Fix warnings flagged by the new warning option -Wunused-but-set-variable
that was added to GCC 4.6 and that is enabled by -Wunused and -Wall. The
option causes a warning whenever a local variable is assigned to but is
later unused. It also warns about meaningless pointer dereferences.
strict aliasing violations.
Essentially, the problem is that large parts of the server were
developed in simpler times (last decades, pre C99 standard) when
strict aliasing and compilers supporting such optimizations were
rare to non-existent. Thus, when compiling the server with a modern
compiler that uses strict aliasing rules to perform optimizations,
there are several places in the code that might trigger undefined
behavior.
As evinced by some recent bugs, GCC does a somewhat good of job
misoptimizing such code, but on the other hand also gives warnings
about suspicious code. One problem is that the warnings aren't
always accurate, yet we can't afford to just shut them off as we
might miss real cases. False-positive cases are aggravated mostly
by casts that are likely to trigger undefined behavior.
The solution is to start a cleanup process focused on fixing and
reducing the amount of strict-aliasing related warnings produced
by GCC and others compilers. A good deal of noise reduction can
be achieved by just removing useless casts that are product of
historical cruft and are likely to trigger undefined behavior if
dereferenced.
The problem is a somewhat common misusage of the strmake function.
The strmake(dst, src, len) function writes at most /len/ bytes to
the string pointed to by src, not including the trailing null byte.
Hence, if /len/ is the exact length of the destination buffer, a
one byte buffer overflow can occur if the length of the source
string is equal to or greater than /len/.
Bug#45243: crash on win in sql thread clear_tables_to_lock() -> free()
Bug#45242: crash on win in mysql_close() -> free()
Bug#45238: rpl_slave_skip, rpl_change_master failed (lost connection) for STOP SLAVE
Bug#46030: rpl_truncate_3innodb causes server crash on windows
Bug#46014: rpl_stm_reset_slave crashes the server sporadically in pb2
When killing a user session on the server, it's necessary to
interrupt (notify) the thread associated with the session that
the connection is being killed so that the thread is woken up
if waiting for I/O. On a few platforms (Mac, Windows and HP-UX)
where the SIGNAL_WITH_VIO_CLOSE flag is defined, this interruption
procedure is to asynchronously close the underlying socket of
the connection.
In order to enable this schema, each connection serving thread
registers its VIO (I/O interface) so that other threads can
access it and close the connection. But only the owner thread of
the VIO might delete it as to guarantee that other threads won't
see freed memory (the thread unregisters the VIO before deleting
it). A side note: closing the socket introduces a harmless race
that might cause a thread attempt to read from a closed socket,
but this is deemed acceptable.
The problem is that this infrastructure was meant to only be used
by server threads, but the slave I/O thread was registering the
VIO of a mysql handle (a client API structure that represents a
connection to another server instance) as a active connection of
the thread. But under some circumstances such as network failures,
the client API might destroy the VIO associated with a handle at
will, yet the VIO wouldn't be properly unregistered. This could
lead to accesses to freed data if a thread attempted to kill a
slave I/O thread whose connection was already broken.
There was a attempt to work around this by checking whether
the socket was being interrupted, but this hack didn't work as
intended due to the aforementioned race -- attempting to read
from the socket would yield a "bad file descriptor" error.
The solution is to add a hook to the client API that is called
from the client code before the VIO of a handle is deleted.
This hook allows the slave I/O thread to detach the active vio
so it does not point to freed memory.
in load_defaults()
load_defaults(), my_search_option_files() and
my_print_default_files() utilized a global variable
containing a pointer to thread local memory. This could lead
to race conditions when those functions were called with high
concurrency.
Fixed by changing the interface of the said functions to avoid
the necessity for using a global variable.
Since we cannot change load_defaults() prototype for API
compatibility reasons, it was renamed my_load_defaults().
Now load_defaults() is a thread-unsafe wrapper around
a thread-safe version, my_load_defaults().
- Remove bothersome warning messages. This change focuses on the warnings
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length
- Remove bothersome warning messages. This change focuses on the warnings
that are covered by the ignore file: support-files/compiler_warnings.supp.
