src/slurmctld/sched_plugin.c - SchedMD/slurm - Git at Google

 /*****************************************************************************\
  *  sched_plugin.c - scheduler plugin stub.
  *****************************************************************************
  *  Copyright (C) 2002-2007 The Regents of the University of California.
  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
  *  Written by Jay Windley <jwindley@lnxi.com>.
  *  UCRL-CODE-226842.
  *
  *  This file is part of SLURM, a resource management program.
  *  For details, see <http://www.llnl.gov/linux/slurm/>.
  *
  *  SLURM is free software; you can redistribute it and/or modify it under
  *  the terms of the GNU General Public License as published by the Free
  *  Software Foundation; either version 2 of the License, or (at your option)
  *  any later version.
  *
  *  In addition, as a special exception, the copyright holders give permission
  *  to link the code of portions of this program with the OpenSSL library under
  *  certain conditions as described in each individual source file, and
  *  distribute linked combinations including the two. You must obey the GNU
  *  General Public License in all respects for all of the code used other than
  *  OpenSSL. If you modify file(s) with this exception, you may extend this
  *  exception to your version of the file(s), but you are not obligated to do
  *  so. If you do not wish to do so, delete this exception statement from your
  *  version.  If you delete this exception statement from all source files in
  *  the program, then also delete it here.
  *
  *  SLURM is distributed in the hope that it will be useful, but WITHOUT ANY
  *  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  *  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  *  details.
  *
  *  You should have received a copy of the GNU General Public License along
  *  with SLURM; if not, write to the Free Software Foundation, Inc.,
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA.
 \*****************************************************************************/

 #include <pthread.h>

 #include "src/common/log.h"
 #include "src/common/plugrack.h"
 #include "src/common/slurm_protocol_api.h"
 #include "src/common/xmalloc.h"
 #include "src/common/xstring.h"

 #include "src/slurmctld/sched_plugin.h"
 #include "src/slurmctld/slurmctld.h"


 /* ************************************************************************ */
 /*  TAG(                        slurm_sched_ops_t                        )  */
 /* ************************************************************************ */
 typedef struct slurm_sched_ops {
 	int		(*schedule)		( void );
 	uint32_t	(*initial_priority)	( uint32_t,
 						  struct job_record * );
 	void            (*job_is_pending)     	( void );
 	int		(*reconfig)		( void );
 	void            (*partition_change)    	( void );
 	int		(*get_errno)		( void );
 	char *		(*strerror)		( int );
 } slurm_sched_ops_t;


 /* ************************************************************************ */
 /*  TAG(                        slurm_sched_contex_t                     )  */
 /* ************************************************************************ */
 typedef struct slurm_sched_context {
 	char	       	*sched_type;
 	plugrack_t     	plugin_list;
 	plugin_handle_t	cur_plugin;
 	int		sched_errno;
 	slurm_sched_ops_t ops;
 } slurm_sched_context_t;

 static slurm_sched_context_t	*g_sched_context = NULL;
 static pthread_mutex_t		g_sched_context_lock = PTHREAD_MUTEX_INITIALIZER;


 /* ************************************************************************ */
 /*  TAG(                       slurm_sched_get_ops                       )  */
 /* ************************************************************************ */
 static slurm_sched_ops_t *
 slurm_sched_get_ops( slurm_sched_context_t *c )
 {
 	/*
 	 * Must be synchronized with slurm_sched_ops_t above.
 	 */
 	static const char *syms[] = {
 		"slurm_sched_plugin_schedule",
 		"slurm_sched_plugin_initial_priority",
 		"slurm_sched_plugin_job_is_pending",
 		"slurm_sched_plugin_reconfig",
 		"slurm_sched_plugin_partition_change",
 		"slurm_sched_get_errno",
 		"slurm_sched_strerror"
 	};
 	int n_syms = sizeof( syms ) / sizeof( char * );

