Add queue_send synchronous message sending. Right now only for SWCODEC. Actual usage to be added to playback and recording shortly in upcoming commits.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11776 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 178 insertions, 11 deletions

diff --git a/uisimulator/sdl/kernel.c b/uisimulator/sdl/kernel.c
index f1eb095e7b..fa573a3cc9 100644
--- a/uisimulator/sdl/kernel.c
+++ b/uisimulator/sdl/kernel.c
@@ -18,6 +18,7 @@
  ****************************************************************************/
 
 #include <stdlib.h>
+#include "memory.h"
 #include "uisdl.h"
 #include "kernel.h"
 #include "thread-sdl.h"
@@ -32,13 +33,71 @@ int set_irq_level (int level)
     return (_lv = level);
 }
 
+#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
+/* Moves waiting thread's descriptor to the current sender when a
+   message is dequeued */
+static void queue_fetch_sender(struct queue_sender_list *send,
+                               unsigned int i)
+{
+    int old_level = set_irq_level(15<<4);
+    struct queue_sender **spp = &send->senders[i];
+
+    if(*spp)
+    {
+        send->curr_sender = *spp;
+        *spp = NULL;
+    }
+
+    set_irq_level(old_level);
+}
+
+/* Puts the specified return value in the waiting thread's return value
+   and wakes the thread  - a sender should be confirmed to exist first */
+static void queue_release_sender(struct queue_sender **sender, void *retval)
+{
+    (*sender)->retval = retval;
+    *sender = NULL;
+}
+
+/* Releases any waiting threads that are queued with queue_send -
+   reply with NULL */
+static void queue_release_all_senders(struct event_queue *q)
+{
+    if(q->send)
+    {
+        unsigned int i;
+        for(i = q->read; i != q->write; i++)
+        {
+            struct queue_sender **spp =
+                &q->send->senders[i & QUEUE_LENGTH_MASK];
+            if(*spp)
+            {
+                queue_release_sender(spp, NULL);
+            }
+        }
+    }
+}
+
+/* Enables queue_send on the specified queue - caller allocates the extra
+   data structure */
+void queue_enable_queue_send(struct event_queue *q,
+                             struct queue_sender_list *send)
+{
+    q->send = send;
+    memset(send, 0, sizeof(*send));
+}
+#endif /* HAVE_EXTENDED_MESSAGING_AND_NAME */
+
 void queue_init(struct event_queue *q, bool register_queue)
 {
     (void)register_queue;
     
-    q->read = 0;
-    q->write = 0;
+    q->read   = 0;
+    q->write  = 0;
     q->thread = NULL;
+#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
+    q->send   = NULL; /* No message sending by default */
+#endif
 }
 
 void queue_delete(struct event_queue *q)
@@ -48,12 +107,23 @@ void queue_delete(struct event_queue *q)
 
 void queue_wait(struct event_queue *q, struct event *ev)
 {
+    unsigned int rd;
+
     while(q->read == q->write)
     {
         switch_thread(true, NULL);
     }
 
-    *ev = q->events[(q->read++) & QUEUE_LENGTH_MASK];
+    rd = q->read++ & QUEUE_LENGTH_MASK;
+    *ev = q->events[rd];
+
+#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
+    if(q->send && q->send->senders[rd])
+    {
+        /* Get data for a waiting thread if one */
+        queue_fetch_sender(q->send, rd);
+    }
+#endif
 }
 
 void queue_wait_w_tmo(struct event_queue *q, struct event *ev, int ticks)
@@ -67,7 +137,16 @@ void queue_wait_w_tmo(struct event_queue *q, struct event *ev, int ticks)
 
