This is the downport of

Bug#24509 - 2048 file descriptor limit on windows needs increasing, also 
WL#3049 - improved Windows I/O
                        
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.
                              
Another major change in this patch that almost all Windows specific file IO code
has been moved to a new file my_winfile.c, greatly reducing the amount of code 
in #ifdef blocks within mysys, thus improving readability.
                               
                                    
Minor enhancements:
- my_(f)stat() is changed to use __stati64 structure with  64 file size
and timestamps. It will return correct file size now (C runtime implementation
used to report outdated information)
- my_lock on Windows is prepared to handle additional timeout parameter
- after review : changed __WIN__ to _WIN32 in the new and changed code.

client/mysqlbinlog.cc:
  fileno -> my_fileno
client/readline.cc:
  fileno -> my_fileno
include/config-win.h:
  Increase OS_FILE_LIMIT for Windows.
  Remove O_SHARE - Windows does not support it. Its definition conflicts with
  O_SHORT_LIVED, that has different semantics.
include/my_dir.h:
  Use stat64 for stat() family of functions on Windows, because of 64 bit file size.
include/my_global.h:
  Increased default value for open file limit to 16K
include/my_sys.h:
  - my_file_info got new structure members - file handle and open flags
  - 2 new Windows-only mysys functions : my_get_osfhandle and my_osmaperr,
    modelled after Windows C runtime functions _get_osfhandle and _dosmaperr
libmysql/CMakeLists.txt:
  new files my_winfile.c and my_winerr.c
mysql-test/suite/large_tests/r/lock_tables_big.result:
  test for more then 2048 open file descriptors on Windows
mysql-test/suite/large_tests/t/lock_tables_big.test:
  test for more then 2048 open file descriptors on Windows
mysys/CMakeLists.txt:
  new files my_winfile.c and my_winerr.c
mysys/Makefile.am:
  new files my_winfile.c and my_winerr.c
mysys/default_modify.c:
  fileno -> my_fileno
mysys/my_chsize.c:
  implementation of chsize on Windows now moved to my_winfile.c
mysys/my_create.c:
  - my_sopen->my_win_open
  - close open file before removing (won't generally work on Windows otherwise)
mysys/my_file.c:
  On Windows, files returned by my_open will not start with 0, but 2048 
  (making it simple to detect incompatible mix of CRT and mysys  io functions)
mysys/my_fopen.c:
  fileno->my_win_fileno , fclose->my_win_fclose, fdopen->my_win_fdopen
  Check for legal filename is done by my_win_[f]open functions
mysys/my_fstream.c:
  fileno->my_fileno
mysys/my_lib.c:
  Windows stat() functions are moved to my_winfile.c
mysys/my_lock.c:
  Move Windows code under #ifdef to a separate function win_lock().
  Add a parameter for lock wait timeout
mysys/my_mmap.c:
   _get_osfhandle->my_get_osfhandle
mysys/my_open.c:
  my_sopen->my_win_open (simpler interface)
mysys/my_pread.c:
  moved most windows specific code to my_win_file.c
  Use my_win_pread
mysys/my_quick.c:
  Use my_win_read/my_win_write
mysys/my_read.c:
  Moved most of windows specific code to my_win_file.c
  Use my_win_read()
mysys/my_seek.c:
  On Windows, use my_win_lseek() in my_seek()/my_tell()
  Removed dead code (synchronization of lseeks)
  Improved DBUG tracing (file position is ulonglong, not ulong)
mysys/my_static.c:
  Removed array initialization. my_file_info_default is global variable
  thus it is initialized with all zeros anyway
mysys/my_sync.c:
  _commit->my_win_fsync
mysys/my_winerr.c:
  New file my_winerr.c
  Exports my_osmaperr modelled after undocumented C runtime
  function _dosmaperr(). The problem with _dosmaperr() used previously is that 
  1) it is nowhere documented and thus code relying on it is not guaranteed to work
     in subsequent releases on the C runtime
  2) it is present only in static C runtime (mysqld does not link if compiled with
    /MD)
mysys/my_winfile.c:
  New file my_winfile.c
  Implements ANSI/Posix file IO routines, when possible using native Windows IO, without
  C runtime (C runtime dropped because of the 2048 file descriptor limit).
mysys/my_write.c:
  write->my_win_write
mysys/mysys_priv.h:
  Declaration of Windows Posix functions (private to mysys, shall not be visible
  outside)
storage/innobase/handler/ha_innodb.cc:
  mysys native Windows IO : correct innodb tmp file handling
  mysql_tmpfile does not return valid CRT file descriptor, thus
  it is not possible to dup() it. Instead, the native file handle has 
  to be duplicated and then converted to CRT descriptor.
storage/myisam/mi_locking.c:
  _commit->my_sync

4 files changed, 60 insertions, 12 deletions

diff --git a/include/config-win.h b/include/config-win.h
index af4915440b1..bcad4e04346 100644
--- a/include/config-win.h
+++ b/include/config-win.h
@@ -65,7 +65,6 @@
 #endif
 
 /* File and lock constants */
-#define O_SHARE		0x1000		/* Open file in sharing mode */
 #ifdef __BORLANDC__
 #define F_RDLCK		LK_NBLCK	/* read lock */
 #define F_WRLCK		LK_NBRLCK	/* write lock */
@@ -336,7 +335,7 @@ inline ulonglong double2ulonglong(double d)
 #define FN_DEVCHAR	':'
 #define FN_NETWORK_DRIVES	/* Uses \\ to indicate network drives */
 #define FN_NO_CASE_SENCE	/* Files are not case-sensitive */
-#define OS_FILE_LIMIT	2048
+#define OS_FILE_LIMIT	UINT_MAX /* No limit*/
 
