(__APPLE__) || defined(HAVE_PTHREAD_DESTRUCTOR)

#define destructor xxdestructor

#endif

#include <pthread.h>

#if defined(__APPLE__) || defined(HAVE_PTHREAD_DESTRUCTOR)

#undef destructor

#endif

#include <signal.h>



/* The POSIX spec requires that use of pthread_attr_setstacksize

   be conditional on _POSIX_THREAD_ATTR_STACKSIZE being defined. */

#ifdef _POSIX_THREAD_ATTR_STACKSIZE

#ifndef THREAD_STACK_SIZE

#define THREAD_STACK_SIZE       0       /* use default stack size */

#endif



#if (defined(__APPLE__) || defined(__FreeBSD__)) && defined(THREAD_STACK_SIZE) && THREAD_STACK_SIZE == 0

   /* The default stack size for new threads on OSX is small enough that

    * we'll get hard crashes instead of 'maximum recursion depth exceeded'

    * exceptions.

    *

    * The default stack size below is the minimal stack size where a

    * simple recursive function doesn't cause a hard crash.

    */

#undef  THREAD_STACK_SIZE

#define THREAD_STACK_SIZE       0x400000

#endif

/* for safety, ensure a viable minimum stacksize */

#define THREAD_STACK_MIN        0x8000  /* 32kB */

#else  /* !_POSIX_THREAD_ATTR_STACKSIZE */

#ifdef THREAD_STACK_SIZE

#error "THREAD_STACK_SIZE defined but _POSIX_THREAD_ATTR_STACKSIZE undefined"

#endif

#endif



/* The POSIX spec says that implementations supporting the sem_*

   family of functions must indicate this by defining

   _POSIX_SEMAPHORES. */

#ifdef _POSIX_SEMAPHORES

/* On FreeBSD 4.x, _POSIX_SEMAPHORES is defined empty, so

   we need to add 0 to make it work there as well. */

#if (_POSIX_SEMAPHORES+0) == -1

#define HAVE_BROKEN_POSIX_SEMAPHORES

#else

#include <semaphore.h>

#include <errno.h>

#endif

#endif



/* Before FreeBSD 5.4, system scope threads was very limited resource

   in default setting.  So the process scope is preferred to get

   enough number of threads to work. */

#ifdef __FreeBSD__

#include <osreldate.h>

#if __FreeBSD_version >= 500000 && __FreeBSD_version < 504101

#undef PTHREAD_SYSTEM_SCHED_SUPPORTED

#endif

#endif



#if !defined(pthread_attr_default)

#  define pthread_attr_default ((pthread_attr_t *)NULL)

#endif

#if !defined(pthread_mutexattr_default)

#  define pthread_mutexattr_default ((pthread_mutexattr_t *)NULL)

#endif

#if !defined(pthread_condattr_default)

#  define pthread_condattr_default ((pthread_condattr_t *)NULL)

#endif





/* Whether or not to use semaphores directly rather than emulating them with

 * mutexes and condition variables:

 */

#if defined(_POSIX_SEMAPHORES) && !defined(HAVE_BROKEN_POSIX_SEMAPHORES)

#  define USE_SEMAPHORES

#else

#  undef USE_SEMAPHORES

#endif





/* On platforms that don't use standard POSIX threads pthread_sigmask()

 * isn't present.  DEC threads uses sigprocmask() instead as do most

 * other UNIX International compliant systems that don't have the full

 * pthread implementation.

 */

#if defined(HAVE_PTHREAD_SIGMASK) && !defined(HAVE_BROKEN_PTHREAD_SIGMASK)

#  define SET_THREAD_SIGMASK pthread_sigmask

#else

#  define SET_THREAD_SIGMASK sigprocmask

#endif





/* A pthread mutex isn't sufficient to model the Python lock type

 * because, according to Draft 5 of the docs (P1003.4a/D5), both of the

 * following are undefined:

 *  -> a thread tries to lock a mutex it already has locked

 *  -> a thread tries to unlock a mutex locked by a different thread

 * pthread mutexes are designed for serializing threads over short pieces

 * of code anyway, so wouldn't be an appropriate implementation of

 * Python's locks regardless.

 *

 * The pthread_lock struct implements a Python lock as a "locked?" bit

 * and a <condition, mutex> pair.  In general, if the bit can be acquired

 * instantly, it is, else the pair is used to block the thread until the

 * bit is cleared.     9 May 1994 tim@ksr.com

 */



typedef struct {

    char             locked; /* 0=unlocked, 1=locked */

    /* a <cond, mutex> pair to handle an acquire of a locked lock */

    pthread_cond_t   lock_released;

    pthread_mutex_t  mut;

} pthread_lock;



#define CHECK_STATUS(name)  if (status != 0) { perror(name); error = 1; }



/*

 * Initialization.

 */



#ifdef _HAVE_BSDI

static

void _noop(void)

{

}



static void

PyThread__init_thread(void)

{

    /* DO AN INIT BY STARTING THE THREAD */

    static int dummy = 0;

    pthread_t thread1;

    pthread_create(&thread1, NULL, (void *) _noop, &dummy);

    pthread_join(thread1, NULL);

}



#else /* !_HAVE_BSDI */



static void

PyThread__init_thread(void)

{

#if defined(_AIX) && defined(__GNUC__)

    pthread_init();

#endif

}



#endif /* !_HAVE_BSDI */



/*

 * Thread support.

