Max open files handling moved to my_set_max_open_files()

This ensures that my_file_info takes this the max number of files into account and one can now use --open-files-limit on windows to increase number of used files up to 2048


client/client_priv.h:
  Added --open-files-limit to mysqlbinlog
client/mysqlbinlog.cc:
  Added --open-files-limit to mysqlbinlog
include/config-win.h:
  Define that you can have up to 2048 files open on windows
include/my_global.h:
  Allow override of OS_FILE_LIMIT
include/my_sys.h:
  Cleanup
  Added prototypes for my_set_max_open_files() and my_free_open_files()
libmysql/Makefile.shared:
  Added my_file.c
myisam/myisamlog.c:
  Use my_set_max_open_files()
mysys/Makefile.am:
  Use my_file.c (for mysqlbinlog)
mysys/my_alloc.c:
  Remove compiler warning
mysys/my_div.c:
  MY_NFILE -> my_file_limit
mysys/my_dup.c:
  MY_NFILE -> my_file_limit
mysys/my_fopen.c:
  MY_NFILE -> my_file_limit
mysys/my_open.c:
  MY_NFILE -> my_file_limit
mysys/my_static.c:
  Allow changing of open files limit
mysys/my_static.h:
  Allow changing of open files limit
sql/mysqld.cc:
  Max open files handling moved to my_set_max_open_files()

client/client_priv.h

@@ -43,4 +43,5 @@ enum options_client
   OPT_PROMPT, OPT_IGN_LINES,OPT_TRANSACTION,OPT_MYSQL_PROTOCOL,
   OPT_SHARED_MEMORY_BASE_NAME, OPT_FRM, OPT_SKIP_OPTIMIZATION,
   OPT_COMPATIBLE, OPT_RECONNECT, OPT_DELIMITER, OPT_SECURE_AUTH,
+  OPT_OPEN_FILES_LIMIT
 };

client/mysqlbinlog.cc

@@ -33,6 +33,7 @@ ulong server_id = 0;
 // needed by net_serv.c
 ulong bytes_sent = 0L, bytes_received = 0L;
 ulong mysqld_net_retry_count = 10L;
+ulong open_files_limit;
 uint test_flags = 0; 
 static uint opt_protocol= 0;
 static FILE *result_file;
@@ -68,7 +69,7 @@ static MYSQL* safe_connect();
 
 class Load_log_processor
 {
-  char target_dir_name[MY_NFILE];
+  char target_dir_name[FN_REFLEN];
   int target_dir_name_len;
   DYNAMIC_ARRAY file_names;
 
@@ -429,6 +430,10 @@ static struct my_option my_long_options[] =
   {"read-from-remote-server", 'R', "Read binary logs from a MySQL server",
    (gptr*) &remote_opt, (gptr*) &remote_opt, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0,
    0, 0},
+  {"open_files_limit", OPT_OPEN_FILES_LIMIT,
+   "Used to reserve file descriptors for usage by this program",
+   (gptr*) &open_files_limit, (gptr*) &open_files_limit, 0, GET_ULONG,
+   REQUIRED_ARG, MY_NFILE, 8, OS_FILE_LIMIT, 0, 1, 0},
   {"short-form", 's', "Just show the queries, no extra info.",
    (gptr*) &short_form, (gptr*) &short_form, 0, GET_BOOL, NO_ARG, 0, 0, 0, 0,
    0, 0},
@@ -878,6 +883,7 @@ int main(int argc, char** argv)
     exit(1);
   }
 
+  my_set_max_open_files(open_files_limit);
   if (remote_opt)
     mysql = safe_connect();
 
