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Implement multiple-signal debug_sync

Browse Source 
The patch is inspired from MySQL. Instead of using a single String to
hold the current active debug_sync signal, use a Hash_set to store
LEX_STRINGS. This patch ensures that a signal can not be lost, by being
overwritten by another thread via set DEBUG_SYNC = '... SIGNAL ...';

All signals are kepts "alive" until they are consumed by a wait event.

This requires updating test cases that assume the GLOBAL signal is never
consumed.

Follow-up work needed:
Port the additional syntax that allows one to set multiple signals
and also conditionally deactivate signals when waiting.
This commit is contained in:
Vicențiu Ciorbaru
2021-09-28 22:17:59 +03:00
parent cc08872c16
commit 8885225de6
7 changed files with 162 additions and 48 deletions
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39
mysql-test/main/debug_sync.result
View File

@ -2,7 +2,7 @@ SET DEBUG_SYNC= 'RESET';
DROP TABLE IF EXISTS t1; DROP TABLE IF EXISTS t1;
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value 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 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 EXECUTE 2';
SET DEBUG_SYNC='p0 SIGNAL s1 WAIT_FOR s2 TIMEOUT 6 HIT_LIMIT 3'; 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; SET DEBUG_SYNC= @myvar;
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value 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); SET DEBUG_SYNC= LEFT('now SIGNAL from_function_cut_here', 24);
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value 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'; SET DEBUG_SYNC= 'now SIGNAL something';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value 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'; SET DEBUG_SYNC= 'now WAIT_FOR nothing TIMEOUT 0';
Warnings: Warnings:
Warning #### debug sync point wait timed out Warning #### debug sync point wait timed out
SET DEBUG_SYNC= 'now SIGNAL nothing'; SET DEBUG_SYNC= 'now SIGNAL nothing';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value 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 WAIT_FOR nothing TIMEOUT 0';
SET DEBUG_SYNC= 'now SIGNAL something EXECUTE 0'; SET DEBUG_SYNC= 'now SIGNAL something EXECUTE 0';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value 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 WAIT_FOR anotherthing TIMEOUT 0 EXECUTE 0';
SET DEBUG_SYNC= 'now HIT_LIMIT 1'; SET DEBUG_SYNC= 'now HIT_LIMIT 1';
ERROR HY000: debug sync point hit limit reached ERROR HY000: debug sync point hit limit reached
SET DEBUG_SYNC= 'RESET'; SET DEBUG_SYNC= 'RESET';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value Variable_name Value
debug_sync ON - current signal: '' debug_sync ON - current signals: ''
SET DEBUG_SYNC= 'p1abcd SIGNAL s1 EXECUTE 2'; SET DEBUG_SYNC= 'p1abcd SIGNAL s1 EXECUTE 2';
SET DEBUG_SYNC= 'p2abc SIGNAL s2 EXECUTE 2'; SET DEBUG_SYNC= 'p2abc SIGNAL s2 EXECUTE 2';
SET DEBUG_SYNC= 'p9abcdef SIGNAL s9 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'; SET DEBUG_SYNC= 'p4a TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value Variable_name Value
debug_sync ON - current signal: 's4' debug_sync ON - current signals: 's4'
SET DEBUG_SYNC= 'p1abcd TEST'; SET DEBUG_SYNC= 'p1abcd TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value Variable_name Value
debug_sync ON - current signal: 's1' debug_sync ON - current signals: 's4,s1'
SET DEBUG_SYNC= 'p7 TEST'; SET DEBUG_SYNC= 'p7 TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value Variable_name Value
debug_sync ON - current signal: 's7' debug_sync ON - current signals: 's1,s7,s4'
SET DEBUG_SYNC= 'p9abcdef TEST'; SET DEBUG_SYNC= 'p9abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value Variable_name Value
debug_sync ON - current signal: 's9' debug_sync ON - current signals: 's1,s7,s4,s9'
SET DEBUG_SYNC= 'p3abcdef TEST'; SET DEBUG_SYNC= 'p3abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value 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= 'p1abcd CLEAR';
SET DEBUG_SYNC= 'p2abc CLEAR'; SET DEBUG_SYNC= 'p2abc CLEAR';
SET DEBUG_SYNC= 'p5abcde CLEAR'; SET DEBUG_SYNC= 'p5abcde CLEAR';
@ -219,19 +226,19 @@ SET DEBUG_SYNC= 'p7 CLEAR';
SET DEBUG_SYNC= 'p1abcd TEST'; SET DEBUG_SYNC= 'p1abcd TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value Variable_name Value
debug_sync ON - current signal: 's3' debug_sync ON - current signals: 's3'
SET DEBUG_SYNC= 'p7 TEST'; SET DEBUG_SYNC= 'p7 TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value Variable_name Value
debug_sync ON - current signal: 's3' debug_sync ON - current signals: 's3'
SET DEBUG_SYNC= 'p9abcdef TEST'; SET DEBUG_SYNC= 'p9abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value Variable_name Value
debug_sync ON - current signal: 's3' debug_sync ON - current signals: 's3'
SET DEBUG_SYNC= 'RESET'; SET DEBUG_SYNC= 'RESET';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
Variable_name Value Variable_name Value
debug_sync ON - current signal: '' debug_sync ON - current signals: ''
CREATE USER mysqltest_1@localhost; CREATE USER mysqltest_1@localhost;
GRANT SUPER ON *.* TO mysqltest_1@localhost; GRANT SUPER ON *.* TO mysqltest_1@localhost;
connect con1,localhost,mysqltest_1,,; connect con1,localhost,mysqltest_1,,;

