open-dsi
/
postgres
mirror of https://github.com/postgres/postgres
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Add pg_terminate_backend() to allow terminating only a single session.

Browse Source
REL8_5_ALPHA1_BRANCH
Bruce Momjian 18 years ago
parent fcf053d782
commit 18b286f3e3
7 changed files with 90 additions and 24 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 19
      doc/src/sgml/func.sgml
  2. 9
      doc/src/sgml/runtime.sgml
  3. 12
      src/backend/tcop/postgres.c
  4. 63
      src/backend/utils/adt/misc.c
  5. 4
      src/include/catalog/pg_proc.h
  6. 4
      src/include/storage/proc.h
  7. 3
      src/include/utils/builtins.h

19
doc/src/sgml/func.sgml
Unescape View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.430 2008/04/14 17:05:32 tgl Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.431 2008/04/15 13:55:11 momjian Exp $ -->
<chapter id="functions">
<title>Functions and Operators</title>
@ -11848,6 +11848,9 @@ SELECT set_config('log_statement_stats', 'off', false);
<indexterm>
<primary>pg_cancel_backend</primary>
</indexterm>
<indexterm>
<primary>pg_terminate_backend</primary>
</indexterm>
<indexterm>
<primary>pg_reload_conf</primary>
</indexterm>
@ -11883,6 +11886,13 @@ SELECT set_config('log_statement_stats', 'off', false);
<entry><type>boolean</type></entry>
<entry>Cancel a backend's current query</entry>
</row>
<row>
<entry>
<literal><function>pg_terminate_backend</function>(<parameter>pid</parameter> <type>int</>)</literal>
</entry>
<entry><type>boolean</type></entry>
<entry>Terminate a backend</entry>
</row>
<row>
<entry>
<literal><function>pg_reload_conf</function>()</literal>
@ -11907,9 +11917,10 @@ SELECT set_config('log_statement_stats', 'off', false);
</para>
<para>
<function>pg_cancel_backend</> sends a query cancel
(<systemitem>SIGINT</>) signal to a backend process identified by
process ID. The process ID of an active backend can be found from
<function>pg_cancel_backend</> and <function>pg_terminate_backend</>
send a query cancel (<systemitem>SIGINT</>) signal to a backend process
identified by process ID. The
process ID of an active backend can be found from
the <structfield>procpid</structfield> column in the
<structname>pg_stat_activity</structname> view, or by listing the
<command>postgres</command> processes on the server with

9
doc/src/sgml/runtime.sgml
Unescape View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.411 2008/03/31 02:43:14 tgl Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.412 2008/04/15 13:55:11 momjian Exp $ -->
<chapter Id="runtime">
<title>Operating System Environment</title>
@ -1372,6 +1372,13 @@ $ <userinput>kill -INT `head -1 /usr/local/pgsql/data/postmaster.pid`</userinput
well.
</para>
</important>
<para>
To terminate a session while allowing other sessions to continue, use
<function>pg_terminate_backend()</> (<xref
linkend="functions-admin-signal-table">) rather than sending a signal
to the child process.
</para>
</sect1>
<sect1 id="preventing-server-spoofing">

12
src/backend/tcop/postgres.c
Unescape View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.548 2008/04/02 18:31:50 tgl Exp $
* $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.549 2008/04/15 13:55:11 momjian Exp $
*
* NOTES
* this is the "main" module of the postgres backend and
@ -2541,7 +2541,8 @@ StatementCancelHandler(SIGNAL_ARGS)
* waiting for input, however.
*/
if (ImmediateInterruptOK && InterruptHoldoffCount == 0 &&
CritSectionCount == 0 && !DoingCommandRead)
CritSectionCount == 0 &&
(!DoingCommandRead || MyProc->terminate))
{
/* bump holdoff count to make ProcessInterrupts() a no-op */
/* until we are done getting ready for it */
@ -2621,6 +2622,10 @@ ProcessInterrupts(void)
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling autovacuum task")));
else if (MyProc->terminate)
ereport(ERROR,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating backend due to administrator command")));
else
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
@ -3459,6 +3464,9 @@ PostgresMain(int argc, char *argv[], const char *username)
/* We don't have a transaction command open anymore */
xact_started = false;
if (MyProc->terminate)
die(SIGINT);
/* Now we can allow interrupts again */
RESUME_INTERRUPTS();
}

