mirror of https://github.com/python/cpython
357 lines
7.5 KiB
C
357 lines
7.5 KiB
C
#include <kernel/OS.h>
|
|
#include <support/SupportDefs.h>
|
|
#include <errno.h>
|
|
|
|
/* ----------------------------------------------------------------------
|
|
* Fast locking mechanism described by Benoit Schillings (benoit@be.com)
|
|
* in the Be Developer's Newsletter, Issue #26 (http://www.be.com/).
|
|
*/
|
|
typedef struct benaphore {
|
|
sem_id _sem;
|
|
int32 _atom;
|
|
} benaphore_t;
|
|
|
|
static status_t benaphore_create( const char *name, benaphore_t *ben );
|
|
static status_t benaphore_destroy( benaphore_t *ben );
|
|
static status_t benaphore_lock( benaphore_t *ben );
|
|
static status_t benaphore_timedlock( benaphore_t *ben, bigtime_t micros );
|
|
static status_t benaphore_unlock( benaphore_t *ben );
|
|
|
|
static status_t benaphore_create( const char *name, benaphore_t *ben )
|
|
{
|
|
if( ben != NULL ) {
|
|
ben->_atom = 0;
|
|
ben->_sem = create_sem( 0, name );
|
|
|
|
if( ben->_sem < B_NO_ERROR ) {
|
|
return B_BAD_SEM_ID;
|
|
}
|
|
} else {
|
|
return EFAULT;
|
|
}
|
|
|
|
return EOK;
|
|
}
|
|
|
|
static status_t benaphore_destroy( benaphore_t *ben )
|
|
{
|
|
if( ben->_sem >= B_NO_ERROR ) {
|
|
status_t retval = benaphore_timedlock( ben, 0 );
|
|
|
|
if( retval == EOK || retval == EWOULDBLOCK ) {
|
|
status_t del_retval = delete_sem( ben->_sem );
|
|
|
|
return del_retval;
|
|
}
|
|
}
|
|
|
|
return B_BAD_SEM_ID;
|
|
}
|
|
|
|
static status_t benaphore_lock( benaphore_t *ben )
|
|
{
|
|
int32 prev = atomic_add( &(ben->_atom), 1 );
|
|
|
|
if( prev > 0 ) {
|
|
return acquire_sem( ben->_sem );
|
|
}
|
|
|
|
return EOK;
|
|
}
|
|
|
|
static status_t benaphore_timedlock( benaphore_t *ben, bigtime_t micros )
|
|
{
|
|
int32 prev = atomic_add( &(ben->_atom), 1 );
|
|
|
|
if( prev > 0 ) {
|
|
status_t retval = acquire_sem_etc( ben->_sem, 1, B_TIMEOUT, micros );
|
|
|
|
switch( retval ) {
|
|
case B_WOULD_BLOCK: /* Fall through... */
|
|
case B_TIMED_OUT:
|
|
return EWOULDBLOCK;
|
|
break;
|
|
case B_OK:
|
|
return EOK;
|
|
break;
|
|
default:
|
|
return retval;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return EOK;
|
|
}
|
|
|
|
static status_t benaphore_unlock( benaphore_t *ben )
|
|
{
|
|
int32 prev = atomic_add( &(ben->_atom), -1 );
|
|
|
|
if( prev > 1 ) {
|
|
return release_sem( ben->_sem );
|
|
}
|
|
|
|
return EOK;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
* Initialization.
|
|
*/
|
|
static void PyThread__init_thread( void )
|
|
{
|
|
/* Do nothing. */
|
|
return;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
* Thread support.
|
|
*
|
|
* Only ANSI C, renamed functions here; you can't use K&R on BeOS,
|
|
* and there's no legacy thread module to support.
