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Diffstat (limited to 'libpthread/linuxthreads.old/oldsemaphore.c')
-rw-r--r--libpthread/linuxthreads.old/oldsemaphore.c241
1 files changed, 0 insertions, 241 deletions
diff --git a/libpthread/linuxthreads.old/oldsemaphore.c b/libpthread/linuxthreads.old/oldsemaphore.c
deleted file mode 100644
index 2a7b40acc..000000000
--- a/libpthread/linuxthreads.old/oldsemaphore.c
+++ /dev/null
@@ -1,241 +0,0 @@
-/*
- * This file contains the old semaphore code that we need to
- * preserve for glibc-2.0 backwards compatibility. Port to glibc 2.1
- * done by Cristian Gafton.
- */
-
-/* Linuxthreads - a simple clone()-based implementation of Posix */
-/* threads for Linux. */
-/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
-/* */
-/* This program is free software; you can redistribute it and/or */
-/* modify it under the terms of the GNU Library General Public License */
-/* as published by the Free Software Foundation; either version 2 */
-/* 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 Library General Public License for more details. */
-
-/* Semaphores a la POSIX 1003.1b */
-
-#include <errno.h>
-#include "pthread.h"
-#include "internals.h"
-#include "spinlock.h"
-#include "restart.h"
-#include "queue.h"
-
-typedef struct {
- long int sem_status;
- int sem_spinlock;
-} old_sem_t;
-
-/* Maximum value the semaphore can have. */
-#define SEM_VALUE_MAX ((int) ((~0u) >> 1))
-
-static __inline__ int sem_compare_and_swap(old_sem_t *sem, long oldval, long newval)
-{
- return compare_and_swap(&sem->sem_status, oldval, newval, &sem->sem_spinlock);
-}
-
-/* The state of a semaphore is represented by a long int encoding
- either the semaphore count if >= 0 and no thread is waiting on it,
- or the head of the list of threads waiting for the semaphore.
- To distinguish the two cases, we encode the semaphore count N
- as 2N+1, so that it has the lowest bit set.
-
- A sequence of sem_wait operations on a semaphore initialized to N
- result in the following successive states:
- 2N+1, 2N-1, ..., 3, 1, &first_waiting_thread, &second_waiting_thread, ...
-*/
-
-static void sem_restart_list(pthread_descr waiting);
-
-int __old_sem_init(old_sem_t *sem, int pshared, unsigned int value);
-int __old_sem_init(old_sem_t *sem, int pshared, unsigned int value)
-{
- if (value > SEM_VALUE_MAX) {
- errno = EINVAL;
- return -1;
- }
- if (pshared) {
- errno = ENOSYS;
- return -1;
- }
- sem->sem_spinlock = 0;
- sem->sem_status = ((long)value << 1) + 1;
- return 0;
-}
-
-/* Function called by pthread_cancel to remove the thread from
- waiting inside __old_sem_wait. Here we simply unconditionally
- indicate that the thread is to be woken, by returning 1. */
-
-static int old_sem_extricate_func(void *obj attribute_unused, pthread_descr th attribute_unused)
-{
- return 1;
-}
-
-int __old_sem_wait(old_sem_t * sem);
-int __old_sem_wait(old_sem_t * sem)
-{
- long oldstatus, newstatus;
- volatile pthread_descr self = thread_self();
- pthread_descr * th;
- pthread_extricate_if extr;
-
- /* Set up extrication interface */
- extr.pu_object = 0;
- extr.pu_extricate_func = old_sem_extricate_func;
-
- while (1) {
- /* Register extrication interface */
- __pthread_set_own_extricate_if(self, &extr);
- do {
- oldstatus = sem->sem_status;
- if ((oldstatus & 1) && (oldstatus != 1))
- newstatus = oldstatus - 2;
- else {
- newstatus = (long) self;
- self->p_nextwaiting = (pthread_descr) oldstatus;
- }
- }
- while (! sem_compare_and_swap(sem, oldstatus, newstatus));
- if (newstatus & 1) {
- /* We got the semaphore. */
- __pthread_set_own_extricate_if(self, 0);
- return 0;
- }
- /* Wait for sem_post or cancellation */
- suspend(self);
- __pthread_set_own_extricate_if(self, 0);
-
- /* This is a cancellation point */
- if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) {
- /* Remove ourselves from the waiting list if we're still on it */
- /* First check if we're at the head of the list. */
- do {
- oldstatus = sem->sem_status;
- if (oldstatus != (long) self) break;
- newstatus = (long) self->p_nextwaiting;
- }
- while (! sem_compare_and_swap(sem, oldstatus, newstatus));
- /* Now, check if we're somewhere in the list.