 */





long

PyThread_start_new_thread(void (*func)(void *), void *arg)

{

    pthread_t th;

    int status;

#if defined(THREAD_STACK_SIZE) || defined(PTHREAD_SYSTEM_SCHED_SUPPORTED)

    pthread_attr_t attrs;

#endif

#if defined(THREAD_STACK_SIZE)

    size_t      tss;

#endif



    dprintf(("PyThread_start_new_thread called\n"));

    if (!initialized)

        PyThread_init_thread();



#if defined(THREAD_STACK_SIZE) || defined(PTHREAD_SYSTEM_SCHED_SUPPORTED)

    if (pthread_attr_init(&attrs) != 0)

        return -1;

#endif

#if defined(THREAD_STACK_SIZE)

    tss = (_pythread_stacksize != 0) ? _pythread_stacksize

                                     : THREAD_STACK_SIZE;

    if (tss != 0) {

        if (pthread_attr_setstacksize(&attrs, tss) != 0) {

            pthread_attr_destroy(&attrs);

            return -1;

        }

    }

#endif

#if defined(PTHREAD_SYSTEM_SCHED_SUPPORTED)

    pthread_attr_setscope(&attrs, PTHREAD_SCOPE_SYSTEM);

#endif



    status = pthread_create(&th,

#if defined(THREAD_STACK_SIZE) || defined(PTHREAD_SYSTEM_SCHED_SUPPORTED)

                             &attrs,

#else

                             (pthread_attr_t*)NULL,

#endif

                             (void* (*)(void *))func,

                             (void *)arg

                             );



#if defined(THREAD_STACK_SIZE) || defined(PTHREAD_SYSTEM_SCHED_SUPPORTED)

    pthread_attr_destroy(&attrs);

#endif

    if (status != 0)

        return -1;



    pthread_detach(th);



#if SIZEOF_PTHREAD_T <= SIZEOF_LONG

    return (long) th;

#else

    return (long) *(long *) &th;

#endif

}



/* XXX This implementation is considered (to quote Tim Peters) "inherently

   hosed" because:

     - It does not guarantee the promise that a non-zero integer is returned.

     - The cast to long is inherently unsafe.

     - It is not clear that the 'volatile' (for AIX?) and ugly casting in the

       latter return statement (for Alpha OSF/1) are any longer necessary.

*/

long

PyThread_get_thread_ident(void)

{

    volatile pthread_t threadid;

    if (!initialized)

        PyThread_init_thread();

    /* Jump through some hoops for Alpha OSF/1 */

    threadid = pthread_self();

#if SIZEOF_PTHREAD_T <= SIZEOF_LONG

    return (long) threadid;

#else

    return (long) *(long *) &threadid;

#endif

}



void

PyThread_exit_thread(void)

{

    dprintf(("PyThread_exit_thread called\n"));

    if (!initialized) {

        exit(0);

    }

}



#ifdef USE_SEMAPHORES



/*

 * Lock support.

 */



PyThread_type_lock

PyThread_allocate_lock(void)

{

    sem_t *lock;

    int status, error = 0;



    dprintf(("PyThread_allocate_lock called\n"));

    if (!initialized)

        PyThread_init_thread();



    lock = (sem_t *)malloc(sizeof(sem_t));



    if (lock) {

        status = sem_init(lock,0,1);

        CHECK_STATUS("sem_init");



        if (error) {

            free((void *)lock);

            lock = NULL;

        }

    }



    dprintf(("PyThread_allocate_lock() -> %p\n", lock));

    return (PyThread_type_lock)lock;

}



void

PyThread_free_lock(PyThread_type_lock lock)

{

    sem_t *thelock = (sem_t *)lock;

    int status, error = 0;



    dprintf(("PyThread_free_lock(%p) called\n", lock));



    if (!thelock)

        return;



    status = sem_destroy(thelock);

    CHECK_STATUS("sem_destroy");



    free((void *)thelock);

}



/*

 * As of February 2002, Cygwin thread implementations mistakenly report error

 * codes in the return value of the sem_ calls (like the pthread_ functions).

 * Correct implementations return -1 and put the code in errno. This supports

 * either.

 */

static int

fix_status(int status)

{

    return (status == -1) ? errno : status;

}



int

PyThread_acquire_lock(PyThread_type_lock lock, int waitflag)

{

    int success;

    sem_t *thelock = (sem_t *)lock;

    int status, error = 0;



    dprintf(("PyThread_acquire_lock(%p, %d) called\n", lock, waitflag));



    do {

        if (waitflag)

            status = fix_status(sem_wait(thelock));

        else

            status = fix_status(sem_trywait(thelock));

    } while (status == EINTR); /* Retry if interrupted by a signal */



    if (waitflag) {

        CHECK_STATUS("sem_wait");

    } else if (status != EAGAIN) {

        CHECK_STATUS("sem_trywait");

    }



    success = (status == 0) ? 1 : 0;



    dprintf(("PyThread_acquire_lock(%p, %d) -> %d\n", lock, waitflag, success));

    return success;

}



void

PyThread_release_lock(PyThread_type_lock lock)

{

    sem_t *thelock = (sem_t *)lock;

    int status, error = 0;



    dprintf(("PyThread_release_lock(%p) called\n", lock));



    status = sem_post(thelock);

    CHECK_STATUS("sem_post");

}



#else /* USE_SEMAPHORES */



/*

 * Lock support.

