Merge branch '10.6.12' into 10.6

2025-01-15 19:42:28 +01:00 · 2023-02-06 20:18:44 +01:00 · 2023-02-06 20:18:44 +01:00 · 70a515df43
commit 70a515df43
parent 4c79e15cc3 80ae69c8bc
17 changed files with 325 additions and 102 deletions
--- a/2
+++ b/2
@ -1,4 +1,4 @@
 MYSQL_VERSION_MAJOR=10
 MYSQL_VERSION_MINOR=6
-MYSQL_VERSION_PATCH=12
+MYSQL_VERSION_PATCH=13
 SERVER_MATURITY=stable
--- a/dbug/dbug.c
+++ b/dbug/dbug.c
@ -86,7 +86,7 @@
 #include <m_string.h>
 #include <errno.h>
 #ifdef HAVE_gcov
-extern void __gcov_flush();
+#include <gcov.h>
 #endif

 #ifndef DBUG_OFF
@ -2212,7 +2212,7 @@ void _db_suicide_()
  fprintf(stderr, "SIGKILL myself\n");
  fflush(stderr);
 #ifdef HAVE_gcov
-  __gcov_flush();
+  __gcov_dump();
 #endif

  retval= kill(getpid(), SIGKILL);
@ -2262,7 +2262,7 @@ my_bool _db_my_assert(const char *file, int line, const char *msg)
    fprintf(stderr, "%s:%d: assert: %s\n", file, line, msg);
    fflush(stderr);
 #ifdef HAVE_gcov
-    __gcov_flush();
+    __gcov_dump();
 #endif
  }
  return a;
--- a/mysql-test/main/debug_sync.result
+++ b/mysql-test/main/debug_sync.result
@ -2,7 +2,7 @@ SET DEBUG_SYNC= 'RESET';
 DROP TABLE IF EXISTS t1;
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: ''
+debug_sync	ON - current signals: ''
 SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2 HIT_LIMIT 3';
 SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 EXECUTE 2';
 SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6           HIT_LIMIT 3';
@ -150,34 +150,34 @@ SET @myvar= 'now SIGNAL from_myvar';
 SET DEBUG_SYNC= @myvar;
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 'from_myvar'
+debug_sync	ON - current signals: 'from_myvar'
 SET DEBUG_SYNC= LEFT('now SIGNAL from_function_cut_here', 24);
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 'from_function'
+debug_sync	ON - current signals: 'from_myvar,from_function'
 SET DEBUG_SYNC= 'now SIGNAL something';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 'something'
+debug_sync	ON - current signals: 'something,from_function,from_myvar'
 SET DEBUG_SYNC= 'now WAIT_FOR nothing TIMEOUT 0';
 Warnings:
 Warning	####	debug sync point wait timed out
 SET DEBUG_SYNC= 'now SIGNAL nothing';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 'nothing'
+debug_sync	ON - current signals: 'something,from_function,nothing,from_myvar'
 SET DEBUG_SYNC= 'now WAIT_FOR nothing TIMEOUT 0';
 SET DEBUG_SYNC= 'now SIGNAL something EXECUTE 0';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 'nothing'
+debug_sync	ON - current signals: 'something,from_function,from_myvar'
 SET DEBUG_SYNC= 'now WAIT_FOR anotherthing TIMEOUT 0 EXECUTE 0';
 SET DEBUG_SYNC= 'now HIT_LIMIT 1';
 ERROR HY000: debug sync point hit limit reached
 SET DEBUG_SYNC= 'RESET';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: ''
+debug_sync	ON - current signals: ''
 SET DEBUG_SYNC= 'p1abcd   SIGNAL s1 EXECUTE 2';
 SET DEBUG_SYNC= 'p2abc    SIGNAL s2 EXECUTE 2';
 SET DEBUG_SYNC= 'p9abcdef SIGNAL s9 EXECUTE 2';
@ -190,23 +190,30 @@ SET DEBUG_SYNC= 'p3abcdef SIGNAL s3 EXECUTE 2';
 SET DEBUG_SYNC= 'p4a      TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 's4'
+debug_sync	ON - current signals: 's4'
 SET DEBUG_SYNC= 'p1abcd   TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 's1'
+debug_sync	ON - current signals: 's4,s1'
 SET DEBUG_SYNC= 'p7       TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 's7'
+debug_sync	ON - current signals: 's1,s7,s4'
 SET DEBUG_SYNC= 'p9abcdef TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 's9'
+debug_sync	ON - current signals: 's1,s7,s4,s9'
 SET DEBUG_SYNC= 'p3abcdef TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 's3'
+debug_sync	ON - current signals: 's1,s3,s4,s9,s7'
+SET DEBUG_SYNC= 'now WAIT_FOR s9';
+SET DEBUG_SYNC= 'now WAIT_FOR s1';
+SET DEBUG_SYNC= 'now WAIT_FOR s4';
