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used to report outdated information)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.
- Because my_seek actually is capable of returning an error code we should
exploit that in the best possible way.
- There might be kernel errors or other errors we can't predict and capturing
the return value of all system calls gives us better understanding of
possible errors.
Call pthread_mutex_destroy() on not used mutex.
Changed comments in .h and .c files from // -> /* */
Added detection of mutex on which one didn't call pthread_mutex_destroy()
Fixed bug in create_tmp_field() which causes a memory overrun in queries that uses "ORDER BY constant_expression"
Added optimisation for ORDER BY NULL
Remember UNION for ALTER TABLE
Added test for if we are supporting transactions.
Don't allow REPLACE to replace a row when we have generated an auto_increment key
Fixed bug when using BLOB keys
Fixed bug in SET @variable=user.
