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/*
* Mach Operating System
* Copyright (c) 1992,1991 Carnegie-Mellon University
* All rights reserved. The CMU software License Agreement specifies
* the terms and conditions for use and redistribution.
*/
/*
* HISTORY
* $Log: cthread_data.c,v $
* Revision 2.4 93/05/10 17:51:20 rvb
* Make cthread_set_data and cthread_data macros.
* [93/05/06 rvb]
*
* Revision 2.3 93/01/14 18:04:52 danner
* Converted file to ANSI C.
* Removed usage of obsolete type any_t.
* [92/12/18 pds]
*
* Revision 2.2 92/05/23 11:35:17 jfriedl
* Snarfed from multi-server sources at CMU.
* No stdio (for use with single-server).
*
*
* Revision 2.2 91/03/25 14:14:45 jjc
* For compatibility with cthread_data:
* 1) Added routines, cthread_data and cthread_set_data,
* which use the new routines in here.
* 2) Defined CTHREAD_KEY_RESERVED as the key used to
* access cthread_data.
* 3) Changed the first free key from CTHREAD_KEY_NULL
* to CTHREAD_KEY_FIRST.
* [91/03/18 jjc]
* Made simple implementation from POSIX threads specification for
* thread specific data.
* [91/03/07 jjc]
*
*/
#include <stdio.h>
#include <cthreads.h>
#define CTHREAD_KEY_MAX (cthread_key_t)8 /* max. no. of keys */
#define CTHREAD_KEY_NULL (cthread_key_t)0
#if defined(CTHREAD_DATA)
/*
* Key reserved for cthread_data
*/
#define CTHREAD_KEY_RESERVED CTHREAD_KEY_NULL
#define CTHREAD_KEY_FIRST (cthread_key_t)1 /* first free key */
#else /* not defined(CTHREAD_DATA) */
#define CTHREAD_KEY_FIRST CTHREAD_KEY_NULL /* first free key */
#endif /* defined(CTHREAD_DATA) */
/* lock protecting key creation */
struct mutex cthread_data_lock = MUTEX_INITIALIZER;
/* next free key */
cthread_key_t cthread_key = CTHREAD_KEY_FIRST;
/*
* Create key to private data visible to all threads in task.
* Different threads may use same key, but the values bound to the key are
* maintained on a thread specific basis.
* Returns 0 if successful and returns -1 otherwise.
*/
int
cthread_keycreate(cthread_key_t *key)
{
if (cthread_key >= CTHREAD_KEY_FIRST && cthread_key < CTHREAD_KEY_MAX) {
mutex_lock((mutex_t)&cthread_data_lock);
*key = cthread_key++;
mutex_unlock((mutex_t)&cthread_data_lock);
return(0);
}
else { /* out of keys */
*key = CTHREAD_KEY_INVALID;
return(-1);
}
}
/*
* Get private data associated with given key
* Returns 0 if successful and returns -1 if the key is invalid.
* If the calling thread doesn't have a value for the given key,
* the value returned is CTHREAD_DATA_VALUE_NULL.
*/
int
cthread_getspecific(cthread_key_t key, void **value)
{
register cthread_t self;
register void **thread_data;
*value = CTHREAD_DATA_VALUE_NULL;
if (key < CTHREAD_KEY_NULL || key >= cthread_key)
return(-1);
self = cthread_self();
thread_data = (void **)(self->private_data);
if (thread_data != NULL)
*value = thread_data[key];
return(0);
}
/*
* Set private data associated with given key
* Returns 0 if successful and returns -1 otherwise.
*/
int
cthread_setspecific(cthread_key_t key, void *value)
{
register int i;
register cthread_t self;
register void **thread_data;
if (key < CTHREAD_KEY_NULL || key >= cthread_key)
return(-1);
self = cthread_self();
thread_data = (void **)(self->private_data);
if (thread_data != NULL)
thread_data[key] = value;
else {
/*
* Allocate and initialize thread data table,
* point cthread_data at it, and then set the
* data for the given key with the given value.
*/
thread_data = malloc(CTHREAD_KEY_MAX * sizeof(void *));
if (thread_data == NULL) {
printf("cthread_setspecific: malloc failed\n");
return(-1);
}
self->private_data = thread_data;
for (i = 0; i < CTHREAD_KEY_MAX; i++)
thread_data[i] = CTHREAD_DATA_VALUE_NULL;
thread_data[key] = value;
}
return(0);
}
#if defined(CTHREAD_DATA_XX)
/*
* Set thread specific "global" variable,
* using new POSIX routines.
* Crash and burn if the thread given isn't the calling thread.
* XXX For compatibility with old cthread_set_data() XXX
*/
int
cthread_set_data(cthread_t t, void *x)
{
register cthread_t self;
self = cthread_self();
if (t == self)
return(cthread_setspecific(CTHREAD_KEY_RESERVED, x));
else {
ASSERT(t == self);
return(-1);
}
}
/*
* Get thread specific "global" variable,
* using new POSIX routines.
* Crash and burn if the thread given isn't the calling thread.
* XXX For compatibility with old cthread_data() XXX
*/
void *
cthread_data(cthread_t t)
{
register cthread_t self;
void *value;
self = cthread_self();
if (t == self) {
(void)cthread_getspecific(CTHREAD_KEY_RESERVED, &value);
return(value);
}
else {
ASSERT(t == self);
return(NULL);
}
}
#endif /* defined(CTHREAD_DATA_XX) */
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