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.
include/violite.h:
Add pipe_overlapped to Vio structure for async IO for named pipes.
sql-common/client.c:
Use asynchronous pipe IO.
sql/mysqld.cc:
Use asynchronous pipe IO.
vio/vio.c:
-Refactor timeouts for win32 protocols: shared memory and named pipes.
Store read/write timeout in VIO structure, instead of storing pointer
to NET. New function vio_win32_timeout called indirectly via
vio_timeout changes these values.
vio/vio_priv.h:
Remove vio_ignore_timeout.
Add vio_win32_timeout to be used for named pipes and shared memory.
vio/viosocket.c:
Use async IO for named pipes.
After issuing IO, wait for either IO completion, pipe_close_event
or timeout.
Refactor timeouts for named pipe and shared memory.
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.
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.
2630.39.1, 2630.28.29, 2630.34.3, 2630.34.2, 2630.34.1, 2630.29.29,
2630.29.28, 2630.31.1, 2630.28.13, 2630.28.10, 2617.23.14 and
some other minor revisions.
This patch implements:
WL#4264 "Backup: Stabilize Service Interface" -- all the
server prerequisites except si_objects.{h,cc} themselves (they can
be just copied over, when needed).
WL#4435: Support OUT-parameters in prepared statements.
(and all issues in the initial patches for these two
tasks, that were discovered in pushbuild and during testing).
Bug#39519: mysql_stmt_close() should flush all data
associated with the statement.
After execution of a prepared statement, send OUT parameters of the invoked
stored procedure, if any, to the client.
When using the binary protocol, send the parameters in an additional result
set over the wire. When using the text protocol, assign out parameters to
the user variables from the CALL(@var1, @var2, ...) specification.
The following refactoring has been made:
- Protocol::send_fields() was renamed to Protocol::send_result_set_metadata();
- A new Protocol::send_result_set_row() was introduced to incapsulate
common functionality for sending row data.
- Signature of Protocol::prepare_for_send() was changed: this operation
does not need a list of items, the number of items is fully sufficient.
The following backward incompatible changes have been made:
- CLIENT_MULTI_RESULTS is now enabled by default in the client;
- CLIENT_PS_MULTI_RESUTLS is now enabled by default in the client.
include/mysql.h:
Add a new flag to MYSQL_METHODS::flush_use_result
function pointer. This flag determines if all results
should be flushed or only the first one:
- if flush_all_results is TRUE, then cli_flush_use_result()
will read/flush all pending results. I.e. it will read
all packets while server status attribute indicates that
there are more results. This is a new semantic, required
to fix the bug.
- if flush_all_results is FALSE, the old sematic
is preserved -- i.e. cli_flush_use_result() reads data
until first EOF-packet.
include/mysql.h.pp:
Update the ABI with new calls (compatible changes).
include/mysql_com.h:
Add CLIENT_PS_OUT_PARAMS -- a client capability indicating that the client supportsю
libmysql/libmysql.c:
Add mysql_stmt_next_result() -- analogue of mysql_next_result() for binary protocol.
Fix a minor bug in alloc_fields() -- not all members were copied over,
and some only shallow-copied (catalog).
Flush all results in mysql_stmt_close() (Bug#39519).
libmysqld/lib_sql.cc:
Rename send_fields() -> send_result_set_metadata().
Refactoring: change prepare_for_send() so that it accepts only
what it really needs -- a number of elements in the list.
mysql-test/r/ps.result:
Update results: WL#4435.
mysql-test/t/ps.test:
WL#4435: A test case for an SQL-part of the problem.
sql-common/client.c:
Bug#39519.
Implement new functionality in cli_flush_use_result():
if flush_all_delete is TRUE, then it should read/flush
all pending results.
sql/Makefile.am:
Add a new header sql_prepare.h to the list
of build headers.
sql/events.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/handler.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/mysql_priv.h:
Move sql_prepare.cc-specific declarations to a new
header - sql_prepare.h.
sql/procedure.h:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/protocol.cc:
Move the logic responsible for sending of one result
set row to the Protocol class. Define a template
for end-of-statement action.
