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.
This patch is a follow up to http://lists.mysql.com/commits/76678.
When an allocation failure occurs for the buffer in the dynamic
array, an error condition was being set. The dynamic array is
usable even if the memory allocation fails. Since in most cases
the thread can continue to work without any problems the error
condition should not be set here.
This patch adds logic to remove the error condition from being set
when the memory allocation for the buffer in dynamic array fails.
mysys/array.c:
Bug#43572 Handle failures from hash_init
Remove the MY_WME flag from the call to malloc in order to
prevent the error status from being set in the init_dynamic_array
method. Since this memory allocation failure is no longer
fatal this method has been modified to return FALSE
(indicate success) irrespective of array->buffer being
allocated.
Because of a regression introduced by bug#19027 the option --enable-foobar
doesn't work anymore for any plugin 'foobar'. The reason is that plugin
names are tristate options variables with optional parameters and integer
values are not accepted. Since the 'enable' prefix attempts to assign '1'
to the option the operation fails.
This patch translates any number n assigned to a plugin variable of type ENUM
to be the corresponding enumerated item. As a side effect --enable-foobar and
--disable-foobar will also start working again.
mysys/my_getopt.c:
* setval now accepts integer values for option variables of type ENUM.
The merge from http://lists.mysql.com/commits/76678 caused the
growth_size parameter to the my_init_dynamic_array function to
be ignored. This patch corrects the problem.
mysys/hash.c:
Bug#43572 Handle failures from hash_init
Replacing the last parameter to my_init_dynamic_array with
growth_size.
Failure to allocate memory for the hash->array element,
caused hash_init to return without initializing the other
members of the hash. Thus although the dynamic array
buffer may be allocated at a later point in the code, the
incompletely initialized hash caused fatal failures.
This patch moves the initialization of the other members
of the hash above the array allocation, so that the usage
of this hash will not result in fatal failures.
include/hash.h:
Bug#43572 Handle failures from hash_init
hash_inited is used to verify that the hash is
valid. After the change induced by the current
patch hash->array.buffer !=0 is not a valid check
for this condition, since, the dynamic array can
be allocated even at a later time. Bootstrap SQL
script is setting some variables, which are
actually not set due to this hash_inited issue.
Thus we get empty grant tables.
A better way to check if the hash is valid is
to verify that hash->blength is greater than 0.
mysys/hash.c:
Bug#43572 Handle failures from hash_init
Move the initialization of the other members
of the hash above the array allocation, so that
the usage of this hash will not result in fatal
failures.
Remove custom DLL loader code from innodb plugin code, use
symbols exported from mysqld.
storage/innodb_plugin/handler/ha_innodb.cc:
Remove a Win32 workaround for current_thd.
The original problem that innodb plugin used
value of TLS variable across DLL boundaries is
solved in MySQL server (current_thd is a function
not TLS variable now)
storage/innodb_plugin/handler/handler0alter.cc:
Remove custom delay loader
storage/innodb_plugin/handler/handler0vars.h:
Remove custom delay loader
storage/innodb_plugin/handler/i_s.cc:
Remove custom delay loader
storage/innodb_plugin/handler/win_delay_loader.cc:
Remove custom delay loader
storage/innodb_plugin/plug.in:
Remove commented out MYSQL_PLUGIN_STATIC,
CMake would not parse that correctly
It is not possible to prevent the server from starting if a mandatory
built-in plugin fails to start. This can in some cases lead to data
corruption when the old table name space suddenly is used by a different
storage engine.
A boolean command line option in the form of --foobar is automatically
created for every existing plugin "foobar". By changing this command line
option from a boolean to a tristate { OFF, ON, FORCE } it is possible to
specify the plugin loading policy for each plugin.
The behavior is specified as follows:
OFF = Disable the plugin and start the server
ON = Enable the plugin and start the server even if an error occurrs
during plugin initialization.
FORCE = Enable the plugin but don't start the server if an error occurrs
during plugin initialization.
mysql-test/lib/mtr_cases.pm:
* Changed --<pluginname> from a boolean to a tristate.
mysys/my_getopt.c:
* Changed --<pluginname> from boolean to tristate. Optional arguments
must still work for tristates. It is praxis that disable means value 0
and enable is value 1. Since plugin name is the only tristate with
optional arguments this principle will still hold.
sql/sql_plugin.cc:
* Changed --<pluginname> option from a boolean type to a tristate.
- FORCE will now terminate the server if the plugin fails to
initialize properly.
* Refactored prototypes for test_plugin_options() and construct_options()
to get rid of the 'enable' value pointer.
* Cleaned up code related to option name constructing.
* Added documentation
sql/sql_plugin.h:
* Introduced new member to st_plugin_int structure.
key_buffer_size.
The cause of corruption was number overflow when multiplying
two ulong values, number of used keycache blocks with size
of a single block. The result of multiplication exceeded ulong
range (4G) and this lead to incorrectly calculated buffer offset
in the key cache.
The fix is to use size_t for multiplication result.
This patch also fixes pointless cast in safemalloc
(size of allocated block to uint), that creates lot of false
alarm warnings when using big keycache (> 4GB) in debug mode.
