On 5/19/15 9:19 PM, Fabrízio de Royes Mello wrote:
We could add a second parameter to the current functions:
allow_own_pid DEFAULT false. To me that seems better than an
entirely separate set of functions.
+1 to add a second parameter to current functions.
Instead of allow_own_pid, I went with skip_own_pid. I have the function
still returning true even when it skips it's own PID... that seems a bit
weird, but I think it's better than returning false. Unless someone
thinks it should return NULL, but I don't see that as any better either.
--
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 89a609f..b405876 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -16508,7 +16508,7 @@ SELECT set_config('log_statement_stats', 'off', false);
<tbody>
<row>
<entry>
- <literal><function>pg_cancel_backend(<parameter>pid</parameter>
<type>int</>)</function></literal>
+ <literal><function>pg_cancel_backend(<parameter>pid</parameter>
<type>int</><optional>, <parameter>skip_my_pid</> <type>boolean</>
</optional>)</function></literal>
</entry>
<entry><type>boolean</type></entry>
<entry>Cancel a backend's current query. This is also allowed if the
@@ -16532,7 +16532,7 @@ SELECT set_config('log_statement_stats', 'off', false);
</row>
<row>
<entry>
- <literal><function>pg_terminate_backend(<parameter>pid</parameter>
<type>int</>)</function></literal>
+ <literal><function>pg_terminate_backend(<parameter>pid</parameter>
<type>int</><optional>, <parameter>skip_my_pid</> <type>boolean</>
</optional>)</function></literal>
</entry>
<entry><type>boolean</type></entry>
<entry>Terminate a backend. This is also allowed if the calling role
@@ -16562,6 +16562,10 @@ SELECT set_config('log_statement_stats', 'off', false);
The role of an active backend can be found from the
<structfield>usename</structfield> column of the
<structname>pg_stat_activity</structname> view.
+
+ There is an optional second parameter of type <type>boolean</type>. If
+ <literal>true</> (the default), <function>pg_cancel_backend</> and
+ <function>pg_terminate_backend</> will not signal the current backend.
</para>
<para>
diff --git a/src/backend/catalog/system_views.sql
b/src/backend/catalog/system_views.sql
index 18921c4..a0cc975 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -869,6 +869,14 @@ COMMENT ON FUNCTION ts_debug(text) IS
--
CREATE OR REPLACE FUNCTION
+ pg_cancel_backend(pid int, skip_my_pid boolean DEFAULT true)
+ RETURNS boolean STRICT VOLATILE LANGUAGE internal AS 'pg_cancel_backend';
+
+CREATE OR REPLACE FUNCTION
+ pg_terminate_backend(pid int, skip_my_pid boolean DEFAULT true)
+ RETURNS boolean STRICT VOLATILE LANGUAGE internal AS 'pg_terminate_backend';
+
+CREATE OR REPLACE FUNCTION
pg_start_backup(label text, fast boolean DEFAULT false)
RETURNS pg_lsn STRICT VOLATILE LANGUAGE internal AS 'pg_start_backup';
diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
index 61d609f..dce8498 100644
--- a/src/backend/utils/adt/misc.c
+++ b/src/backend/utils/adt/misc.c
@@ -94,8 +94,12 @@ current_query(PG_FUNCTION_ARGS)
#define SIGNAL_BACKEND_NOPERMISSION 2
#define SIGNAL_BACKEND_NOSUPERUSER 3
static int
-pg_signal_backend(int pid, int sig)
+pg_signal_backend(int pid, int sig, bool skip_own_pid)
{
