WL#4259 - Debug Sync Facility

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).

1 files changed, 9 insertions, 0 deletions

diff --git a/mysql-test/mysql-test-run.pl b/mysql-test/mysql-test-run.pl
index 114b6c84aa3..da94f02fb27 100755
--- a/mysql-test/mysql-test-run.pl
+++ b/mysql-test/mysql-test-run.pl
@@ -226,6 +226,7 @@ my @default_valgrind_args= ("--show-reachable=yes");
 my @valgrind_args;
 my $opt_valgrind_path;
 my $opt_callgrind;
+my $opt_debug_sync_timeout= 300; # Default timeout for WAIT_FOR actions.
 
 our $opt_warnings= 1;
 
@@ -867,6 +868,7 @@ sub command_line_setup {
              'valgrind-option=s'        => \@valgrind_args,
              'valgrind-path=s'          => \$opt_valgrind_path,
 	     'callgrind'                => \$opt_callgrind,
+	     'debug-sync-timeout=i'     => \$opt_debug_sync_timeout,
 
 	     # Directories
              'tmpdir=s'                 => \$opt_tmpdir,
@@ -4170,6 +4172,11 @@ sub mysqld_arguments ($$$) {
     mtr_add_arg($args, "%s", "--core-file");
   }
 
+  # Enable the debug sync facility, set default wait timeout.
+  # Facility stays disabled if timeout value is zero.
+  mtr_add_arg($args, "--loose-debug-sync-timeout=%s",
+              $opt_debug_sync_timeout);
+
   return $args;
 }
 
@@ -5280,6 +5287,8 @@ Misc options
                         to turn off.
 
   sleep=SECONDS         Passed to mysqltest, will be used as fixed sleep time
+  debug-sync-timeout=NUM Set default timeout for WAIT_FOR debug sync
+                        actions. Disable facility with NUM=0.
   gcov                  Collect coverage information after the test.
                         The result is a gcov file per source and header file.
   experimental=<file>   Refer to list of tests considered experimental;