 */

PyThread_type_lock

PyThread_allocate_lock(void)

{

    pthread_lock *lock;

    int status, error = 0;



    dprintf(("PyThread_allocate_lock called\n"));

    if (!initialized)

        PyThread_init_thread();



    lock = (pthread_lock *) malloc(sizeof(pthread_lock));

    if (lock) {

        memset((void *)lock, '\0', sizeof(pthread_lock));

        lock->locked = 0;



        status = pthread_mutex_init(&lock->mut,

                                    pthread_mutexattr_default);

        CHECK_STATUS("pthread_mutex_init");



        status = pthread_cond_init(&lock->lock_released,

                                   pthread_condattr_default);

        CHECK_STATUS("pthread_cond_init");



        if (error) {

            free((void *)lock);

            lock = 0;

        }

    }



    dprintf(("PyThread_allocate_lock() -> %p\n", lock));

    return (PyThread_type_lock) lock;

}



void

PyThread_free_lock(PyThread_type_lock lock)

{

    pthread_lock *thelock = (pthread_lock *)lock;

    int status, error = 0;



    dprintf(("PyThread_free_lock(%p) called\n", lock));



    status = pthread_mutex_destroy( &thelock->mut );

    CHECK_STATUS("pthread_mutex_destroy");



    status = pthread_cond_destroy( &thelock->lock_released );

    CHECK_STATUS("pthread_cond_destroy");



    free((void *)thelock);

}



int

PyThread_acquire_lock(PyThread_type_lock lock, int waitflag)

{

    int success;

    pthread_lock *thelock = (pthread_lock *)lock;

    int status, error = 0;



    dprintf(("PyThread_acquire_lock(%p, %d) called\n", lock, waitflag));



    status = pthread_mutex_lock( &thelock->mut );

    CHECK_STATUS("pthread_mutex_lock[1]");

    success = thelock->locked == 0;



    if ( !success && waitflag ) {

        /* continue trying until we get the lock */



        /* mut must be locked by me -- part of the condition

         * protocol */

        while ( thelock->locked ) {

            status = pthread_cond_wait(&thelock->lock_released,

                                       &thelock->mut);

            CHECK_STATUS("pthread_cond_wait");

        }

        success = 1;

    }

    if (success) thelock->locked = 1;

    status = pthread_mutex_unlock( &thelock->mut );

    CHECK_STATUS("pthread_mutex_unlock[1]");



    if (error) success = 0;

    dprintf(("PyThread_acquire_lock(%p, %d) -> %d\n", lock, waitflag, success));

    return success;

}



void

PyThread_release_lock(PyThread_type_lock lock)

{

    pthread_lock *thelock = (pthread_lock *)lock;

    int status, error = 0;



    dprintf(("PyThread_release_lock(%p) called\n", lock));



    status = pthread_mutex_lock( &thelock->mut );

    CHECK_STATUS("pthread_mutex_lock[3]");



    thelock->locked = 0;



    status = pthread_mutex_unlock( &thelock->mut );

    CHECK_STATUS("pthread_mutex_unlock[3]");



    /* wake up someone (anyone, if any) waiting on the lock */

    status = pthread_cond_signal( &thelock->lock_released );

    CHECK_STATUS("pthread_cond_signal");

}



#endif /* USE_SEMAPHORES */



/* set the thread stack size.

 * Return 0 if size is valid, -1 if size is invalid,

 * -2 if setting stack size is not supported.

 */

static int

_pythread_pthread_set_stacksize(size_t size)

{

#if defined(THREAD_STACK_SIZE)

    pthread_attr_t attrs;

    size_t tss_min;

    int rc = 0;

#endif



    /* set to default */

    if (size == 0) {

        _pythread_stacksize = 0;

        return 0;

    }



#if defined(THREAD_STACK_SIZE)

#if defined(PTHREAD_STACK_MIN)

    tss_min = PTHREAD_STACK_MIN > THREAD_STACK_MIN ? PTHREAD_STACK_MIN

                                                   : THREAD_STACK_MIN;

#else

    tss_min = THREAD_STACK_MIN;

#endif

    if (size >= tss_min) {

        /* validate stack size by setting thread attribute */

        if (pthread_attr_init(&attrs) == 0) {

            rc = pthread_attr_setstacksize(&attrs, size);

            pthread_attr_destroy(&attrs);

            if (rc == 0) {

                _pythread_stacksize = size;

                return 0;

            }

        }

    }

    return -1;

#else

    return -2;

#endif

}



#define THREAD_SET_STACKSIZE(x) _pythread_pthread_set_stacksize(x)