newlib-cygwin/newlib/libc/reent/sbrkr.c

66 lines
1.3 KiB
C

/* Reentrant version of sbrk system call. */
#include <reent.h>
#include <unistd.h>
#include <_syslist.h>
/* Some targets provides their own versions of these functions. Those
targets should define REENTRANT_SYSCALLS_PROVIDED in TARGET_CFLAGS. */
#ifdef _REENT_ONLY
#ifndef REENTRANT_SYSCALLS_PROVIDED
#define REENTRANT_SYSCALLS_PROVIDED
#endif
#endif
/* If MALLOC_PROVIDED is defined, we don't need this function. */
#if defined (REENTRANT_SYSCALLS_PROVIDED) || defined (MALLOC_PROVIDED)
int _dummy_sbrk_syscalls = 1;
#else
/* We use the errno variable used by the system dependent layer. */
#undef errno
extern int errno;
/*
FUNCTION
<<_sbrk_r>>---Reentrant version of sbrk
INDEX
_sbrk_r
ANSI_SYNOPSIS
#include <reent.h>
void *_sbrk_r(struct _reent *<[ptr]>, ptrdiff_t <[incr]>);
TRAD_SYNOPSIS
#include <reent.h>
void *_sbrk_r(<[ptr]>, <[incr]>)
struct _reent *<[ptr]>;
ptrdiff_t <[incr]>;
DESCRIPTION
This is a reentrant version of <<sbrk>>. It
takes a pointer to the global data block, which holds
<<errno>>.
*/
void *
_DEFUN (_sbrk_r, (ptr, incr),
struct _reent *ptr _AND
ptrdiff_t incr)
{
char *ret;
void *_sbrk(ptrdiff_t);
errno = 0;
if ((ret = (char *)(_sbrk (incr))) == (void *) -1 && errno != 0)
ptr->_errno = errno;
return ret;
}
#endif /* ! defined (REENTRANT_SYSCALLS_PROVIDED) */