Refactoring: change prepare_for_send() so that it accepts
only what it really needs -- a number of elements in the list.
Rename send_fields() to send_result_set_metadata().
sql/protocol.h:
Update with new declarations (WL#4435).
Rename send_fields() -> send_result_set_metadata().
prepare_for_send() only needs the number of columns to send,
and doesn't use the item list - update signature to require
only what's needed.
Add a new protocol type -- Protocol_local.
sql/repl_failsafe.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/slave.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_acl.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_base.cc:
Include sql_prepare.h (for Reprepare_observer).
sql/sql_cache.cc:
Extend the query cache flags block to be able
to store a numeric id for the result format,
not just a flag binary/non-binary.
sql/sql_class.cc:
Update to use the rename of Protocol::send_fields()
to Protocol::send_result_set_metadata().
Use Protocol::send_one_result_set_row().
sql/sql_class.h:
Move the declaration of Reprepare_observer to the
new header - sql_prepare.h.
Update to the new signature of class Protocol::send_fields().
sql/sql_connect.cc:
Use a protocol template method instead of
raw NET layer API at the end of a statement.
sql/sql_cursor.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_error.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_handler.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
Use new method Protocol::send_one_result_set_row().
sql/sql_help.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_lex.cc:
Initialize multi_statements variable.
Add a handy constant for empty lex
string.
sql/sql_lex.h:
Add a separate member for a standalone
parsing option - multi-statements support.
sql/sql_list.cc:
sql_list.h is a standalone header now,
no need to include mysql_priv.h.
sql/sql_list.h:
Make sql_list.h a stand-alone header.
sql/sql_parse.cc:
Include sql_prepare.h for prepared
statements- related declarations.
Use a new Protocol template method to end
each statement (send OK, EOF or ERROR to
the client).
sql/sql_prepare.cc:
Implement Execute Direct API (WL#4264),
currently unused. It will be used by the service
interface (Backup).
Use a new header - sql_prepare.h.
Add support for OUT parameters in the
binary and text protocol (prepared statements
only).
sql/sql_prepare.h:
Add a new header to contain (for now)
all prepared statement- external
related declarations.
sql/sql_profile.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_repl.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_select.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_show.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_string.h:
Add a way to convert a String to LEX_STRING.
sql/sql_table.cc:
Rename: Protocol::send_fields() ->
Protocol::send_result_set_metadata().
sql/sql_update.cc:
Remove an extraneous my_error(). The error
is already reported in update_non_unique_table_error().
sql/sql_yacc.yy:
Support for multi-statements is an independent
property of parsing, not derived from
the protocol type.
tests/mysql_client_test.c:
Add tests for WL#4435 (binary protocol).
2630.39.1, 2630.28.29, 2630.34.3, 2630.34.2, 2630.34.1, 2630.29.29,
2630.29.28, 2630.31.1, 2630.28.13, 2630.28.10, 2617.23.14 and
some other minor revisions.
This patch implements:
WL#4264 "Backup: Stabilize Service Interface" -- all the
server prerequisites except si_objects.{h,cc} themselves (they can
be just copied over, when needed).
WL#4435: Support OUT-parameters in prepared statements.
(and all issues in the initial patches for these two
tasks, that were discovered in pushbuild and during testing).
Bug#39519: mysql_stmt_close() should flush all data
associated with the statement.
After execution of a prepared statement, send OUT parameters of the invoked
stored procedure, if any, to the client.
When using the binary protocol, send the parameters in an additional result
set over the wire. When using the text protocol, assign out parameters to
the user variables from the CALL(@var1, @var2, ...) specification.
The following refactoring has been made:
- Protocol::send_fields() was renamed to Protocol::send_result_set_metadata();
- A new Protocol::send_result_set_row() was introduced to incapsulate
common functionality for sending row data.