+SET DEBUG_SYNC= 'now WAIT_FOR s7';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+Variable_name	Value
+debug_sync	ON - current signals: 's3'
 SET DEBUG_SYNC= 'p1abcd   CLEAR';
 SET DEBUG_SYNC= 'p2abc    CLEAR';
 SET DEBUG_SYNC= 'p5abcde  CLEAR';
@ -219,19 +226,19 @@ SET DEBUG_SYNC= 'p7       CLEAR';
 SET DEBUG_SYNC= 'p1abcd   TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 's3'
+debug_sync	ON - current signals: 's3'
 SET DEBUG_SYNC= 'p7       TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 's3'
+debug_sync	ON - current signals: 's3'
 SET DEBUG_SYNC= 'p9abcdef TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: 's3'
+debug_sync	ON - current signals: 's3'
 SET DEBUG_SYNC= 'RESET';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 Variable_name	Value
-debug_sync	ON - current signal: ''
+debug_sync	ON - current signals: ''
 CREATE USER mysqltest_1@localhost;
 GRANT SUPER ON *.* TO mysqltest_1@localhost;
 connect  con1,localhost,mysqltest_1,,;
@ -292,4 +299,24 @@ disconnect con1;
 disconnect con2;
 connection default;
 DROP TABLE t1;
+#
+# Test NO_CLEAR_EVENT flag. The signal should still be visible after
+# the wait has completed succesfully.
+#
+SET DEBUG_SYNC= 'now SIGNAL s1';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+Variable_name	Value
+debug_sync	ON - current signals: 's1'
+SET DEBUG_SYNC= 'now WAIT_FOR s1 NO_CLEAR_EVENT';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+Variable_name	Value
+debug_sync	ON - current signals: 's1'
+SET DEBUG_SYNC= 'now WAIT_FOR s1';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+Variable_name	Value
+debug_sync	ON - current signals: ''
+SET DEBUG_SYNC= 'now SIGNAL s1,s2,s5,s7';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+Variable_name	Value
+debug_sync	ON - current signals: 's2,s7,s1,s5'
 SET DEBUG_SYNC= 'RESET';
--- a/mysql-test/main/debug_sync.test
+++ b/mysql-test/main/debug_sync.test
@ -298,6 +298,16 @@ SET DEBUG_SYNC= 'p9abcdef TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 SET DEBUG_SYNC= 'p3abcdef TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
+
+#
+# Wait for all signals currently active except s3.
+#
+SET DEBUG_SYNC= 'now WAIT_FOR s9';
+SET DEBUG_SYNC= 'now WAIT_FOR s1';
+SET DEBUG_SYNC= 'now WAIT_FOR s4';
+SET DEBUG_SYNC= 'now WAIT_FOR s7';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+
 #
 # Clear the actions.
 #
@ -320,7 +330,7 @@ SHOW VARIABLES LIKE 'DEBUG_SYNC';
 SET DEBUG_SYNC= 'p9abcdef TEST';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
 #
-# Now cleanup. Actions are clear already, but signal needs to be cleared.
+# Now cleanup. Actions are clear already, but s3 signal needs to be cleared.
 #
 SET DEBUG_SYNC= 'RESET';
 SHOW VARIABLES LIKE 'DEBUG_SYNC';
@ -418,10 +428,24 @@ disconnect con2;
 connection default;
 DROP TABLE t1;

+--echo #
+--echo # Test NO_CLEAR_EVENT flag. The signal should still be visible after
+--echo # the wait has completed succesfully.
+--echo #
+SET DEBUG_SYNC= 'now SIGNAL s1';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+SET DEBUG_SYNC= 'now WAIT_FOR s1 NO_CLEAR_EVENT';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+SET DEBUG_SYNC= 'now WAIT_FOR s1';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+
+SET DEBUG_SYNC= 'now SIGNAL s1,s2,s5,s7';
+SHOW VARIABLES LIKE 'DEBUG_SYNC';
+
+
 #
 # Cleanup after test case.
-# Otherwise signal would contain 'flushed' here,
-# which could confuse the next test.
+# Otherwise signal would confuse the next test.
 #
 SET DEBUG_SYNC= 'RESET';

--- a/mysql-test/mariadb-test-run.pl
+++ b/mysql-test/mariadb-test-run.pl
@ -145,6 +145,7 @@ my $opt_start_exit;
 my $start_only;
 my $file_wsrep_provider;
 my $num_saved_cores= 0;  # Number of core files saved in vardir/log/ so far.
+my $test_name_for_report;

 our @global_suppressions;

