0,0 → 1,61 |
/* |
FUNCTION |
<<__env_lock>>, <<__env_unlock>>---lock environ variable |
|
INDEX |
__env_lock |
INDEX |
__env_unlock |
|
ANSI_SYNOPSIS |
#include <envlock.h> |
void __env_lock (struct _reent *<[reent]>); |
void __env_unlock (struct _reent *<[reent]>); |
|
TRAD_SYNOPSIS |
void __env_lock(<[reent]>) |
struct _reent *<[reent]>; |
|
void __env_unlock(<[reent]>) |
struct _reent *<[reent]>; |
|
DESCRIPTION |
The <<setenv>> family of routines call these functions when they need to |
modify the environ variable. The version of these routines supplied in the |
library use the lock API defined in sys/lock.h. If multiple threads of |
execution can call <<setenv>>, or if <<setenv>> can be called reentrantly, |
then you need to define your own versions of these functions in order to |
safely lock the memory pool during a call. If you do not, the memory pool |
may become corrupted. |
|
A call to <<setenv>> may call <<__env_lock>> recursively; that is, |
the sequence of calls may go <<__env_lock>>, <<__env_lock>>, |
<<__env_unlock>>, <<__env_unlock>>. Any implementation of these |
routines must be careful to avoid causing a thread to wait for a lock |
that it already holds. |
*/ |
|
#include "envlock.h" |
#include <sys/lock.h> |
|
#ifndef __SINGLE_THREAD__ |
__LOCK_INIT_RECURSIVE(static, __env_lock_object); |
#endif |
|
void |
_EXFUN(__env_lock, |
(struct _reent *reent)) |
{ |
#ifndef __SINGLE_THREAD__ |
__lock_acquire_recursive (__env_lock_object); |
#endif |
} |
|
void |
_EXFUN(__env_unlock, |
(struct _reent *reent)) |
{ |
#ifndef __SINGLE_THREAD__ |
__lock_release_recursive (__env_lock_object); |
#endif |
} |