os0file.c

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		access = 0;
		ut_error;
	}

	file = CreateFile((LPCTSTR) name,
			access,
			share_mode,
			NULL,	/* default security attributes */
			create_flag,
			attributes,
			NULL);	/* no template file */

	if (file == INVALID_HANDLE_VALUE) {
		*success = FALSE;
	} else {
		*success = TRUE;
	}

	return(file);
#else /* __WIN__ */
	os_file_t	file;
	int		create_flag;
	
	ut_a(name);

	if (create_mode == OS_FILE_OPEN) {
		if (access_type == OS_FILE_READ_ONLY) {
			create_flag = O_RDONLY;
		} else {
			create_flag = O_RDWR;
		}
	} else if (create_mode == OS_FILE_CREATE) {
		create_flag = O_RDWR | O_CREAT | O_EXCL;
	} else {
		create_flag = 0;
		ut_error;
	}

	if (create_mode == OS_FILE_CREATE) {
	        file = open(name, create_flag, S_IRUSR | S_IWUSR
						| S_IRGRP | S_IWGRP);
        } else {
                file = open(name, create_flag);
        }
	
	if (file == -1) {
		*success = FALSE;
#ifdef USE_FILE_LOCK
	} else if (access_type == OS_FILE_READ_WRITE
			&& os_file_lock(file, name)) {
		*success = FALSE;
		close(file);
		file = -1;
#endif
	} else {
		*success = TRUE;
	}

	return(file);	
#endif /* __WIN__ */
}

/********************************************************************
Opens an existing file or creates a new. */

os_file_t
os_file_create(
/*===========*/
				/* out, own: handle to the file, not defined
				if error, error number can be retrieved with
				os_file_get_last_error */
	const char*	name,	/* in: name of the file or path as a
				null-terminated string */
	ulint		create_mode,/* in: OS_FILE_OPEN if an existing file
				is opened (if does not exist, error), or
				OS_FILE_CREATE if a new file is created
				(if exists, error),
				OS_FILE_OVERWRITE if a new file is created
				or an old overwritten;
				OS_FILE_OPEN_RAW, if a raw device or disk
				partition should be opened */
	ulint		purpose,/* in: OS_FILE_AIO, if asynchronous,
				non-buffered i/o is desired,
				OS_FILE_NORMAL, if any normal file;
				NOTE that it also depends on type, os_aio_..
				and srv_.. variables whether we really use
				async i/o or unbuffered i/o: look in the
				function source code for the exact rules */
	ulint		type,	/* in: OS_DATA_FILE or OS_LOG_FILE */
	ibool*		success)/* out: TRUE if succeed, FALSE if error */
{
#ifdef __WIN__
	os_file_t	file;
	DWORD		share_mode	= FILE_SHARE_READ;
	DWORD		create_flag;
	DWORD		attributes;
	ibool		retry;
try_again:	
	ut_a(name);

	if (create_mode == OS_FILE_OPEN_RAW) {
		create_flag = OPEN_EXISTING;
		share_mode = FILE_SHARE_WRITE;
	} else if (create_mode == OS_FILE_OPEN
			|| create_mode == OS_FILE_OPEN_RETRY) {
		create_flag = OPEN_EXISTING;
	} else if (create_mode == OS_FILE_CREATE) {
		create_flag = CREATE_NEW;
	} else if (create_mode == OS_FILE_OVERWRITE) {
		create_flag = CREATE_ALWAYS;
	} else {
		create_flag = 0;
		ut_error;
	}

	if (purpose == OS_FILE_AIO) {
		/* If specified, use asynchronous (overlapped) io and no
		buffering of writes in the OS */
		attributes = 0;
#ifdef WIN_ASYNC_IO
		if (os_aio_use_native_aio) {
			attributes = attributes | FILE_FLAG_OVERLAPPED;
		}
#endif			
#ifdef UNIV_NON_BUFFERED_IO
		if (type == OS_LOG_FILE && srv_flush_log_at_trx_commit == 2) {
		        /* Do not use unbuffered i/o to log files because
		        value 2 denotes that we do not flush the log at every
		        commit, but only once per second */
		} else if (srv_win_file_flush_method ==
						      SRV_WIN_IO_UNBUFFERED) {
		        attributes = attributes | FILE_FLAG_NO_BUFFERING;
		}
#endif
	} else if (purpose == OS_FILE_NORMAL) {
	        attributes = 0;
#ifdef UNIV_NON_BUFFERED_IO
		if (type == OS_LOG_FILE && srv_flush_log_at_trx_commit == 2) {
		        /* Do not use unbuffered i/o to log files because
		        value 2 denotes that we do not flush the log at every
		        commit, but only once per second */
		} else if (srv_win_file_flush_method ==
						      SRV_WIN_IO_UNBUFFERED) {
		        attributes = attributes | FILE_FLAG_NO_BUFFERING;
		}
#endif
	} else {
		attributes = 0;
		ut_error;
	}