- Strings are guaranteed to be max uint in length
- Cherry pick 6.0 changes for Visual Studio 2008 support
- Add scripts win\build-vs9.bat and win\build-vs9_x64.bat
Also, remove CMake generated visual studio project files.
Rename client_last_error to last_error and client_last_errno to last_errno
to not break connectors which use the internal net structure for error handling.
cause ROLLBACK of statement", part 1. Review fixes.
Do not send OK/EOF packets to the client until we reached the end of
the current statement.
This is a consolidation, to keep the functionality that is shared by all
SQL statements in one place in the server.
Currently this functionality includes:
- close_thread_tables()
- log_slow_statement().
After this patch and the subsequent patch for Bug#12713, it shall also include:
- ha_autocommit_or_rollback()
- net_end_statement()
- query_cache_end_of_result().
In future it may also include:
- mysql_reset_thd_for_next_command().
make sure that if builder configured with a non-standard (!= 3306)
default TCP port that value actually gets used throughout. if they
didn't configure a value, assume "use a sensible default", which
will be read from /etc/services or, failing that, from the factory
default. That makes the order of preference
- command-line option
- my.cnf, where applicable
- $MYSQL_TCP_PORT environment variable
- /etc/services (unless configured --with-tcp-port)
- default port (--with-tcp-port=... or factory default)
Faster thr_alarm()
Added 'Opened_files' status variable to track calls to my_open()
Don't give warnings when running mysql_install_db
Added option --source-install to mysql_install_db
I had to do the following renames() as used polymorphism didn't work with Forte compiler on 64 bit systems
index_read() -> index_read_map()
index_read_idx() -> index_read_idx_map()
index_read_last() -> index_read_last_map()
Additional changes for bug#29903
- Changed to do embedded build part as normal build, when
WITH_EMBEDDED_SERVER is set.
- Allow both normal and debug build with embedded.
- Build static embedded library by pointing out all source and compile
it all, i.e. not building libraries from libraries, not portable.
- Let embedded use generated files from the "sql" directory, added
dependencies to make sure built before embedded.
- Mark library "dbug" in TARGET_LINK_LIBRARIES() with "debug", so only
linked in when debug target is used.
- Removed change of target name with "mysqld${MYSQLD_EXE_SUFFIX}", as
others can't depend on it, not defined at configure time. Instead
set the output file name.
- Created work around for bug in CMake 2.4.6 and output names, to
set the "mysqld<suffix>.pdb" name to the same base name.
- Set the correct manifest "name" (patch by iggy)
They had been introduced in 5.1 and were only later backported to 5.0;
as a consequence, the files in the 5.1 tree do not depend on the 5.0 ones,
and changes in 5.0 do not propagate into the 5.1 files.
To fix this, the (previous) files in 5.1 now are deleted ("bk rm"),
and the previously deleted files depending on 5.0 are now moved to the
respective source directories ("bk mv").
The current 5.1 contents is restored in these files.
If you need the previous history of the 5.1 files ("bk revtool"),
access those in "BitKeeper/deleted".
Contrary to the original plan, I did not introduce the name
"CMakeLists.historic" - mostly in order not to clutter the source tree.
This fixes bug#29982.
The problem was a race condition on shutdown -- when IM got shutdown
request while a guarded mysqld is starting. In this case the Guardian
thread tried to stop the mysqld, but might fail if the mysqld hadn't
created pid-file so far. When this happened, the mysqld-monitor thread
didn't stop, so the assert in Thread_registry happened.
The fix is to make several attempts to stop mysqld if it is active.
On the windows platform, if an instance object failed to initialize during
program start, the instance manager would crash.
This could happen if an incorrect mysqld path was supplied in the
defaults configuration file.
The patch prevents the program from crashing and makes it show an
error message instead.
Added --with-system-type=<systype> and --with-machine-type=<machtype>
options, to be able to override the one detected, for --version strings
field.cc, field.h, listener.cc:
C++ compatibility change for IBM VisualAge 6 and i5/OS
- The "mysql client in mysqld"(which is used by
replication and federated) should use alarms instead of setting
socket timeout value if the rest of the server uses alarm. By
always calling 'my_net_set_write_timeout'
or 'my_net_set_read_timeout' when changing the timeout value(s), the
selection whether to use alarms or timeouts will be handled by
ifdef's in those two functions.