     if(q->read != q->write)
     {
-        *ev = q->events[(q->read++) & QUEUE_LENGTH_MASK];
+        unsigned int rd = q->read++ & QUEUE_LENGTH_MASK;
+        *ev = q->events[rd];
+
+#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
+        if(q->send && q->send->senders[rd])
+        {
+            /* Get data for a waiting thread if one */
+            queue_fetch_sender(q->send, rd);
+        }
+#endif
     }
     else
     {
@@ -77,16 +156,81 @@ void queue_wait_w_tmo(struct event_queue *q, struct event *ev, int ticks)
 
 void queue_post(struct event_queue *q, long id, void *data)
 {
-    int wr;
-    int oldlevel;
+    int oldlevel = set_irq_level(15<<4);
+    unsigned int wr = q->write++ & QUEUE_LENGTH_MASK;
+
+    q->events[wr].id   = id;
+    q->events[wr].data = data;
+
+#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
+    if(q->send)
+    {
+        struct queue_sender **spp = &q->send->senders[wr];
+
+        if(*spp)
+        {
+            /* overflow protect - unblock any thread waiting at this index */
+            queue_release_sender(spp, NULL);
+        }
+    }
+#endif
 
-    oldlevel = set_irq_level(15<<4);
-    wr = (q->write++) & QUEUE_LENGTH_MASK;
+    set_irq_level(oldlevel);
+}
 
-    q->events[wr].id = id;
+#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
+void * queue_send(struct event_queue *q, long id, void *data)
+{
+    int oldlevel = set_irq_level(15<<4);
+    unsigned int wr = q->write++ & QUEUE_LENGTH_MASK;
+
+    q->events[wr].id   = id;
     q->events[wr].data = data;
+
+    if(q->send)
+    {
+        struct queue_sender **spp = &q->send->senders[wr];
+        struct queue_sender sender;
+
+        if(*spp)
+        {
+            /* overflow protect - unblock any thread waiting at this index */
+            queue_release_sender(spp, NULL);
+        }
+
+        *spp = &sender;
+
+        set_irq_level(oldlevel);
+        while (*spp != NULL)
+        {
+            switch_thread(true, NULL);
+        }
+
+        return sender.retval;
+    }
+
+    /* Function as queue_post if sending is not enabled */
     set_irq_level(oldlevel);
+    return NULL;
+}
+
+#if 0 /* not used now but probably will be later */
+/* Query if the last message dequeued was added by queue_send or not */
+bool queue_in_queue_send(struct event_queue *q)
+{
+    return q->send && q->send->curr_sender;
 }
+#endif
+
+/* Replies with retval to any dequeued message sent with queue_send */
+void queue_reply(struct event_queue *q, void *retval)
+{
+    if(q->send && q->send->curr_sender)
+    {
+        queue_release_sender(&q->send->curr_sender, retval);
+    }
+}
+#endif /* HAVE_EXTENDED_MESSAGING_AND_NAME */
 
 bool queue_empty(const struct event_queue* q)
 {
@@ -96,6 +240,11 @@ bool queue_empty(const struct event_queue* q)
 void queue_clear(struct event_queue* q)
 {
     /* fixme: This is potentially unsafe in case we do interrupt-like processing */
+#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
+    /* Release all thread waiting in the queue for a reply -
+       dequeued sent message will be handled by owning thread */
+    queue_release_all_senders(q);
+#endif
     q->read = 0;
     q->write = 0;
 }
@@ -104,9 +253,27 @@ void queue_remove_from_head(struct event_queue *q, long id)
 {
     int oldlevel = set_irq_level(15<<4);
     
-    while (q->read != q->write && 
-      q->events[(q->read) & QUEUE_LENGTH_MASK].id == id)
+    while(q->read != q->write)
     {
+        unsigned int rd = q->read & QUEUE_LENGTH_MASK;
+
+        if(q->events[rd].id != id)
+        {
+            break;
+        }
+
+#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
+        if(q->send)
+        {
+            struct queue_sender **spp = &q->send->senders[rd];
+
+            if(*spp)
+            {
+                /* Release any thread waiting on this message */
+                queue_release_sender(spp, NULL);
+            }
+        }
+#endif
         q->read++;
     }