 #define DO_NOT_REMOVE_THREAD_WRAPPERS
 #define thread_safe_increment(V,L) InterlockedIncrement((long*) &(V))
diff --git a/include/my_dir.h b/include/my_dir.h
index 06509a3af19..90d708ac811 100644
--- a/include/my_dir.h
+++ b/include/my_dir.h
@@ -69,7 +69,11 @@ typedef struct my_stat
 
 #else
 
+#if(_MSC_VER)
+#define MY_STAT struct _stati64 /* 64 bit file size */
+#else
 #define MY_STAT struct stat	/* Orginal struct have what we need */
+#endif
 
 #endif /* USE_MY_STAT_STRUCT */
 
diff --git a/include/my_global.h b/include/my_global.h
index 4ad851e9e5d..f7e65d80dbb 100644
--- a/include/my_global.h
+++ b/include/my_global.h
@@ -736,7 +736,41 @@ typedef SOCKET_SIZE_TYPE size_socket;
 #define FN_LIBCHAR	'/'
 #define FN_ROOTDIR	"/"
 #endif
-#define MY_NFILE	64	/* This is only used to save filenames */
+
+/* 
+  MY_FILE_MIN is  Windows speciality and is used to quickly detect
+  the mismatch of CRT and mysys file IO usage on Windows at runtime.
+  CRT file descriptors can be in the range 0-2047, whereas descriptors returned
+  by my_open() will start with 2048. If a file descriptor with value less then
+  MY_FILE_MIN is passed to mysys IO function, chances are it stemms from
+  open()/fileno() and not my_open()/my_fileno.
+
+  For Posix,  mysys functions are light wrappers around libc, and MY_FILE_MIN
+  is logically 0.
+*/
+
+#ifdef _WIN32
+#define MY_FILE_MIN  2048
+#else
+#define MY_FILE_MIN  0
+#endif
+
+/* 
+  MY_NFILE is the default size of my_file_info array.
+
+  It is larger on Windows, because it all file handles are stored in my_file_info
+  Default size is 16384 and this should be enough for most cases.If it is not 
+  enough, --max-open-files with larger value can be used.
+
+  For Posix , my_file_info array is only used to store filenames for
+  error reporting and its size is not a limitation for number of open files.
+*/ 
+#ifdef _WIN32
+#define MY_NFILE (16384 + MY_FILE_MIN)
+#else
+#define MY_NFILE 64
+#endif
+
 #ifndef OS_FILE_LIMIT
 #define OS_FILE_LIMIT	65535
 #endif
@@ -773,9 +807,8 @@ typedef SOCKET_SIZE_TYPE size_socket;
 	/* Some things that this system doesn't have */
 
 #define NO_HASH			/* Not needed anymore */
-#ifdef __WIN__
-#define NO_DIR_LIBRARY		/* Not standar dir-library */
-#define USE_MY_STAT_STRUCT	/* For my_lib */
+#ifdef _WIN32
+#define NO_DIR_LIBRARY		/* Not standard dir-library */
 #endif
 
 /* Some defines of functions for portability */
diff --git a/include/my_sys.h b/include/my_sys.h
index 222564e0b44..849c35606b1 100644
--- a/include/my_sys.h
+++ b/include/my_sys.h
@@ -310,9 +310,13 @@ enum file_type
 
 struct st_my_file_info
 {
-  char *		name;
-  enum file_type	type;
-#if defined(THREAD) && !defined(HAVE_PREAD)
+  char  *name;
+#ifdef _WIN32
+  HANDLE fhandle;   /* win32 file handle */
+  int    oflag;     /* open flags, e.g O_APPEND */
+#endif
+  enum   file_type	type;
+#if defined(THREAD) && !defined(HAVE_PREAD) && !defined(_WIN32)
   pthread_mutex_t	mutex;
 #endif
 };
@@ -617,12 +621,12 @@ extern void *my_memmem(const void *haystack, size_t haystacklen,
                        const void *needle, size_t needlelen);
 
 
-#ifdef __WIN__
-extern int my_access(const char *path, int amode);
-extern File my_sopen(const char *path, int oflag, int shflag, int pmode);
+#ifdef _WIN32
+extern int      my_access(const char *path, int amode);
 #else
 #define my_access access
 #endif
+
 extern int check_if_legal_filename(const char *path);
 extern int check_if_legal_tablename(const char *path);
 
@@ -633,6 +637,13 @@ extern int nt_share_delete(const char *name,myf MyFlags);
 #define my_delete_allow_opened(fname,flags)  my_delete((fname),(flags))
 #endif
 
+#ifdef _WIN32
+/* Windows-only functions (CRT equivalents)*/
+extern File     my_sopen(const char *path, int oflag, int shflag, int pmode);
+extern HANDLE   my_get_osfhandle(File fd);
+extern void     my_osmaperr(unsigned long last_error);
+#endif
+
 #ifndef TERMINATE
 extern void TERMINATE(FILE *file, uint flag);
 #endif
@@ -641,6 +652,7 @@ extern void wait_for_free_space(const char *filename, int errors);
 extern FILE *my_fopen(const char *FileName,int Flags,myf MyFlags);
 extern FILE *my_fdopen(File Filedes,const char *name, int Flags,myf MyFlags);
 extern int my_fclose(FILE *fd,myf MyFlags);
+extern File my_fileno(FILE *fd);
 extern int my_chsize(File fd,my_off_t newlength, int filler, myf MyFlags);
 extern int my_sync(File fd, myf my_flags);
 extern int my_sync_dir(const char *dir_name, myf my_flags);