-
Pedro Gonnet authored
Former-commit-id: 67aa9f90856740bbfec0f4a0768aefead4ce51c5
Pedro Gonnet authoredFormer-commit-id: 67aa9f90856740bbfec0f4a0768aefead4ce51c5
queue.c 6.97 KiB
/*******************************************************************************
* This file is part of SWIFT.
* Coypright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser 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 Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
/* Config parameters. */
#include "../config.h"
/* Some standard headers. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* MPI headers. */
#ifdef WITH_MPI
#include <mpi.h>
#endif
/* Local headers. */
#include "const.h"
#include "cycle.h"
#include "lock.h"
#include "task.h"
#include "timers.h"
#include "space.h"
#include "part.h"
#include "multipole.h"
#include "cell.h"
#include "queue.h"
#include "error.h"
#include "inline.h"
/* Counter macros. */
#ifdef COUNTER
#define COUNT(c) ( __sync_add_and_fetch( &queue_counter[ c ] , 1 ) )
#else
#define COUNT(c)
#endif
/* The counters. */
int queue_counter[ queue_counter_count ];
/**
* @brief Insert a used tasks into the given queue.
*
* @param q The #queue.
* @param t The #task.
*/
void queue_insert ( struct queue *q , struct task *t ) {
int k, *tid;
struct task *tasks;
/* Lock the queue. */
if ( lock_lock( &q->lock ) != 0 )
error( "Failed to get queue lock." );
tid = q->tid;
tasks = q->tasks;
/* Does the queue need to be grown? */
if ( q->count == q->size ) {
int *temp;
q->size *= queue_sizegrow;
if ( ( temp = (int *)malloc( sizeof(int) * q->size ) ) == NULL )
error( "Failed to allocate new indices." );
memcpy( temp , tid , sizeof(int) * q->count );
free( tid );
q->tid = tid = temp;
}
/* Drop the task at the end of the queue. */
tid[ q->count ] = ( t - tasks );
q->count += 1;
/* Shuffle up. */
for ( k = q->count - 1 ; k > 0 ; k = (k-1)/2 )
if ( tasks[ tid[k] ].weight > tasks[ tid[(k-1)/2] ].weight ) {
int temp = tid[k];
tid[k] = tid[(k-1)/2];
tid[(k-1)/2] = temp;
}
else
break;
/* Check the queue's consistency. */
/* for ( k = 1 ; k < q->count ; k++ )
if ( tasks[ tid[(k-1)/2] ].weight < tasks[ tid[k] ].weight )
error( "Queue heap is disordered." ); */
/* Unlock the queue. */
if ( lock_unlock( &q->lock ) != 0 )
error( "Failed to unlock queue." );
}
/**
* @brief Initialize the given queue.
*
* @param q The #queue.
* @param size The maximum size of the queue.
* @param tasks List of tasks to which the queue indices refer to.
*/
void queue_init ( struct queue *q , struct task *tasks ) {
/* Allocate the task list if needed. */
q->size = queue_sizeinit;
if ( ( q->tid = (int *)malloc( sizeof(int) * q->size ) ) == NULL )
error( "Failed to allocate queue tids." );
/* Set the tasks pointer. */
q->tasks = tasks;
/* Init counters. */
q->count = 0;
/* Init the queue lock. */
if ( lock_init( &q->lock ) != 0 )
error( "Failed to init queue lock." );
}
/**
* @brief Get a task free of dependencies and conflicts.
*
* @param q The task #queue.
* @param blocking Block until access to the queue is granted.
* @param keep Remove the returned task from this queue.
*/
struct task *queue_gettask ( struct queue *q , struct cell *super , int blocking ) {
int k, qcount, *qtid, gotcha;
lock_type *qlock = &q->lock;
struct task *qtasks, *res = NULL;
/* If there are no tasks, leave immediately. */
if ( q->count == 0 )
return NULL;
/* Grab the task lock. */
if ( blocking ) {
if ( lock_lock( qlock ) != 0 )
error( "Locking the qlock failed.\n" );
}
else {
if ( lock_trylock( qlock ) != 0 )
return NULL;
}
/* Set some pointers we will use often. */
qtid = q->tid;
qtasks = q->tasks;
qcount = q->count;
gotcha = 0;
/* Loop over the task IDs looking for tasks with the same super-cell. */
if ( super != NULL ) {
for ( k = 0 ; k < qcount && k < queue_maxsuper ; k++ ) {
/* Put a finger on the task. */
res = &qtasks[ qtid[k] ];
/* Try to lock the task and exit if successful. */
if ( ( res->ci->super == super || ( res->cj != NULL && res->cj->super == super ) ) &&
task_lock( res ) ) {
gotcha = 1;
break;
}
} /* loop over the task IDs. */
}
/* Loop over the task IDs again if nothing was found, take anything. */
if ( !gotcha ) {
for ( k = 0 ; k < qcount ; k++ ) {
/* Put a finger on the task. */
res = &qtasks[ qtid[k] ];
/* Try to lock the task and exit if successful. */
if ( task_lock( res ) )
break;
} /* loop over the task IDs. */
}
/* Did we get a task? */ if ( k < qcount ) {
/* Another one bites the dust. */
qcount = q->count -= 1;
/* Swap this task with the last task and re-heap. */
if ( k < qcount ) {
qtid[ k ] = qtid[ qcount ];
int w = qtasks[ qtid[k] ].weight;
while ( k > 0 && w > qtasks[ qtid[(k-1)/2] ].weight ) {
int temp = q->tid[k];
q->tid[k] = q->tid[(k-1)/2];
q->tid[(k-1)/2] = temp;
k = (k-1)/2;
}
int i;
while ( ( i = 2*k+1 ) < qcount ) {
if ( i+1 < qcount && qtasks[ qtid[i+1] ].weight > qtasks[ qtid[i] ].weight )
i += 1;
if ( qtasks[ qtid[i] ].weight > w ) {
int temp = qtid[i];
qtid[i] = qtid[k];
qtid[k] = temp;
k = i;
}
else
break;
}
}
}
else
res = NULL;
/* Check the queue's consistency. */
/* for ( k = 1 ; k < q->count ; k++ )
if ( qtasks[ qtid[(k-1)/2] ].weight < qtasks[ qtid[k] ].weight )
error( "Queue heap is disordered." ); */
/* Release the task lock. */
if ( lock_unlock( qlock ) != 0 )
error( "Unlocking the qlock failed.\n" );
/* Take the money and run. */
return res;
}