@@ -915,6 +921,7 @@ int main(int argc, char** argv)
     mysql_close(mysql);
   cleanup();
   free_defaults(defaults_argv);
+  my_free_open_file_info();
   my_end(0);
   exit(exit_value);
   DBUG_RETURN(exit_value);			// Keep compilers happy

include/config-win.h

@@ -323,7 +323,7 @@ inline double ulonglong2double(ulonglong value)
 #define FN_ROOTDIR	"\\"
 #define FN_NETWORK_DRIVES	/* Uses \\ to indicate network drives */
 #define FN_NO_CASE_SENCE	/* Files are not case-sensitive */
-#define MY_NFILE	1024
+#define OS_FILE_LIMIT	2048
 
 #define DO_NOT_REMOVE_THREAD_WRAPPERS
 #define thread_safe_increment(V,L) InterlockedIncrement((long*) &(V))

include/my_global.h

@@ -535,7 +535,10 @@ typedef SOCKET_SIZE_TYPE size_socket;
 #define FN_LIBCHAR	'/'
 #define FN_ROOTDIR	"/"
 #endif
-#define MY_NFILE	1024	/* This is only used to save filenames */
+#endif
+#define MY_NFILE	64	/* This is only used to save filenames */
+#ifndef OS_FILE_LIMIT
+#define OS_FILE_LIMIT	65535
 #endif
 
 /* #define EXT_IN_LIBNAME     */

include/my_sys.h

@@ -202,26 +202,13 @@ extern char NEAR curr_dir[];		/* Current directory for user */
 extern int (*error_handler_hook)(uint my_err, const char *str,myf MyFlags);
 extern int (*fatal_error_handler_hook)(uint my_err, const char *str,
 				       myf MyFlags);
+extern uint my_file_limit;
 
 /* charsets */
 extern CHARSET_INFO *default_charset_info;
 extern CHARSET_INFO *all_charsets[256];
 extern CHARSET_INFO compiled_charsets[];
 
-extern uint get_charset_number(const char *cs_name, uint cs_flags);
-extern uint get_collation_number(const char *name);
-extern const char *get_charset_name(uint cs_number);
-
-extern CHARSET_INFO *get_charset(uint cs_number, myf flags);
-extern CHARSET_INFO *get_charset_by_name(const char *cs_name, myf flags);
-extern CHARSET_INFO *get_charset_by_csname(const char *cs_name,
-					   uint cs_flags, myf my_flags);
-extern void free_charsets(void);
-extern char *get_charsets_dir(char *buf);
-extern my_bool my_charset_same(CHARSET_INFO *cs1, CHARSET_INFO *cs2);
-extern my_bool init_compiled_charsets(myf flags);
-extern void add_compiled_collation(CHARSET_INFO *cs);
-
 /* statistics */
 extern ulong	my_cache_w_requests, my_cache_write, my_cache_r_requests,
 		my_cache_read;
@@ -288,14 +275,16 @@ enum file_type
   FILE_BY_MKSTEMP, FILE_BY_DUP
 };
 
-extern struct my_file_info
+struct st_my_file_info
 {
   my_string		name;
   enum file_type	type;
 #if defined(THREAD) && !defined(HAVE_PREAD)
   pthread_mutex_t	mutex;
 #endif
-} my_file_info[MY_NFILE];
+};
+
+extern struct st_my_file_info *my_file_info;
 
 typedef struct st_my_tmpdir
 {
@@ -747,6 +736,23 @@ extern uint my_bit_log2(ulong value);
 extern uint my_count_bits(ulonglong v);
 extern void my_sleep(ulong m_seconds);
 extern ulong crc32(ulong crc, const uchar *buf, uint len);
+extern uint my_set_max_open_files(uint files);
+void my_free_open_file_info(void);
+
+/* character sets */
+extern uint get_charset_number(const char *cs_name, uint cs_flags);
+extern uint get_collation_number(const char *name);
+extern const char *get_charset_name(uint cs_number);
+
+extern CHARSET_INFO *get_charset(uint cs_number, myf flags);
+extern CHARSET_INFO *get_charset_by_name(const char *cs_name, myf flags);
+extern CHARSET_INFO *get_charset_by_csname(const char *cs_name,
+					   uint cs_flags, myf my_flags);
+extern void free_charsets(void);
+extern char *get_charsets_dir(char *buf);
+extern my_bool my_charset_same(CHARSET_INFO *cs1, CHARSET_INFO *cs2);
+extern my_bool init_compiled_charsets(myf flags);
+extern void add_compiled_collation(CHARSET_INFO *cs);
 