 	/* Get plugin list. */
 	if ( c->plugin_list == NULL ) {
 		char *plugin_dir;
 		c->plugin_list = plugrack_create();
 		if ( c->plugin_list == NULL ) {
 			error( "cannot create plugin manager" );
 			return NULL;
 		}
 		plugrack_set_major_type( c->plugin_list, "sched" );
 		plugrack_set_paranoia( c->plugin_list,
 				       PLUGRACK_PARANOIA_NONE,
 				       0 );
 		plugin_dir = slurm_get_plugin_dir();
 		plugrack_read_dir( c->plugin_list, plugin_dir );
 		xfree(plugin_dir);
 	}

 	c->cur_plugin = plugrack_use_by_type( c->plugin_list, c->sched_type );
 	if ( c->cur_plugin == PLUGIN_INVALID_HANDLE ) {
 		error( "cannot find scheduler plugin for %s", c->sched_type );
 		return NULL;
 	}

 	/* Dereference the API. */
 	if ( plugin_get_syms( c->cur_plugin,
 			      n_syms,
 			      syms,
 			      (void **) &c->ops ) < n_syms ) {
 		error( "incomplete scheduling plugin detected" );
 		return NULL;
 	}

 	return &c->ops;
 }


 /* ************************************************************************ */
 /*  TAG(                  slurm_sched_context_create                     )  */
 /* ************************************************************************ */
 static slurm_sched_context_t *
 slurm_sched_context_create( const char *sched_type )
 {
 	slurm_sched_context_t *c;

 	if ( sched_type == NULL ) {
 		debug3( "slurm_sched_context:  no scheduler type" );
 		return NULL;
 	}

 	c = xmalloc( sizeof( slurm_sched_context_t ) );
 	c->sched_type	= xstrdup( sched_type );
 	c->plugin_list	= NULL;
 	c->cur_plugin	= PLUGIN_INVALID_HANDLE;
 	c->sched_errno 	= SLURM_SUCCESS;

 	return c;
 }


 /* ************************************************************************ */
 /*  TAG(                  slurm_sched_context_destroy                    )  */
 /* ************************************************************************ */
 static int
 slurm_sched_context_destroy( slurm_sched_context_t *c )
 {
 	/*
 	 * Must check return code here because plugins might still
 	 * be loaded and active.
 	 */
 	if ( c->plugin_list ) {
 		if ( plugrack_destroy( c->plugin_list ) != SLURM_SUCCESS ) {
 			return SLURM_ERROR;
 		}
 	}

 	xfree( c->sched_type );
 	xfree( c );

 	return SLURM_SUCCESS;
 }


 /* *********************************************************************** */
 /*  TAG(                        slurm_sched_init                        )  */
 /*                                                                         */
 /*  NOTE: The scheduler plugin can not be changed via reconfiguration      */
 /*        due to background threads, job priorities, etc. Slurmctld must   */
 /*        be restarted  and job priority changes may be required to change */
 /*        the scheduler type.                                              */
 /* *********************************************************************** */
 extern int
 slurm_sched_init( void )
 {
 	int retval = SLURM_SUCCESS;
 	char *sched_type = NULL;

 	slurm_mutex_lock( &g_sched_context_lock );

 	if ( g_sched_context ) goto done;

 	sched_type = slurm_get_sched_type();
 	g_sched_context = slurm_sched_context_create( sched_type );
 	if ( g_sched_context == NULL ) {
 		error( "cannot create scheduler context for %s",
 			 sched_type );
 		retval = SLURM_ERROR;
 		goto done;
 	}

 	if ( slurm_sched_get_ops( g_sched_context ) == NULL ) {
 		error( "cannot resolve scheduler plugin operations" );
 		slurm_sched_context_destroy( g_sched_context );
 		g_sched_context = NULL;
 		retval = SLURM_ERROR;
 	}

  done:
 	slurm_mutex_unlock( &g_sched_context_lock );
 	xfree(sched_type);
 	return retval;
 }

 /* *********************************************************************** */
 /*  TAG(                        slurm_sched_fini                        )  */
 /* *********************************************************************** */
 extern int
 slurm_sched_fini( void )
 {
 	int rc;

 	if (!g_sched_context)
 		return SLURM_SUCCESS;

 	rc = slurm_sched_context_destroy(g_sched_context);
 	g_sched_context = NULL;
 	return rc;
 }


