- Changed storage to be 2 bytes instead of sizeof(size_t) (simple optimization)
- Fixed bug when using query_cache_strip_comments and query that started with '('
- Fixed DBUG_PRINT() that used wrong (not initialized) variables.
mysql-test/mysql-test-run.pl:
Added some space to make output more readable.
mysql-test/r/query_cache.result:
Updated test results
mysql-test/t/query_cache.test:
Added test with query_cache_strip_comments
sql/mysql_priv.h:
Added QUERY_CACHE_DB_LENGTH_SIZE
sql/sql_cache.cc:
Fixed bug when using query_cache_strip_comments and query that started with '('
Store db length in 2 characters instead of size_t.
Get db length from correct position (earlier we had an error when query started with ' ')
Fixed DBUG_PRINT() that used wrong (not initialized) variables.
A buffer large enough to hold the query _plus_ some additional
data is allocated before parsing is started. The additional data
is used by the query cache, and consists of the name of the current
database and a set of flags.
When a packet containing multiple SQL statements is sent to the
server and one of the statements changes the current database
(a "USE <db>" statement), and the name of the new current database
is longer than of the previous, there is not enough space in the
buffer for the new name, and we write out over the buffer boundary.
The fix adds an extra field to store the number of bytes
allocated to the database name in the buffer. If the current
database name changes, and the new name is longer than the
previous one, we refuse to cache the query.
- If USER is given, all threads for that user is signaled
- If SOFT is used then the KILL will not be sent to the handler. This can be used to not interrupt critical things in the handler like 'REPAIR'.
Internally added more kill signals. This gives us more information of why a query/connection was killed.
- KILL_SERVER is used when server is going down. In this case the users gets ER_SHUTDOWN as the reason connection was killed.
- Changed signals to number in correct order, which makes it easier to test how the signal should affect the code.
- New error message ER_CONNECTION_KILLED if connection was killed by 'KILL CONNECTION'. Before we got error ER_SHUTDOWN.
Changed names of not used parameters KILL_QUERY & KILL_CONNCTION to mysql_kill() to not conflict with defines in the server
include/mysql.h.pp:
Updated file
include/mysql_com.h:
Changed names of not used parameters KILL_QUERY & KILL_CONNCTION to mysql_kill() to not conflict with defines in the server
mysql-test/r/kill.result:
Added test of KILL USER
mysql-test/suite/rpl/r/rpl_stm_000001.result:
Updated error code
mysql-test/suite/rpl/t/rpl_stm_000001.test:
Updated error codes
mysql-test/t/flush_read_lock_kill.test:
Updated error codes
mysql-test/t/kill.test:
Added test of KILL USER
plugin/handler_socket/handlersocket/database.cpp:
Removed THD:: from KILL
sql/debug_sync.cc:
Removed THD:: from KILL
sql/event_scheduler.cc:
Removed THD:: from KILL
sql/filesort.cc:
Removed THD:: from KILL
sql/ha_ndbcluster_binlog.cc:
Removed THD:: from KILL
sql/handler.cc:
Removed THD:: from KILL
Simplify code.
sql/lex.h:
Added new keywords HARD | SOFT
sql/log.cc:
Removed THD:: from KILL
Added testing of new error ER_CONNECTION_KILLED
sql/log_event.cc:
Removed THD:: from KILL
Added testing of new error ER_CONNECTION_KILLED
sql/mysql_priv.h:
Added new prototypes
sql/mysqld.cc:
Removed THD:: from KILL
Use KILL_SERVER_HARD signal on shutdown.
sql/scheduler.cc:
Removed THD:: from KILL
Simplify test if connection should be killed
sql/share/errmsg.txt:
New error message ER_CONNECTION_KILLED
sql/slave.cc:
Removed THD:: from KILL
sql/sp_head.cc:
Removed THD:: from KILL
sql/sql_base.cc:
Removed THD:: from KILL
sql/sql_cache.cc:
Removed THD:: from KILL
sql/sql_class.cc:
Removed THD:: from KILL
Added killed_errno()
Only signal kill to storage engine if HARD bit is set.
