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

6 files changed, 78 insertions, 11 deletions

diff --git a/storage/archive/ha_archive.cc b/storage/archive/ha_archive.cc
index d70de0dd13c..7ee411f94dc 100644
--- a/storage/archive/ha_archive.cc
+++ b/storage/archive/ha_archive.cc
@@ -684,11 +684,11 @@ int ha_archive::create(const char *name, TABLE *table_arg,
     {
       if (!my_fstat(frm_file, &file_stat, MYF(MY_WME)))
       {
-        frm_ptr= (uchar *)my_malloc(sizeof(uchar) * file_stat.st_size, MYF(0));
+        frm_ptr= (uchar *)my_malloc(sizeof(uchar) * (size_t)file_stat.st_size, MYF(0));
         if (frm_ptr)
         {
-          my_read(frm_file, frm_ptr, file_stat.st_size, MYF(0));
-          azwrite_frm(&create_stream, (char *)frm_ptr, file_stat.st_size);
+          my_read(frm_file, frm_ptr, (size_t)file_stat.st_size, MYF(0));
+          azwrite_frm(&create_stream, (char *)frm_ptr, (size_t)file_stat.st_size);
           my_free((uchar*)frm_ptr, MYF(0));
         }
       }
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index 6f58fd70fbd..d5c92ff7c22 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -1061,7 +1061,29 @@ innobase_mysql_tmpfile(void)
 		will be passed to fdopen(), it will be closed by invoking
 		fclose(), which in turn will invoke close() instead of
 		my_close(). */
+
+#ifdef _WIN32
+		/* Note that on Windows, the integer returned by mysql_tmpfile 
+		has no relation to C runtime file descriptor. Here, we need 
+		to call my_get_osfhandle to get the HANDLE and then convert it 
+		to C runtime filedescriptor. */
+		{
+			HANDLE hFile = my_get_osfhandle(fd);
+			HANDLE hDup;
+			BOOL bOK = 
+				DuplicateHandle(GetCurrentProcess(), hFile, GetCurrentProcess(),
+								&hDup, 0, FALSE, DUPLICATE_SAME_ACCESS);
+			if(bOK) {
+				fd2 = _open_osfhandle((intptr_t)hDup,0);
+			}
+			else {
+				my_osmaperr(GetLastError());
+				fd2 = -1;
+			}	
+		}
+#else
 		fd2 = dup(fd);
+#endif
 		if (fd2 < 0) {
 			DBUG_PRINT("error",("Got error %d on dup",fd2));
 			my_errno=errno;
diff --git a/storage/innodb_plugin/handler/ha_innodb.cc b/storage/innodb_plugin/handler/ha_innodb.cc
index a9b81116a90..6ccdd9e3574 100644
--- a/storage/innodb_plugin/handler/ha_innodb.cc
+++ b/storage/innodb_plugin/handler/ha_innodb.cc
@@ -48,7 +48,9 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include <m_ctype.h>
 #include <mysys_err.h>
 #include <mysql/plugin.h>
-
+#ifdef _WIN32
+#include <io.h>
+#endif
 /** @file ha_innodb.cc */
 