12
mysql-test/main/debug_sync.test
View File

@ -298,6 +298,16 @@ SET DEBUG_SYNC= 'p9abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'p3abcdef TEST'; SET DEBUG_SYNC= 'p3abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; 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. # Clear the actions.
# #
@ -320,7 +330,7 @@ SHOW VARIABLES LIKE 'DEBUG_SYNC';
SET DEBUG_SYNC= 'p9abcdef TEST'; SET DEBUG_SYNC= 'p9abcdef TEST';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; 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'; SET DEBUG_SYNC= 'RESET';
SHOW VARIABLES LIKE 'DEBUG_SYNC'; SHOW VARIABLES LIKE 'DEBUG_SYNC';

3
mysql-test/suite/innodb/r/mdev-14846.result
View File

@ -31,11 +31,12 @@ pk f1 f2 f3
3 t q 1 3 t q 1
5 z t NULL 5 z t NULL
SET DEBUG_SYNC='now SIGNAL default_dml'; SET DEBUG_SYNC='now SIGNAL default_dml';
SET DEBUG_SYNC='now SIGNAL con2_dml';
connection default; connection default;
SET DEBUG_SYNC='now WAIT_FOR default_dml'; 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'; 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; 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'; SET DEBUG_SYNC='now SIGNAL con1_dml2';
disconnect con2; disconnect con2;
connection con1; connection con1;

3
mysql-test/suite/innodb/t/mdev-14846.test
View File

@ -35,6 +35,7 @@ SET DEBUG_SYNC='now WAIT_FOR con1_dml';
begin; begin;
SELECT * FROM t1 for update; # Holds x lock of all records in the table t1 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 default_dml';
SET DEBUG_SYNC='now SIGNAL con2_dml';
--connection default --connection default
SET DEBUG_SYNC='now WAIT_FOR default_dml'; 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. # It holds the lock of all record in t3 and tries to acquire record lock for the table t1.
--connect (con2,localhost,root,,test) --connect (con2,localhost,root,,test)
set debug_sync='now WAIT_FOR default_dml'; set debug_sync='now WAIT_FOR con2_dml';
let $wait_condition= let $wait_condition=
select count(*) > 0 from information_schema.innodb_lock_waits; select count(*) > 0 from information_schema.innodb_lock_waits;
--source include/wait_condition.inc --source include/wait_condition.inc

6
mysql-test/suite/sys_vars/r/debug_sync_basic.result
View File

@ -2,17 +2,17 @@ select @@global.debug_sync;
ERROR HY000: Variable 'debug_sync' is a SESSION variable ERROR HY000: Variable 'debug_sync' is a SESSION variable
select @@session.debug_sync; select @@session.debug_sync;
@@session.debug_sync @@session.debug_sync
ON - current signal: '' ON - current signals: ''
show global variables like "debug_sync"; show global variables like "debug_sync";
Variable_name Value Variable_name Value
show session variables like "debug_sync"; show session variables like "debug_sync";
Variable_name Value Variable_name Value
debug_sync ON - current signal: '' debug_sync ON - current signals: ''
select * from information_schema.global_variables where variable_name="debug_sync"; select * from information_schema.global_variables where variable_name="debug_sync";
VARIABLE_NAME VARIABLE_VALUE VARIABLE_NAME VARIABLE_VALUE
select * from information_schema.session_variables where variable_name="debug_sync"; select * from information_schema.session_variables where variable_name="debug_sync";
VARIABLE_NAME VARIABLE_VALUE VARIABLE_NAME VARIABLE_VALUE
DEBUG_SYNC ON - current signal: '' DEBUG_SYNC ON - current signals: ''
set @@session.debug_sync=1; set @@session.debug_sync=1;
ERROR 42000: Incorrect argument type to variable 'debug_sync' ERROR 42000: Incorrect argument type to variable 'debug_sync'
set @@session.debug_sync=1.1; set @@session.debug_sync=1.1;