sql/sql_class.h:
Move KILL options out from THD to make them easier to use in sql_yacc.yy
sql/sql_connect.cc:
Removed THD:: from KILL
sql/sql_delete.cc:
Removed THD:: from KILL
sql/sql_error.cc:
Removed THD:: from KILL
sql/sql_insert.cc:
Removed THD:: from KILL
Simplifed testing if thread is killed.
sql/sql_lex.h:
Added kill options to st_lex
sql/sql_load.cc:
Removed THD:: from KILL
sql/sql_parse.cc:
Added kill options to st_lex
Simplifed and optimzed testing of thd->killed at end of query
Added support for KILL USER
Extended sql_kill() to allow use of more kill signals.
sql/sql_repl.cc:
Removed THD:: from KILL
sql/sql_show.cc:
Removed THD:: from KILL
Simplied testing if query/connection was killed
sql/sql_table.cc:
Removed THD:: from KILL
sql/sql_update.cc:
Removed THD:: from KILL
sql/sql_yacc.yy:
Added support for new KILL syntax: KILL [HARD|SOFT] [CONNECTION|QUERY] [ID | USER user_name]
storage/archive/ha_archive.cc:
Simplify compilation
storage/maria/ha_maria.cc:
Removed THD:: from KILL
Fixed crash when setting query_cache_type to 0.
client/Makefile.am:
Added zlib include (needed by checksum.c)
sql/set_var.cc:
Updated call to disable_query_cache()
sql/sql_cache.cc:
Don't give warning if we start mysqld with --query_cache_type=0 --query_cache-size=0
Fixed crash when setting query_cache_type to 0 (we shouldn't call query_cache.disable_query_cache() when there is no current_thd)
sql/sql_cache.h:
Added THD to disable_query_cache()
client/mysqltest.cc:
Column names.
mysql-test/r/grant_cache_no_prot.result:
fix of text.
mysql-test/r/grant_cache_ps_prot.result:
Fix of test.
mysql-test/r/query_cache.result:
Switching on and off query cache.
mysql-test/t/query_cache.test:
Switching on and off query cache.
mysys/charset.c:
Fix of parser.
sql/handler.cc:
thd added to parameters.
sql/log_event.cc:
thd added to parameters.
sql/log_event_old.cc:
thd added to parameters.
sql/mysql_priv.h:
Fixed functions definitions.
sql/mysqld.cc:
Comments stripping.
sql/set_var.cc:
Switching on and off query cache.
sql/set_var.h:
Switching on and off query cache.
sql/share/errmsg.txt:
New errors.
sql/sql_cache.cc:
Switching query cache on and off, removing comments.
sql/sql_cache.h:
thd added to parameters.
sql/sql_class.h:
Comments stripping.
sql/sql_db.cc:
thd added to parameters.
sql/sql_lex.cc:
lex fixed.
sql/sql_parse.cc:
thd added to parameters.
Resolved all conflicts, bad merges and fixed a few minor bugs in the code.
Commented out the queries from multi_update, view, subselect_sj, func_str,
derived_view, view_grant that failed either with crashes in ps-protocol or
with wrong results.
The failures are clear indications of some bugs in the code and these bugs
are to be fixed.