|
|
*/
|
|
|
|
static int32 thread_count = 0;
|
|
|
|
int PyThread_start_new_thread( void (*func)(void *), void *arg )
|
|
{
|
|
status_t success = 0;
|
|
thread_id tid;
|
|
char name[B_OS_NAME_LENGTH];
|
|
int32 this_thread;
|
|
|
|
dprintf(("PyThread_start_new_thread called\n"));
|
|
|
|
/* We are so very thread-safe... */
|
|
this_thread = atomic_add( &thread_count, 1 );
|
|
sprintf( name, "python thread (%d)", this_thread );
|
|
|
|
tid = spawn_thread( (thread_func)func, name,
|
|
B_NORMAL_PRIORITY, arg );
|
|
if( tid > B_NO_ERROR ) {
|
|
success = resume_thread( tid );
|
|
}
|
|
|
|
return ( success == B_NO_ERROR ? 1 : 0 );
|
|
}
|
|
|
|
long PyThread_get_thread_ident( void )
|
|
{
|
|
/* Presumed to return the current thread's ID... */
|
|
thread_id tid;
|
|
tid = find_thread( NULL );
|
|
|
|
return ( tid != B_NAME_NOT_FOUND ? tid : -1 );
|
|
}
|
|
|
|
static void do_PyThread_exit_thread( int no_cleanup )
|
|
{
|
|
int32 threads;
|
|
|
|
dprintf(("PyThread_exit_thread called\n"));
|
|
|
|
/* Thread-safe way to read a variable without a mutex: */
|
|
threads = atomic_add( &thread_count, 0 );
|
|
|
|
if( threads == 0 ) {
|
|
/* No threads around, so exit main(). */
|
|
if( no_cleanup ) {
|
|
_exit(0);
|
|
} else {
|
|
exit(0);
|
|
}
|
|
} else {
|
|
/* Oh, we're a thread, let's try to exit gracefully... */
|
|
exit_thread( B_NO_ERROR );
|
|
}
|
|
}
|
|
|
|
void PyThread_exit_thread( void )
|
|
{
|
|
do_PyThread_exit_thread(0);
|
|
}
|
|
|
|
void PyThread__exit_thread( void )
|
|
{
|
|
do_PyThread_exit_thread(1);
|
|
}
|
|
|
|
#ifndef NO_EXIT_PROG
|
|
static void do_PyThread_exit_prog( int status, int no_cleanup )
|
|
{
|
|
dprintf(("PyThread_exit_prog(%d) called\n", status));
|
|
|
|
/* No need to do anything, the threads get torn down if main() exits. */
|
|
|
|
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.
|
|
*/
|
|
|
|
static int32 lock_count = 0;
|
|
|
|
PyThread_type_lock PyThread_allocate_lock( void )
|
|
{
|
|
benaphore_t *lock;
|
|
status_t retval;
|
|
char name[B_OS_NAME_LENGTH];
|
|
int32 this_lock;
|
|
|
|
dprintf(("PyThread_allocate_lock called\n"));
|
|
|
|
lock = (benaphore_t *)malloc( sizeof( benaphore_t ) );
|
|
if( lock == NULL ) {
|
|
/* TODO: that's bad, raise MemoryError */
|
|
return (PyThread_type_lock)NULL;
|
|
}
|
|
|
|
this_lock = atomic_add( &lock_count, 1 );
|
|
sprintf( name, "python lock (%d)", this_lock );
|
|
|
|
retval = benaphore_create( name, lock );
|
|
if( retval != EOK ) {
|
|
/* TODO: that's bad, raise an exception */
|
|
return (PyThread_type_lock)NULL;
|
|
}
|
|
|
|
dprintf(("PyThread_allocate_lock() -> %p\n", lock));
|
|
return (PyThread_type_lock) lock;
|
|
}
|
|
|
|
void PyThread_free_lock( PyThread_type_lock lock )
|
|
{
|
|
status_t retval;
|
|
|
|
dprintf(("PyThread_free_lock(%p) called\n", lock));