- Signature of Protocol::prepare_for_send() was changed: this operation
does not need a list of items, the number of items is fully sufficient.
The following backward incompatible changes have been made:
- CLIENT_MULTI_RESULTS is now enabled by default in the client;
- CLIENT_PS_MULTI_RESUTLS is now enabled by default in the client.
------------------------------------------------------------
revno: 2476.657.208
committer: anozdrin/alik@station.
timestamp: Tue 2007-12-04 17:22:53 +0300
message:
Remove rpl_probe, enable_rpl_parse and disable_rpl_parse commands
from mysqltest, the corresponding funtctions have been removed from
MySQL C API
client/mysqltest.cc:
Remove unused functions.
libmysql/CMakeLists.txt:
Remove manager.c from Windows build.
sql-common/client.c:
A post-merge fix.
------------------------------------------------------------
revno: 2476.657.208
committer: anozdrin/alik@station.
timestamp: Tue 2007-12-04 17:22:53 +0300
message:
Remove rpl_probe, enable_rpl_parse and disable_rpl_parse commands
from mysqltest, the corresponding funtctions have been removed from
MySQL C API
------------------------------------------------------------
revno: 2476.981.1
committer: msvensson@pilot.mysql.com
timestamp: Mon 2007-11-26 19:03:23 +0100
message:
Bug#31952 Remove undocumented mysql_rpl_* functions.
- Functions removed + variables in st_mysql and st_mysql_options
renamed to "unused".
- Code updated to work without those functions and variables
------------------------------------------------------------
revno: 2476.981.1
committer: msvensson@pilot.mysql.com
timestamp: Mon 2007-11-26 19:03:23 +0100
message:
Bug#31952 Remove undocumented mysql_rpl_* functions.
- Functions removed + variables in st_mysql and st_mysql_options
renamed to "unused".
- Code updated to work without those functions and variables
given an already connected MYSQL handle
mysql_real_connect() did not check whether the MYSQL connection
handler was already connected and connected again even if so.
Now a CR_ALREADY_CONNECTED error is returned.
given an already connected MYSQL handle
mysql_real_connect() did not check whether the MYSQL connection
handler was already connected and connected again even if so.
Now a CR_ALREADY_CONNECTED error is returned.
Options loaded from config files were added before command line
arguments, and they were parsed together, which could interprete
the following:
option-a
option-b
as --option-a=--option-b if 'option-a' requires a value, and
caused confusing.
Because all options that requires a value are always given in
the form '--option=value', so it's an error if there is no
'=value' part for such an option read from config file.
This patch added a separator to separate the arguments from
config files and that from command line, so that they can be
handled differently. And report an error for options loaded
from config files that requires a value and is not given in the
form '--option=value'.
Options loaded from config files were added before command line
arguments, and they were parsed together, which could interprete
the following:
option-a
option-b
as --option-a=--option-b if 'option-a' requires a value, and
caused confusing.
Because all options that requires a value are always given in
the form '--option=value', so it's an error if there is no
'=value' part for such an option read from config file.
This patch added a separator to separate the arguments from
config files and that from command line, so that they can be
handled differently. And report an error for options loaded
from config files that requires a value and is not given in the
form '--option=value'.
We cann connect() in a non-blocking mode to be able to specify a
non-standard timeout.
The problem was that we did not fetch the status from the
non-blocking connect(). We assumed that poll() would not return
a POLLIN flag if the connect failed. But on some platforms this
is not true.
After a successful poll() we do now retrieve the status value
from connect() with getsockopt(...SO_ERROR...). Now we do know
if (and how) the connect failed.
The test case for my investigation was rpl.rlp_ssl1 on an
Ubuntu 9.04 x86_64 machine. Both, IPV4 and IPV6 were active.
