mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-19 03:05:15 +00:00
62 lines
1.5 KiB
C
62 lines
1.5 KiB
C
|
/*
|
||
|
|
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
|
||
|
|
__env_lock (ptr)
|
||
|
|
struct _reent *ptr;
|
||
|
|
{
|
||
|
|
#ifndef __SINGLE_THREAD__
|
||
|
|
__lock_acquire_recursive (__env_lock_object);
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
|
||
|
|
void
|
||
|
|
__env_unlock (ptr)
|
||
|
|
struct _reent *ptr;
|
||
|
|
{
|
||
|
|
#ifndef __SINGLE_THREAD__
|
||
|
|
__lock_release_recursive (__env_lock_object);
|
||
|
|
#endif
|
||
|
|
}
|