mlock.c

来自「用于嵌入式Linux系统的标准C的库函数」· C语言 代码 · 共 53 行

#ifndef MALLOC_PROVIDED
/*
FUNCTION
<<__malloc_lock>>, <<__malloc_unlock>>--lock malloc pool

INDEX
	__malloc_lock
INDEX
	__malloc_unlock

ANSI_SYNOPSIS
	#include <malloc.h>
	void __malloc_lock (struct _reent *<[reent]>);
	void __malloc_unlock (struct _reent *<[reent]>);

TRAD_SYNOPSIS
	void __malloc_lock(<[reent]>)
	struct _reent *<[reent]>;

	void __malloc_unlock(<[reent]>)
	struct _reent *<[reent]>;

DESCRIPTION
The <<malloc>> family of routines call these functions when they need
to lock the memory pool.  The version of these routines supplied in
the library does not do anything.  If multiple threads of execution
can call <<malloc>>, or if <<malloc>> 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 <<malloc>> may call <<__malloc_lock>> recursively; that is,
the sequence of calls may go <<__malloc_lock>>, <<__malloc_lock>>,
<<__malloc_unlock>>, <<__malloc_unlock>>.  Any implementation of these
routines must be careful to avoid causing a thread to wait for a lock
that it already holds.
*/

#include <malloc.h>

void
__malloc_lock (ptr)
     struct _reent *ptr;
{
}

void
__malloc_unlock (ptr)
     struct _reent *ptr;
{
}
#endif