 #ifdef __WIN__
 extern my_bool have_tcpip;		/* Is set if tcpip is used */

libmysql/Makefile.shared

@@ -50,7 +50,7 @@ mysysheaders =		mysys_priv.h my_static.h
 vioheaders =		vio_priv.h
 mysysobjects1 =		my_init.lo my_static.lo my_malloc.lo my_realloc.lo \
 			my_create.lo my_delete.lo mf_tempfile.lo my_open.lo \
-			my_read.lo my_write.lo errors.lo \
+			my_file.lo my_read.lo my_write.lo errors.lo \
 			my_error.lo my_getwd.lo my_div.lo \
 			mf_pack.lo my_messnc.lo mf_dirname.lo mf_fn_ext.lo\
 			mf_wcomp.lo typelib.lo safemalloc.lo my_alloc.lo \

myisam/myisamlog.c

@@ -60,7 +60,6 @@ static int file_info_compare(void *cmp_arg, void *a,void *b);
 static int test_if_open(struct file_info *key,element_count count,
 			struct test_if_open_param *param);
 static void fix_blob_pointers(MI_INFO *isam,byte *record);
-static uint set_maximum_open_files(uint);
 static int test_when_accessed(struct file_info *key,element_count count,
 			      struct st_access_param *access_param);
 static void file_info_free(struct file_info *info);
@@ -89,9 +88,8 @@ int main(int argc, char **argv)
 
   log_filename=myisam_log_filename;
   get_options(&argc,&argv);
- /* Nr of isam-files */
-  max_files=(set_maximum_open_files(min(max_files,8))-6)/2;
-
+  /* Number of MyISAM files we can have open at one time */
+  max_files= (my_set_max_open_files(min(max_files,8))-6)/2;
   if (update)
     printf("Trying to %s MyISAM files according to log '%s'\n",
 	   (recover ? "recover" : "update"),log_filename);
@@ -123,6 +121,7 @@ int main(int argc, char **argv)
     printf("Had to do %d re-open because of too few possibly open files\n",
 	   re_open_count);
   VOID(mi_panic(HA_PANIC_CLOSE));
+  my_free_open_file_info();
   my_end(test_info ? MY_CHECK_ERROR | MY_GIVE_INFO : MY_CHECK_ERROR);
   exit(error);
   return 0;				/* No compiler warning */
@@ -732,38 +731,6 @@ static void fix_blob_pointers(MI_INFO *info, byte *record)
   }
 }
 
-static uint set_maximum_open_files(uint maximum_files)
-{
-#if defined(HAVE_GETRUSAGE) && defined(RLIMIT_NOFILE)
-  struct rlimit rlimit;
-  int old_max;
-
-  if (maximum_files > MY_NFILE)
-    maximum_files=MY_NFILE;			/* Don't crash my_open */
-
-  if (!getrlimit(RLIMIT_NOFILE,&rlimit))
-  {
-    old_max=rlimit.rlim_max;
-    if (maximum_files && (int) maximum_files > old_max)
-      rlimit.rlim_max=maximum_files;
-    rlimit.rlim_cur=rlimit.rlim_max;
-    if (setrlimit(RLIMIT_NOFILE,&rlimit))
-    {
-      if (old_max != (int) maximum_files)
-      {						/* Set as much as we can */
-	rlimit.rlim_max=rlimit.rlim_cur=old_max;
-	setrlimit(RLIMIT_NOFILE,&rlimit);
-      }
-    }
-    getrlimit(RLIMIT_NOFILE,&rlimit);		/* Read if broken setrlimit */
-    if (maximum_files && maximum_files < rlimit.rlim_cur)
-      VOID(fprintf(stderr,"Warning: Error from setrlimit: Max open files is %d\n",old_max));
-    return rlimit.rlim_cur;
-  }
-#endif
-  return min(maximum_files,MY_NFILE);
-}
-
 	/* close the file with hasn't been accessed for the longest time */
 	/* ARGSUSED */
 