2
mysql-test/suite/sys_vars/r/sysvars_debug.result
View File

@ -77,7 +77,7 @@ READ_ONLY YES
COMMAND_LINE_ARGUMENT OPTIONAL COMMAND_LINE_ARGUMENT OPTIONAL
GLOBAL_VALUE_PATH NULL GLOBAL_VALUE_PATH NULL
VARIABLE_NAME DEBUG_SYNC VARIABLE_NAME DEBUG_SYNC
SESSION_VALUE ON - current signal: '' SESSION_VALUE ON - current signals: ''
GLOBAL_VALUE NULL GLOBAL_VALUE NULL
GLOBAL_VALUE_ORIGIN COMPILE-TIME GLOBAL_VALUE_ORIGIN COMPILE-TIME
DEFAULT_VALUE DEFAULT_VALUE

145
sql/debug_sync.cc
View File

@ -67,21 +67,99 @@ struct st_debug_sync_control
}; };
/** /**
Definitions for the debug sync facility. 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. 2. Global condition variable for signaling and waiting.
3. Global mutex to synchronize access to the above. 3. Global mutex to synchronize access to the above.
*/ */
struct st_debug_sync_globals 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_cond_t ds_cond; /* condition variable */
mysql_mutex_t ds_mutex; /* mutex variable */ mysql_mutex_t ds_mutex; /* mutex variable */
ulonglong dsp_hits; /* statistics */ ulonglong dsp_hits; /* statistics */
ulonglong dsp_executed; /* statistics */ ulonglong dsp_executed; /* statistics */
ulonglong dsp_max_active; /* 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 String &signal_name)
{
return ds_signal_set.find(signal_name.ptr(), 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 String &signal_name)
{
/* 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))
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) +
signal_name.length() + 1, MYF(0));
char *str= (char *)(s + 1);
memcpy(str, signal_name.ptr(), signal_name.length());
str[signal_name.length()]= '\0';
s->length= signal_name.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 */ static st_debug_sync_globals debug_sync_global; /* All globals in one object */
/** /**
@ -161,7 +239,7 @@ int debug_sync_init(void)
int rc; int rc;
/* Initialize the global variables. */ /* 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, if ((rc= mysql_cond_init(key_debug_sync_globals_ds_cond,
&debug_sync_global.ds_cond, NULL)) || &debug_sync_global.ds_cond, NULL)) ||
(rc= mysql_mutex_init(key_debug_sync_globals_ds_mutex, (rc= mysql_mutex_init(key_debug_sync_globals_ds_mutex,
@ -195,7 +273,7 @@ void debug_sync_end(void)
debug_sync_C_callback_ptr= NULL; debug_sync_C_callback_ptr= NULL;
/* Destroy the global variables. */ /* Destroy the global variables. */
debug_sync_global.ds_signal.free(); debug_sync_global.clear_set();
mysql_cond_destroy(&debug_sync_global.ds_cond); mysql_cond_destroy(&debug_sync_global.ds_cond);
mysql_mutex_destroy(&debug_sync_global.ds_mutex); mysql_mutex_destroy(&debug_sync_global.ds_mutex);
@ -554,7 +632,7 @@ static void debug_sync_reset(THD *thd)
/* Clear the global signal. */ /* Clear the global signal. */
mysql_mutex_lock(&debug_sync_global.ds_mutex); 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); mysql_mutex_unlock(&debug_sync_global.ds_mutex);
DBUG_VOID_RETURN; DBUG_VOID_RETURN;
@ -1325,13 +1403,19 @@ uchar *debug_sync_value_ptr(THD *thd)
if (opt_debug_sync_timeout) 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 // Ensure exclusive access to debug_sync_global.ds_signal
mysql_mutex_lock(&debug_sync_global.ds_mutex); mysql_mutex_lock(&debug_sync_global.ds_mutex);
size_t lgt= (sizeof(on) /* includes '\0' */ + size_t lgt= sizeof(on) + 1; /* +1 as we'll have to append ' at the end. */
debug_sync_global.ds_signal.length() + 1 /* for '\'' */);
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 *vend;
char *vptr; char *vptr;
@ -1339,10 +1423,15 @@ uchar *debug_sync_value_ptr(THD *thd)
{ {
vend= value + lgt - 1; /* reserve space for '\0'. */ vend= value + lgt - 1; /* reserve space for '\0'. */
vptr= debug_sync_bmove_len(value, vend, STRING_WITH_LEN(on)); vptr= debug_sync_bmove_len(value, vend, STRING_WITH_LEN(on));
vptr= debug_sync_bmove_len(vptr, vend, debug_sync_global.ds_signal.ptr(), for (size_t i= 0; i < debug_sync_global.ds_signal_set.size(); i++)
debug_sync_global.ds_signal.length()); {
if (vptr < vend) const LEX_CSTRING *s= debug_sync_global.ds_signal_set.at(i);
