/* GNU pth threads interface   http://www.gnu.org/software/pth   2000-05-03 Andy Dustman <andy@dustman.net>    Adapted from Posix threads interface    12 May 1997 -- david arnold <davida@pobox.com> */ #include <stdlib.h>#include <string.h>#include <pth.h> /* A pth mutex isn't sufficient to model the Python lock type * because pth mutexes can be acquired multiple times by the * same thread. * * The pth_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. */ typedef struct {	char             locked; /* 0=unlocked, 1=locked */	/* a <cond, mutex> pair to handle an acquire of a locked lock */	pth_cond_t   lock_released;	pth_mutex_t  mut;} pth_lock; #define CHECK_STATUS(name)  if (status == -1) { printf("%d ", status); perror(name); error = 1; } pth_attr_t PyThread_attr; /* * Initialization. */ static void PyThread__init_thread(void){	pth_init();	PyThread_attr = pth_attr_new();	pth_attr_set(PyThread_attr, PTH_ATTR_STACK_SIZE, 1<<18);	pth_attr_set(PyThread_attr, PTH_ATTR_JOINABLE, FALSE);} /* * Thread support. */  long PyThread_start_new_thread(void (*func)(void *), void *arg){	pth_t th;	dprintf(("PyThread_start_new_thread called\n"));	if (!initialized)		PyThread_init_thread(); 	th = pth_spawn(PyThread_attr,				 (void* (*)(void *))func,				 (void *)arg				 ); 	return th;} long PyThread_get_thread_ident(void){	volatile pth_t threadid;	if (!initialized)		PyThread_init_thread();	/* Jump through some hoops for Alpha OSF/1 */	threadid = pth_self();	return (long) *(long *) &threadid;} static void do_PyThread_exit_thread(int no_cleanup){	dprintf(("PyThread_exit_thread called\n"));	if (!initialized) {		if (no_cleanup)			_exit(0);		else			exit(0);	}} void PyThread_exit_thread(void){	do_PyThread_exit_thread(0);} void PyThread__exit_thread(void){	do_PyThread_exit_thread(1);} #ifndef NO_EXIT_PROGstatic void do_PyThread_exit_prog(int status, int no_cleanup){	dprintf(("PyThread_exit_prog(%d) called\n", status));	if (!initialized)		if (no_cleanup)			_exit(status);		else			exit(status);} void PyThread_exit_prog(int status){	do_PyThread_exit_prog(status, 0);} void PyThread__exit_prog(int status){	do_PyThread_exit_prog(status, 1);}#endif /* NO_EXIT_PROG */ /* * Lock support. */PyThread_type_lock PyThread_allocate_lock(void){	pth_lock *lock;	int status, error = 0; 	dprintf(("PyThread_allocate_lock called\n"));	if (!initialized)		PyThread_init_thread(); 	lock = (pth_lock *) malloc(sizeof(pth_lock));        memset((void *)lock, '\0', sizeof(pth_lock));	if (lock) {		lock->locked = 0;		status = pth_mutex_init(&lock->mut);		CHECK_STATUS("pth_mutex_init");		status = pth_cond_init(&lock->lock_released);		CHECK_STATUS("pth_cond_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){	pth_lock *thelock = (pth_lock *)lock; 	dprintf(("PyThread_free_lock(%p) called\n", lock)); 	free((void *)thelock);} int PyThread_acquire_lock(PyThread_type_lock lock, int waitflag){	int success;	pth_lock *thelock = (pth_lock *)lock;	int status, error = 0; 	dprintf(("PyThread_acquire_lock(%p, %d) called\n", lock, waitflag)); 	status = pth_mutex_acquire(&thelock->mut, !waitflag, NULL);	CHECK_STATUS("pth_mutex_acquire[1]");	success = thelock->locked == 0;        if (success) thelock->locked = 1;        status = pth_mutex_release( &thelock->mut );        CHECK_STATUS("pth_mutex_release[1]");         if ( !success && waitflag ) {                /* continue trying until we get the lock */                 /* mut must be locked by me -- part of the condition                 * protocol */                status = pth_mutex_acquire( &thelock->mut, !waitflag, NULL );                CHECK_STATUS("pth_mutex_acquire[2]");                while ( thelock->locked ) {                        status = pth_cond_await(&thelock->lock_released,                                                &thelock->mut, NULL);                        CHECK_STATUS("pth_cond_await");                }                thelock->locked = 1;                status = pth_mutex_release( &thelock->mut );                CHECK_STATUS("pth_mutex_release[2]");                success = 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){        pth_lock *thelock = (pth_lock *)lock;        int status, error = 0;         dprintf(("PyThread_release_lock(%p) called\n", lock));         status = pth_mutex_acquire( &thelock->mut, 0, NULL );        CHECK_STATUS("pth_mutex_acquire[3]");         thelock->locked = 0;         status = pth_mutex_release( &thelock->mut );        CHECK_STATUS("pth_mutex_release[3]");         /* wake up someone (anyone, if any) waiting on the lock */        status = pth_cond_notify( &thelock->lock_released, 0 );        CHECK_STATUS("pth_cond_notify");}