mysys/Makefile.am

@@ -25,8 +25,8 @@ noinst_HEADERS =	mysys_priv.h my_static.h \
 			my_os2cond.c my_os2dirsrch.c my_os2dirsrch.h \
 			my_os2dlfcn.c my_os2file64.c my_os2mutex.c \
 			my_os2thread.c my_os2tls.c
-libmysys_a_SOURCES =	my_init.c my_getwd.c mf_getdate.c\
-			mf_path.c mf_loadpath.c\
+libmysys_a_SOURCES =	my_init.c my_getwd.c mf_getdate.c \
+			mf_path.c mf_loadpath.c my_file.c \
 			my_open.c my_create.c my_dup.c my_seek.c my_read.c \
 			my_pread.c my_write.c \
 			mf_keycache.c mf_keycaches.c my_crc32.c \

mysys/my_alloc.c

@@ -68,7 +68,7 @@ void init_alloc_root(MEM_ROOT *mem_root, uint block_size,
  */
 
 void reset_root_defaults(MEM_ROOT *mem_root, uint block_size,
-                         uint pre_alloc_size)
+                         uint pre_alloc_size __attribute__((unused)))
 {
   mem_root->block_size= block_size-MALLOC_OVERHEAD-sizeof(USED_MEM)-8;
 #if !(defined(HAVE_purify) && defined(EXTRA_DEBUG))

mysys/my_div.c

@@ -27,7 +27,7 @@
 my_string my_filename(File fd)
 {
   DBUG_ENTER("my_filename");
-  if (fd >= MY_NFILE)
+  if ((uint) fd >= (uint) my_file_limit)
     DBUG_RETURN((char*) "UNKNOWN");
   if (fd >= 0 && my_file_info[fd].type != UNOPEN)
   {

mysys/my_dup.c

@@ -32,7 +32,7 @@ File my_dup(File file, myf MyFlags)
   DBUG_ENTER("my_dup");
   DBUG_PRINT("my",("file: %d  MyFlags: %d", MyFlags));
   fd = dup(file);
-  filename= (((int) file < MY_NFILE) ?
+  filename= (((uint) file < my_file_limit) ?
 	     my_file_info[(int) file].name : "Unknown");
   DBUG_RETURN(my_register_filename(fd, filename, FILE_BY_DUP,
 				   EE_FILENOTFOUND, MyFlags));