@ -515,13 +516,13 @@ sub main {
  }

  if ( not @$completed ) {
-    my $test_name= mtr_grab_file($path_testlog);
-    $test_name =~ s/^CURRENT_TEST:\s//;
-    chomp($test_name);
-    my $tinfo = My::Test->new(name => $test_name);
+    if ($test_name_for_report)
+    {
+      my $tinfo = My::Test->new(name => $test_name_for_report);
      $tinfo->{result}= 'MTR_RES_FAILED';
      $tinfo->{comment}=' ';
      mtr_report_test($tinfo);
+    }
    mtr_error("Test suite aborted");
  }

@ -3740,8 +3741,8 @@ sub resfile_report_test ($) {
 sub run_testcase ($$) {
  my ($tinfo, $server_socket)= @_;
  my $print_freq=20;
-
-  mtr_verbose("Running test:", $tinfo->{name});
+  $test_name_for_report= $tinfo->{name};
+  mtr_verbose("Running test:", $test_name_for_report);
  $ENV{'MTR_TEST_NAME'} = $tinfo->{name};
  resfile_report_test($tinfo) if $opt_resfile;

@ -5130,12 +5131,10 @@ sub mysqld_start ($$) {
  if (!$rc)
  {
    # Report failure about the last test case before exit
-    my $test_name= mtr_grab_file($path_current_testlog);
-    $test_name =~ s/^CURRENT_TEST:\s//;
-    my $tinfo = My::Test->new(name => $test_name);
+    my $tinfo = My::Test->new(name => $test_name_for_report);
    $tinfo->{result}= 'MTR_RES_FAILED';
    $tinfo->{failures}= 1;
-    $tinfo->{logfile}=get_log_from_proc($mysqld->{'proc'}, $tinfo->{name});
+    $tinfo->{logfile}=get_log_from_proc($mysqld->{'proc'}, $test_name_for_report);
    report_option('verbose', 1);
    mtr_report_test($tinfo);
  }
--- a/mysql-test/suite/innodb/r/mdev-14846.result
+++ b/mysql-test/suite/innodb/r/mdev-14846.result
@ -31,11 +31,12 @@ pk	f1	f2	f3
 3	t	q	1
 5	z	t	NULL
 SET DEBUG_SYNC='now SIGNAL default_dml';
+SET DEBUG_SYNC='now SIGNAL con2_dml';
 connection default;
 SET DEBUG_SYNC='now WAIT_FOR default_dml';
 UPDATE t3 AS alias1 LEFT JOIN t3 AS alias2 ON ( alias1.f1 <> alias1.f2 ) SET alias1.f3 = 59 WHERE ( EXISTS ( SELECT t1.f3 FROM t1 WHERE t1.f1 = alias1.f1 ) ) OR alias2.f1 = 'h';
 connect  con2,localhost,root,,test;
-set debug_sync='now WAIT_FOR default_dml';
+set debug_sync='now WAIT_FOR con2_dml';
 SET DEBUG_SYNC='now SIGNAL con1_dml2';
 disconnect con2;
 connection con1;
--- a/mysql-test/suite/innodb/t/mdev-14846.test
+++ b/mysql-test/suite/innodb/t/mdev-14846.test
@ -35,6 +35,7 @@ SET DEBUG_SYNC='now WAIT_FOR con1_dml';
 begin;
 SELECT * FROM t1 for update; # Holds x lock of all records in the table t1
 SET DEBUG_SYNC='now SIGNAL default_dml';
+SET DEBUG_SYNC='now SIGNAL con2_dml';

 --connection default
 SET DEBUG_SYNC='now WAIT_FOR default_dml';
@ -42,7 +43,7 @@ SET DEBUG_SYNC='now WAIT_FOR default_dml';
 # It holds the lock of all record in t3 and tries to acquire record lock for the table  t1.