- Move declaration of 'vio_timeout' into "vio_priv.h"
The following type conversions was done:
- Changed byte to uchar
- Changed gptr to uchar*
- Change my_string to char *
- Change my_size_t to size_t
- Change size_s to size_t
Removed declaration of byte, gptr, my_string, my_size_t and size_s.
Following function parameter changes was done:
- All string functions in mysys/strings was changed to use size_t
instead of uint for string lengths.
- All read()/write() functions changed to use size_t (including vio).
- All protocoll functions changed to use size_t instead of uint
- Functions that used a pointer to a string length was changed to use size_t*
- Changed malloc(), free() and related functions from using gptr to use void *
as this requires fewer casts in the code and is more in line with how the
standard functions work.
- Added extra length argument to dirname_part() to return the length of the
created string.
- Changed (at least) following functions to take uchar* as argument:
- db_dump()
- my_net_write()
- net_write_command()
- net_store_data()
- DBUG_DUMP()
- decimal2bin() & bin2decimal()
- Changed my_compress() and my_uncompress() to use size_t. Changed one
argument to my_uncompress() from a pointer to a value as we only return
one value (makes function easier to use).
- Changed type of 'pack_data' argument to packfrm() to avoid casts.
- Changed in readfrm() and writefrom(), ha_discover and handler::discover()
the type for argument 'frmdata' to uchar** to avoid casts.
- Changed most Field functions to use uchar* instead of char* (reduced a lot of
casts).
- Changed field->val_xxx(xxx, new_ptr) to take const pointers.
Other changes:
- Removed a lot of not needed casts
- Added a few new cast required by other changes
- Added some cast to my_multi_malloc() arguments for safety (as string lengths
needs to be uint, not size_t).
- Fixed all calls to hash-get-key functions to use size_t*. (Needed to be done
explicitely as this conflict was often hided by casting the function to
hash_get_key).
- Changed some buffers to memory regions to uchar* to avoid casts.
- Changed some string lengths from uint to size_t.
- Changed field->ptr to be uchar* instead of char*. This allowed us to
get rid of a lot of casts.
- Some changes from true -> TRUE, false -> FALSE, unsigned char -> uchar
- Include zlib.h in some files as we needed declaration of crc32()
- Changed MY_FILE_ERROR to be (size_t) -1.
- Changed many variables to hold the result of my_read() / my_write() to be
size_t. This was needed to properly detect errors (which are
returned as (size_t) -1).
- Removed some very old VMS code
- Changed packfrm()/unpackfrm() to not be depending on uint size
(portability fix)
- Removed windows specific code to restore cursor position as this
causes slowdown on windows and we should not mix read() and pread()
calls anyway as this is not thread safe. Updated function comment to
reflect this. Changed function that depended on original behavior of
my_pwrite() to itself restore the cursor position (one such case).
- Added some missing checking of return value of malloc().
- Changed definition of MOD_PAD_CHAR_TO_FULL_LENGTH to avoid 'long' overflow.
- Changed type of table_def::m_size from my_size_t to ulong to reflect that
m_size is the number of elements in the array, not a string/memory
length.
- Moved THD::max_row_length() to table.cc (as it's not depending on THD).
Inlined max_row_length_blob() into this function.
- More function comments
- Fixed some compiler warnings when compiled without partitions.
- Removed setting of LEX_STRING() arguments in declaration (portability fix).
- Some trivial indentation/variable name changes.
- Some trivial code simplifications:
- Replaced some calls to alloc_root + memcpy to use
strmake_root()/strdup_root().
- Changed some calls from memdup() to strmake() (Safety fix)
- Simpler loops in client-simple.c
- Added script to generate application specific manifest.
- Added new CMake MACRO to add customer build events which will first
generate a manifest and then embeds that manifest into an executable.
Change to use remove_file instead of 'system rm' in a lot of tests. (Should fix some windows test problems)
Removed memory leak in mysql_test if sync_with_master fails.
Do not terminate ndb_cluster_binary_log before the util thread has finnished. This should fix a shutdown bug where a thread is accessing injector_mutex after it's freed.
Patch may fix Bug#27622 "mysqld shutdown, util thread continues, while binlog thread exits"
