Essentially, the problem is that safemalloc is excruciatingly
slow as it checks all allocated blocks for overrun at each
memory management primitive, yielding a almost exponential
slowdown for the memory management functions (malloc, realloc,
free). The overrun check basically consists of verifying some
bytes of a block for certain magic keys, which catches some
simple forms of overrun. Another minor problem is violation
of aliasing rules and that its own internal list of blocks
is prone to corruption.
Another issue with safemalloc is rather the maintenance cost
as the tool has a significant impact on the server code.
Given the magnitude of memory debuggers available nowadays,
especially those that are provided with the platform malloc
implementation, maintenance of a in-house and largely obsolete
memory debugger becomes a burden that is not worth the effort
due to its slowness and lack of support for detecting more
common forms of heap corruption.
Since there are third-party tools that can provide the same
functionality at a lower or comparable performance cost, the
solution is to simply remove safemalloc. Third-party tools
can provide the same functionality at a lower or comparable
performance cost.
The removal of safemalloc also allows a simplification of the
malloc wrappers, removing quite a bit of kludge: redefinition
of my_malloc, my_free and the removal of the unused second
argument of my_free. Since free() always check whether the
supplied pointer is null, redudant checks are also removed.
Also, this patch adds unit testing for my_malloc and moves
my_realloc implementation into the same file as the other
memory allocation primitives.
In order to allow thread schedulers to be dynamically loaded,
it is necessary to make the following changes to the server:
- Two new service interfaces
- Modifications to InnoDB to inform the thread scheduler of state changes.
- Changes to the VIO subsystem for checking if data is available on a socket.
- Elimination of remains of the old thread pool implementation.
The two new service interfaces introduces are:
my_thread_scheduler
A service interface to register a thread
scheduler.
thd_wait
A service interface to inform thread scheduler
that the thread is about to start waiting.
In addition, the patch adds code that:
- Add a call to thd_wait for table locks in mysys
thd_lock.c by introducing a set function that
can be used to set a callback to be used when
waiting on a lock and resuming from waiting.
- Calling the mysys set function from the server
to set the callbacks correctly.
The thing is that on some platforms (e.g. Mac OS X) sockaddr_in / sockaddr_in6
contain a non-standard field (sin_len / sin6_len), that must be set.
The problem was that only standard fields were set, thus getnameinfo() returned
EAI_SYSTEM instead of EAI_NONAME.
The fix is to introduce configure-time checks (for GNU auto-tools and CMake) for
those additional fields and to set them if they are available.
(make relies GNU extentions). The patch was partially
backport from 6.0.
Original comment:
bug#30708: make relies GNU extensions. Now that we no longer use
BitKeeper we can safely remove the SCCS handling with no loss of
functionality.
Bug#16565 mysqld --help --verbose does not order variablesBug#20413 sql_slave_skip_counter is not shown in show variables
Bug#20415 Output of mysqld --help --verbose is incomplete
Bug#25430 variable not found in SELECT @@global.ft_max_word_len;
Bug#32902 plugin variables don't know their names
Bug#34599 MySQLD Option and Variable Reference need to be consistent in formatting!
Bug#34829 No default value for variable and setting default does not raise error
Bug#34834 ? Is accepted as a valid sql mode
Bug#34878 Few variables have default value according to documentation but error occurs
Bug#34883 ft_boolean_syntax cant be assigned from user variable to global var.
Bug#37187 `INFORMATION_SCHEMA`.`GLOBAL_VARIABLES`: inconsistent status
Bug#40988 log_output_basic.test succeeded though syntactically false.
Bug#41010 enum-style command-line options are not honoured (maria.maria-recover fails)
Bug#42103 Setting key_buffer_size to a negative value may lead to very large allocations
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
Bug#44797 plugins w/o command-line options have no disabling option in --help
Bug#46314 string system variables don't support expressions
Bug#46470 sys_vars.max_binlog_cache_size_basic_32 is broken
Bug#46586 When using the plugin interface the type "set" for options caused a crash.
Bug#47212 Crash in DBUG_PRINT in mysqltest.cc when trying to print octal number
Bug#48758 mysqltest crashes on sys_vars.collation_server_basic in gcov builds
Bug#49417 some complaints about mysqld --help --verbose output
Bug#49540 DEFAULT value of binlog_format isn't the default value
Bug#49640 ambiguous option '--skip-skip-myisam' (double skip prefix)
Bug#49644 init_connect and \0
Bug#49645 init_slave and multi-byte characters
Bug#49646 mysql --show-warnings crashes when server dies
Original changeset:
------------------------------------------------------------
revno: 2626
committer: davi@mysql.com/endora.local
timestamp: Wed 2008-04-23 09:33:25 -0300
message:
Fix for main.ssl and main.ssl_compress test case failures under pool-of-threads.
The problem is that the SSL layer has a read buffer and might read
more data than requested by the VIO layer. The SSL layer empties the
socket buffer which causes the socket to not be signaled for IO if
the client is waiting for a command which is sitting in the read
buffer.
The solution is to retrieve from the transport layer the number of
bytes waiting in the read buffer. The data in the read buffer needs
to be processed before waiting for more data.