+ /* Skip our own pid unless we're told not to */
+ if (skip_own_pid && pid == MyProcPid)
+ return SIGNAL_BACKEND_SUCCESS;
+
PGPROC *proc = BackendPidGetProc(pid);
/*
@@ -158,7 +162,7 @@ pg_signal_backend(int pid, int sig)
Datum
pg_cancel_backend(PG_FUNCTION_ARGS)
{
- int r = pg_signal_backend(PG_GETARG_INT32(0),
SIGINT);
+ int r = pg_signal_backend(PG_GETARG_INT32(0),
SIGINT, PG_GETARG_BOOL(1));
if (r == SIGNAL_BACKEND_NOSUPERUSER)
ereport(ERROR,
@@ -182,7 +186,7 @@ pg_cancel_backend(PG_FUNCTION_ARGS)
Datum
pg_terminate_backend(PG_FUNCTION_ARGS)
{
- int r = pg_signal_backend(PG_GETARG_INT32(0),
SIGTERM);
+ int r = pg_signal_backend(PG_GETARG_INT32(0),
SIGTERM, PG_GETARG_BOOL(1));
if (r == SIGNAL_BACKEND_NOSUPERUSER)
ereport(ERROR,
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index b5b9345..475545b 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -3128,9 +3128,9 @@ DESCR("get OID of current session's temp schema, if any");
DATA(insert OID = 2855 ( pg_is_other_temp_schema PGNSP PGUID 12 1 0 0 0
f f f f t f s 1 0 16 "26" _null_ _null_ _null_ _null_ _null_
pg_is_other_temp_schema _null_ _null_ _null_ ));
DESCR("is schema another session's temp schema?");
-DATA(insert OID = 2171 ( pg_cancel_backend PGNSP PGUID 12 1 0 0 0
f f f f t f v 1 0 16 "23" _null_ _null_ _null_ _null_ _null_ pg_cancel_backend
_null_ _null_ _null_ ));
+DATA(insert OID = 2171 ( pg_cancel_backend PGNSP PGUID 12 1 0 0 0
f f f f t f v 2 0 16 "23 16" _null_ _null_ _null_ _null_ _null_
pg_cancel_backend _null_ _null_ _null_ ));
DESCR("cancel a server process' current query");
-DATA(insert OID = 2096 ( pg_terminate_backend PGNSP PGUID 12 1 0 0 0
f f f f t f v 1 0 16 "23" _null_ _null_ _null_ _null_ _null_
pg_terminate_backend _null_ _null_ _null_ ));
+DATA(insert OID = 2096 ( pg_terminate_backend PGNSP PGUID 12 1 0 0 0
f f f f t f v 2 0 16 "23 16" _null_ _null_ _null_ _null_ _null_
pg_terminate_backend _null_ _null_ _null_ ));
DESCR("terminate a server process");
DATA(insert OID = 2172 ( pg_start_backup PGNSP PGUID 12 1 0 0 0
f f f f t f v 2 0 3220 "25 16" _null_ _null_ _null_ _null_ _null_
pg_start_backup _null_ _null_ _null_ ));
DESCR("prepare for taking an online backup");
diff --git a/src/test/regress/expected/hs_standby_functions.out
b/src/test/regress/expected/hs_standby_functions.out
index 16d50a8..7ab98a6 100644
--- a/src/test/regress/expected/hs_standby_functions.out
+++ b/src/test/regress/expected/hs_standby_functions.out
@@ -36,5 +36,5 @@ from pg_locks where virtualxid = '1/1';
(1 row)
-- suicide is painless
-select pg_cancel_backend(pg_backend_pid());
+select pg_cancel_backend(pg_backend_pid(), false);
ERROR: canceling statement due to user request
diff --git a/src/test/regress/sql/hs_standby_functions.sql
b/src/test/regress/sql/hs_standby_functions.sql
index 7577045..e953de2 100644
--- a/src/test/regress/sql/hs_standby_functions.sql
+++ b/src/test/regress/sql/hs_standby_functions.sql
@@ -21,4 +21,4 @@ select locktype, virtualxid, virtualtransaction, mode, granted
from pg_locks where virtualxid = '1/1';
-- suicide is painless
-select pg_cancel_backend(pg_backend_pid());
+select pg_cancel_backend(pg_backend_pid(), false);
--
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