Fix some bugs where we stored values other than 0 or 1 in my_bool
Fixed some compiler warnings
client/mysql.cc:
Changed interrupted_query from my_bool to int, as we stored 2 in it.
client/mysqladmin.cc:
Changed return variable type to same type as function value type
client/mysqltest.cc:
Changed 'found' to int as we store other values than 0 or 1 into it
Changed type for parameter of set_reconnect() to match usage.
extra/libevent/evbuffer.c:
Added __attribute__((unused))
extra/libevent/event.c:
Added __attribute__((unused))
extra/libevent/signal.c:
Added __attribute__((unused))
sql/event_data_objects.h:
my_bool -> bool
sql/event_db_repository.cc:
my_bool -> bool
sql/event_db_repository.h:
my_bool -> bool
sql/event_parse_data.h:
my_bool -> bool
sql/events.cc:
my_bool -> bool
sql/events.h:
my_bool -> bool
sql/field.cc:
my_bool -> bool
sql/field.h:
my_bool -> bool
sql/hash_filo.h:
my_bool -> bool
sql/item.cc:
my_bool -> bool
sql/item.h:
my_bool -> bool
sql/item_cmpfunc.h:
my_bool -> bool
Changed result_for_null_param from my_bool to int as we stored -1 in it.
sql/item_func.cc:
my_bool -> bool
Modified udf wrapper functions so that the UDF functions would continue to use my_bool. (To keep compatibility with UDF:s)
sql/item_func.h:
my_bool -> bool
sql/item_subselect.h:
my_bool -> bool
sql/item_sum.cc:
Modified udf wrapper functions so that the UDF functions would continue to use my_bool. (To keep compatibility with UDF:s)
sql/parse_file.h:
my_bool -> bool
sql/rpl_mi.h:
my_bool -> bool
sql/sp_rcontext.h:
my_bool -> bool
sql/sql_analyse.h:
my_bool -> bool
sql/sql_base.cc:
Change some assignments so that we don't initialize bool variables with int's.
sql/sql_bitmap.h:
my_bool -> bool
sql/sql_cache.cc:
my_bool -> bool
sql/sql_cache.h:
my_bool -> bool
sql/sql_class.h:
my_bool -> bool
sql/sql_insert.cc:
Change some assignments so that we don't initialize bool variables with int's.
sql/sql_prepare.cc:
my_bool -> bool
sql/table.h:
my_bool -> bool
storage/maria/ma_check.c:
Removed duplicate assignment
strings/decimal.c:
Fixed wrong variable usage.
Don't do complex arithmetic on bool when simple works.
- Changed to still use bcmp() in certain cases becasue
- Faster for short unaligneed strings than memcmp()
- Bettern when using valgrind
- Changed to use my_sprintf() instead of sprintf() to get higher portability for old systems
- Changed code to use MariaDB version of select->skip_record()
- Removed -%::SCCS/s.% from Makefile.am:s to remove automake warnings
compression protocol.
The loss of connection was caused by a malformed packet
sent by the server in case when query cache was in use.
When storing data in the query cache, the query cache
memory allocation algorithm had a tendency to reduce
the amount of memory block necessary to store a result
set, up to finally storing the entire result set in a single
block. With a significant result set, this memory block
could turn out to be quite large - 30, 40 MB and on.
When such a result set was sent to the client, the entire
memory block was compressed and written to network as a
single network packet. However, the length of the
network packet is limited by 0xFFFFFF (16MB), since
the packet format only allows 3 bytes for packet length.
As a result, a malformed, overly large packet
with truncated length would be sent to the client
and break the client/server protocol.
The solution is, when sending result sets from the query
cache, to ensure that the data is chopped into
network packets of size <= 16MB, so that there
is no corruption of packet length. This solution,
however, has a shortcoming: since the result set
is still stored in the query cache as a single block,
at the time of sending, we've lost boundaries of individual
logical packets (one logical packet = one row of the result
set) and thus can end up sending a truncated logical
packet in a compressed network packet.
As a result, on the client we may require more memory than
max_allowed_packet to keep, both, the truncated
last logical packet, and the compressed next packet.
This never (or in practice never) happens without compression,
since without compression it's very unlikely that
a) a truncated logical packet would remain on the client
when it's time to read the next packet
b) a subsequent logical packet that is being read would be
so large that size-of-new-packet + size-of-old-packet-tail >
max_allowed_packet.