|
|
|
|
retval = benaphore_destroy( (benaphore_t *)lock );
|
|
if( retval != EOK ) {
|
|
/* TODO: that's bad, raise an exception */
|
|
return;
|
|
}
|
|
}
|
|
|
|
int PyThread_acquire_lock( PyThread_type_lock lock, int waitflag )
|
|
{
|
|
int success;
|
|
status_t retval;
|
|
|
|
dprintf(("PyThread_acquire_lock(%p, %d) called\n", lock, waitflag));
|
|
|
|
if( waitflag ) {
|
|
retval = benaphore_lock( (benaphore_t *)lock );
|
|
} else {
|
|
retval = benaphore_timedlock( (benaphore_t *)lock, 0 );
|
|
}
|
|
|
|
if( retval == EOK ) {
|
|
success = 1;
|
|
} else {
|
|
success = 0;
|
|
|
|
/* TODO: that's bad, raise an exception */
|
|
}
|
|
|
|
dprintf(("PyThread_acquire_lock(%p, %d) -> %d\n", lock, waitflag, success));
|
|
return success;
|
|
}
|
|
|
|
void PyThread_release_lock( PyThread_type_lock lock )
|
|
{
|
|
status_t retval;
|
|
|
|
dprintf(("PyThread_release_lock(%p) called\n", lock));
|
|
|
|
retval = benaphore_unlock( (benaphore_t *)lock );
|
|
if( retval != EOK ) {
|
|
/* TODO: that's bad, raise an exception */
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
* Semaphore support.
|
|
*
|
|
* Guido says not to implement this because it's not used anywhere;
|
|
* I'll do it anyway, you never know when it might be handy, and it's
|
|
* easy...
|
|
*/
|
|
PyThread_type_sema PyThread_allocate_sema( int value )
|
|
{
|
|
sem_id sema;
|
|
|
|
dprintf(("PyThread_allocate_sema called\n"));
|
|
|
|
sema = create_sem( value, "python semaphore" );
|
|
if( sema < B_NO_ERROR ) {
|
|
/* TODO: that's bad, raise an exception */
|
|
return 0;
|
|
}
|
|
|
|
dprintf(("PyThread_allocate_sema() -> %p\n", sema));
|
|
return (PyThread_type_sema) sema;
|
|
}
|
|
|
|
void PyThread_free_sema( PyThread_type_sema sema )
|
|
{
|
|
status_t retval;
|
|
|
|
dprintf(("PyThread_free_sema(%p) called\n", sema));
|
|
|
|
retval = delete_sem( (sem_id)sema );
|
|
if( retval != B_NO_ERROR ) {
|
|
/* TODO: that's bad, raise an exception */
|
|
return;
|
|
}
|
|
}
|
|
|
|
int PyThread_down_sema( PyThread_type_sema sema, int waitflag )
|
|
{
|
|
status_t retval;
|
|
|
|
dprintf(("PyThread_down_sema(%p, %d) called\n", sema, waitflag));
|
|
|
|
if( waitflag ) {
|
|
retval = acquire_sem( (sem_id)sema );
|
|
} else {
|
|
retval = acquire_sem_etc( (sem_id)sema, 1, B_TIMEOUT, 0 );
|
|
}
|
|
|
|
if( retval != B_NO_ERROR ) {
|
|
/* TODO: that's bad, raise an exception */
|
|
return 0;
|
|
}
|
|
|
|
dprintf(("PyThread_down_sema(%p) return\n", sema));
|
|
return -1;
|
|
}
|
|
|
|
void PyThread_up_sema( PyThread_type_sema sema )
|
|
{
|
|
status_t retval;
|
|
|
|
dprintf(("PyThread_up_sema(%p)\n", sema));
|
|
|
|
retval = release_sem( (sem_id)sema );
|
|
if( retval != B_NO_ERROR ) {
|
|
/* TODO: that's bad, raise an exception */
|
|
return;
|
|
}
|
|
}
|