 --connect (con2,localhost,root,,test)
-set debug_sync='now WAIT_FOR default_dml';
+set debug_sync='now WAIT_FOR con2_dml';
 let $wait_condition=
 select count(*) > 0 from information_schema.innodb_lock_waits;
 --source include/wait_condition.inc
--- a/mysql-test/suite/stress/r/deadlock_drop_table.result
+++ b/mysql-test/suite/stress/r/deadlock_drop_table.result
@ -19,11 +19,12 @@ a	b	c
 1	NULL	NULL
 set debug_sync='now SIGNAL go';
 set debug_sync='now WAIT_FOR parked2';
-set debug_sync='before_wait_for_refs SIGNAL waiting WAIT_FOR go2';
+set debug_sync='before_wait_for_refs SIGNAL waiting WAIT_FOR go3';
 drop table t1;;
 connection con2;
 set debug_sync='now WAIT_FOR waiting';
 set debug_sync='now SIGNAL go2';
+set debug_sync='now SIGNAL go3';
 connection default;
 connection con1;
 connection default;
--- a/mysql-test/suite/stress/t/deadlock_drop_table.test
+++ b/mysql-test/suite/stress/t/deadlock_drop_table.test
@ -20,15 +20,12 @@ set debug_sync='now WAIT_FOR parked';
 select * from t1;
 set debug_sync='now SIGNAL go';
 set debug_sync='now WAIT_FOR parked2';
-set debug_sync='before_wait_for_refs SIGNAL waiting WAIT_FOR go2';
+set debug_sync='before_wait_for_refs SIGNAL waiting WAIT_FOR go3';
 --send drop table t1;
 --connection con2
 set debug_sync='now WAIT_FOR waiting';
 set debug_sync='now SIGNAL go2';
-
-# Write out show processlist if the debug sync point times out
-let $wait_condition= select count(*)=0 from information_schema.processlist where state like "%debug%";
-source include/wait_condition.inc;
+set debug_sync='now SIGNAL go3';

 --connection default
 --reap
--- a/mysql-test/suite/sys_vars/r/debug_sync_basic.result
+++ b/mysql-test/suite/sys_vars/r/debug_sync_basic.result
@ -2,17 +2,17 @@ select @@global.debug_sync;
 ERROR HY000: Variable 'debug_sync' is a SESSION variable
 select @@session.debug_sync;
@@session.debug_sync
-ON - current signal: ''
+ON - current signals: ''
 show global variables like "debug_sync";
 Variable_name	Value
 show session variables like "debug_sync";
 Variable_name	Value
-debug_sync	ON - current signal: ''
+debug_sync	ON - current signals: ''
 select * from information_schema.global_variables where variable_name="debug_sync";
 VARIABLE_NAME	VARIABLE_VALUE
 select * from information_schema.session_variables where variable_name="debug_sync";
 VARIABLE_NAME	VARIABLE_VALUE
-DEBUG_SYNC	ON - current signal: ''
+DEBUG_SYNC	ON - current signals: ''
 set @@session.debug_sync=1;
 ERROR 42000: Incorrect argument type to variable 'debug_sync'
 set @@session.debug_sync=1.1;
--- a/mysql-test/suite/sys_vars/r/sysvars_debug.result
+++ b/mysql-test/suite/sys_vars/r/sysvars_debug.result
@ -77,7 +77,7 @@ READ_ONLY	YES
 COMMAND_LINE_ARGUMENT	OPTIONAL
 GLOBAL_VALUE_PATH	NULL
 VARIABLE_NAME	DEBUG_SYNC
-SESSION_VALUE	ON - current signal: ''
+SESSION_VALUE	ON - current signals: ''
 GLOBAL_VALUE	NULL
 GLOBAL_VALUE_ORIGIN	COMPILE-TIME
 DEFAULT_VALUE	
--- a/mysys/stacktrace.c
+++ b/mysys/stacktrace.c
@ -34,6 +34,9 @@
 #include <execinfo.h>
 #endif

+#ifdef HAVE_gcov
+#include <gcov.h>
+#endif
 /**
   Default handler for printing stacktrace
 */
@ -409,9 +412,6 @@ end:
 /* Produce a core for the thread */
 void my_write_core(int sig)
 {
-#ifdef HAVE_gcov
-  extern void __gcov_flush(void);
-#endif
  signal(sig, SIG_DFL);
 #ifdef HAVE_gcov
  /*
@ -419,7 +419,7 @@ void my_write_core(int sig)
    information from this process, causing gcov output to be incomplete.
    So we force the writing of coverage information here before terminating.
  */
-  __gcov_flush();
+  __gcov_dump();
 #endif
  pthread_kill(pthread_self(), sig);
 #if defined(P_MYID) && !defined(SCO)
--- a/sql/debug_sync.cc
+++ b/sql/debug_sync.cc
@ -18,6 +18,7 @@

 #include "mariadb.h"
 #include "debug_sync.h"
+#include <cstring>

 #if defined(ENABLED_DEBUG_SYNC)

@ -48,6 +49,8 @@ struct st_debug_sync_action
  String        wait_for;               /* signal to wait for */
  String        sync_point;             /* sync point name */
  bool          need_sort;              /* if new action, array needs sort */
+  bool          clear_event;            /* do not clear signal when waited
+                                           for if false. */
 };