 /* *********************************************************************** */
 /*  TAG(                        slurm_sched_reconfig                    )  */
 /* *********************************************************************** */
 extern int
 slurm_sched_reconfig( void )
 {
 	if ( slurm_sched_init() < 0 )
 		return SLURM_ERROR;

 	return (*(g_sched_context->ops.reconfig))();
 }

 /* *********************************************************************** */
 /*  TAG(                        slurm_sched_schedule                    )  */
 /* *********************************************************************** */
 int
 slurm_sched_schedule( void )
 {
 	if ( slurm_sched_init() < 0 )
 		return SLURM_ERROR;

 	return (*(g_sched_context->ops.schedule))();
 }


 /* *********************************************************************** */
 /*  TAG(                   slurm_sched_initital_priority                )  */
 /* *********************************************************************** */
 uint32_t
 slurm_sched_initial_priority( u_int32_t last_prio,
 			      struct job_record *job_ptr )
 {
 	if ( slurm_sched_init() < 0 )
 		return SLURM_ERROR;

 	return (*(g_sched_context->ops.initial_priority))( last_prio,
 							   job_ptr );
 }

 /* *********************************************************************** */
 /*  TAG(                   slurm_sched_job_is_pending                   )  */
 /* *********************************************************************** */
 void
 slurm_sched_job_is_pending( void )
 {
 	if ( slurm_sched_init() < 0 )
 		return;

 	(*(g_sched_context->ops.job_is_pending))();
 }

 /* *********************************************************************** */
 /*  TAG(                   slurm_sched_partition_change                 )  */
 /* *********************************************************************** */
 void
 slurm_sched_partition_change( void )
 {
 	if ( slurm_sched_init() < 0 )
 		return;

 	(*(g_sched_context->ops.partition_change))();
 }

 /* *********************************************************************** */
 /*  TAG(                   slurm_sched_p_get_errno                      )  */
 /* *********************************************************************** */
 int
 slurm_sched_p_get_errno( void )
 {
 	if ( slurm_sched_init() < 0 )
 		return SLURM_ERROR;

 	return (*(g_sched_context->ops.get_errno))( );
 }

 /* *********************************************************************** */
 /*  TAG(                   slurm_sched_p_strerror                       )  */
 /* *********************************************************************** */
 char *
 slurm_sched_p_strerror( int errnum )
 {
 	if ( slurm_sched_init() < 0 )
 		return NULL;

 	return (*(g_sched_context->ops.strerror))( errnum );
 }
	/*****************************************************************************\
	* sched_plugin.c - scheduler plugin stub.
	*****************************************************************************
	* Copyright (C) 2002-2007 The Regents of the University of California.
	* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
	* Written by Jay Windley <jwindley@lnxi.com>.
	* UCRL-CODE-226842.
	*
	* This file is part of SLURM, a resource management program.
	* For details, see <http://www.llnl.gov/linux/slurm/>.
	*
	* SLURM is free software; you can redistribute it and/or modify it under
	* the terms of the GNU General Public License as published by the Free
	* Software Foundation; either version 2 of the License, or (at your option)
	* any later version.
	*
	* In addition, as a special exception, the copyright holders give permission
	* to link the code of portions of this program with the OpenSSL library under
	* certain conditions as described in each individual source file, and
	* distribute linked combinations including the two. You must obey the GNU
	* General Public License in all respects for all of the code used other than
	* OpenSSL. If you modify file(s) with this exception, you may extend this
	* exception to your version of the file(s), but you are not obligated to do
	* so. If you do not wish to do so, delete this exception statement from your
	* version. If you delete this exception statement from all source files in
	* the program, then also delete it here.
	*
	* SLURM is distributed in the hope that it will be useful, but WITHOUT ANY
	* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
	* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
	* details.
	*
	* You should have received a copy of the GNU General Public License along
	* with SLURM; if not, write to the Free Software Foundation, Inc.,
	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	\*****************************************************************************/

	#include <pthread.h>

	#include "src/common/log.h"
	#include "src/common/plugrack.h"
	#include "src/common/slurm_protocol_api.h"
	#include "src/common/xmalloc.h"
	#include "src/common/xstring.h"

