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/.
client/mysqldump.c:
Make room for the trailing null byte.
libmysql/libmysql.c:
Add comment, there is enough room in the buffer.
Increase buffer length, two strings are concatenated.
libmysqld/lib_sql.cc:
Make room for the trailing null byte.
mysys/default.c:
Make room for the trailing null bytes.
mysys/mf_pack.c:
Make room for the trailing null byte.
server-tools/instance-manager/commands.cc:
Copy only if overflow isn't possible in both cases.
server-tools/instance-manager/listener.cc:
Make room for the trailing null byte.
sql/log.cc:
Make room for the trailing null byte.
sql/sp_pcontext.h:
Cosmetic fix.
sql/sql_acl.cc:
MAX_HOSTNAME already specifies space for the trailing null byte.
sql/sql_parse.cc:
Make room for the trailing null byte.
sql/sql_table.cc:
Make room for the trailing null byte.
When compressed myisam files are opened, they are always memory mapped
sometimes causing memory swapping problems.
When we mmap the myisam compressed tables of size greater than the memory
available, the kswapd0 process utilization is very high consuming 30-40% of
the cpu. This happens only with linux kernels older than 2.6.9
With newer linux kernels, we don't have this problem of high cpu consumption
and this option may not be required.
The option 'myisam_mmap_size' is added to limit the amount of memory used for
memory mapping of myisam files. This option is not dynamic.
The default value on 32 bit system is 4294967295 bytes and on 64 bit system it
is 18446744073709547520 bytes.
Note: Testcase only tests the option variable. The actual bug has be to
tested manually.
include/my_global.h:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
define SIZE_T_MAX
include/myisam.h:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
declare 'myisam_mmap_size' and 'myisam_mmap_used' variables and the mutex
THR_LOCK_myisam_mmap
myisam/mi_packrec.c:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
add 'myisam_mmap_size' option which limits the memory available to mmap of
myisam files
myisam/mi_static.c:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
declare 'myisam_mmap_size' and 'myisam_mmap_used' variables and the mutex
THR_LOCK_myisam_mmap
myisam/myisamdef.h:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
move MEMMAP_EXTRA_MARGIN to myisam.h so that it can be used in mysqld.cc
mysql-test/r/variables.result:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
Testcase for BUG#37408 to test the myisam_mmap_size option
mysql-test/t/variables.test:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
Testcase for BUG#37408 to test the myisam_mmap_size option
mysys/my_thr_init.c:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
intialize the lock THR_LOCK_myisam_mmap
sql/mysqld.cc:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
add the 'myisam_mmap_size' option
sql/set_var.cc:
Fix for Bug #37408 - Compressed MyISAM files should not require/use mmap()
add the 'myisam_mmap_size' to the SHOW VARIABLES list
Problem: add_collation did not check that cs->number is smaller
than the number of elements in the array all_charsets[],
so server could crash when loading an Index.xml file with
a collation ID greater the number of elements
(for example when downgrading from 5.5).
Fix: adding a condition to check that cs->number is not out of valid range.
As documented in the bug report, the double checked locking
pattern has inherent issues, and cannot guarantee correct
initialization.
This patch replaces the logic in init_available_charsets()
with the use of pthread_once(3). A wrapper function,
my_pthread_once(), is introduced and is used in lieu of direct
calls to init_available_charsets(). Related defines
MY_PTHREAD_ONCE_* are also introduced.
For the Windows platform, the implementation in lp:sysbench is
ported. For single-thread use, a simple define calls the
function and sets the pthread_once control variable.
Charset initialization is modified to use my_pthread_once().
include/my_no_pthread.h:
Dummy my_pthread_once() for single thread use.
include/my_pthread.h:
Declaration for new function my_pthread_once().
mysys/charset.c:
Logic in init_available_charsets() is simplified.
Using my_pthread_once() for all calls to this func.
mysys/my_winthread.c:
Windows implementation of my_pthread_once().
Testing for presence of stuff in a hash inside the function
that's filling in the hash creates chicken-and-egg type of problems.
This results in test suite failures in mysql-pe in debug mode and
adds bad initialization dependency in 5.1.
Fixed by removing the debug code.