'localhost' resolved first for IPV6 and then for IPV4. The
connection over IPV6 was blocked. rpl.rlp_ssl1 timed out
as it did not notice the failed connect(). The first read()
failed, which was interpreted as a master crash and the
connection was tried to reestablish with the same result
until the retry limit was reached.
With the fix, the connect() problem is immediately recognized,
and the connect() is retried on the second resolution for
'localhost', which is successful.
libmysqld/libmysqld.c:
Bug#37267 - connect() EINPROGRESS failures mishandled in client library
Changed a DBUG print string to distinguish the two mysql_real_connect()
implementations in DBUG traces.
mysql-test/include/wait_for_slave_param.inc:
Bug#37267 - connect() EINPROGRESS failures mishandled in client library
Made timeout value available in error message.
mysql-test/suite/rpl/r/rpl_get_master_version_and_clock.result:
Bug#37267 - connect() EINPROGRESS failures mishandled in client library
Fixed test result. Connect error is now detected as CR_CONN_HOST_ERROR
(2003) instead of CR_SERVER_LOST (2013).
sql-common/client.c:
Bug#37267 - connect() EINPROGRESS failures mishandled in client library
Added retrieval of the error code from the non-blocking connect().
Added DBUG.
Added comment.
We cann connect() in a non-blocking mode to be able to specify a
non-standard timeout.
The problem was that we did not fetch the status from the
non-blocking connect(). We assumed that poll() would not return
a POLLIN flag if the connect failed. But on some platforms this
is not true.
After a successful poll() we do now retrieve the status value
from connect() with getsockopt(...SO_ERROR...). Now we do know
if (and how) the connect failed.
The test case for my investigation was rpl.rlp_ssl1 on an
Ubuntu 9.04 x86_64 machine. Both, IPV4 and IPV6 were active.
'localhost' resolved first for IPV6 and then for IPV4. The
connection over IPV6 was blocked. rpl.rlp_ssl1 timed out
as it did not notice the failed connect(). The first read()
failed, which was interpreted as a master crash and the
connection was tried to reestablish with the same result
until the retry limit was reached.
With the fix, the connect() problem is immediately recognized,
and the connect() is retried on the second resolution for
'localhost', which is successful.
DECIMAL and TIMESTAMP used to have NUM_FLAG, but NEWDECIMAL was forgotten.
It's correct that TIMESTAMP does not have the flag nowadays (manual will be updated, connectors
developers will be notified).
client/mysqldump.c:
IS_NUM_FIELD(f) removed and replaced by its definition (f>flags & NUM_FLAG).
include/mysql.h:
- IS_NUM_FIELD() is removed because name is too close to IS_NUM() and it is not used a lot
- INTERNAL_NUM_FIELD() is removed:
* it forgets to test NEWDECIMAL (when IS_NUM() was updated for NEWDECIMAL we forgot
to update INTERNAL_NUM_FIELD()), that's why client didn't mark NEWDECIMAL with NUM_FLAG (a bug).
* it has an obsolete test for length of the TIMESTAMP field: test became accidentally wrong when length
of TIMESTAMP was changed to always be 19 (when the format was changed from YYYYMMDDhhmmss to
YYYY-MM-DD hh:mm:ss), never 8 or 14 anymore. That obsolete test caused TIMESTAMP to lose NUM_FLAG,
which was an accidental but good change (see below).
* IS_NUM() should be used instead
- IS_NUM(f) is changed: TIMESTAMP used to be parsable as a number without quotes (when it was formatted as
"YYYYMMDDhhmmss"); but it is not anymore (now that it is "YYYY-MM-DD hh:mm:ss"), so it should not have NUM_FLAG
(mysqldump needs to quote TIMESTAMP values), so IS_NUM() should return false for it.