63
src/backend/utils/adt/misc.c
Unescape View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.59 2008/04/04 16:57:21 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.60 2008/04/15 13:55:11 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -27,6 +27,7 @@
#include "postmaster/syslogger.h"
#include "storage/fd.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "utils/builtins.h"
#include "tcop/tcopprot.h"
@ -89,7 +90,7 @@ current_query(PG_FUNCTION_ARGS)
* Functions to send signals to other backends.
*/
static bool
pg_signal_backend(int pid, int sig)
pg_signal_check(int pid)
{
if (!superuser())
ereport(ERROR,
@ -106,7 +107,16 @@ pg_signal_backend(int pid, int sig)
(errmsg("PID %d is not a PostgreSQL server process", pid)));
return false;
}
else
return true;
}
/*
* Functions to send signals to other backends.
*/
static bool
pg_signal_backend(int pid, int sig)
{
/* If we have setsid(), signal the backend's whole process group */
#ifdef HAVE_SETSID
if (kill(-pid, sig))
@ -125,7 +135,43 @@ pg_signal_backend(int pid, int sig)
Datum
pg_cancel_backend(PG_FUNCTION_ARGS)
{
PG_RETURN_BOOL(pg_signal_backend(PG_GETARG_INT32(0), SIGINT));
int pid = PG_GETARG_INT32(0);
if (pg_signal_check(pid))
PG_RETURN_BOOL(pg_signal_backend(pid, SIGINT));
else
PG_RETURN_BOOL(false);
}
/*
* To cleanly terminate a backend, we set PGPROC(pid)->terminate
* then send a cancel signal. We get ProcArrayLock only when
* setting PGPROC->terminate so the function might fail in
* several places, but that is fine because in those cases the
* backend is already gone.
*/
Datum
pg_terminate_backend(PG_FUNCTION_ARGS)
{
int pid = PG_GETARG_INT32(0);
volatile PGPROC *term_proc;
/* Is this the super-user, and can we find the PGPROC entry for the pid? */
if (pg_signal_check(pid) && (term_proc = BackendPidGetProc(pid)) != NULL)
{
LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
/* Recheck now that we have the ProcArray lock. */
if (term_proc->pid == pid)
{
term_proc->terminate = true;
LWLockRelease(ProcArrayLock);
PG_RETURN_BOOL(pg_signal_backend(pid, SIGINT));
}
else
LWLockRelease(ProcArrayLock);
}
PG_RETURN_BOOL(false);
}
Datum
@ -169,17 +215,6 @@ pg_rotate_logfile(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(true);
}
#ifdef NOT_USED
/* Disabled in 8.0 due to reliability concerns; FIXME someday */
Datum
pg_terminate_backend(PG_FUNCTION_ARGS)
{
PG_RETURN_INT32(pg_signal_backend(PG_GETARG_INT32(0), SIGTERM));
}
#endif
/* Function to find out which databases make use of a tablespace */
typedef struct

4
src/include/catalog/pg_proc.h
Unescape View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.489 2008/04/14 17:05:33 tgl Exp $
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.490 2008/04/15 13:55:11 momjian Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
@ -3157,6 +3157,8 @@ DESCR("is schema another session's temp schema?");
DATA(insert OID = 2171 ( pg_cancel_backend PGNSP PGUID 12 1 0 f f t f v 1 16 "23" _null_ _null_ _null_ pg_cancel_backend - _null_ _null_ ));
DESCR("cancel a server process' current query");
DATA(insert OID = 2096 ( pg_terminate_backend PGNSP PGUID 12 1 0 f f t f v 1 16 "23" _null_ _null_ _null_ pg_terminate_backend - _null_ _null_ ));
DESCR("terminate a server process");
DATA(insert OID = 2172 ( pg_start_backup PGNSP PGUID 12 1 0 f f t f v 1 25 "25" _null_ _null_ _null_ pg_start_backup - _null_ _null_ ));
DESCR("prepare for taking an online backup");
DATA(insert OID = 2173 ( pg_stop_backup PGNSP PGUID 12 1 0 f f t f v 0 25 "" _null_ _null_ _null_ pg_stop_backup - _null_ _null_ ));

4
src/include/storage/proc.h
Unescape View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/storage/proc.h,v 1.104 2008/01/26 19:55:08 tgl Exp $
* $PostgreSQL: pgsql/src/include/storage/proc.h,v 1.105 2008/04/15 13:55:12 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -91,6 +91,8 @@ struct PGPROC
bool inCommit; /* true if within commit critical section */
bool terminate; /* admin requested termination */
uint8 vacuumFlags; /* vacuum-related flags, see above */
/* Info about LWLock the process is currently waiting for, if any. */

3
src/include/utils/builtins.h
Unescape View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.312 2008/04/04 18:45:36 tgl Exp $
* $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.313 2008/04/15 13:55:12 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -416,6 +416,7 @@ extern Datum nonnullvalue(PG_FUNCTION_ARGS);
extern Datum current_database(PG_FUNCTION_ARGS);
extern Datum current_query(PG_FUNCTION_ARGS);
extern Datum pg_cancel_backend(PG_FUNCTION_ARGS);
extern Datum pg_terminate_backend(PG_FUNCTION_ARGS);
extern Datum pg_reload_conf(PG_FUNCTION_ARGS);
extern Datum pg_tablespace_databases(PG_FUNCTION_ARGS);
extern Datum pg_rotate_logfile(PG_FUNCTION_ARGS);

Write Preview
Loading…
Cancel
Save