- There's a race condition with sem_post here, but it does not matter:
- the net result is that at the time pthread_exit is called,
- self is no longer reachable from sem->sem_status. */
- if (oldstatus != (long) self && (oldstatus & 1) == 0) {
- for (th = &(((pthread_descr) oldstatus)->p_nextwaiting);
- *th != NULL && *th != (pthread_descr) 1;
- th = &((*th)->p_nextwaiting)) {
- if (*th == self) {
- *th = self->p_nextwaiting;
- break;
- }
- }
- }
- __pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME);
- }
- }
-}
-
-int __old_sem_trywait(old_sem_t * sem);
-int __old_sem_trywait(old_sem_t * sem)
-{
- long oldstatus, newstatus;
-
- do {
- oldstatus = sem->sem_status;
- if ((oldstatus & 1) == 0 || (oldstatus == 1)) {
- errno = EAGAIN;
- return -1;
- }
- newstatus = oldstatus - 2;
- }
- while (! sem_compare_and_swap(sem, oldstatus, newstatus));
- return 0;
-}
-
-int __old_sem_post(old_sem_t * sem);
-int __old_sem_post(old_sem_t * sem)
-{
- long oldstatus, newstatus;
-
- do {
- oldstatus = sem->sem_status;
- if ((oldstatus & 1) == 0)
- newstatus = 3;
- else {
- if (oldstatus >= SEM_VALUE_MAX) {
- /* Overflow */
- errno = ERANGE;
- return -1;
- }
- newstatus = oldstatus + 2;
- }
- }
- while (! sem_compare_and_swap(sem, oldstatus, newstatus));
- if ((oldstatus & 1) == 0)
- sem_restart_list((pthread_descr) oldstatus);
- return 0;
-}
-
-int __old_sem_getvalue(old_sem_t * sem, int * sval);
-int __old_sem_getvalue(old_sem_t * sem, int * sval)
-{
- long status = sem->sem_status;
- if (status & 1)
- *sval = (int)((unsigned long) status >> 1);
- else
- *sval = 0;
- return 0;
-}
-
-int __old_sem_destroy(old_sem_t * sem);
-int __old_sem_destroy(old_sem_t * sem)
-{
- if ((sem->sem_status & 1) == 0) {
- errno = EBUSY;
- return -1;
- }
- return 0;
-}
-
-/* Auxiliary function for restarting all threads on a waiting list,
- in priority order. */
-
-static void sem_restart_list(pthread_descr waiting)
-{
- pthread_descr th, towake, *p;
-
- /* Sort list of waiting threads by decreasing priority (insertion sort) */
- towake = NULL;
- while (waiting != (pthread_descr) 1) {
- th = waiting;
- waiting = waiting->p_nextwaiting;
- p = &towake;
- while (*p != NULL && th->p_priority < (*p)->p_priority)
- p = &((*p)->p_nextwaiting);
- th->p_nextwaiting = *p;
- *p = th;
- }
- /* Wake up threads in priority order */
- while (towake != NULL) {
- th = towake;
- towake = towake->p_nextwaiting;
- th->p_nextwaiting = NULL;
- restart(th);
- }
-}
-
-#if defined __PIC__ && defined DO_VERSIONING
-symbol_version (__old_sem_init, sem_init, GLIBC_2.0);
-symbol_version (__old_sem_wait, sem_wait, GLIBC_2.0);
-symbol_version (__old_sem_trywait, sem_trywait, GLIBC_2.0);
-symbol_version (__old_sem_post, sem_post, GLIBC_2.0);
-symbol_version (__old_sem_getvalue, sem_getvalue, GLIBC_2.0);
-symbol_version (__old_sem_destroy, sem_destroy, GLIBC_2.0);
-#endif
-
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