cuflow/sched_types.h

/* Part of the culibs project, <http://www.eideticdew.org/culibs/>.
 * Copyright (C) 2007  Petter Urkedal <urkedal@nbi.dk>
 *
 * This program 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef CUFLOW_SCHED_TYPES_H
#define CUFLOW_SCHED_TYPES_H

#include <cuflow/fwd.h>
#include <cu/clos.h>
#include <atomic_ops.h>

CU_BEGIN_DECLARATIONS
/** \addtogroup cuflow_sched_h
 ** @{ */

/* The number of entries in each thread-local execution queue.  This must be
 * a power of 2. */
#define CUFLOW_EXEQ_SIZE 8
#define CUFLOW_EXEQ_MASK (CUFLOW_EXEQ_SIZE - 1)
#define CUFLOW_PROFILE_SCHED 0
#define CUFLOW_CALLS_BETWEEN_SCHED 1

typedef struct cuflow_exeq *cuflow_exeq_t;
typedef struct cuflow_exeq_entry *cuflow_exeq_entry_t;

/** A type to hold the priority of scheduled work. */
typedef enum {
    cuflow_exeqpri_begin        = 0,
    cuflow_exeqpri_normal       = 0,
    cuflow_exeqpri_background   = 1,
    cuflow_exeqpri_end
} cuflow_exeqpri_t;

#define cuflow_exeqpri_succ(pri) ((cuflow_exeqpri_t)((pri) + 1))

/** True iff \a pri0 is at least as high a priority as \a pri1. */
CU_SINLINE cu_bool_t
cuflow_exeqpri_prioreq(cuflow_exeqpri_t pri0, cuflow_exeqpri_t pri1)
{ return pri0 <= pri1; }

/** True iff \a pri0 is a higher priority than \a pri1. */
CU_SINLINE cu_bool_t
cuflow_exeqpri_prior(cuflow_exeqpri_t pri0, cuflow_exeqpri_t pri1)
{ return pri0 < pri1; }

struct cuflow_exeq_entry
{
    cu_clop0(fn, void);
    AO_t *cdisj;
};

/** An SMP workloading queue.  This is a short queue used to float work between
 ** threads.  The internal structure is private, you only need to pass it
 ** around to \ref cuflow_sched_call_on etc. as an optimisation to avoid the
 ** individual thread-local lookup of \ref cuflow_sched_call etc. */
struct cuflow_exeq
{
    pthread_mutex_t pickup_mutex;
    cuflow_exeqpri_t priority;
    struct cuflow_exeq_entry call_arr[CUFLOW_EXEQ_SIZE];
    AO_t head, tail;
#if CUFLOW_CALLS_BETWEEN_SCHED > 1
    int calls_till_sched;
#endif
};

/** @} */
CU_END_DECLARATIONS

#endif