	file = CreateFile((LPCTSTR) name,
			GENERIC_READ | GENERIC_WRITE, /* read and write
							access */
			share_mode,     /* File can be read also by other
					processes; we must give the read
					permission because of ibbackup. We do
					not give the write permission to
					others because if one would succeed to
					start 2 instances of mysqld on the
					SAME files, that could cause severe
					database corruption! When opening
					raw disk partitions, Microsoft manuals
					say that we must give also the write
					permission. */
			NULL,	/* default security attributes */
			create_flag,
			attributes,
			NULL);	/* no template file */

	if (file == INVALID_HANDLE_VALUE) {
		*success = FALSE;

		retry = os_file_handle_error(name,
				create_mode == OS_FILE_CREATE ?
				"create" : "open");
		if (retry) {
			goto try_again;
		}
	} else {
		*success = TRUE;
	}

	return(file);
#else /* __WIN__ */
	os_file_t	file;
	int		create_flag;
	ibool		retry;
	const char*	mode_str	= NULL;
	const char*	type_str	= NULL;
	const char*	purpose_str	= NULL;
	
try_again:	
	ut_a(name);

	if (create_mode == OS_FILE_OPEN || create_mode == OS_FILE_OPEN_RAW
			|| create_mode == OS_FILE_OPEN_RETRY) {
		mode_str = "OPEN";
		create_flag = O_RDWR;
	} else if (create_mode == OS_FILE_CREATE) {
		mode_str = "CREATE";
		create_flag = O_RDWR | O_CREAT | O_EXCL;
	} else if (create_mode == OS_FILE_OVERWRITE) {
		mode_str = "OVERWRITE";
		create_flag = O_RDWR | O_CREAT | O_TRUNC;
	} else {
		create_flag = 0;
		ut_error;
	}

	if (type == OS_LOG_FILE) {
		type_str = "LOG";
	} else if (type == OS_DATA_FILE) {
		type_str = "DATA";
	} else {
	        ut_error;
	}
	  
	if (purpose == OS_FILE_AIO) {
		purpose_str = "AIO";
	} else if (purpose == OS_FILE_NORMAL) {
		purpose_str = "NORMAL";
	} else {
	        ut_error;
	}

/*	fprintf(stderr, "Opening file %s, mode %s, type %s, purpose %s\n",
			       name, mode_str, type_str, purpose_str); */
#ifdef O_SYNC
        /* We let O_SYNC only affect log files; note that we map O_DSYNC to
	O_SYNC because the datasync options seemed to corrupt files in 2001
	in both Linux and Solaris */
	if (type == OS_LOG_FILE
	    && srv_unix_file_flush_method == SRV_UNIX_O_DSYNC) {

/*		fprintf(stderr, "Using O_SYNC for file %s\n", name); */

	        create_flag = create_flag | O_SYNC;
	}
#endif
#ifdef O_DIRECT
        /* We let O_DIRECT only affect data files */
	if (type != OS_LOG_FILE
	    && srv_unix_file_flush_method == SRV_UNIX_O_DIRECT) {

/*		fprintf(stderr, "Using O_DIRECT for file %s\n", name); */

	        create_flag = create_flag | O_DIRECT;
	}
#endif
	if (create_mode == OS_FILE_CREATE) {
	        file = open(name, create_flag, os_innodb_umask);
        } else {
                file = open(name, create_flag);
        }
	
	if (file == -1) {
		*success = FALSE;

		retry = os_file_handle_error(name,
				create_mode == OS_FILE_CREATE ?
				"create" : "open");
		if (retry) {
			goto try_again;
		}
#ifdef USE_FILE_LOCK
	} else if (create_mode != OS_FILE_OPEN_RAW
			&& os_file_lock(file, name)) {
		*success = FALSE;
		if (create_mode == OS_FILE_OPEN_RETRY) {
			int i;
			ut_print_timestamp(stderr);
			fputs("  InnoDB: Retrying to lock the first data file\n",
				stderr);
			for (i = 0; i < 100; i++) {
				os_thread_sleep(1000000);
				if (!os_file_lock(file, name)) {
					*success = TRUE;
					return(file);
				}
			}
			ut_print_timestamp(stderr);
			fputs("  InnoDB: Unable to open the first data file\n",
				stderr);
		}
		close(file);
		file = -1;
#endif
	} else {
		*success = TRUE;
	}