*(vptr++)= '\''; 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. */ *vptr= '\0'; /* We have one byte reserved for the worst case. */
} }
mysql_mutex_unlock(&debug_sync_global.ds_mutex); mysql_mutex_unlock(&debug_sync_global.ds_mutex);
@ -1358,6 +1447,9 @@ uchar *debug_sync_value_ptr(THD *thd)
} }
/** /**
Execute requested action at a synchronization point. Execute requested action at a synchronization point.
@ -1413,12 +1505,12 @@ 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 read access too, to create a memory barrier in order to avoid that
threads just reads an old cached version of the signal. threads just reads an old cached version of the signal.
*/ */
mysql_mutex_lock(&debug_sync_global.ds_mutex); mysql_mutex_lock(&debug_sync_global.ds_mutex);
if (action->signal.length()) if (action->signal.length())
{ {
/* Copy the signal to the global variable. */ if (debug_sync_global.set_signal(action->signal))
if (debug_sync_global.ds_signal.copy(action->signal))
{ {
/* /*
Error is reported by my_malloc(). Error is reported by my_malloc().
@ -1461,12 +1553,12 @@ static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
restore_current_mutex = false; restore_current_mutex = false;
set_timespec(abstime, action->timeout); set_timespec(abstime, action->timeout);
DBUG_EXECUTE("debug_sync_exec", // TODO turn this into a for loop printing.
DBUG_EXECUTE("debug_sync_exec", {
/* Functions as DBUG_PRINT args can change keyword and line nr. */ /* Functions as DBUG_PRINT args can change keyword and line nr. */
DBUG_PRINT("debug_sync_exec", DBUG_PRINT("debug_sync_exec",
("wait for '%s' at: '%s' curr: '%s'", ("wait for '%s' at: '%s'",
sig_wait, dsp_name, sig_wait, dsp_name));});
debug_sync_global.ds_signal.c_ptr())););
/* /*
Wait until global signal string matches the wait_for string. Wait until global signal string matches the wait_for string.
@ -1474,18 +1566,19 @@ static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
The facility can become disabled when some thread cannot get The facility can become disabled when some thread cannot get
the required dynamic memory allocated. the required dynamic memory allocated.
*/ */
while (stringcmp(&debug_sync_global.ds_signal, &action->wait_for) && while (!debug_sync_global.is_signalled(action->wait_for) &&
!(thd->killed & KILL_HARD_BIT) && opt_debug_sync_timeout) !(thd->killed & KILL_HARD_BIT)&&
opt_debug_sync_timeout)
{ {
error= mysql_cond_timedwait(&debug_sync_global.ds_cond, error= mysql_cond_timedwait(&debug_sync_global.ds_cond,
&debug_sync_global.ds_mutex, &debug_sync_global.ds_mutex,
&abstime); &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. */ /* Functions as DBUG_PRINT args can change keyword and line nr. */
DBUG_PRINT("debug_sync", DBUG_PRINT("debug_sync",
("awoke from %s global: %s error: %d", ("awoke from %s error: %d",
sig_wait, debug_sync_global.ds_signal.c_ptr(), sig_wait, error));});
error)););
if (unlikely(error == ETIMEDOUT || error == ETIME)) if (unlikely(error == ETIMEDOUT || error == ETIME))
{ {
// We should not make the statement fail, even if in strict mode. // We should not make the statement fail, even if in strict mode.
@ -1498,6 +1591,8 @@ static void debug_sync_execute(THD *thd, st_debug_sync_action *action)
} }
error= 0; error= 0;
} }
// TODO conditional on clear-event
debug_sync_global.clear_signal(action->wait_for);
DBUG_EXECUTE("debug_sync_exec", DBUG_EXECUTE("debug_sync_exec",
if (thd->killed) if (thd->killed)
DBUG_PRINT("debug_sync_exec", DBUG_PRINT("debug_sync_exec",
@ -1571,10 +1666,10 @@ 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_control *ds_control= thd->debug_sync_control;
st_debug_sync_action *action; st_debug_sync_action *action;
DBUG_ENTER("debug_sync"); DBUG_ENTER("debug_sync");
DBUG_PRINT("debug_sync_point", ("hit: '%s'", sync_point_name));
DBUG_ASSERT(sync_point_name); DBUG_ASSERT(sync_point_name);
DBUG_ASSERT(name_len); DBUG_ASSERT(name_len);
DBUG_ASSERT(ds_control); DBUG_ASSERT(ds_control);
DBUG_PRINT("debug_sync_point", ("hit: '%s'", sync_point_name));
/* Statistics. */ /* Statistics. */
ds_control->dsp_hits++; ds_control->dsp_hits++;