Change proc_mgmt/pending_clients.h to use reply queues instead of hashtables.

[barrelfish] / usr / proc_mgmt / spawnd_state.c

diff --git a/usr/proc_mgmt/spawnd_state.c b/usr/proc_mgmt/spawnd_state.c
index f07d196..3fb7535 100644 (file)
--- a/usr/proc_mgmt/spawnd_state.c
+++ b/usr/proc_mgmt/spawnd_state.c
@@ -13,7 +13,7 @@
 
 #include "spawnd_state.h"
 
-static struct spawnd_state *spawnds[MAX_SPAWNDS];
+static struct spawnd_state *spawnds[MAX_COREID];
 
 errval_t spawnd_state_alloc(coreid_t core_id, struct spawn_binding *b)
 {
@@ -24,6 +24,13 @@ errval_t spawnd_state_alloc(coreid_t core_id, struct spawn_binding *b)
     }
 
     spawnds[core_id]->b = b;
+    spawnds[core_id]->core_id = core_id;
+    spawnds[core_id]->sendq.head = NULL;
+    spawnds[core_id]->sendq.tail = NULL;
+    spawnds[core_id]->recvq.head = NULL;
+    spawnds[core_id]->recvq.tail = NULL;
+
+    b->st = spawnds[core_id];
 
     return SYS_ERR_OK;
 }
@@ -40,7 +47,130 @@ inline bool spawnd_state_exists(coreid_t core_id)
     return spawnds[core_id] != NULL;
 }
 
-inline struct spawn_binding *spawnd_state_get_binding(coreid_t core_id)
+inline struct spawnd_state *spawnd_state_get(coreid_t core_id)
 {
-    return spawnds[core_id]->b;
+    return spawnds[core_id];
 }
+
+/**
+ * \brief Enqueue on a waitset queue.
+ *
+ * \param q    Pointer to queue to enqueue on
+ * \param m    Pointer to element to enqueue
+ *
+ * \return true if queue was empty, false if not.
+ */
+static bool enqueue(struct msg_queue *q, struct msg_queue_elem *m)
+{
+    assert(m->next == NULL);
+
+    // Enqueue on the queue
+    if(q->tail != NULL) {
+        q->tail->next = m;
+    } else {
+        assert(q->head == NULL);
+        q->head = m;
+    }
+    q->tail = m;
+
+    return q->head == q->tail ? true : false;
+}
+
+/**
+ * \brief Dequeues from a waitset queue.
+ *
+ * \param q    Pointer to queue to dequeue from
+ *
+ * \return the newly dequeued element.
+ */
+static struct msg_queue_elem *dequeue(struct msg_queue *q)
+{
+    // Queue should have at least one element
+    assert(q->head != NULL && q->tail != NULL);
+
+    struct msg_queue_elem *e = q->head;
+    q->head = e->next;
+    if(q->head == NULL) {
+        q->tail = NULL;
+    }
+
+    return e;
+}
+
+/**
+ * \brief Enqueue an element on a waitset queue IN FRONT.
+ *
+ * \param q    Pointer to queue to enqueue on
+ * \param m    Pointer to element to enqueue
+ *
+ * \return true if queue was empty, false if not.
+ */
+static bool enqueue_at_front(struct msg_queue *q, struct msg_queue_elem *m)
+{
+    assert(m->next == NULL);
+    if(q->tail == NULL) {
+        assert(q->head == NULL);
+        q->head = m;
+        q->tail = m;
+    } else {
+        m->next = q->head;
+        q->head = m;
+    }
+    return q->head == q->tail ? true : false;
+}
+
+static void spawnd_send_handler(void *arg)
+{
+    struct spawnd_state *spawnd = (struct spawnd_state*) arg;
+    struct msg_queue *q = &spawnd->sendq;
+
+    // Dequeue next element from the queue
+    struct msg_queue_elem *m = (struct msg_queue_elem*) dequeue(q);
+
+    assert(m->cont != NULL);
+    if (m->cont(m)) {
+        // Send continuation succeeded, need to enqueue a receive.
+        struct msg_queue_elem *recvm = (struct msg_queue_elem*) malloc(
+                sizeof(struct msg_queue_elem));
+        recvm->st = m->st;
+        recvm->next = NULL;
+        enqueue(&spawnd->recvq, recvm);
+    } else {
+        // Send continuation failed, need to re-enqueue message.
+        // TODO(razvan): Re-enqueuing at the front of the queue, to preserve
+        // original message order. Could a different strategy be preferrable?
+        enqueue_at_front(q, m);
+    }
+
+    if (q->head != NULL) {
+        // Queue is non-empty, therefore re-register.
+        errval_t err = spawnd->b->register_send(spawnd->b, spawnd->b->waitset,
+                                                MKCONT(spawnd_send_handler,
+                                                       arg));
+        if (err_is_fail(err)) {
+            DEBUG_ERR(err, "regitering for spawnd send");
+            return;
+        }
+    }
+}
+
+errval_t spawnd_state_enqueue_send(struct spawnd_state *spawnd,
+                                   struct msg_queue_elem *msg)
+{
+    msg->next = NULL;
+
+    // If queue was empty, enqueue on waitset
+    if(enqueue(&spawnd->sendq, msg)) {
+        return spawnd->b->register_send(spawnd->b, spawnd->b->waitset,
+                                        MKCONT(spawnd_send_handler, spawnd));
+    } else {
+        return SYS_ERR_OK;
+    }
+}
+
+void *spawnd_state_dequeue_recv(struct spawnd_state *spawnd)
+{
+    struct msg_queue_elem *m = dequeue(&spawnd->recvq);
+    assert(m != NULL);
+    return m->st;
+}
\ No newline at end of file