------------------------------------------------------------
revno: 3317
revision-id: davi.arnaut@sun.com-20090522170916-fzc5ca3tjs9roy1t
parent: patrick.crews@sun.com-20090522152933-ole8s3suy4zqyvku
committer: Davi Arnaut <Davi.Arnaut@Sun.COM>
branch nick: 41860-6.0
timestamp: Fri 2009-05-22 14:09:16 -0300
message:
Bug#41860: Without Windows named pipe
The problem was that the patch for Bug#10374 broke named pipe
and shared memory transports on Windows due to a failure to
implement a dummy poll method for transports other than BSD
sockets. Another problem was that mysqltest lacked support
for named pipe and shared memory connections, which lead to
misleading test cases that were supposed run common queries
over both transports.
The solution is to properly implement, at the VIO layer, the
poll and is_connected methods. The is_connected method is
implemented for every suppported transport and the poll one
only where it makes sense. Furthermore, support for named pipe
and shared memory connections is added to mysqltest as to
enable testing of both transports using the test suite.
------------------------------------------------------------
revno: 2597.37.3
revision-id: sp1r-davi@mysql.com/endora.local-20080328123626-16430
parent: sp1r-anozdrin/alik@quad.opbmk-20080327125300-11290
committer: davi@mysql.com/endora.local
timestamp: Fri 2008-03-28 09:36:26 -0300
message:
Bug#10374 GET_LOCK does not let connection to close on the server side if it's aborted
The problem is that the server doesn't detect aborted connections which
are waiting on a lock or sleeping (user sleep), wasting system resources
for a connection that is already dead.
The solution is to peek at the connection every five seconds to verify if
the connection is not aborted. A aborted connection is detect by polling
the connection socket for available data to be read or end of file and in
case of eof, the wait is aborted and the connection killed.
Bug#31621: Windows server hanging during shutdown using named pipes
and idle connection
Problem: when idle pipe connection is forcefully closed with KILL
statement or when the server goes down, thread that is closing connection
would hang infinitely in CloseHandle(). The reason for the hang is that
named pipe operations are performed synchronously. In this mode all IOs
on pipe are serialized, that is CloseHandle() will not abort ReadFile()
in another thread, but wait for ReadFile() to complete.
The fix implements asynchrnous mode for named pipes, where operation of file
are not synchronized. Read/Write operation would fire an async IO and wait for
either IO completion or timeout.
Note, that with this patch timeouts are properly handled for named pipes.
Post-review: Win32 timeout code has been fixed for named pipes and shared
memory. We do not store pointer to NET in vio structure, only the read and
write timeouts.
Conflicts
=========
Text conflict in .bzr-mysql/default.conf
Text conflict in libmysqld/CMakeLists.txt
Text conflict in libmysqld/Makefile.am
Text conflict in mysql-test/collections/default.experimental
Text conflict in mysql-test/extra/rpl_tests/rpl_row_sp006.test
Text conflict in mysql-test/suite/binlog/r/binlog_tmp_table.result
Text conflict in mysql-test/suite/rpl/r/rpl_loaddata.result
Text conflict in mysql-test/suite/rpl/r/rpl_loaddata_fatal.result
Text conflict in mysql-test/suite/rpl/r/rpl_row_create_table.result
Text conflict in mysql-test/suite/rpl/r/rpl_row_sp006_InnoDB.result
Text conflict in mysql-test/suite/rpl/r/rpl_stm_log.result
Text conflict in mysql-test/suite/rpl_ndb/r/rpl_ndb_circular_simplex.result
Text conflict in mysql-test/suite/rpl_ndb/r/rpl_ndb_sp006.result
Text conflict in mysql-test/t/mysqlbinlog.test
Text conflict in sql/CMakeLists.txt
Text conflict in sql/Makefile.am
Text conflict in sql/log_event_old.cc
Text conflict in sql/rpl_rli.cc
Text conflict in sql/slave.cc
Text conflict in sql/sql_binlog.cc
Text conflict in sql/sql_lex.h
21 conflicts encountered.
NOTE
====
mysql-5.1-rpl-merge has been made a mirror of mysql-next-mr:
- "mysql-5.1-rpl-merge$ bzr pull ../mysql-next-mr"
This is the first cset (merge/...) committed after pulling
from mysql-next-mr.
2677 Vladislav Vaintroub 2008-11-04
CMakeLists.txt files cleanup
- remove SAFEMALLOC and SAFE_MUTEX definitions that were
present in *each* CMakeLists.txt. Instead, put them into top level
CMakeLists.txt, but disable on Windows, because
a) SAFEMALLOC does not add any functionality that is not already
present in Debug C runtime ( and 2 safe malloc one on top of the other
only unnecessarily slows down the server)
b)SAFE_MUTEX does not work on Windows and have been
explicitely disabled on Windows with #undef previously. Fortunately,
ntdll does pretty good job identifying l problems with
CRITICAL_SECTIONs.
DebugBreak()s on using uninited critical section, unlocking unowned
critical section)
-Also, remove occationally used -D_DEBUG (added by compiler
anyway)
