169 lines
4.0 KiB
C
169 lines
4.0 KiB
C
/* Reentrant versions of read system call. */
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#include <reent.h>
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#include <unistd.h>
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#include <_syslist.h>
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#include <errno.h>
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/* Some targets provides their own versions of this functions. Those
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targets should define REENTRANT_SYSCALLS_PROVIDED in TARGET_CFLAGS. */
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#ifdef _REENT_ONLY
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#ifndef REENTRANT_SYSCALLS_PROVIDED
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#define REENTRANT_SYSCALLS_PROVIDED
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#endif
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#endif
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#ifndef REENTRANT_SYSCALLS_PROVIDED
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/* We use the errno variable used by the system dependent layer. */
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/*
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FUNCTION
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<<_read_r>>---Reentrant version of read
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INDEX
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_read_r
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ANSI_SYNOPSIS
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#include <reent.h>
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_ssize_t _read_r(struct _reent *<[ptr]>,
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int <[fd]>, void *<[buf]>, size_t <[cnt]>);
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TRAD_SYNOPSIS
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#include <reent.h>
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_ssize_t _read_r(<[ptr]>, <[fd]>, <[buf]>, <[cnt]>)
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struct _reent *<[ptr]>;
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int <[fd]>;
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char *<[buf]>;
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size_t <[cnt]>;
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DESCRIPTION
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This is a reentrant version of <<read>>. It
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takes a pointer to the global data block, which holds
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<<errno>>.
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*/
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extern unsigned __NFiles;
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#define _READ 0x0001 /* file opened for reading */
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#define _BINARY 0x0040 /* file is binary, skip CRLF processing */
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#define _ISTTY 0x2000 /* is console device */
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#define __handle_check( __h, __r ) \
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if( (__h) < 0 || (__h) > __NFiles ) { \
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ptr->_errno = EBADF; \
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return( __r ); \
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}
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_ssize_t
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_DEFUN (_read, (fd, buf, cnt),
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int fd _AND
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_PTR buf _AND
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size_t cnt)
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{
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return _read_r( _REENT, fd, buf, cnt);
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}
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_ssize_t
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_DEFUN (_read_r, (ptr, fd, buf, cnt),
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struct _reent *ptr _AND
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int fd _AND
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_PTR buf _AND
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size_t cnt)
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{
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_ssize_t ret;
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_ssize_t read_len, total_len;
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unsigned reduce_idx, finish_idx;
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unsigned iomode_flags;
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char *buffer = buf;
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int rc;
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int h;
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unsigned amount_read;
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int err;
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__file_handle *fh;
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__handle_check( fd, -1 );
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__ChkTTYIOMode( fd );
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iomode_flags = __GetIOMode( fd );
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if( iomode_flags == 0 )
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{
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ptr->_errno = EBADF;
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return( -1 );
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}
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if( !(iomode_flags & _READ) )
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{
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ptr->_errno = EACCES; /* changed from EBADF to EACCES 23-feb-89 */
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return( -1 );
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}
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fh = (__file_handle*) __getOSHandle( fd );
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if( iomode_flags & _BINARY ) /* if binary mode */
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{
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err = read_file(fh->name, buffer, fh->offset, cnt, &amount_read);
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fh->offset+= amount_read;
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total_len = amount_read;
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if(err)
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if ( amount_read == 0)
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return (-1);
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}
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else
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{
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total_len = 0;
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read_len = cnt;
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do
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{
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err=read_file(fh->name,buffer, fh->offset, cnt, &amount_read);
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fh->offset+=amount_read;
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if( amount_read == 0 )
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break; /* EOF */
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reduce_idx = 0;
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finish_idx = reduce_idx;
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for( ; reduce_idx < amount_read; ++reduce_idx )
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{
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if( buffer[ reduce_idx ] == 0x1a ) /* EOF */
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{
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_lseek_r(ptr, fd, ((long)reduce_idx - (long)amount_read)+1L,
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SEEK_CUR );
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total_len += finish_idx;
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return( total_len );
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}
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if( buffer[ reduce_idx ] != '\r' )
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{
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buffer[ finish_idx++ ] = buffer[ reduce_idx ];
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};
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}
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total_len += finish_idx;
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buffer += finish_idx;
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read_len -= finish_idx;
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if( iomode_flags & _ISTTY )
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{
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break; /* 04-feb-88, FWC */
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}
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} while( read_len != 0 );
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}
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return( total_len );
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}
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_ssize_t
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_DEFUN (read, (fd, buf, cnt),
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int fd _AND
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_PTR buf _AND
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size_t cnt)
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{
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return _read_r(_REENT, fd, buf, cnt);
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};
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#endif /* ! defined (REENTRANT_SYSCALLS_PROVIDED) */
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