 /* Include necessary InnoDB headers */
@@ -1172,7 +1174,28 @@ innobase_mysql_tmpfile(void)
 		will be passed to fdopen(), it will be closed by invoking
 		fclose(), which in turn will invoke close() instead of
 		my_close(). */
+#ifdef _WIN32
+		/* Note that on Windows, the integer returned by mysql_tmpfile
+		has no relation to C runtime file descriptor. Here, we need
+		to call my_get_osfhandle to get the HANDLE and then convert it 
+		to C runtime filedescriptor. */
+		{
+			HANDLE hFile = my_get_osfhandle(fd);
+			HANDLE hDup;
+			BOOL bOK = 
+				DuplicateHandle(GetCurrentProcess(), hFile, GetCurrentProcess(),
+								&hDup, 0, FALSE, DUPLICATE_SAME_ACCESS);
+			if(bOK) {
+				fd2 = _open_osfhandle((intptr_t)hDup,0);
+			}
+			else {
+				my_osmaperr(GetLastError());
+				fd2 = -1;
+			}
+		}
+#else
 		fd2 = dup(fd);
+#endif
 		if (fd2 < 0) {
 			DBUG_PRINT("error",("Got error %d on dup",fd2));
 			my_errno=errno;
diff --git a/storage/maria/ma_extra.c b/storage/maria/ma_extra.c
index d986525814e..28b7a93164d 100644
--- a/storage/maria/ma_extra.c
+++ b/storage/maria/ma_extra.c
@@ -415,9 +415,8 @@ int maria_extra(MARIA_HA *info, enum ha_extra_function function,
     if (!share->temporary)
       error= _ma_flush_table_files(info, MARIA_FLUSH_DATA | MARIA_FLUSH_INDEX,
                                    FLUSH_KEEP, FLUSH_KEEP);
-#ifdef HAVE_PREAD
+
     _ma_decrement_open_count(info, 1);
-#endif
     if (share->not_flushed)
     {
       share->not_flushed= 0;
diff --git a/storage/myisam/mi_locking.c b/storage/myisam/mi_locking.c
index 97011831af8..17c1fc83f13 100644
--- a/storage/myisam/mi_locking.c
+++ b/storage/myisam/mi_locking.c
@@ -239,7 +239,7 @@ int mi_lock_database(MI_INFO *info, int lock_type)
       break;				/* Impossible */
     }
   }
-#ifdef __WIN__
+#ifdef _WIN32
   else
   {
     /*
@@ -521,11 +521,11 @@ int _mi_writeinfo(register MI_INFO *info, uint operation)
       share->state.update_count= info->last_loop= ++info->this_loop;
       if ((error=mi_state_info_write(share->kfile, &share->state, 1)))
 	olderror=my_errno;
-#ifdef __WIN__
+#ifdef _WIN32
       if (myisam_flush)
       {
-	_commit(share->kfile);
-	_commit(info->dfile);
+        my_sync(share->kfile,0);
+        my_sync(info->dfile,0);
       }
 #endif
     }
diff --git a/storage/xtradb/handler/ha_innodb.cc b/storage/xtradb/handler/ha_innodb.cc
index dfe98f09e4f..6d233a4219d 100644
--- a/storage/xtradb/handler/ha_innodb.cc
+++ b/storage/xtradb/handler/ha_innodb.cc
@@ -55,7 +55,9 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include <m_ctype.h>
 #include <mysys_err.h>
 #include <mysql/plugin.h>
-
+#ifdef _WIN32
+#include <io.h>
+#endif
 /** @file ha_innodb.cc */
 
 /* Include necessary InnoDB headers */
@@ -1219,7 +1221,28 @@ innobase_mysql_tmpfile(void)
 		will be passed to fdopen(), it will be closed by invoking
 		fclose(), which in turn will invoke close() instead of
 		my_close(). */
+#ifdef _WIN32
+		/* Note that on Windows, the integer returned by mysql_tmpfile
+		has no relation to C runtime file descriptor. Here, we need
+		to call my_get_osfhandle to get the HANDLE and then convert it 
+		to C runtime filedescriptor. */
+		{
+			HANDLE hFile = my_get_osfhandle(fd);
+			HANDLE hDup;
+			BOOL bOK = 
+				DuplicateHandle(GetCurrentProcess(), hFile, GetCurrentProcess(),
+								&hDup, 0, FALSE, DUPLICATE_SAME_ACCESS);
+			if(bOK) {
+				fd2 = _open_osfhandle((intptr_t)hDup,0);
+			}
+			else {
+				my_osmaperr(GetLastError());
+				fd2 = -1;
+			}
+		}
+#else
 		fd2 = dup(fd);
+#endif
 		if (fd2 < 0) {
 			DBUG_PRINT("error",("Got error %d on dup",fd2));
 			my_errno=errno;