To remedy this issue, we send data in 1MB sized packets,
that's below the current client default of 16MB for
max_allowed_packet, but large enough to ensure there is no
unnecessary overhead from too many syscalls per result set.
sql/net_serv.cc:
net_realloc() modified: consider already used memory
when compare packet buffer length
sql/sql_cache.cc:
modified Query_cache::send_result_to_client: send result to client
in chunks limited by 1 megabyte.
to write into a closed socket
sql/protocol.cc:
Protocol::flush modified: set thd->main_da.can_overwrite_status= TRUE
before call to net_flush() in order to prevent crash on assert in case
of socket write failure, reset it to FALSE when net_flush() returned;
Protocol::send_fields modified: return from method with error if call to
my_net_write(), proto.write() or write_eof_packet() failed.
sql/sql_cache.cc:
Query_cache::send_result_to_client modified: call to
thd->main_da.disable_status() only if write to socket
was successful.
sql/sql_cursor.cc:
Materialized_cursor::fetch modified: leave method if call to
result->send_data() failed.
sql/sql_prepare.cc:
send_prep_stmt() modified: call to thd->main_da.disable_status()
only if thd->protocol_text.send_fields() completed successfully.
Fixed bug in Yassle to get correct error messages in case of errors
Provide better error messages in case of ssl connect failure
Updated out-of-date ssl certificates to fix failing mysql-test-system (certificates now active for 10 years)
Fixed bug in query_cache that could cause asserts and hangs in DEBUG builds.
Fixed bug where one connection did not see changes done by another connection.
configure.in:
Changed version number from RC to stable
extra/yassl/src/yassl_error.cpp:
Fixed bug in Yassle to get correct error messages in case of errors
- 'error' is an enum that hold more error numbers than the enum was defined for
include/violite.h:
Added error output string for sslaccept() and sslconnect() to get reason for connect failure
mysql-test/mysql-test-run.pl:
Write failed test cases if mysql-test-run fails because of too many errors
mysql-test/r/grant.result:
Update results to reflect new certificates
mysql-test/r/openssl_1.result:
Update results to reflect new certificates
mysql-test/std_data/cacert.pem:
Update ssl certificate
mysql-test/std_data/client-cert.pem:
Update ssl certificate
mysql-test/std_data/client-key.pem:
Update ssl certificate
mysql-test/std_data/server-cert.pem:
Update ssl certificate
mysql-test/std_data/server-key.pem:
Update ssl certificate
mysql-test/t/grant.test:
Update test to reflect new certificates
mysql-test/t/openssl_1.test:
Update test to reflect new certificates
mysql-test/t/query_cache_debug.test:
Remove 'big_test' as test is now fast
sql-common/client.c:
Give a better error message if ssl connect fails
sql/net_serv.cc:
Fixed compiler warnings
sql/slave.cc:
Give a better error message in logs if ssl connect fails
sql/sql_cache.cc:
debug_wait_for_kill() now removes the set watch variable after kill signal
This is needed as invalidate_table() may be called twice for one query.
Ensure that net->query_cache_query is reset after query. This fixes assert in
query_cache_end_of_result() if query_cache_query holds results from previous query.
Removed DBUG_ASSERT(0), as this code can be run by query_cache_debug.test
sql/sql_connect.cc:
Give a better error message if ssl connect fails
sql/sql_parse.cc:
Fixed bug where one connection did not see changes done by another connection.
For statements that changes tables, close_thread_tables() MUST be called before
sending OK as a table handler may not make the changes available for other connections
before unlock_tables().
vio/viossl.c:
Give a better error message if ssl connect fails
- Marked a couple of tests with --big
- Fixed xtradb/handler/ha_innodb.cc to call explain_filename()
storage/xtradb/handler/ha_innodb.cc:
Call explain_filename() to get proper names for partitioned tables
This patch introduce a limit on the time the query cache can
block with a lock on SELECTs.