mysys/my_file.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; either version 2 of the License, or
+   (at your option) any later version.
+
+   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 "my_static.h"
+#include <m_string.h>
+
+/*
+  set how many open files we want to be able to handle
+
+  SYNOPSIS
+    set_maximum_open_files()
+    max_file_limit		Files to open
+
+  NOTES
+    The request may not fulfilled becasue of system limitations
+
+  RETURN
+    Files available to open.
+    May be more or less than max_file_limit!
+*/
+
+#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE) && !defined(HAVE_mit_thread)
+
+#ifndef RLIM_INFINITY
+#define RLIM_INFINITY ((uint) 0xffffffff)
+#endif
+
+static uint set_max_open_files(uint max_file_limit)
+{
+  struct rlimit rlimit;
+  uint old_cur;
+  DBUG_ENTER("set_max_open_files");
+  DBUG_PRINT("enter",("files: %u", max_file_limit));
+
+  if (!getrlimit(RLIMIT_NOFILE,&rlimit))
+  {
+    old_cur= (uint) rlimit.rlim_cur;
+    DBUG_PRINT("info", ("rlim_cur: %u  rlim_max: %u",
+			(uint) rlimit.rlim_cur,
+			(uint) rlimit.rlim_max));
+    if (rlimit.rlim_cur == RLIM_INFINITY)
+      rlimit.rlim_cur = max_file_limit;
+    if (rlimit.rlim_cur >= max_file_limit)
+      DBUG_RETURN(rlimit.rlim_cur);		/* purecov: inspected */
+    rlimit.rlim_cur= rlimit.rlim_max= max_file_limit;
+    if (setrlimit(RLIMIT_NOFILE, &rlimit))
+      max_file_limit= old_cur;			/* Use original value */
+    else
+    {
+      rlimit.rlim_cur= 0;			/* Safety if next call fails */
+      (void) getrlimit(RLIMIT_NOFILE,&rlimit);
+      DBUG_PRINT("info", ("rlim_cur: %u", (uint) rlimit.rlim_cur));
+      if (rlimit.rlim_cur)			/* If call didn't fail */
+	max_file_limit= (uint) rlimit.rlim_cur;
+    }
+  }
+  DBUG_PRINT("exit",("max_file_limit: %u", max_file_limit));
+  DBUG_RETURN(max_file_limit);
+}
+
+#elif defined (OS2)
+
+static uint set_max_open_files(uint max_file_limit)
+{
+  LONG     cbReqCount;
+  ULONG    cbCurMaxFH0;
+  APIRET   ulrc;
+  DBUG_ENTER("set_max_open_files");
+
+  /* get current limit */
+  cbReqCount = 0;
+  DosSetRelMaxFH( &cbReqCount, &cbCurMaxFH0);
+
+  /* set new limit */
+  if ((cbReqCount = max_file_limit - cbCurMaxFH0) > 0)
+    ulrc = DosSetRelMaxFH( &cbReqCount, &cbCurMaxFH);
+  DBUG_RETURN(cbCurMaxFH0);
+}
+
+#else
+static int set_max_open_files(uint max_file_limit)
+{
+  /* We don't know the limit. Return best guess */
+  return min(max_file_limit, OS_FILE_LIMIT);
+}
+#endif
+
+
+/*
+  Change number of open files
+
+  SYNOPSIS:
+    my_set_max_open_files()
+    files		Number of requested files
+
+  RETURN
+    number of files available for open
+*/
+
+uint my_set_max_open_files(uint files)
+{
+  struct st_my_file_info *tmp;
+  DBUG_ENTER("my_set_max_open_files");
+  DBUG_PRINT("enter",("files: %u  my_file_limit: %u", files, my_file_limit));
+
+  files= set_max_open_files(min(files, OS_FILE_LIMIT));
+  if (files <= MY_NFILE)
+    DBUG_RETURN(files);
+
+  if (!(tmp= (struct st_my_file_info*) my_malloc(sizeof(*tmp) * files,
+						 MYF(MY_WME))))
+    DBUG_RETURN(MY_NFILE);
+
+  /* Copy any initialized files */
+  memcpy((char*) tmp, (char*) my_file_info, sizeof(*tmp) * my_file_limit);
+  my_free_open_file_info();			/* Free if already allocated */
+  my_file_info= tmp;
+  my_file_limit= files;
+  DBUG_PRINT("exit",("files: %u", files));
+  DBUG_RETURN(files);
+}
+
+
+void my_free_open_file_info()
+{
+  DBUG_ENTER("my_free_file_info");
+  if (my_file_info != my_file_info_default)
+  {
+    my_free((char*) my_file_info, MYF(0));
+    my_file_info= my_file_info_default;
+  }
+  DBUG_VOID_RETURN;
+}