	#include "src/slurmctld/sched_plugin.h"
	#include "src/slurmctld/slurmctld.h"


	/* ************************************************************************ */
	/* TAG( slurm_sched_ops_t ) */
	/* ************************************************************************ */
	typedef struct slurm_sched_ops {
	int (*schedule) ( void );
	uint32_t (*initial_priority) ( uint32_t,
	struct job_record * );
	void (*job_is_pending) ( void );
	int (*reconfig) ( void );
	void (*partition_change) ( void );
	int (*get_errno) ( void );
	char * (*strerror) ( int );
	} slurm_sched_ops_t;


	/* ************************************************************************ */
	/* TAG( slurm_sched_contex_t ) */
	/* ************************************************************************ */
	typedef struct slurm_sched_context {
	char *sched_type;
	plugrack_t plugin_list;
	plugin_handle_t cur_plugin;
	int sched_errno;
	slurm_sched_ops_t ops;
	} slurm_sched_context_t;

	static slurm_sched_context_t *g_sched_context = NULL;
	static pthread_mutex_t g_sched_context_lock = PTHREAD_MUTEX_INITIALIZER;


	/* ************************************************************************ */
	/* TAG( slurm_sched_get_ops ) */
	/* ************************************************************************ */
	static slurm_sched_ops_t *
	slurm_sched_get_ops( slurm_sched_context_t *c )
	{
	/*
	* Must be synchronized with slurm_sched_ops_t above.
	*/
	static const char *syms[] = {
	"slurm_sched_plugin_schedule",
	"slurm_sched_plugin_initial_priority",
	"slurm_sched_plugin_job_is_pending",
	"slurm_sched_plugin_reconfig",
	"slurm_sched_plugin_partition_change",
	"slurm_sched_get_errno",
	"slurm_sched_strerror"
	};
	int n_syms = sizeof( syms ) / sizeof( char * );

	/* Get plugin list. */
	if ( c->plugin_list == NULL ) {
	char *plugin_dir;
	c->plugin_list = plugrack_create();
	if ( c->plugin_list == NULL ) {
	error( "cannot create plugin manager" );
	return NULL;
	}
	plugrack_set_major_type( c->plugin_list, "sched" );
	plugrack_set_paranoia( c->plugin_list,
	PLUGRACK_PARANOIA_NONE,
	0 );
	plugin_dir = slurm_get_plugin_dir();
	plugrack_read_dir( c->plugin_list, plugin_dir );
	xfree(plugin_dir);
	}

	c->cur_plugin = plugrack_use_by_type( c->plugin_list, c->sched_type );
	if ( c->cur_plugin == PLUGIN_INVALID_HANDLE ) {
	error( "cannot find scheduler plugin for %s", c->sched_type );
	return NULL;
	}

	/* Dereference the API. */
	if ( plugin_get_syms( c->cur_plugin,
	n_syms,
	syms,
	(void **) &c->ops ) < n_syms ) {
	error( "incomplete scheduling plugin detected" );
	return NULL;
	}

	return &c->ops;
	}


	/* ************************************************************************ */
	/* TAG( slurm_sched_context_create ) */
	/* ************************************************************************ */
	static slurm_sched_context_t *
	slurm_sched_context_create( const char *sched_type )
	{
	slurm_sched_context_t *c;

	if ( sched_type == NULL ) {
	debug3( "slurm_sched_context: no scheduler type" );
	return NULL;
	}

	c = xmalloc( sizeof( slurm_sched_context_t ) );
	c->sched_type = xstrdup( sched_type );
	c->plugin_list = NULL;
	c->cur_plugin = PLUGIN_INVALID_HANDLE;
	c->sched_errno = SLURM_SUCCESS;

	return c;
	}


	/* ************************************************************************ */
	/* TAG( slurm_sched_context_destroy ) */
	/* ************************************************************************ */
	static int
	slurm_sched_context_destroy( slurm_sched_context_t *c )
	{
	/*
	* Must check return code here because plugins might still
	* be loaded and active.
	*/
	if ( c->plugin_list ) {
	if ( plugrack_destroy( c->plugin_list ) != SLURM_SUCCESS ) {
	return SLURM_ERROR;
	}
	}