libmysqld/lib_sql.cc:
use IS_NUM() instead of INTERNAL_NUM_FIELD()
mysql-test/r/bigint.result:
result change: NEWDECIMAL fields now have NUM_FLAG (32768)
mysql-test/r/metadata.result:
result change: NEWDECIMAL fields now have NUM_FLAG (32768)
mysql-test/r/mysqldump.result:
DECIMAL columns are not quoted anymore by mysqldump. Which is ok, the parser does not need '' for them
mysql-test/r/ps_2myisam.result:
result change: NEWDECIMAL fields now have NUM_FLAG (32768)
mysql-test/r/ps_3innodb.result:
result change: NEWDECIMAL fields now have NUM_FLAG (32768)
mysql-test/r/ps_4heap.result:
result change: NEWDECIMAL fields now have NUM_FLAG (32768)
mysql-test/r/ps_5merge.result:
result change: NEWDECIMAL fields now have NUM_FLAG (32768)
mysql-test/suite/ndb/r/ps_7ndb.result:
result change: NEWDECIMAL fields now have NUM_FLAG (32768)
mysql-test/t/metadata.test:
test for BUG#42980
sql-common/client.c:
use IS_NUM() instead of INTERNAL_NUM_FIELD()
DECIMAL and TIMESTAMP used to have NUM_FLAG, but NEWDECIMAL was forgotten.
It's correct that TIMESTAMP does not have the flag nowadays (manual will be updated, connectors
developers will be notified).
* Finished Monty and Jani's merge
* Some InnoDB tests still fail (because it's old xtradb code run against
newer testsuite). They are expected to go after mergning with the latest
xtradb.
Failing to connect would release parts of the MYSQL struct.
We would then proceed to try again to connect without re-
initializing the struct.
We prevent the unwanted freeing of data we'll still need now.
client/mysqladmin.cc:
Losing a connection (or not even getting on in the first place) should
not trash the MYSQL-struct.
Add a lot of comments.
Rewrite re-connection fu.
sql-common/client.c:
Assert against bad parameters usually caused by de-initing a
MYSQL-struct without re-initing it again before re-use.
Failing to connect would release parts of the MYSQL struct.
We would then proceed to try again to connect without re-
initializing the struct.
We prevent the unwanted freeing of data we'll still need now.
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.
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.
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.
server-tools/instance-manager/mysql_connection.cc:
Add stub method required for linking.
sql-common/client.c:
Invoke hook.
sql/client_settings.h:
Export hook.
sql/slave.cc:
Introduce hook that clears the active VIO before it is freed
by the client API.
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.
The problem is that the C API function mysql_real_connect
only attempts to connect to the first IP address returned
for a hostname. This can be a problem if a hostname maps
to multiple IP address and the server is not bound to the
first one that is returned.
The solution is to augment mysql_real_connect so that it
attempts to connect to all IPv4 addresses that a domain
name maps to. The function goes over the list of address
until a successful connection is established.
No test case is provided as its not possible to test this
automatically with the current testing infrastructure.
sql-common/client.c:
The client will try to connect to each IPv4 address from
the list of addresses that hostname maps to until a successful
connection is established or there are no more address.
The problem is that the C API function mysql_real_connect
only attempts to connect to the first IP address returned
for a hostname. This can be a problem if a hostname maps
to multiple IP address and the server is not bound to the
first one that is returned.
The solution is to augment mysql_real_connect so that it
attempts to connect to all IPv4 addresses that a domain
name maps to. The function goes over the list of address
until a successful connection is established.
No test case is provided as its not possible to test this
automatically with the current testing infrastructure.
Fix sleep() synchronisation in innodb_information_schema test case.
mysql-test/t/innodb_information_schema.test:
Using sleep for synchronisation does not work!!!
Replace by looping until the required condition is met.
sql-common/client.c:
mysql_ssl_set() did not free old pointers before overwriting with new ones (happens when
mysql_ssl_set() is called twice without calling mysql_close() in-between).
This sometimes caused memory leaks in the slave depending on exact timing of
master/slave shutdown.
Fixed by freeing old pointers before installing new ones in mysql_ssl_set(), just like
mysql_options() does.
