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/* $OpenBSD: rthread_libc.c,v 1.2 2006/01/05 04:24:30 tedu Exp $ */
/* $snafu: libc_tag.c,v 1.4 2004/11/30 07:00:06 marc Exp $ */
/* PUBLIC DOMAIN: No Rights Reserved. Marco S Hyman <marc@snafu.org> */
#define _POSIX_THREADS
#include <sys/time.h>
#include <machine/spinlock.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include "thread_private.h" /* in libc/include */
#include "rthread.h"
/*
* A thread tag is a pointer to a structure of this type. An opaque
* tag is used to decouple libc from the thread library.
*/
struct _thread_tag {
pthread_mutex_t m; /* the tag's mutex */
pthread_key_t k; /* a key for private data */
};
/*
* local mutex to protect against tag creation races.
*/
static pthread_mutex_t _thread_tag_mutex = PTHREAD_MUTEX_INITIALIZER;
/*
* Initialize a thread tag structure once. This function is called
* if the tag is null. Allocation and initialization are controlled
* by a mutex. If the tag is not null when the mutex is obtained
* the caller lost a race -- some other thread initialized the tag.
* This function will never return NULL.
*/
static void
_thread_tag_init(void **tag)
{
struct _thread_tag *tt;
int result;
result = pthread_mutex_lock(&_thread_tag_mutex);
if (result == 0) {
if (*tag == NULL) {
tt = malloc(sizeof *tt);
if (tt != NULL) {
result = pthread_mutex_init(&tt->m, NULL);
result |= pthread_key_create(&tt->k, free);
*tag = tt;
}
}
result |= pthread_mutex_unlock(&_thread_tag_mutex);
}
if (result != 0)
_rthread_debug(1, "tag init failure");
}
/*
* lock the mutex associated with the given tag
*/
void
_thread_tag_lock(void **tag)
{
struct _thread_tag *tt;
if (__isthreaded) {
if (*tag == NULL)
_thread_tag_init(tag);
tt = *tag;
if (pthread_mutex_lock(&tt->m) != 0)
_rthread_debug(1, "tag mutex lock failure");
}
}
/*
* unlock the mutex associated with the given tag
*/
void
_thread_tag_unlock(void **tag)
{
struct _thread_tag *tt;
if (__isthreaded) {
if (*tag == NULL)
_thread_tag_init(tag);
tt = *tag;
if (pthread_mutex_unlock(&tt->m) != 0)
_rthread_debug(1, "tag mutex unlock failure");
}
}
/*
* return the thread specific data for the given tag. If there
* is no date for this thread initialize it from 'storage'.
* On any error return 'err'.
*/
void *
_thread_tag_storage(void **tag, void *storage, size_t sz, void *err)
{
struct _thread_tag *tt;
void *ret;
if (*tag == NULL)
_thread_tag_init(tag);
tt = *tag;
ret = pthread_getspecific(tt->k);
if (ret == NULL) {
ret = malloc(sz);
if (ret == NULL)
ret = err;
else {
if (pthread_setspecific(tt->k, ret) == 0)
memcpy(ret, storage, sz);
else {
free(ret);
ret = err;
}
}
}
return ret;
}
/*
* the malloc lock
*/
static _spinlock_lock_t malloc_lock = _SPINLOCK_UNLOCKED;
void
_thread_malloc_lock(void)
{
_spinlock(&malloc_lock);
}
void
_thread_malloc_unlock(void)
{
_spinunlock(&malloc_lock);
}
void
_thread_malloc_init(void)
{
}
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