mysys/my_fopen.c

@@ -42,7 +42,7 @@ FILE *my_fopen(const char *FileName, int Flags, myf MyFlags)
       on some OS (SUNOS). Actually the filename save isn't that important
       so we can ignore if this doesn't work.
     */
-    if ((uint) fileno(fd) >= MY_NFILE)
+    if ((uint) fileno(fd) >= my_file_limit)
     {
       thread_safe_increment(my_stream_opened,&THR_LOCK_open);
       DBUG_RETURN(fd);				/* safeguard */
@@ -91,7 +91,7 @@ int my_fclose(FILE *fd, myf MyFlags)
   }
   else
     my_stream_opened--;
-  if ((uint) file < MY_NFILE && my_file_info[file].type != UNOPEN)
+  if ((uint) file < my_file_limit && my_file_info[file].type != UNOPEN)
   {
     my_file_info[file].type = UNOPEN;
     my_free(my_file_info[file].name, MYF(MY_ALLOW_ZERO_PTR));
@@ -123,11 +123,11 @@ FILE *my_fdopen(File Filedes, const char *name, int Flags, myf MyFlags)
   {
     pthread_mutex_lock(&THR_LOCK_open);
     my_stream_opened++;
-    if (Filedes < MY_NFILE)
+    if ((uint) Filedes < (uint) my_file_limit)
     {
       if (my_file_info[Filedes].type != UNOPEN)
       {
-        my_file_opened--;			/* File is opened with my_open ! */
+        my_file_opened--;		/* File is opened with my_open ! */
       }
       else
       {

mysys/my_open.c

@@ -86,7 +86,7 @@ int my_close(File fd, myf MyFlags)
     if (MyFlags & (MY_FAE | MY_WME))
       my_error(EE_BADCLOSE, MYF(ME_BELL+ME_WAITTANG),my_filename(fd),errno);
   }
-  if ((uint) fd < MY_NFILE && my_file_info[fd].type != UNOPEN)
+  if ((uint) fd < my_file_limit && my_file_info[fd].type != UNOPEN)
   {
     my_free(my_file_info[fd].name, MYF(0));
 #if defined(THREAD) && !defined(HAVE_PREAD)
@@ -115,7 +115,7 @@ File my_register_filename(File fd, const char *FileName, enum file_type
 {
   if ((int) fd >= 0)
   {
-    if ((int) fd >= MY_NFILE)
+    if ((uint) fd >= my_file_limit)
     {
 #if defined(THREAD) && !defined(HAVE_PREAD)
       (void) my_close(fd,MyFlags);

mysys/my_static.c

@@ -34,7 +34,9 @@ int		NEAR my_umask=0664, NEAR my_umask_dir=0777;
 #ifndef THREAD
 int		NEAR my_errno=0;
 #endif
-struct my_file_info my_file_info[MY_NFILE]= {{0,UNOPEN}};
+struct st_my_file_info my_file_info_default[MY_NFILE]= {{0,UNOPEN}};
+uint   my_file_limit= MY_NFILE;
+struct st_my_file_info *my_file_info= my_file_info_default;
 
 	/* From mf_brkhant */
 int			NEAR my_dont_interrupt=0;

mysys/my_static.h

@@ -68,6 +68,8 @@ extern byte	*sf_min_adress,*sf_max_adress;
 extern uint	sf_malloc_count;
 extern struct st_irem *sf_malloc_root;
 
+extern struct st_my_file_info my_file_info_default[MY_NFILE];
+
 #if defined(THREAD) && !defined(__WIN__)
 extern sigset_t my_signals;		/* signals blocked by mf_brkhant */
 #endif

sql/mysqld.cc

@@ -183,9 +183,6 @@ inline void reset_floating_point_exceptions()
 #else
 #include <my_pthread.h>			// For thr_setconcurency()
 #endif
-#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE) && !defined(HAVE_mit_thread)
-#define SET_RLIMIT_NOFILE
-#endif
 