 /* Debug sync control. Referenced by THD. */
@ -67,21 +70,99 @@ struct st_debug_sync_control
 };


+
+
 /**
  Definitions for the debug sync facility.
-  1. Global string variable to hold a "signal" ("signal post", "flag mast").
+  1. Global string variable to hold a set of of "signals".
  2. Global condition variable for signaling and waiting.
  3. Global mutex to synchronize access to the above.
 */
 struct st_debug_sync_globals
 {
-  String                ds_signal;              /* signal variable */
+  Hash_set<LEX_CSTRING> ds_signal_set;          /* A set of active signals */
  mysql_cond_t          ds_cond;                /* condition variable */
  mysql_mutex_t         ds_mutex;               /* mutex variable */
  ulonglong             dsp_hits;               /* statistics */
  ulonglong             dsp_executed;           /* statistics */
  ulonglong             dsp_max_active;         /* statistics */
+
+  st_debug_sync_globals() : ds_signal_set(PSI_NOT_INSTRUMENTED, signal_key) {};
+  ~st_debug_sync_globals()
+  {
+    clear_set();
+  }
+
+  void clear_set()
+  {
+    Hash_set<LEX_CSTRING>::Iterator it{ds_signal_set};
+    LEX_CSTRING *s;
+    while ((s= it++))
+      my_free(s);
+    ds_signal_set.clear();
+  }
+
+  /* Hash key function for ds_signal_set. */
+  static uchar *signal_key(const LEX_CSTRING *str, size_t *klen, my_bool)
+  {
+    *klen= str->length;
+    return (uchar*) str->str;
+  }
+
+  /**
+    Return true if the signal is found in global signal list.
+
+    @param signal_name Signal name identifying the signal.
+
+    @note
+      If signal is found in the global signal set, it means that the
+      signal thread has signalled to the waiting thread. This method
+      must be called with the debug_sync_global.ds_mutex held.
+
+    @retval true  if signal is found in the global signal list.
+    @retval false otherwise.
+  */
+
+  inline bool is_signalled(const char *signal_name, size_t length)
+  {
+    return ds_signal_set.find(signal_name, length);
+  }
+
+  void clear_signal(const String &signal_name)
+  {
+    DBUG_ENTER("clear_signal");
+    LEX_CSTRING *record= ds_signal_set.find(signal_name.ptr(),
+                                            signal_name.length());
+    if (record)
+    {
+      ds_signal_set.remove(record);
+      my_free(record);
+    }
+    DBUG_VOID_RETURN;
+  }
+
+  bool set_signal(const char *signal_name, size_t length)
+  {
+    /* Need to check if the signal is already in the hash set, because
+       Hash_set doesn't differentiate between OOM and key already in. */
+    if (is_signalled(signal_name, length))
+      return FALSE;
+    /* LEX_CSTRING and the string allocated with only one malloc. */
+    LEX_CSTRING *s= (LEX_CSTRING *) my_malloc(PSI_NOT_INSTRUMENTED,
+                                              sizeof(LEX_CSTRING) + length + 1,
+                                              MYF(0));
+    char *str= (char *)(s + 1);
+    memcpy(str, signal_name, length);
+    str[length]= '\0';
+
+    s->length= length;
+    s->str= str;
+    if (ds_signal_set.insert(s))
+      return TRUE;
+    return FALSE;
+  }
 };
+
 static st_debug_sync_globals debug_sync_global; /* All globals in one object */

 /**
@ -161,7 +242,7 @@ int debug_sync_init(void)
    int rc;

    /* Initialize the global variables. */
-    debug_sync_global.ds_signal.length(0);
+    debug_sync_global.clear_set();
    if ((rc= mysql_cond_init(key_debug_sync_globals_ds_cond,
                             &debug_sync_global.ds_cond, NULL)) ||
        (rc= mysql_mutex_init(key_debug_sync_globals_ds_mutex,
@ -195,7 +276,7 @@ void debug_sync_end(void)
    debug_sync_C_callback_ptr= NULL;

    /* Destroy the global variables. */
-    debug_sync_global.ds_signal.free();
+    debug_sync_global.clear_set();
    mysql_cond_destroy(&debug_sync_global.ds_cond);
    mysql_mutex_destroy(&debug_sync_global.ds_mutex);

