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/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2001-2009. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved online at http://www.erlang.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* %CopyrightEnd%
*
*/
/* FIXME why not use ei_malloc here? */
#include "eidef.h"
#include <stdlib.h>
#include "ei.h"
#include "ei_locking.h"
#ifdef __WIN32__
#ifdef USE_DECLSPEC_THREAD
/* Define (and initialize) the variable __erl_errno */
volatile __declspec(thread) int __erl_errno = 0;
#else
static volatile DWORD errno_tls_index = TLS_OUT_OF_INDEXES;
static LONG volatile tls_init_mutex = 0;
#endif
#endif
#if defined(VXWORKS)
/*
Moved to each of the erl_*threads.c files, as they seem to know how
to get thread-safety.
*/
static volatile int __erl_errno;
volatile int *__erl_errno_place(void)
{
/* This check is somewhat insufficient, double task var entries will occur
if __erl_errno is actually -1, which on the other hand is an invalid
error code. */
if (taskVarGet(taskIdSelf(), &__erl_errno) == ERROR) {
taskVarAdd(taskIdSelf(), &__erl_errno);
}
return &__erl_errno;
}
#endif /* VXWORKS */
#if defined(__WIN32__)
#ifdef USE_DECLSPEC_THREAD
volatile int *__erl_errno_place(void)
{
return &__erl_errno;
}
#else
static void tls_init_once(void)
{
if (errno_tls_index != TLS_OUT_OF_INDEXES) {
return;
}
if (InterlockedExchange((LPLONG) &tls_init_mutex,1L) == 0) {
/* I was first */
errno_tls_index = TlsAlloc();
if (errno_tls_index == TLS_OUT_OF_INDEXES) {
fprintf(stderr,
"FATAL ERROR: can not allocate TLS index for "
"erl_errno (error code = %d)!\n",GetLastError());
exit(1);
}
} else {
while (errno_tls_index == TLS_OUT_OF_INDEXES) {
SwitchToThread();
}
}
}
volatile int *__erl_errno_place(void)
{
volatile int *ptr;
tls_init_once();
ptr = TlsGetValue(errno_tls_index);
if (ptr == NULL) {
ptr = malloc(sizeof(int));
*ptr = 0;
TlsSetValue(errno_tls_index, (PVOID) ptr);
}
return ptr;
}
#endif /* USE_DECLSPEC_THREAD */
#endif /* __WIN32__ */
#if defined(_REENTRANT) && !defined(VXWORKS) && !defined(__WIN32__)
#if defined(HAVE_PTHREAD_H) || defined(HAVE_MIT_PTHREAD_H)
void *ei_m_create(void)
{
pthread_mutex_t *l;
if ((l = malloc(sizeof(*l)))) { /* FIXME get memory or abort */
pthread_mutex_init(l,NULL);
}
return l;
}
int ei_m_destroy(void *l)
{
int r = pthread_mutex_destroy(l);
free(l);
return r;
}
int ei_m_lock(void *l)
{
return pthread_mutex_lock(l);
}
int ei_m_trylock(void *l)
{
return pthread_mutex_trylock(l);
}
int ei_m_unlock(void *l)
{
return pthread_mutex_unlock(l);
}
/*
* Thread-specific erl_errno variable.
*
* The second line below will give a "missing braces around initializer"
* on Solaris but the code will work.
*/
static pthread_key_t erl_errno_key;
static pthread_once_t erl_errno_key_once = PTHREAD_ONCE_INIT;
/*
* Destroy per-thread erl_errno locus
*/
static void erl_errno_destroy(void * ptr)
{
free(ptr);
}
/*
* Allocate erl_errno key.
* This will be done once for all threads
*/
static void erl_errno_key_alloc(void)
{
pthread_key_create(&erl_errno_key, erl_errno_destroy);
}
/*
* Return a pointer to the erl_errno locus.
* If pthread functions fail we fall back to using fallback_errno
* so that the main thread (actually not a thread in all ascpects)
* still will set and get an erl_errno value.
* Actually this is a bit to nice, it would be preferrable to exit fatal
* as we do on windows, but we might break some code with one thread
* but still compiled with -D_REENTRANT, so we'll leave it here.
*/
volatile int *__erl_errno_place(void)
{
int *erl_errno_p;
static volatile int use_fallback = 0;
static volatile int fallback_errno = 0;
if (use_fallback) {
return &fallback_errno;
}
/* This will create the key once for all threads */
if (pthread_once(&erl_errno_key_once, erl_errno_key_alloc) != 0) {
use_fallback = 1;
return &fallback_errno;
}
/* This is the normal case, return the pointer to the data */
if ((erl_errno_p = pthread_getspecific(erl_errno_key)) != NULL) {
return erl_errno_p;
}
if ((erl_errno_p = malloc(sizeof(int))) == NULL) {
use_fallback = 1;
return &fallback_errno;
}
if (pthread_setspecific(erl_errno_key, erl_errno_p) != 0 ||
(erl_errno_p = pthread_getspecific(erl_errno_key)) == NULL) {
free(erl_errno_p);
return &fallback_errno;
}
return erl_errno_p;
}
#endif /* HAVE_PTHREAD_H || HAVE_MIT_PTHREAD_H */
#endif /* _REENTRANT && !VXWORKS && !__WIN32__ */
#if !defined(_REENTRANT) && !defined(VXWORKS) && !defined(__WIN32__)
volatile int __erl_errno;
#endif
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