Introducing the workqueue

1 files changed, 156 insertions, 0 deletions

diff --git a/ot_mutex.c b/ot_mutex.c
index bb82f46..b39baaa 100644
--- a/ot_mutex.c
+++ b/ot_mutex.c
@@ -4,6 +4,8 @@
 /* System */
 #include <pthread.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
 
 /* Libowfat */
 #include "byte.h"
@@ -15,6 +17,7 @@
 /* Our global all torrents list */
 static ot_vector all_torrents[OT_BUCKET_COUNT];
 
+/* Bucket Magic */
 static int bucket_locklist[ OT_MAX_THREADS ];
 static int bucket_locklist_count = 0;
 static pthread_mutex_t bucket_mutex;
@@ -91,6 +94,159 @@ void mutex_bucket_unlock_by_hash( ot_hash *hash ) {
   mutex_bucket_unlock( bucket );
 }
 
+/* TaskQueue Magic */
+
+struct ot_task {
+  ot_taskid       taskid;
+  ot_tasktype     tasktype;
+  int64           socket;
+  int             iovec_entries;
+  struct iovec   *iovec;
+  struct ot_task *next;
+};
+
+static ot_taskid next_free_taskid = 1;
+static struct ot_task *tasklist = NULL;
+static pthread_mutex_t tasklist_mutex;
+static pthread_cond_t tasklist_being_filled;
+
+int mutex_workqueue_pushtask( int64 socket, ot_tasktype tasktype ) {
+  struct ot_task ** tmptask, * task;
+
+  /* Want exclusive access to tasklist */
+  pthread_mutex_lock( &tasklist_mutex );
+
+  task = malloc(sizeof( struct ot_task));
+  if( !task ) {
+    pthread_mutex_unlock( &tasklist_mutex );
+    return -1;
+  }
+    
+  /* Skip to end of list */
+  tmptask = &tasklist; 
+  while( *tmptask )
+    tmptask = &(*tmptask)->next;
+  *tmptask = task;
+
+  task->taskid        = 0;
+  task->tasktype      = tasktype;
+  task->socket        = socket;
+  task->iovec_entries = 0;
+  task->iovec         = NULL;
+  task->next          = 0;
+
+  /* Inform waiting workers and release lock */
+  pthread_cond_broadcast( &tasklist_being_filled );
+  pthread_mutex_unlock( &tasklist_mutex );
+  return 0;
+}
+
+void mutex_workqueue_canceltask( int64 socket ) {
+  struct ot_task ** task;
+
+  /* Want exclusive access to tasklist */
+  pthread_mutex_lock( &tasklist_mutex );
+
+  task = &tasklist;
+  while( *task && ( (*task)->socket != socket ) )
+    *task = (*task)->next;
+
+  if( *task && ( (*task)->socket == socket ) ) {
+    struct iovec *iovec = (*task)->iovec;
+    struct ot_task *ptask = *task;
+    int i;
+
+    /* Free task's iovec */
+    for( i=0; i<(*task)->iovec_entries; ++i )
+      munmap( iovec[i].iov_base , iovec[i].iov_len );
+
+    *task = (*task)->next;
+    free( ptask );
+  }
+
+  /* Release lock */
+  pthread_mutex_unlock( &tasklist_mutex );
+}
+
+ot_taskid mutex_workqueue_poptask( ot_tasktype tasktype ) {
+  struct ot_task * task;
+  ot_taskid taskid = 0;
+
+  /* Want exclusive access to tasklist */
+  pthread_mutex_lock( &tasklist_mutex );
+
+  while( !taskid ) {
+    /* Skip to the first unassigned task this worker wants to do */
+    task = tasklist;
+    while( task && ( task->tasktype != tasktype ) && ( task->taskid ) )
+      task = task->next;
+
+    /* If we found an outstanding task, assign a taskid to it
+       and leave the loop */
+    if( task ) {
+      task->taskid = taskid = ++next_free_taskid;
+      break;
+    }
+
+    /* Wait until the next task is being fed */
+    pthread_cond_wait( &tasklist_being_filled, &tasklist_mutex );
+  }
+
+  /* Release lock */
+  pthread_mutex_unlock( &tasklist_mutex );
+
+  return taskid;
+}
+
+int mutex_workqueue_pushresult( ot_taskid taskid, int iovec_entries, struct iovec *iovec ) {
+  struct ot_task * task;
+  /* Want exclusive access to tasklist */
+  pthread_mutex_lock( &tasklist_mutex );
+
+  task = tasklist;
+  while( task && ( task->taskid != taskid ) )
+    task = task->next;
+
+  if( task ) {
+    task->iovec_entries = iovec_entries;
+    task->iovec         = iovec;
+    task->tasktype      = OT_TASKTYPE_DONE;
+  }
+
+  /* Release lock */
+  pthread_mutex_unlock( &tasklist_mutex );
+  
+  /* Indicate whether the worker has to throw away results */
+  return task ? 0 : -1;
+}
+
+int64 mutex_workqueue_popresult( int *iovec_entries, struct iovec ** iovec ) {
+  struct ot_task ** task;
+  int64 socket = -1;
+
+  /* Want exclusive access to tasklist */
+  pthread_mutex_lock( &tasklist_mutex );
+
+  task = &tasklist;
+  while( *task && ( (*task)->tasktype != OT_TASKTYPE_DONE ) )
+    *task = (*task)->next;
+
+  if( *task && ( (*task)->tasktype == OT_TASKTYPE_DONE ) ) {
+    struct ot_task *ptask = *task;
+
+    *iovec_entries = (*task)->iovec_entries;
+    *iovec         = (*task)->iovec;
+    socket         = (*task)->socket;
+    
+    *task = (*task)->next;
+    free( ptask );
+  }
+
+  /* Release lock */
+  pthread_mutex_unlock( &tasklist_mutex );
+  return socket;
+}
+
 void mutex_init( ) {
   pthread_mutex_init(&bucket_mutex, NULL);
   pthread_cond_init (&bucket_being_unlocked, NULL);