Other operations which causes a change in the table
data will still be blocked.
sql/sql_cache.cc:
* Introduced a timeout value for the qc lock when entering send_result_to_client()
and store_query() methods.
sql/sql_cache.h:
* New signature for Query_cache::try_lock()
- Moved some code from innodb_plugin to xtradb, to ensure that all tests runs
- Did changes in pbxt and maria storage engines becasue of changes in thd->query
- Reverted wrong code in sql_table.cc for how ROW_FORMAT is used.
This is a re-commit of Monty's merge to eliminate an extra commit from
MySQL-5.1.42 that was accidentally included in the merge.
This is a merge of the MySQL 5.1.41 clone-off (clone-5.1.41-build). In
case there are any extra changes done before final MySQL 5.1.41
release, these will need to be merged later before MariaDB 5.1.41
release.
- Added checking of return value for system(), freopen(), fgets() and chown()
- Ensure that calls that require a format strings gets a format string
- Other trivial things
Updated test suite results (especially for pbxt and embedded server)
Removed warning for "Invalid (old?) table or database name 'mysqld.1'" from pbxt tests
Speed up some pbxt tests by inserting begin ; commit; around "while loops with inserts"
Added mysqld startup option '--debug-flush'
Create maria_recovery.trace in data directory instead of current directory
client/mysql.cc:
Check return value from system()
client/mysql_upgrade.c:
Check return value from fgets()
client/mysqladmin.cc:
Check return value from fgets()
client/mysqlslap.c:
Check return value from system() (but ignore it, as it's not critical)
extra/yassl/src/crypto_wrapper.cpp:
Check return value from fgets() (but ignore it, as it's internal file)
extra/yassl/taocrypt/src/aes.cpp:
Added extra {} to remove compiler warning
extra/yassl/taocrypt/src/blowfish.cpp:
Added extra {} to remove compiler warning
extra/yassl/taocrypt/src/misc.cpp:
Ifdef not used code
include/mysys_err.h:
Added error message for failing chown()
mysql-test/mysql-test-run.pl:
Don't give warning for skipping ndbcluster (never enabled in MariaDB)
mysql-test/suite/funcs_1/r/is_columns_is_embedded.result:
Update with new information schema information
mysql-test/suite/funcs_1/r/is_tables_is_embedded.result:
New test
mysql-test/suite/funcs_1/r/is_tables_myisam_embedded.result:
Update test results (has not been tested for a long time)
mysql-test/suite/funcs_1/r/is_tables_mysql_embedded.result:
Update test results (has not been tested for a long time)
mysql-test/suite/funcs_1/t/is_tables_is.test:
Don't run with embedded server (as results differ)
I added a new test for embedded server
mysql-test/suite/funcs_1/t/is_tables_is_embedded.test:
New test
mysql-test/suite/pbxt/my.cnf:
Allow one to run pbxt tests without having to specify --mysqld=--default-storage-engine=pbxt
mysql-test/suite/pbxt/t/count_distinct3.test:
Speed up test by inserting begin; ... commit;
mysql-test/suite/pbxt/t/subselect.test:
Speed up test by inserting begin; ... commit;
mysys/errors.c:
Added error message for failing chown()
mysys/my_copy.c:
Added error message for failing chown()
mysys/my_redel.c:
Added error message for failing chown()
mysys/safemalloc.c:
Added cast to get rid of compiler warning
sql/ha_partition.cc:
Fixed wrong argument to sql_print_error() (it requires a format string)
sql/log.cc:
Test return value of freopen()
sql/mysqld.cc:
Test return value of freopen()
Added startup option '--debug-flush' to be used when one gets a core dump (easy to explain to people on IRC)
sql/rpl_rli.cc:
Fixed wrong argument to sql_print_error() (it requires a format string)
sql/set_var.cc:
Added {} to get rid of compiler warnings
sql/slave.cc:
Fixed wrong argument to mi->report() and sql_print...() (they require a format string)
sql/sql_cache.cc:
Fixed wrong argument to sql_printinformation() (it requires a format string)
sql/sql_parse.cc:
Test return value of fgets()
sql/sql_plugin.cc:
Fixed wrong argument to sql_print_error() (it requires a format string)
sql/sql_select.cc:
Use unique table name for internal temp tables instead of full path
(Simple speed & space optimization)
sql/udf_example.c:
Removed compiler warning about not used variable
storage/maria/ha_maria.cc:
Fixed wrong argument to sql_print_error() and ma_check_print_error() (they require a format string)
storage/maria/ma_recovery.c:
Create maria_recovery.trace in data directory instead of current directory
storage/maria/unittest/ma_test_loghandler-t.c:
Fixed wrong argument to ok(); Requires a format string
storage/pbxt/src/strutil_xt.cc:
Detect temporary tables by checking if that path for the table is in the mysql data directory.