 #ifdef SOLARIS
 extern "C" int gethostname(char *name, int namelen);
@@ -492,9 +489,6 @@ extern "C" pthread_handler_decl(handle_connections_namedpipes,arg);
 static pthread_handler_decl(handle_connections_shared_memory,arg);
 #endif
 extern "C" pthread_handler_decl(handle_slave,arg);
-#ifdef SET_RLIMIT_NOFILE
-static uint set_maximum_open_files(uint max_file_limit);
-#endif
 static ulong find_bit_type(const char *x, TYPELIB *bit_lib);
 static void clean_up(bool print_message);
 static void clean_up_mutexes(void);
@@ -919,6 +913,7 @@ void clean_up(bool print_message)
 #ifdef USE_RAID
   end_raid();
 #endif
+  my_free_open_file_info();
   my_free((char*) global_system_variables.date_format,
 	  MYF(MY_ALLOW_ZERO_PTR));
   my_free((char*) global_system_variables.time_format,
@@ -2108,28 +2103,32 @@ static int init_common_variables(const char *conf_file_name, int argc,
   DBUG_PRINT("info",("%s  Ver %s for %s on %s\n",my_progname,
 		     server_version, SYSTEM_TYPE,MACHINE_TYPE));
 
-#if defined( SET_RLIMIT_NOFILE) || defined( OS2)
   /* connections and databases needs lots of files */
   {
-    uint wanted_files=10+(uint) max(max_connections*5,
-				    max_connections+table_cache_size*2);
+    uint files, wanted_files;
+
+    wanted_files= 10+(uint) max(max_connections*5,
+				 max_connections+table_cache_size*2);
     set_if_bigger(wanted_files, open_files_limit);
-    // Note that some system returns 0 if we succeed here:
-    uint files=set_maximum_open_files(wanted_files);
-    if (files && files < wanted_files && ! open_files_limit)
+    files= my_set_max_open_files(wanted_files);
+
+    if (files < wanted_files)
     {
-      max_connections=	(ulong) min((files-10),max_connections);
-      table_cache_size= (ulong) max((files-10-max_connections)/2,64);
-      DBUG_PRINT("warning",
-		 ("Changed limits: max_connections: %ld  table_cache: %ld",
-		  max_connections,table_cache_size));
-      sql_print_error("Warning: Changed limits: max_connections: %ld  table_cache: %ld",max_connections,table_cache_size);
+      if (!open_files_limit)
+      {
+	max_connections=	(ulong) min((files-10),max_connections);
+	table_cache_size= (ulong) max((files-10-max_connections)/2,64);
+	DBUG_PRINT("warning",
+		   ("Changed limits: max_open_files: %u  max_connections: %ld  table_cache: %ld",
+		    files, max_connections, table_cache_size));
+	sql_print_error("Warning: Changed limits: max_open_files: %u  max_connections: %ld  table_cache: %ld",
+			files, max_connections, table_cache_size);
+      }
+      else
+	sql_print_error("Warning: Could not increase number of max_open_files to more than %u (request: %u)", files, wanted_files);
     }
     open_files_limit= files;
   }
-#else
-  open_files_limit= 0;		/* Can't set or detect limit */
-#endif
   unireg_init(opt_specialflag); /* Set up extern variabels */
   if (init_errmessage())	/* Read error messages from file */
     return 1;
@@ -4506,7 +4505,7 @@ The minimum value for this variable is 4096.",
   {"open_files_limit", OPT_OPEN_FILES_LIMIT,
    "If this is not 0, then mysqld will use this value to reserve file descriptors to use with setrlimit(). If this value is 0 then mysqld will reserve max_connections*5 or max_connections + table_cache*2 (whichever is larger) number of files.",
    (gptr*) &open_files_limit, (gptr*) &open_files_limit, 0, GET_ULONG,
-   REQUIRED_ARG, 0, 0, 65535, 0, 1, 0},
+   REQUIRED_ARG, 0, 0, OS_FILE_LIMIT, 0, 1, 0},
    {"preload_buffer_size", OPT_PRELOAD_BUFFER_SIZE,
     "The size of the buffer that is allocated when preloading indexes",
     (gptr*) &global_system_variables.preload_buff_size,
@@ -5812,95 +5811,6 @@ static void fix_paths(void)
 }
 