Not all my_hash_insert() calls are checked for return value.
This patch adds appropriate checks and failure responses
where needed.
mysys/hash.c:
* Debug hook for testing failures in my_hash_insert()
"What do you mean, there's a bug? There isn't even code!"
There was some token code for plug-in variables of the SET type,
but clearly this never worked, or was subject to massive bit rot
since. Bug-fixes ... fail-safes ... tests -- fais au mieux, mon chou!
mysys/my_getopt.c:
SETs set-up should set up a default value, but no min/max bounding.
mysys/typelib.c:
fail-safe requested by serg: don't try to skip separator when we're
already at end of string.
sql/sql_plugin.cc:
check_func_set:
Initialize error_len as find_set() will only update it on error,
and we're using the value to see whether an error has occurred (!= 0),
so we'd better not have a random val in there.
value_ptr:
There's no guarantee we're handed string lengths, so play it safe!
Use prepared string lengths where possible for minimum speed gain,
otherwise determine on the fly!
The prefix --skip- didn't work on 64 bit big endian machines
because of how the value pointer was casted.
mysys/my_getopt.c:
* Use the interface! The value pointer must correspond to the type mask or it will break on big endian platforms.
The bug is a compilation issue:
Function "find_key_block()" had thread operations
which were not guarded by "#if THREAD", add that now.
mysys/mf_keycache.c:
Without thread-support, we are in a single-threaded world,
so there is no parallelism, and the keycache cannot be
within a resize operation while this request is being processed.
The pthread_cond_wait implementations for windows might
dead lock in some rare circumstances.
1) One thread (I) enter a timed wait and at a point in
time ends up after mutex unlock and before
WaitForMultipleObjects(...)
2) Another thread (II) enters pthread_cond_broadcast.
Grabs the mutex and discovers one waiter. It set
the broadcast event and closes the broadcast gate
then unlocks the mutex.
3) A third thread (III) issues a pthread_cond_signal.
It grabs the mutex, discovers one waiter, sets the
signal event then unlock the mutex.
4) The first threads (I) enters WaitForMultipleObjects
and finds out that the signal object is in a
signalled state and exits the wait.
5) Thread (I) grabs the mutex and checks result status.
The number of waiters is decreased and becomes equal
to 0. The event returned was a signal event so the
broadcast gate isn't opened. The mutex is released.
6) Thread (II) issues a new broadcast. The mutex is
acquired but the number of waiters are 0 hence
the broadcast gate remains closed.
7) Thread (I) enters the wait again but is blocked by
the broadcast gate.
This fix resolves the above issue by always resetting
broadcast gate when there are no more waiters in th queue.
mysys/my_wincond.c:
* Always reset the broadcast gate if there are no more waiters left.
Backport from 6.0 to 5.1.
Only those sync points are included, which are used in debug_sync.test.
The Debug Sync Facility allows to place synchronization points
in the code:
open_tables(...)
DEBUG_SYNC(thd, "after_open_tables");
lock_tables(...)
When activated, a sync point can
- Send a signal and/or
- Wait for a signal
Nomenclature:
- signal: A value of a global variable that persists
until overwritten by a new signal. The global
variable can also be seen as a "signal post"
or "flag mast". Then the signal is what is
attached to the "signal post" or "flag mast".
- send a signal: Assign the value (the signal) to the global
variable ("set a flag") and broadcast a
global condition to wake those waiting for
a signal.
- wait for a signal: Loop over waiting for the global condition until
the global value matches the wait-for signal.
Please find more information in the top comment in debug_sync.cc
or in the worklog entry.
.bzrignore:
WL#4259 - Debug Sync Facility
Added the symbolic link libmysqld/debug_sync.cc.