	xfree( c->sched_type );
	xfree( c );

	return SLURM_SUCCESS;
	}


	/* *********************************************************************** */
	/* TAG( slurm_sched_init ) */
	/* */
	/* NOTE: The scheduler plugin can not be changed via reconfiguration */
	/* due to background threads, job priorities, etc. Slurmctld must */
	/* be restarted and job priority changes may be required to change */
	/* the scheduler type. */
	/* *********************************************************************** */
	extern int
	slurm_sched_init( void )
	{
	int retval = SLURM_SUCCESS;
	char *sched_type = NULL;

	slurm_mutex_lock( &g_sched_context_lock );

	if ( g_sched_context ) goto done;

	sched_type = slurm_get_sched_type();
	g_sched_context = slurm_sched_context_create( sched_type );
	if ( g_sched_context == NULL ) {
	error( "cannot create scheduler context for %s",
	sched_type );
	retval = SLURM_ERROR;
	goto done;
	}

	if ( slurm_sched_get_ops( g_sched_context ) == NULL ) {
	error( "cannot resolve scheduler plugin operations" );
	slurm_sched_context_destroy( g_sched_context );
	g_sched_context = NULL;
	retval = SLURM_ERROR;
	}

	done:
	slurm_mutex_unlock( &g_sched_context_lock );
	xfree(sched_type);
	return retval;
	}

	/* *********************************************************************** */
	/* TAG( slurm_sched_fini ) */
	/* *********************************************************************** */
	extern int
	slurm_sched_fini( void )
	{
	int rc;

	if (!g_sched_context)
	return SLURM_SUCCESS;

	rc = slurm_sched_context_destroy(g_sched_context);
	g_sched_context = NULL;
	return rc;
	}


	/* *********************************************************************** */
	/* TAG( slurm_sched_reconfig ) */
	/* *********************************************************************** */
	extern int
	slurm_sched_reconfig( void )
	{
	if ( slurm_sched_init() < 0 )
	return SLURM_ERROR;

	return (*(g_sched_context->ops.reconfig))();
	}

	/* *********************************************************************** */
	/* TAG( slurm_sched_schedule ) */
	/* *********************************************************************** */
	int
	slurm_sched_schedule( void )
	{
	if ( slurm_sched_init() < 0 )
	return SLURM_ERROR;

	return (*(g_sched_context->ops.schedule))();
	}


	/* *********************************************************************** */
	/* TAG( slurm_sched_initital_priority ) */
	/* *********************************************************************** */
	uint32_t
	slurm_sched_initial_priority( u_int32_t last_prio,
	struct job_record *job_ptr )
	{
	if ( slurm_sched_init() < 0 )
	return SLURM_ERROR;

	return (*(g_sched_context->ops.initial_priority))( last_prio,
	job_ptr );
	}

	/* *********************************************************************** */
	/* TAG( slurm_sched_job_is_pending ) */
	/* *********************************************************************** */
	void
	slurm_sched_job_is_pending( void )
	{
	if ( slurm_sched_init() < 0 )
	return;

	(*(g_sched_context->ops.job_is_pending))();
	}

	/* *********************************************************************** */
	/* TAG( slurm_sched_partition_change ) */
	/* *********************************************************************** */
	void
	slurm_sched_partition_change( void )
	{
	if ( slurm_sched_init() < 0 )
	return;

	(*(g_sched_context->ops.partition_change))();
	}

	/* *********************************************************************** */
	/* TAG( slurm_sched_p_get_errno ) */
	/* *********************************************************************** */
	int
	slurm_sched_p_get_errno( void )
	{
	if ( slurm_sched_init() < 0 )
	return SLURM_ERROR;

	return (*(g_sched_context->ops.get_errno))( );
	}

	/* *********************************************************************** */
	/* TAG( slurm_sched_p_strerror ) */
	/* *********************************************************************** */
	char *
	slurm_sched_p_strerror( int errnum )
	{
	if ( slurm_sched_init() < 0 )
	return NULL;

	return (*(g_sched_context->ops.strerror))( errnum );
	}