 
-/*
-  set how many open files we want to be able to handle
-
-  SYNOPSIS
-    set_maximum_open_files()
-    max_file_limit		Files to open
-
-  NOTES
-    The request may not fulfilled becasue of system limitations
-
-  RETURN
-    Files available to open
-*/
-
-#ifdef SET_RLIMIT_NOFILE
-
-#ifndef RLIM_INFINITY
-#define RLIM_INFINITY ((uint) 0xffffffff)
-#endif
-
-static uint set_maximum_open_files(uint max_file_limit)
-{
-  struct rlimit rlimit;
-  uint old_cur;
-  DBUG_ENTER("set_maximum_open_files");
-  DBUG_PRINT("enter",("files: %u", max_file_limit));
-
-  if (!getrlimit(RLIMIT_NOFILE,&rlimit))
-  {
-    old_cur= (uint) rlimit.rlim_cur;
-    DBUG_PRINT("info", ("rlim_cur: %u  rlim_max: %u",
-			(uint) rlimit.rlim_cur,
-			(uint) rlimit.rlim_max));
-    if (rlimit.rlim_cur >= max_file_limit ||
-	rlimit.rlim_cur == RLIM_INFINITY)
-      DBUG_RETURN(rlimit.rlim_cur);		/* purecov: inspected */
-    rlimit.rlim_cur= rlimit.rlim_max= max_file_limit;
-    if (setrlimit(RLIMIT_NOFILE,&rlimit))
-    {
-      if (global_system_variables.log_warnings)
-	sql_print_error("Warning: setrlimit couldn't increase number of open files to more than %u (request: %u)",
-			old_cur, max_file_limit); /* purecov: inspected */
-      max_file_limit= old_cur;
-    }
-    else
-    {
-      rlimit.rlim_cur= 0;			// Safety if next call fails
-      (void) getrlimit(RLIMIT_NOFILE,&rlimit);
-      DBUG_PRINT("info", ("rlim_cur: %u", (uint) rlimit.rlim_cur));
-      if ((uint) rlimit.rlim_cur < max_file_limit &&
-	  global_system_variables.log_warnings)
-	sql_print_error("Warning: setrlimit returned ok, but didn't change limits. Max open files is %u (request: %u)",
-			(uint) rlimit.rlim_cur,
-			max_file_limit); /* purecov: inspected */
-      max_file_limit= (uint) rlimit.rlim_cur;
-    }
-  }
-  DBUG_PRINT("exit",("max_file_limit: %u", max_file_limit));
-  DBUG_RETURN(max_file_limit);
-}
-#endif
-
-
-#ifdef OS2
-static uint set_maximum_open_files(uint max_file_limit)
-{
-  LONG     cbReqCount;
-  ULONG    cbCurMaxFH, cbCurMaxFH0;
-  APIRET   ulrc;
-  DBUG_ENTER("set_maximum_open_files");
-
-  // get current limit
-  cbReqCount = 0;
-  DosSetRelMaxFH( &cbReqCount, &cbCurMaxFH0);
-
-  // set new limit
-  cbReqCount = max_file_limit - cbCurMaxFH0;
-  ulrc = DosSetRelMaxFH( &cbReqCount, &cbCurMaxFH);
-  if (ulrc) {
-    sql_print_error("Warning: DosSetRelMaxFH couldn't increase number of open files to more than %d",
-		    cbCurMaxFH0);
-    cbCurMaxFH = cbCurMaxFH0;
-  }
-
-  DBUG_RETURN(cbCurMaxFH);
-}
-#endif
-
-
 /*
   Return a bitfield from a string of substrings separated by ','
   returns ~(ulong) 0 on error.