CMakeLists.txt:
WL#4259 - Debug Sync Facility
Added definition for ENABLED_DEBUG_SYNC.
configure.in:
WL#4259 - Debug Sync Facility
Added definition for ENABLED_DEBUG_SYNC.
include/my_sys.h:
WL#4259 - Debug Sync Facility
Added definition for the DEBUG_SYNC_C macro.
libmysqld/CMakeLists.txt:
WL#4259 - Debug Sync Facility
Added sql/debug_sync.cc.
libmysqld/Makefile.am:
WL#4259 - Debug Sync Facility
Added sql/debug_sync.cc.
mysql-test/include/have_debug_sync.inc:
WL#4259 - Debug Sync Facility
New include file.
mysql-test/mysql-test-run.pl:
WL#4259 - Debug Sync Facility
Added option --debug_sync_timeout.
mysql-test/r/debug_sync.result:
WL#4259 - Debug Sync Facility
New test result.
mysql-test/r/have_debug_sync.require:
WL#4259 - Debug Sync Facility
New require file.
mysql-test/t/debug_sync.test:
WL#4259 - Debug Sync Facility
New test file.
mysys/my_static.c:
WL#4259 - Debug Sync Facility
Added definition for debug_sync_C_callback_ptr.
mysys/thr_lock.c:
WL#4259 - Debug Sync Facility
Added sync point "wait_for_lock".
sql/CMakeLists.txt:
WL#4259 - Debug Sync Facility
Added debug_sync.cc and debug_sync.h.
sql/Makefile.am:
WL#4259 - Debug Sync Facility
Added debug_sync.cc and debug_sync.h.
sql/debug_sync.cc:
WL#4259 - Debug Sync Facility
New source file.
sql/debug_sync.h:
WL#4259 - Debug Sync Facility
New header file.
sql/mysqld.cc:
WL#4259 - Debug Sync Facility
Added opt_debug_sync_timeout.
Added calls to debug_sync_init() and debug_sync_end().
Fixed a purecov comment (unrelated).
sql/set_var.cc:
WL#4259 - Debug Sync Facility
Added server variable "debug_sync".
sql/set_var.h:
WL#4259 - Debug Sync Facility
Added declaration for server variable "debug_sync".
sql/share/errmsg.txt:
WL#4259 - Debug Sync Facility
Added error messages ER_DEBUG_SYNC_TIMEOUT and ER_DEBUG_SYNC_HIT_LIMIT.
sql/sql_base.cc:
WL#4259 - Debug Sync Facility
Added sync points "after_flush_unlock" and "before_lock_tables_takes_lock".
sql/sql_class.cc:
WL#4259 - Debug Sync Facility
Added initialization for debug_sync_control to THD::THD.
Added calls to debug_sync_init_thread() and debug_sync_end_thread().
sql/sql_class.h:
WL#4259 - Debug Sync Facility
Added element debug_sync_control to THD.
storage/myisam/myisamchk.c:
Fixed a typo in an error message string (unrelated).
- Create the "dummy" thread joinable and wait for it to
exit before continuing in 'my_thread_global_init'
- This way we know that the pthread library is initialized
by one thread only
Large pages allocator could not allocate more than 4 GB due to
incorrect size alignment.
mysys/my_largepage.c:
Large pages allocator could not allocate more than 4 GB due to
incorrect size alignment.
Option "--without-server" still not working in 5.1
The general approach is to make sure that source files
which require thread support are only compiled if the build
really needs thread support,
which means when the server is built or a thread-safe client
library.
This required several changes:
- Make sure the subdirectories "storage/" and "plugin/" are
only processed if the server is built, not ifclient-only.
- Make the compilation of some modules which inherently
require threading depend on thread supportin the build.
- Separate the handling of threading in "configure.in" from
that of server issues, threading is also needed in a
non-server build of a thread-safe client library.
Also, "libdbug" must get built even in a client-only build,
so "dbug/" must be in the list of client directories.
In addition, calls to thread functions in source files which
can be built without thread support must use the wrapper
functions which handle the non-threaded build.
So the modules "client/mysqlimport.c" and "client/mysqlslap.c"
must call "my_thread_end()" only via "mysql_thread_end()".
Makefile.am:
The directories "storage/" and "plugin/" contain files
which are needed for the server only, so their contents
is to be built only if a server is built.
They must not be named unconditionally, because building
their contents will fail unless threads are enabled.
These directories are now listed in the "configure"
variable "sql_server_dirs" which becomes part of
"sql_union_dirs" if the server is to be built.
client/mysqlimport.c:
Use the wrapper function "mysql_thread_end()" which
correctly handles the case of a non-threaded build.
client/mysqlslap.c:
Use the wrapper function "mysql_thread_end()" which
correctly handles the case of a non-threaded build.
configure.in:
Various changes to support builds "--without-server":
1) For the unit tests, we need "libdbug".
