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Rewrite profiler code to be easier to maintain and less buggy.

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Between 5.0 and 5.1, the step of incrementing the global query id
changed, which broke how the profiler noticed when a new query had
started.  That reset the state list and caused all but the last 
five (or so) states to be thrown away.

Now, don't watch for query_id changes in the lower level.

Add a bogus state change at the end of profiling so that the last 
real state change is timed.

Emit source reference for the start of the span of time instead of
the end of it.


mysql-test/r/profiling.result:
  Add a test that shows continuation of execution with multi-statement
  packets.
mysql-test/t/profiling.test:
  Add a test that shows continuation of execution with multi-statement
  packets.
sql/sql_parse.cc:
  Insert profiling calls at beginnings and ends of each query.
  
  Remove the old way of keeping or discarding profiles, and flipping 
  to new query profiles.
sql/sql_profile.cc:
  No longer use the thread's query_id to determine when we flip
  to a new statement.
  
  Some status statements are set to be NULL in the server.  We don't
  log those, as it doesn't fit this style of profiling yet.
  
  Rewrite the parser code to be more active and legible.  
  
  Relying on passive/lazy discovery of new queries was buggy.
  
  Add a bogus status change before ending a profile, so that the 
  previous real status has a endpoint.
  
  Emit source reference of the start of the span-of-time instead of
  the end of it.
sql/sql_profile.h:
  Store the server_query_id at instantiation time for a new query.
  
  Rewrite the parser code to be more active.  Relying on passive/lazy
  discovery of new queries was buggy.
  
  Name first state to more honestly describe the state.  We don't 
  really know of initialization that will follow.
sql/sql_show.cc:
  Update comment to note the decidedly weird field_length behavior
  on Decimal types in information_schema.
This commit is contained in:
unknown
2007-11-09 14:45:44 -05:00
parent 6dbc0c5ab1
commit 69aee07373
6 changed files with 307 additions and 276 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
sql/sql_parse.cc
View File

@ -426,6 +426,10 @@ pthread_handler_t handle_bootstrap(void *arg)
QUERY_CACHE_FLAGS_SIZE);
thd->query[length] = '\0';
DBUG_PRINT("query",("%-.4096s",thd->query));
#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
thd->profiling.set_query_source(thd->query, length);
#endif
/*
We don't need to obtain LOCK_thread_count here because in bootstrap
mode we have only one thread.
@ -645,6 +649,9 @@ int end_trans(THD *thd, enum enum_mysql_completiontype completion)
/*
Read one command from connection and execute it (query or simple command).
This function is called in loop from thread function.
For profiling to work, it must never be called recursively.
SYNOPSIS
do_command()
RETURN VALUE
@ -654,12 +661,16 @@ int end_trans(THD *thd, enum enum_mysql_completiontype completion)
bool do_command(THD *thd)
{
bool return_value;
char *packet= 0;
ulong packet_length;
NET *net= &thd->net;
enum enum_server_command command;
DBUG_ENTER("do_command");
#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
thd->profiling.start_new_query();
#endif
/*
indicator of uninitialized lex => normal flow of errors handling
(see my_message_sql)
@ -686,11 +697,15 @@ bool do_command(THD *thd)
/* Check if we can continue without closing the connection */
if (net->error != 3)
DBUG_RETURN(TRUE); // We have to close it.
{
return_value= TRUE; // We have to close it.
goto out;
}
net_send_error(thd, net->last_errno, NullS);
net->error= 0;
DBUG_RETURN(FALSE);
return_value= FALSE;
goto out;
}
packet= (char*) net->read_pos;
@ -724,7 +739,13 @@ bool do_command(THD *thd)
my_net_set_read_timeout(net, thd->variables.net_read_timeout);
DBUG_ASSERT(packet_length);
DBUG_RETURN(dispatch_command(command, thd, packet+1, (uint) (packet_length-1)));
return_value= dispatch_command(command, thd, packet+1, (uint) (packet_length-1));
out:
#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
thd->profiling.finish_current_query();
#endif
DBUG_RETURN(return_value);
}
#endif /* EMBEDDED_LIBRARY */
@ -982,19 +1003,22 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
break; // fatal error is set
char *packet_end= thd->query + thd->query_length;
/* 'b' stands for 'buffer' parameter', special for 'my_snprintf' */
const char* found_semicolon= NULL;
const char* end_of_stmt= NULL;
general_log_write(thd, command, thd->query, thd->query_length);
DBUG_PRINT("query",("%-.4096s",thd->query));
#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
thd->profiling.set_query_source(thd->query, thd->query_length);
#endif
if (!(specialflag & SPECIAL_NO_PRIOR))
my_pthread_setprio(pthread_self(),QUERY_PRIOR);
mysql_parse(thd, thd->query, thd->query_length, & found_semicolon);
mysql_parse(thd, thd->query, thd->query_length, &end_of_stmt);
while (!thd->killed && found_semicolon && !thd->net.report_error)
while (!thd->killed && (end_of_stmt != NULL) && !thd->net.report_error)
{
char *next_packet= (char*) found_semicolon;
char *beginning_of_next_stmt= (char*) end_of_stmt;
net->no_send_error= 0;
/*
Multiple queries exits, execute them individually
@ -1002,24 +1026,31 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
if (thd->lock || thd->open_tables || thd->derived_tables ||
thd->prelocked_mode)
close_thread_tables(thd);
ulong length= (ulong)(packet_end - next_packet);
ulong length= (ulong)(packet_end - beginning_of_next_stmt);
log_slow_statement(thd);
/* Remove garbage at start of query */
while (my_isspace(thd->charset(), *next_packet) && length > 0)
while (length > 0 && my_isspace(thd->charset(), *beginning_of_next_stmt))
{
next_packet++;
beginning_of_next_stmt++;
length--;
}
#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
thd->profiling.finish_current_query();
thd->profiling.start_new_query("continuing");
thd->profiling.set_query_source(beginning_of_next_stmt, length);
#endif
VOID(pthread_mutex_lock(&LOCK_thread_count));
thd->query_length= length;
thd->query= next_packet;
thd->query= beginning_of_next_stmt;
thd->query_id= next_query_id();
thd->set_time(); /* Reset the query start time. */
/* TODO: set thd->lex->sql_command to SQLCOM_END here */
VOID(pthread_mutex_unlock(&LOCK_thread_count));
mysql_parse(thd, next_packet, length, & found_semicolon);
mysql_parse(thd, beginning_of_next_stmt, length, &end_of_stmt);
}
if (!(specialflag & SPECIAL_NO_PRIOR))
@ -1516,8 +1547,8 @@ int prepare_schema_table(THD *thd, LEX *lex, Table_ident *table_ident,
Mark this current profiling record to be discarded. We don't
wish to have SHOW commands show up in profiling.
*/
#ifdef ENABLED_PROFILING
thd->profiling.discard();
#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
thd->profiling.discard_current_query();
#endif
break;
case SCH_OPEN_TABLES:
@ -2012,8 +2043,7 @@ mysql_execute_command(THD *thd)
case SQLCOM_SHOW_PROFILES:
{
#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
thd->profiling.store();
thd->profiling.discard();
thd->profiling.discard_current_query();
res= thd->profiling.show_profiles();
if (res)
goto error;
@ -5274,9 +5304,6 @@ void mysql_reset_thd_for_next_command(THD *thd)
thd->total_warn_count=0; // Warnings for this query
thd->rand_used= 0;
thd->sent_row_count= thd->examined_row_count= 0;
#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
thd->profiling.reset();
#endif
}
/*
Because we come here only for start of top-statements, binlog format is