mariadb/mysys/my_open.c
Vladislav Vaintroub 4171483b53 Backport Fix for Bug#24509 - 2048 file descriptor limit on windows needs increasing.
The patch replaces the use of the POSIX I/O interfaces in mysys on Windows with 
the Win32 API calls (CreateFile, WriteFile, etc). The Windows HANDLE for the open
 file is stored in the my_file_info struct, along with a flag for append mode 
(because the Windows API does not support opening files in append mode in all cases)
The default max open files has been increased to 16384 and can be increased further
by setting --max-open-files=<value> during the server start.

Noteworthy benefit of this patch is that it removes limits from the table_cache size - 
allowing for more simultaneus users
2011-06-12 15:52:07 +02:00

181 lines
4.2 KiB
C

/* Copyright (C) 2000 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include "mysys_priv.h"
#include "mysys_err.h"
#include <my_dir.h>
#include <errno.h>
/*
Open a file
SYNOPSIS
my_open()
FileName Fully qualified file name
Flags Read | write
MyFlags Special flags
RETURN VALUE
File descriptor
*/
File my_open(const char *FileName, int Flags, myf MyFlags)
/* Path-name of file */
/* Read | write .. */
/* Special flags */
{
File fd;
DBUG_ENTER("my_open");
DBUG_PRINT("my",("Name: '%s' Flags: %d MyFlags: %d",
FileName, Flags, MyFlags));
#if defined(_WIN32)
fd= my_win_open(FileName, Flags);
#elif !defined(NO_OPEN_3)
fd = open(FileName, Flags, my_umask); /* Normal unix */
#else
fd = open((char *) FileName, Flags);
#endif
DBUG_RETURN(my_register_filename(fd, FileName, FILE_BY_OPEN,
EE_FILENOTFOUND, MyFlags));
} /* my_open */
/*
Close a file
SYNOPSIS
my_close()
fd File sescriptor
myf Special Flags
*/
int my_close(File fd, myf MyFlags)
{
int err;
DBUG_ENTER("my_close");
DBUG_PRINT("my",("fd: %d MyFlags: %d",fd, MyFlags));
pthread_mutex_lock(&THR_LOCK_open);
#ifndef _WIN32
do
{
err= close(fd);
} while (err == -1 && errno == EINTR);
#else
err= my_win_close(fd);
#endif
if (err)
{
DBUG_PRINT("error",("Got error %d on close",err));
my_errno=errno;
if (MyFlags & (MY_FAE | MY_WME))
my_error(EE_BADCLOSE, MYF(ME_BELL+ME_WAITTANG),my_filename(fd),errno);
}
if ((uint) fd < my_file_limit && my_file_info[fd].type != UNOPEN)
{
my_free(my_file_info[fd].name, MYF(0));
my_file_info[fd].type = UNOPEN;
}
my_file_opened--;
pthread_mutex_unlock(&THR_LOCK_open);
DBUG_RETURN(err);
} /* my_close */
/*
Register file in my_file_info[]
SYNOPSIS
my_register_filename()
fd File number opened, -1 if error on open
FileName File name
type_file_type How file was created
error_message_number Error message number if caller got error (fd == -1)
MyFlags Flags for my_close()
RETURN
-1 error
# Filenumber
*/
File my_register_filename(File fd, const char *FileName, enum file_type
type_of_file, uint error_message_number, myf MyFlags)
{
DBUG_ENTER("my_register_filename");
if ((int) fd >= MY_FILE_MIN)
{
if ((uint) fd >= my_file_limit)
{
thread_safe_increment(my_file_opened,&THR_LOCK_open);
DBUG_RETURN(fd); /* safeguard */
}
else
{
pthread_mutex_lock(&THR_LOCK_open);
if ((my_file_info[fd].name = (char*) my_strdup(FileName,MyFlags)))
{
my_file_opened++;
my_file_total_opened++;
my_file_info[fd].type = type_of_file;
pthread_mutex_unlock(&THR_LOCK_open);
DBUG_PRINT("exit",("fd: %d",fd));
DBUG_RETURN(fd);
}
pthread_mutex_unlock(&THR_LOCK_open);
my_errno= ENOMEM;
}
(void) my_close(fd, MyFlags);
}
else
my_errno= errno;
DBUG_PRINT("error",("Got error %d on open", my_errno));
if (MyFlags & (MY_FFNF | MY_FAE | MY_WME))
{
if (my_errno == EMFILE)
error_message_number= EE_OUT_OF_FILERESOURCES;
DBUG_PRINT("error",("print err: %d",error_message_number));
my_error(error_message_number, MYF(ME_BELL+ME_WAITTANG),
FileName, my_errno);
}
DBUG_RETURN(-1);
}
#ifdef EXTRA_DEBUG
void my_print_open_files(void)
{
if (my_file_opened | my_stream_opened)
{
uint i;
for (i= 0 ; i < my_file_limit ; i++)
{
if (my_file_info[i].type != UNOPEN)
{
fprintf(stderr, EE(EE_FILE_NOT_CLOSED), my_file_info[i].name, i);
fputc('\n', stderr);
}
}
}
}
#endif