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/*-------------------------------------------------------------------------
*
* misc.c
*
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/misc.c,v 1.34 2004/06/02 21:29:29 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <sys/file.h>
#include <signal.h>
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "storage/sinval.h"
#include "utils/builtins.h"
/*
* Check if data is Null
*/
Datum
nullvalue(PG_FUNCTION_ARGS)
{
if (PG_ARGISNULL(0))
PG_RETURN_BOOL(true);
PG_RETURN_BOOL(false);
}
/*
* Check if data is not Null
*/
Datum
nonnullvalue(PG_FUNCTION_ARGS)
{
if (PG_ARGISNULL(0))
PG_RETURN_BOOL(false);
PG_RETURN_BOOL(true);
}
/*
* current_database()
* Expose the current database to the user
*/
Datum
current_database(PG_FUNCTION_ARGS)
{
Name db;
db = (Name) palloc(NAMEDATALEN);
namestrcpy(db, get_database_name(MyDatabaseId));
PG_RETURN_NAME(db);
}
/*
* Functions to terminate a backend or cancel a query running on
* a different backend.
*/
static int pg_signal_backend(int pid, int sig)
{
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("only superuser can signal other backends"))));
if (!IsBackendPid(pid))
{
/* This is just a warning so a loop-through-resultset will not abort
* if one backend terminated on it's own during the run */
ereport(WARNING,
(errmsg("pid %i is not a postgresql backend",pid)));
return 0;
}
if (kill(pid, sig))
{
/* Again, just a warning to allow loops */
ereport(WARNING,
(errmsg("failed to send signal to backend %i: %m",pid)));
return 0;
}
return 1;
}
Datum
pg_terminate_backend(PG_FUNCTION_ARGS)
{
PG_RETURN_INT32(pg_signal_backend(PG_GETARG_INT32(0),SIGTERM));
}
Datum
pg_cancel_backend(PG_FUNCTION_ARGS)
{
PG_RETURN_INT32(pg_signal_backend(PG_GETARG_INT32(0),SIGINT));
}
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