2) Separate the treatment of the server from that of the
thread-safe client library.
3) Introduce an "automake conditional" "NEED_THREAD"
which can be checked in some "Makefile.am".
4) Include "storage/" and "plugin/" in the list of
"sql_server_dirs" so that they are handled in the
top "Makefile.am" only if the server is to be built
(see the change in that file).
mysys/Makefile.am:
The code of "mf_keycache.c" in 5.1 is no longer safe
to be built without thread support.
(In 5.0, this was possible.)
Rather than fix these issues, which is tedious and risky,
avoid the need to ever build it without thread support:
It is needed in the server only, which needs thread support.
The only case where we build a "libmysys" without thread
support is for a non-threaded client, where "mf_keycache"
is not neded.
So its inclusion in the list of source files can depend
on the new conditional "NEED_THREAD".
unittest/mysys/Makefile.am:
Test program "my_atomic-t" is to verify the correct handling
of threads only, it cannot be built without thread support
and is not needed in such cases either.
Let its build depend on the new conditional "NEED_THREAD".
can crash under load
Merge from 5.0, after backport from 5.1/5.4 to 5.0.
This makes the fixes for
Bug 44068 (RESTORE can disable the MyISAM Key Cache)
Bug 40944 (Backup: crash after myisampack)
available to 5.1.
can crash under load
Backport from 5.1.
Does also include key cache fixes from:
Bug 44068 (RESTORE can disable the MyISAM Key Cache)
Bug 40944 (Backup: crash after myisampack)
include/keycache.h:
Bug#17332 - changing key_buffer_size on a running server
can crash under load
Added KEY_CACHE components in_resize and waiting_for_resize_cnt.
myisam/mi_preload.c:
Bug#17332 - changing key_buffer_size on a running server
can crash under load
Added code to allow LOAD INDEX to load indexes of different block size.
mysys/mf_keycache.c:
Bug#17332 - changing key_buffer_size on a running server
can crash under load
.
Changed resize_key_cache() to not disable the key cache
after the flush phase. Changed queue handling to use
standard functions. Wake all threads waiting on resize_queue.
We can now have read/write threads waiting there (see below).
.
Combined add_to_queue() and the wait loops that were always
following it to the new function wait_on_queue().
Combined release_queue() and the condition that was always
preceding it to the new function release_whole_queue().
.
Added code to flag and respect the exceptional situation
BLOCK_IN_EVICTION.
.
Rewrote the resize branch of find_key_block().
.
Added code to the eviction handling in find_key_block()
to catch more exceptional cases.
.
Changed key_cache_read(), key_cache_insert() and key_cache_write()
so that they lock keycache->cache_lock whenever the key cache is
initialized. Checking for a disabled cache and incrementing and
decrementing the "resize counter" is always done within the lock.
Locking and unlocking as well as counting the "resize counter" is
now done once outside the loop. All three functions can now handle
a NULL return from find_key_block. This happens in the flush phase
of a resize and demands direct file I/O. Care is taken for
secondary requests (PAGE_WAIT_TO_BE_READ) to wait in any case.
Moved block status changes behind the copying of buffer data.
key_cache_insert() does now read the block if the caller did
supply less data than a full cache block.
key_cache_write() does now take care of parallel running flushes
(BLOCK_FOR_UPDATE, BLOCK_IN_FLUSHWRITE).
.
Changed free_block() to un-initialize block variables in the
correct order and respect an exceptional BLOCK_IN_EVICTION state.
.
Changed flushing to take care for parallel running writes.
Changed flushing to avoid freeing blocks in eviction.
Changed flushing to consider that parallel writes can move blocks
from the file_blocks hash to the changed_blocks hash.
Changed flushing to take care for other parallel flushes.
Changed flushing to assure that it ends with everything flushed.
Optimized normal flush at end of statement (FLUSH_KEEP),
but let other flush types be stringent.
.