@ -271,6 +352,40 @@ void debug_sync_init_thread(THD *thd)
 }


+/**
+  Returns an allocated buffer containing a comma-separated C string of all
+  active signals.
+
+  Buffer must be freed by the caller.
+*/
+static const char *get_signal_set_as_string()
+{
+  mysql_mutex_assert_owner(&debug_sync_global.ds_mutex);
+  size_t req_size= 1; // In case of empty set for the end '\0' char.
+
+  for (size_t i= 0; i < debug_sync_global.ds_signal_set.size(); i++)
+    req_size+= debug_sync_global.ds_signal_set.at(i)->length + 1;
+
+  char *buf= (char *) my_malloc(PSI_NOT_INSTRUMENTED, req_size, MYF(0));
+  if (!buf)
+    return nullptr;
+  memset(buf, '\0', req_size);
+
+  char *cur_pos= buf;
+  for (size_t i= 0; i < debug_sync_global.ds_signal_set.size(); i++)
+  {
+    const LEX_CSTRING *signal= debug_sync_global.ds_signal_set.at(i);
+    memcpy(cur_pos, signal->str, signal->length);
+    if (i != debug_sync_global.ds_signal_set.size() - 1)
+      cur_pos[signal->length]= ',';
+    else
+      cur_pos[signal->length] = '\0';
+    cur_pos+= signal->length + 1;
+  }
+  return buf;
+}
+
+
 /**
  End the debug sync facility at thread end.

@ -554,7 +669,7 @@ static void debug_sync_reset(THD *thd)

  /* Clear the global signal. */
  mysql_mutex_lock(&debug_sync_global.ds_mutex);
-  debug_sync_global.ds_signal.length(0);
+  debug_sync_global.clear_set();
  mysql_mutex_unlock(&debug_sync_global.ds_mutex);

  DBUG_VOID_RETURN;
@ -1175,6 +1290,7 @@ static bool debug_sync_eval_action(THD *thd, char *action_str, char *action_end)
    /* Set default for EXECUTE and TIMEOUT options. */
    action->execute= 1;
    action->timeout= opt_debug_sync_timeout;
+    action->clear_event= true;

    /* Get next token. If none follows, set action. */
    if (!(ptr= debug_sync_token(&token, &token_length, ptr, action_end)))
@ -1225,6 +1341,15 @@ static bool debug_sync_eval_action(THD *thd, char *action_str, char *action_end)
      goto set_action;
  }

+  /*
+    Try NO_CLEAR_EVENT.
+  */
+  if (!my_strcasecmp(system_charset_info, token, "NO_CLEAR_EVENT")) {
+    action->clear_event= false;
+    /* Get next token. If none follows, set action. */
+    if (!(ptr = debug_sync_token(&token, &token_length, ptr, action_end))) goto set_action;
+  }
+
  /*
    Try HIT_LIMIT.
  */
@ -1325,13 +1450,19 @@ uchar *debug_sync_value_ptr(THD *thd)

  if (opt_debug_sync_timeout)
  {
-    static char on[]= "ON - current signal: '"; 
+    static char on[]= "ON - current signals: '";

    // Ensure exclusive access to debug_sync_global.ds_signal
    mysql_mutex_lock(&debug_sync_global.ds_mutex);

-    size_t lgt= (sizeof(on) /* includes '\0' */ +
-                 debug_sync_global.ds_signal.length() + 1 /* for '\'' */);
+    size_t lgt= sizeof(on) + 1; /* +1 as we'll have to append ' at the end. */
+
+    for (size_t i= 0; i < debug_sync_global.ds_signal_set.size(); i++)
+    {
+      /* Assume each signal is separated by a comma, hence +1. */
+      lgt+= debug_sync_global.ds_signal_set.at(i)->length + 1;
+    }
+
    char *vend;
    char *vptr;

@ -1339,9 +1470,14 @@ uchar *debug_sync_value_ptr(THD *thd)
    {
      vend= value + lgt - 1; /* reserve space for '\0'. */
      vptr= debug_sync_bmove_len(value, vend, STRING_WITH_LEN(on));
-      vptr= debug_sync_bmove_len(vptr, vend, debug_sync_global.ds_signal.ptr(),
-                                 debug_sync_global.ds_signal.length());
-      if (vptr < vend)
+      for (size_t i= 0; i < debug_sync_global.ds_signal_set.size(); i++)
+      {
+        const LEX_CSTRING *s= debug_sync_global.ds_signal_set.at(i);
+        vptr= debug_sync_bmove_len(vptr, vend, s->str, s->length);
+        if (i != debug_sync_global.ds_signal_set.size() - 1)
+          *(vptr++)= ',';
+      }
+      DBUG_ASSERT(vptr < vend);
      *(vptr++)= '\'';
      *vptr= '\0'; /* We have one byte reserved for the worst case. */
    }
@ -1358,6 +1494,9 @@ uchar *debug_sync_value_ptr(THD *thd)
 }


+
+
+
 /**
  Execute requested action at a synchronization point.

