-/* $Id: sel_thread.c,v 1.2 2007-04-20 10:15:19 adam Exp $
+/* $Id: sel_thread.c,v 1.4 2007-04-23 08:06:21 adam Exp $
Copyright (c) 2006-2007, Index Data.
This file is part of Pazpar2.
#include <unistd.h>
#include <stdlib.h>
#include <pthread.h>
+#include <assert.h>
struct work_item {
void *data;
struct work_item *next;
};
+static struct work_item *queue_remove_last(struct work_item **q)
+{
+ struct work_item **work_p = q, *work_this = 0;
+
+ while (*work_p && (*work_p)->next)
+ work_p = &(*work_p)->next;
+ if (*work_p)
+ {
+ work_this = *work_p;
+ *work_p = 0;
+ }
+ return work_this;
+}
+
+static void queue_trav(struct work_item *q, void (*f)(void *data))
+{
+ for (; q; q = q->next)
+ f(q->data);
+}
+
struct sel_thread {
int fd[2];
NMEM nmem;
- pthread_t thread_id;
+ pthread_t *thread_id;
pthread_mutex_t mutex;
pthread_cond_t input_data;
int stop_flag;
+ int no_threads;
struct work_item *input_queue;
struct work_item *output_queue;
struct work_item *free_queue;
- void (*work_handler)(void *work_data);;
+ void (*work_handler)(void *work_data);
+ void (*work_destroy)(void *work_data);
};
static void *sel_thread_handler(void *vp)
while(1)
{
- struct work_item **work_p, *work_this;
+ struct work_item *work_this = 0;
/* wait for some work */
pthread_mutex_lock(&p->mutex);
while (!p->stop_flag && !p->input_queue)
if (p->stop_flag)
break;
/* got something. Take the last one out of input_queue */
- work_p = &p->input_queue;
- while ((*work_p)->next)
- work_p = &(*work_p)->next;
- work_this = *work_p;
- *work_p = 0;
+
+ assert(p->input_queue);
+ work_this = queue_remove_last(&p->input_queue);
+ assert(work_this);
+
pthread_mutex_unlock(&p->mutex);
/* work on this item */
p->work_handler(work_this->data);
-
+
/* put it back into output queue */
pthread_mutex_lock(&p->mutex);
work_this->next = p->output_queue;
}
sel_thread_t sel_thread_create(void (*work_handler)(void *work_data),
- int *read_fd)
+ void (*work_destroy)(void *work_data),
+ int *read_fd, int no_of_threads)
{
+ int i;
NMEM nmem = nmem_create();
sel_thread_t p = nmem_malloc(nmem, sizeof(*p));
+ assert(work_handler);
+ /* work_destroy may be NULL */
+ assert(read_fd);
+ assert(no_of_threads >= 1);
+
p->nmem = nmem;
if (pipe(p->fd))
{
p->output_queue = 0;
p->free_queue = 0;
p->work_handler = work_handler;
+ p->work_destroy = work_destroy;
p->stop_flag = 0;
+ p->no_threads = no_of_threads;
pthread_mutex_init(&p->mutex, 0);
pthread_cond_init(&p->input_data, 0);
- pthread_create (&p->thread_id, 0, sel_thread_handler, p);
+
+ p->thread_id = nmem_malloc(nmem, sizeof(*p->thread_id) * p->no_threads);
+ for (i = 0; i < p->no_threads; i++)
+ pthread_create (p->thread_id + i, 0, sel_thread_handler, p);
return p;
}
void sel_thread_destroy(sel_thread_t p)
{
+ int i;
pthread_mutex_lock(&p->mutex);
-
p->stop_flag = 1;
pthread_cond_broadcast(&p->input_data);
pthread_mutex_unlock(&p->mutex);
- pthread_join(p->thread_id, 0);
+ for (i = 0; i< p->no_threads; i++)
+ pthread_join(p->thread_id[i], 0);
+
+ if (p->work_destroy)
+ {
+ queue_trav(p->input_queue, p->work_destroy);
+ queue_trav(p->output_queue, p->work_destroy);
+ }
close(p->fd[0]);
close(p->fd[1]);
struct work_item *work_p;
pthread_mutex_lock(&p->mutex);
- work_p = p->free_queue;
- if (!work_p)
+
+ if (p->free_queue)
+ {
+ work_p = p->free_queue;
+ p->free_queue = p->free_queue->next;
+ }
+ else
work_p = nmem_malloc(p->nmem, sizeof(*work_p));
work_p->data = data;
work_p->next = p->input_queue;
p->input_queue = work_p;
+
+ pthread_cond_signal(&p->input_data);
pthread_mutex_unlock(&p->mutex);
}
void *sel_thread_result(sel_thread_t p)
{
- struct work_item **work_p, *work_this;
- void *data;
+ struct work_item *work_this = 0;
+ void *data = 0;
char read_buf[1];
- /* got something. Take the last one out of output_queue */
- work_p = &p->output_queue;
- if (!*work_p)
- return 0;
-
- read(p->fd[0], read_buf, 1);
-
- while ((*work_p)->next)
- work_p = &(*work_p)->next;
- work_this = *work_p;
- *work_p = 0;
-
- /* put freed item in free list */
- work_this->next = p->free_queue;
- p->free_queue = work_this;
+ pthread_mutex_lock(&p->mutex);
- data = work_this->data;
+ /* got something. Take the last one out of output_queue */
+ work_this = queue_remove_last(&p->output_queue);
+ if (work_this)
+ {
+ /* put freed item in free list */
+ work_this->next = p->free_queue;
+ p->free_queue = work_this;
+
+ data = work_this->data;
+ read(p->fd[0], read_buf, 1);
+ }
pthread_mutex_unlock(&p->mutex);
-
return data;
}