Added some comments and debugging statements.
mysys/my_static.c:
Bug#17332 - changing key_buffer_size on a running server
can crash under load
Removed an unused global variable.
sql/ha_myisam.cc:
Bug#17332 - changing key_buffer_size on a running server
can crash under load
Moved an automatic (stack) variable to the scope where it is used.
sql/sql_table.cc:
Bug#17332 - changing key_buffer_size on a running server
can crash under load
Changed TL_READ to TL_READ_NO_INSERT in mysql_preload_keys.
CREATE TABLE...LIKE...
The mysql server option 'sync_frm' is ignored when table is created with
syntax CREATE TABLE .. LIKE..
Fixed by adding the MY_SYNC flag and calling my_sync() from my_copy() when
the flag is set.
In mysql_create_table(), when the 'sync_frm' is set, MY_SYNC flag is passed
to my_copy().
Note: TestCase is not attached and can be tested manually using debugger.
client/Makefile.am:
BUG#46591 - .frm file isn't sync'd with sync_frm enabled for
CREATE TABLE...LIKE...
add my_sync to sources as it is used in my_copy() method
include/my_sys.h:
BUG#46591 - .frm file isn't sync'd with sync_frm enabled for
CREATE TABLE...LIKE...
MY_SYNC flag is added to call my_sync() method
mysys/my_copy.c:
BUG#46591 - .frm file isn't sync'd with sync_frm enabled for
CREATE TABLE...LIKE...
my_sync() is method is called when MY_SYNC is set in my_copy()
sql/sql_table.cc:
BUG#46591 - .frm file isn't sync'd with sync_frm enabled for
CREATE TABLE...LIKE...
Fixed mysql_create_like_table() to call my_sync() when opt_sync_frm variable
is set
with gcc 4.3.2
This patch fixes a number of GCC warnings about variables used
before initialized. A new macro UNINIT_VAR() is introduced for
use in the variable declaration, and LINT_INIT() usage will be
gradually deprecated. (A workaround is used for g++, pending a
patch for a g++ bug.)
GCC warnings for unused results (attribute warn_unused_result)
for a number of system calls (present at least in later
Ubuntus, where the usual void cast trick doesn't work) are
also fixed.
client/mysqlmanager-pwgen.c:
A fix for warn_unused_result, adding fallback to use of
srand()/rand() if /dev/random cannot be used. Also actually
adds calls to rand() in the second branch so that it actually
creates a random password.
client/mysql.cc:
Remove leading whitespace.
Remove extra text after #else directive.
client/mysqldump.c:
Function does not take a parameter.
mysys/array.c:
buffer is a uchar pointer.
sql/item.cc:
Assert if it should not happen.
storage/myisam/mi_check.c:
Cast to expected type. This is probably a bug, but it is
casted in a similar way in another part of the code.
storage/ndb/include/mgmapi/ndb_logevent.h:
Apply fix from cluster team.
tests/mysql_client_test.c:
Remove extraneous slash.
decrease for INSERTs
Bulk inserts (multiple row, CREATE ... SELECT, INSERT ... SELECT) into
MyISAM tables were performed inefficiently. This was mainly affecting
use cases where read_buffer_size was considerably large (>256K) and low
number of rows was inserted (e.g. 30-100).
The problem was that during I/O cache initialization (this happens
before each bulk insert) allocated I/O buffer was unnecessarily
initialized to '\0'.
This was happening because of mess in flag values. MyISAM informs I/O
cache to wait for free space (if out of disk space) by passing
MY_WAIT_IF_FULL flag. Since MY_WAIT_IF_FULL and MY_ZEROFILL have the
same values, memory allocator was initializing memory to '\0'.
The performance gain provided with this patch may only be visible with
non-debug binaries, since safemalloc always initializes allocated memory
to 0xA5A5...
mysys/mf_iocache.c:
Remove MY_WAIT_IF_FULL from myflags before calling my_malloc
to prevent conflict with MY_ZEROFILL.
- Define and pass compile time path variables as pre-processor definitions to
mimic the makefile build.
- Set new CMake version and policy requirements explicitly.
- Changed DATADIR to MYSQL_DATADIR to avoid conflicting definition in
Platform SDK header ObjIdl.h which also defines DATADIR.