@ -1413,12 +1552,28 @@ static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
      read access too, to create a memory barrier in order to avoid that
      threads just reads an old cached version of the signal.
    */
+
    mysql_mutex_lock(&debug_sync_global.ds_mutex);

    if (action->signal.length())
    {
-      /* Copy the signal to the global variable. */
-      if (debug_sync_global.ds_signal.copy(action->signal))
+      int offset= 0, pos;
+      bool error= false;
+
+      /* This loop covers all signals in the list except for the last one.
+         Split the signal string by commas and set a signal in the global
+         variable for each one. */
+      while (!error && (pos= action->signal.strstr(",", 1, offset)) > 0)
+      {
+        error= debug_sync_global.set_signal(action->signal.ptr() + offset,
+                                            pos - offset);
+        offset= pos + 1;
+      }
+
+      if (error ||
+          /* The last signal in the list. */
+          debug_sync_global.set_signal(action->signal.ptr() + offset,
+                                       action->signal.length() - offset))
      {
        /*
          Error is reported by my_malloc().
@ -1461,12 +1616,22 @@ static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
        restore_current_mutex = false;

      set_timespec(abstime, action->timeout);
-      DBUG_EXECUTE("debug_sync_exec",
+      DBUG_EXECUTE("debug_sync_exec", {
+          const char *signal_set= get_signal_set_as_string();
+          if (!signal_set)
+          {
+            DBUG_PRINT("debug_sync_exec",
+                       ("Out of memory when fetching signal set"));
+          }
+          else
+          {
            /* Functions as DBUG_PRINT args can change keyword and line nr. */
            DBUG_PRINT("debug_sync_exec",
-                     ("wait for '%s'  at: '%s'  curr: '%s'",
-                      sig_wait, dsp_name,
-                      debug_sync_global.ds_signal.c_ptr())););
+                       ("wait for '%s'  at: '%s', curr: '%s'",
+                        sig_wait, dsp_name, signal_set));
+            my_free((void *)signal_set);
+          }});
+

      /*
        Wait until global signal string matches the wait_for string.
@ -1474,18 +1639,20 @@ static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
        The facility can become disabled when some thread cannot get
        the required dynamic memory allocated.
      */
-      while (stringcmp(&debug_sync_global.ds_signal, &action->wait_for) &&
-             !(thd->killed & KILL_HARD_BIT) && opt_debug_sync_timeout)
+      while (!debug_sync_global.is_signalled(action->wait_for.ptr(),
+                                             action->wait_for.length()) &&
+             !(thd->killed & KILL_HARD_BIT) &&
+             opt_debug_sync_timeout)
      {
        error= mysql_cond_timedwait(&debug_sync_global.ds_cond,
                                    &debug_sync_global.ds_mutex,
                                    &abstime);
-        DBUG_EXECUTE("debug_sync",
+        // TODO turn this into a for loop printing.
+        DBUG_EXECUTE("debug_sync", {
            /* Functions as DBUG_PRINT args can change keyword and line nr. */
            DBUG_PRINT("debug_sync",
-                       ("awoke from %s  global: %s  error: %d",
-                        sig_wait, debug_sync_global.ds_signal.c_ptr(),
-                        error)););
+                       ("awoke from %s error: %d",
+                        sig_wait, error));});
        if (unlikely(error == ETIMEDOUT || error == ETIME))
        {
          // We should not make the statement fail, even if in strict mode.
@ -1498,6 +1665,10 @@ static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
        }
        error= 0;
      }
+
+      if (action->clear_event)
+        debug_sync_global.clear_signal(action->wait_for);
+
      DBUG_EXECUTE("debug_sync_exec",
                   if (thd->killed)
                     DBUG_PRINT("debug_sync_exec",
@ -1571,10 +1742,10 @@ static void debug_sync(THD *thd, const char *sync_point_name, size_t name_len)
  st_debug_sync_control *ds_control= thd->debug_sync_control;
  st_debug_sync_action  *action;
  DBUG_ENTER("debug_sync");
+  DBUG_PRINT("debug_sync_point", ("hit: '%s'", sync_point_name));
  DBUG_ASSERT(sync_point_name);
  DBUG_ASSERT(name_len);
  DBUG_ASSERT(ds_control);
-  DBUG_PRINT("debug_sync_point", ("hit: '%s'", sync_point_name));

  /* Statistics. */
  ds_control->dsp_hits++;
--- a/sql/sql_hset.h
+++ b/sql/sql_hset.h
@ -15,6 +15,7 @@
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1335  USA */

+#include "my_global.h"
 #include "hash.h"