	return(file);	
#endif /* __WIN__ */
}

/***************************************************************************
Deletes a file if it exists. The file has to be closed before calling this. */

ibool
os_file_delete_if_exists(
/*=====================*/
				/* out: TRUE if success */
	const char*	name)	/* in: file path as a null-terminated string */
{
#ifdef __WIN__
	BOOL	ret;
	ulint	count	= 0;
loop:
	/* In Windows, deleting an .ibd file may fail if ibbackup is copying
	it */

	ret = DeleteFile((LPCTSTR)name);

	if (ret) {
		return(TRUE);
	}

	if (GetLastError() == ERROR_FILE_NOT_FOUND) {
		/* the file does not exist, this not an error */

		return(TRUE);
	}

	count++;

	if (count > 100 && 0 == (count % 10)) {
		fprintf(stderr,
"InnoDB: Warning: cannot delete file %s\n"
"InnoDB: Are you running ibbackup to back up the file?\n", name);
		
		os_file_get_last_error(TRUE); /* print error information */
	}

	os_thread_sleep(1000000);	/* sleep for a second */

	if (count > 2000) {

		return(FALSE);
	}

	goto loop;
#else
	int	ret;

	ret = unlink((const char*)name);

	if (ret != 0 && errno != ENOENT) {
		os_file_handle_error_no_exit(name, "delete");

		return(FALSE);
	}

	return(TRUE);
#endif
}

/***************************************************************************
Deletes a file. The file has to be closed before calling this. */

ibool
os_file_delete(
/*===========*/
				/* out: TRUE if success */
	const char*	name)	/* in: file path as a null-terminated string */
{
#ifdef __WIN__
	BOOL	ret;
	ulint	count	= 0;
loop:
	/* In Windows, deleting an .ibd file may fail if ibbackup is copying
	it */

	ret = DeleteFile((LPCTSTR)name);

	if (ret) {
		return(TRUE);
	}

	if (GetLastError() == ERROR_FILE_NOT_FOUND) {
		/* If the file does not exist, we classify this as a 'mild'
		error and return */

		return(FALSE);
	}

	count++;

	if (count > 100 && 0 == (count % 10)) {
		fprintf(stderr,
"InnoDB: Warning: cannot delete file %s\n"
"InnoDB: Are you running ibbackup to back up the file?\n", name);
		
		os_file_get_last_error(TRUE); /* print error information */
	}

	os_thread_sleep(1000000);	/* sleep for a second */

	if (count > 2000) {

		return(FALSE);
	}

	goto loop;
#else
	int	ret;

	ret = unlink((const char*)name);

	if (ret != 0) {
		os_file_handle_error_no_exit(name, "delete");

		return(FALSE);
	}

	return(TRUE);
#endif
}

/***************************************************************************
Renames a file (can also move it to another directory). It is safest that the
file is closed before calling this function. */

ibool
os_file_rename(
/*===========*/
				/* out: TRUE if success */
	const char*	oldpath,/* in: old file path as a null-terminated
				string */
	const char*	newpath)/* in: new file path */
{
#ifdef __WIN__
	BOOL	ret;

	ret = MoveFile((LPCTSTR)oldpath, (LPCTSTR)newpath);

	if (ret) {
		return(TRUE);
	}

	os_file_handle_error(oldpath, "rename");

	return(FALSE);
#else
	int	ret;

	ret = rename((const char*)oldpath, (const char*)newpath);

	if (ret != 0) {
		os_file_handle_error(oldpath, "rename");

		return(FALSE);
	}

	return(TRUE);
#endif
}

/***************************************************************************
Closes a file handle. In case of error, error number can be retrieved with
os_file_get_last_error. */

ibool
os_file_close(
/*==========*/
				/* out: TRUE if success */
	os_file_t	file)	/* in, own: handle to a file */
{
#ifdef __WIN__
	BOOL	ret;

	ut_a(file);

	ret = CloseHandle(file);

	if (ret) {
		return(TRUE);
	}

	os_file_handle_error(NULL, "close");

	return(FALSE);
#else
	int	ret;

	ret = close(file);

	if (ret == -1) {
		os_file_handle_error(NULL, "close");

		return(FALSE);
	}

	return(TRUE);
#endif
}

/***************************************************************************
Closes a file handle. */

ibool
os_file_close_no_error_handling(
/*============================*/
				/* out: TRUE if success */
	os_file_t	file)	/* in, own: handle to a file */
{
#ifdef __WIN__
	BOOL	ret;

	ut_a(file);

	ret = CloseHandle(file);

	if (ret) {
		return(TRUE);
	}

	return(FALSE);
#else
	int	ret;

	ret = close(file);

	if (ret == -1) {

		return(FALSE);
	}