The database for temporary tables is after this patch, from PBXT point of view, ""
This is needed to stop PBXT from calling filename_to_tablename() with the base directory as an argument, which caused
ERROR: Invalid (old?) table or database name 'mysqld.1'" in the log when running the test suite.
tests/mysql_client_test.c:
Fixed compiler warnings
unittest/mysys/base64-t.c:
Fixed wrong argument to diag() (it requires a format string)
Added a comment that the current 'print' of differing buffers doesn't print the right thing,
but didn't fix this as it's not important (unless we find a bug in the real code)
Implemented the server infrastructure for the fix:
1. Added a function LEX_STRING *thd_query_string(THD) to return
a LEX_STRING structure instead of char *.
This is the function that must be called in innodb instead of
thd_query()
2. Did some encapsulation in THD : aggregated thd_query and
thd_query_length into a LEX_STRING and made accessor and mutator
methods for easy code updating.
3. Updated the server code to use the new methods where applicable.
* 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.
Added (rewritten) patch from Percona to get extended statistics in slow.log:
- Added handling of 'set' variables to set_var.cc. Changed sql_mode to use this
- Added extra logging to slow log of 'Thread_id, Schema, Query Cache hit, Rows sent and Rows examined'
- Added optional logging to slow log, through log_slow_verbosity, of query plan statistics
- Added new user variables log_slow_rate_limit, log_slow_verbosity, log_slow_filter
- Added log-slow-file as synonym for 'slow-log-file', as most slow-log variables starts with 'log-slow'
- Added log-slow-time as synonym for long-query-time
Some trivial MyISAM optimizations:
- In prepare for drop, flush key blocks
- Don't call mi_lock_database if my_disable_locking is used
KNOWN_BUGS.txt:
Updated file to reflect MariaDB and not the Maria storage engine
README:
Updated file to reflect MariaDB
mysql-test/r/log_slow.result:
Test new options for slow query log
mysql-test/r/variables.result:
Updated result (old version cut of things at 79 characters)
mysql-test/t/log_slow.test:
Test new options for slow query log
sql/Makefile.am:
Added log_slow.h
sql/event_data_objects.cc:
Removed not needed test for enable_slow_log (is done when the flag is tested elsewhere)
sql/events.cc:
Use the general make_set() function instead of 'symbolic_mode_representation'
sql/filesort.cc:
Added status for used query plans
sql/log.cc:
Reset counters if no query_length (from Percona's patch; Not sure if needed, but can do no harm)
Added extra logging to slow log of 'Thread_id, Schema, Query Cache hit, Rows sent and Rows examined'
Added optional logging to slow log, through log_slow_verbosity, of query plan statistics
Fixed wrong test of error condition
sql/log_slow.h:
Defines and variables for log_slow_verbosity and log_slow_filter
sql/mysql_priv.h:
Include log_slow.h
sql/mysqld.cc:
Added new user variables log_slow_rate_limit, log_slow_verbosity, log_slow_filter
Added log-slow-file as synonym for 'slow-log-file', as most slow-log variables starts with 'log-slow'
Added log-slow-time as synonym for long-query-time
Added note that one should use log-slow-filter instead of log-slow-admin-statements
Updated comment from 'slow_query_log_file'
sql/set_var.cc:
Added long_slow_time as synonym for long_query_time
Added new user variables log_slow_rate_limit, log_slow_verbosity, log_slow_filter
dded handling of 'set' variables to set_var.cc. Changed sql_mode to use this