@ -28,20 +29,18 @@ class Hash_set
 public:
  enum { START_SIZE= 8 };
  /**
-    Constructs an empty hash. Does not allocate memory, it is done upon
-    the first insert. Thus does not cause or return errors.
+    Constructs an empty unique hash.
  */
  Hash_set(PSI_memory_key psi_key, uchar *(*K)(const T *, size_t *, my_bool),
           CHARSET_INFO *cs= &my_charset_bin)
  {
-    my_hash_clear(&m_hash);
-    m_hash.get_key= (my_hash_get_key)K;
-    m_hash.charset= cs;
-    m_hash.array.m_psi_key= psi_key;
+    my_hash_init(psi_key, &m_hash, cs, START_SIZE, 0, 0, (my_hash_get_key)K, 0,
+                 HASH_UNIQUE);
  }
+
  Hash_set(PSI_memory_key psi_key, CHARSET_INFO *charset, ulong default_array_elements,
           size_t key_offset, size_t key_length, my_hash_get_key get_key,
-           void (*free_element)(void*), uint flags)
+           void (*free_element)(void*),uint flags)
  {
    my_hash_init(psi_key, &m_hash, charset, default_array_elements, key_offset,
                 key_length, get_key, free_element, flags);
@ -65,8 +64,6 @@ public:
  */
  bool insert(T *value)
  {
-    my_hash_init_opt(m_hash.array.m_psi_key, &m_hash, m_hash.charset,
-                     START_SIZE, 0, 0, m_hash.get_key, 0, HASH_UNIQUE);
    return my_hash_insert(&m_hash, reinterpret_cast<const uchar*>(value));
  }
  bool remove(T *value)
--- a/sql/sql_string.cc
+++ b/sql/sql_string.cc
@ -677,24 +677,23 @@ bool String::append_with_prefill(const char *s,uint32 arg_length,
 }


-int Binary_string::strstr(const Binary_string &s, uint32 offset)
+int Binary_string::strstr(const char *search, uint32 search_length, uint32 offset)
 {
-  if (s.length()+offset <= str_length)
+  if (search_length + offset <= str_length)
  {
-    if (!s.length())
+    if (!search_length)
      return ((int) offset);	// Empty string is always found

-    const char *str = Ptr+offset;
-    const char *search=s.ptr();
-    const char *end=Ptr+str_length-s.length()+1;
-    const char *search_end=s.ptr()+s.length();
+    const char *str= Ptr + offset;
+    const char *end= Ptr + str_length - search_length + 1;
+    const char *search_end= search + search_length;
 skip:
    while (str != end)
    {
      if (*str++ == *search)
      {
-	char *i,*j;
-	i=(char*) str; j=(char*) search+1;
+        char *i= (char*) str;
+        char *j= (char*) search + 1 ;
        while (j != search_end)
          if (*i++ != *j++) goto skip;
        return (int) (str-Ptr) -1;
@ -704,6 +703,11 @@ skip:
  return -1;
 }

+int Binary_string::strstr(const Binary_string &s, uint32 offset)
+{
+  return strstr(s.ptr(), s.length(), offset);
+}
+
 /*
 ** Search string from end. Offset is offset to the end of string
 */
--- a/sql/sql_string.h
+++ b/sql/sql_string.h
@ -330,6 +330,7 @@ public:

  // Returns offset to substring or -1
  int strstr(const Binary_string &search, uint32 offset=0);
+  int strstr(const char *search, uint32 search_length, uint32 offset=0);
  // Returns offset to substring or -1
  int strrstr(const Binary_string &search, uint32 offset=0);

--- a/storage/connect/bsonudf.cpp
+++ b/storage/connect/bsonudf.cpp
@ -3571,7 +3571,7 @@ char *bson_item_merge(UDF_INIT *initid, UDF_ARGS *args, char *result,
 	} // endif Xchk

 	if (!CheckMemory(g, initid, args, 2, false, false, true)) {
-		JTYP  type;
+		JTYP  type= TYPE_JAR;
 		BJNX  bnx(g);
 		PBVAL jvp = NULL, top = NULL;
 		PBVAL jsp[2] = {NULL, NULL};
@ -5724,7 +5724,7 @@ char *bbin_item_merge(UDF_INIT *initid, UDF_ARGS *args, char *result,
 	} // endif Xchk

 	if (!CheckMemory(g, initid, args, 2, false, false, true)) {
-		JTYP  type;
+		JTYP  type = TYPE_JAR;
 		BJNX  bnx(g);
 		PBVAL jvp = NULL, top = NULL;
 		PBVAL jsp[2] = {NULL, NULL};