summary refs log tree commit diff
path: root/linuxthreads/oldsemaphore.c
diff options
context:
space:
mode:
Diffstat (limited to 'linuxthreads/oldsemaphore.c')
-rw-r--r--linuxthreads/oldsemaphore.c241
1 files changed, 0 insertions, 241 deletions
diff --git a/linuxthreads/oldsemaphore.c b/linuxthreads/oldsemaphore.c
deleted file mode 100644
index d35683b98b..0000000000
--- a/linuxthreads/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 <shlib-compat.h>
-#if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
-
-#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;
-
-extern int __old_sem_init (old_sem_t *__sem, int __pshared, unsigned int __value);
-extern int __old_sem_wait (old_sem_t *__sem);
-extern int __old_sem_trywait (old_sem_t *__sem);
-extern int __old_sem_post (old_sem_t *__sem);
-extern int __old_sem_getvalue (old_sem_t *__sem, int *__sval);
-extern int __old_sem_destroy (old_sem_t *__sem);
-
-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)
-{
-    if (value > SEM_VALUE_MAX) {
-	errno = EINVAL;
-	return -1;
-    }
-    if (pshared) {
-	errno = ENOSYS;
-	return -1;
-    }
-  sem->sem_spinlock = __LT_SPINLOCK_INIT;
-  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, pthread_descr th)
-{
-    return 1;
-}
-
-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);
-	    self->p_nextwaiting = NULL;
-	    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)
-{
-  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)
-{
-  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)
-{
-  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)
-{
-  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);
-  }
-}
-
-compat_symbol (libpthread, __old_sem_init, sem_init, GLIBC_2_0);
-compat_symbol (libpthread, __old_sem_wait, sem_wait, GLIBC_2_0);
-compat_symbol (libpthread, __old_sem_trywait, sem_trywait, GLIBC_2_0);
-compat_symbol (libpthread, __old_sem_post, sem_post, GLIBC_2_0);
-compat_symbol (libpthread, __old_sem_getvalue, sem_getvalue, GLIBC_2_0);
-compat_symbol (libpthread, __old_sem_destroy, sem_destroy, GLIBC_2_0);
-
-#endif