sql/set_var.h:
- Added handling of 'set' variables. Changed sql_mode to use this
sql/slave.cc:
Use global filter also for slaves
sql/sp_head.cc:
Simplify saving of general_slow_log state
Use the general make_set() function instead of 'symbolic_mode_representation'
sql/sql_cache.cc:
Added status for used query plans
sql/sql_class.cc:
Remember/restore query_plan_flags over complex statements
sql/sql_class.h:
Added variables to handle extended slow log statistics
sql/sql_parse.cc:
Added status for used query plans
Added test for filtering slow_query_log
sql/sql_select.cc:
Added status for used query plans
sql/sql_show.cc:
Use the general make_set() function instead of 'symbolic_mode_representation'
sql/strfunc.cc:
Report first error (not last) if something is wrong in a set
Removed compiler warning
storage/myisam/mi_extra.c:
In prepare for drop, flush key blocks (speed optimization)
storage/myisam/mi_locking.c:
Don't call mi_lock_database if my_disable_locking is used (speed optimization)
Early patch submitted for discussion.
It is possible for more than one thread to enter the condition
in query_cache_insert(), but the condition predicate is to
signal one thread each time the cache status changes between
the following states: {NO_FLUSH_IN_PROGRESS,FLUSH_IN_PROGRESS,
TABLE_FLUSH_IN_PROGRESS}
Consider three threads THD1, THD2, THD3
THD2: select ... => Got a writer in ::store_query
THD3: select ... => Got a writer in ::store_query
THD1: flush tables => qc status= FLUSH_IN_PROGRESS;
new writers are blocked.
THD2: select ... => Still got a writer and enters cond in
query_cache_insert
THD3: select ... => Still got a writer and enters cond in
query_cache_insert
THD1: flush tables => finished and signal status change.
THD2: select ... => Wakes up and completes the insert.
THD3: select ... => Happily waiting for better times. Why hurry?
This patch is a refactoring of this lock system. It introduces four new methods:
Query_cache::try_lock()
Query_cache::lock()
Query_cache::lock_and_suspend()
Query_cache::unlock()
This change also deprecates wait_while_table_flush_is_in_progress(). All threads are
queued and put on a conditional wait. On each unlock the queue is signalled. This resolve
the issues with left over threads. To assure that no threads are spending unnecessary
time waiting a signal broadcast is issued every time a lock is taken before a full
cache flush.
mysql-test/r/query_cache_debug.result:
* Added test case for bug43758
mysql-test/t/query_cache_debug.test:
* Added test case for bug43758
sql/sql_cache.cc:
* Replaced calls to wait_while_table_flush_is_in_progress() with
calls to try_lock(), lock_and_suspend() and unlock().
* Renamed enumeration Cache_status to Cache_lock_status.
* Renamed enumeration items to UNLOCKED, LOCKED_NO_WAIT and LOCKED.
If the LOCKED_NO_WAIT lock type is used to lock the query cache, other
threads using try_lock() will fail to acquire the lock.
This is useful if the query cache is temporary disabled due to
a full table flush.
sql/sql_cache.h:
* Replaced calls to wait_while_table_flush_is_in_progress() with
calls to try_lock(), lock_and_suspend() and unlock().
* Renamed enumeration Cache_status to Cache_lock_status.
* Renamed enumeration items to UNLOCKED, LOCKED_NO_WAIT and LOCKED.
If the LOCKED_NO_WAIT lock type is used to lock the query cache, other
threads using try_lock() will fail to acquire the lock.
This is useful if the query cache is temporary disabled due to
a full table flush.
