TCP Read-Ahead: Convert to use I/O buffer chains

8 files changed, 33 insertions, 33 deletions

diff --git a/nuttx/net/iob/Kconfig b/nuttx/net/iob/Kconfig
index b8481ab9e..5bb6e4c6b 100644
--- a/nuttx/net/iob/Kconfig
+++ b/nuttx/net/iob/Kconfig
@@ -48,8 +48,8 @@ config IOB_NCHAINS
 config IOB_THROTTLE
 	int "I/O buffer throttle value"
 	default 0 if !NET_TCP_WRITE_BUFFERS || !NET_TCP_READAHEAD
-	default 8 if NET_TCP_WRITE_BUFFERS && !NET_TCP_READAHEAD
-	depends on NET_TCP_WRITE_BUFFERS && !NET_TCP_READAHEAD
+	default 8 if NET_TCP_WRITE_BUFFERS && NET_TCP_READAHEAD
+	depends on NET_TCP_WRITE_BUFFERS && NET_TCP_READAHEAD
 	---help---
 		TCP write buffering and read-ahead buffer use the same pool of free
 		I/O buffers.  In order to prevent uncontrolled incoming TCP packets
diff --git a/nuttx/net/iob/Make.defs b/nuttx/net/iob/Make.defs
index 205ef72ea..0eb2e0f9b 100644
--- a/nuttx/net/iob/Make.defs
+++ b/nuttx/net/iob/Make.defs
@@ -40,8 +40,8 @@ ifeq ($(CONFIG_NET_IOB),y)
 NET_CSRCS += iob_add_queue.c iob_alloc.c iob_alloc_qentry.c iob_clone.c
 NET_CSRCS += iob_concat.c iob_copyin.c iob_copyout.c iob_contig.c iob_free.c
 NET_CSRCS += iob_free_chain.c iob_free_qentry.c iob_free_queue.c
-NET_CSRCS += iob_initialize.c iob_pack.c iob_remove_queue.c iob_trimhead.c
-NET_CSRCS += iob_trimtail.c
+NET_CSRCS += iob_initialize.c iob_pack.c iob_peek_queue.c iob_remove_queue.c
+NET_CSRCS += iob_trimhead.c iob_trimtail.c
 
 ifeq ($(CONFIG_DEBUG),y)
 NET_CSRCS += iob_dump.c
diff --git a/nuttx/net/iob/iob_alloc.c b/nuttx/net/iob/iob_alloc.c
index 672d1e2e7..179908d46 100644
--- a/nuttx/net/iob/iob_alloc.c
+++ b/nuttx/net/iob/iob_alloc.c
@@ -95,7 +95,7 @@ static FAR struct iob_s *iob_tryalloc(bool throttled)
 #if CONFIG_IOB_THROTTLE > 0
   /* Select the semaphore count to check. */
 
-  sem = (throttled ? : &g_throttled_sem, &g_iob_sem);
+  sem = (throttled ? &g_throttle_sem : &g_iob_sem);
 #endif
 
   /* We don't know what context we are called from so we use extreme measures
@@ -107,7 +107,7 @@ static FAR struct iob_s *iob_tryalloc(bool throttled)
 #if CONFIG_IOB_THROTTLE > 0
   /* If there are free I/O buffers for this allocation */
 
-  DEBUGVERIFY(sem_getvalue(sem, semcount));
+  DEBUGVERIFY(sem_getvalue(sem, &semcount));
   if (semcount > 0)
 #endif
     {
@@ -124,7 +124,9 @@ static FAR struct iob_s *iob_tryalloc(bool throttled)
           g_iob_freelist = iob->io_flink;
           DEBUGVERIFY(sem_trywait(&g_iob_sem));
 #if CONFIG_IOB_THROTTLE > 0
-          DEBUGVERIFY(sem_trywait(&g_throttle_sem));
+          //DEBUGVERIFY(sem_trywait(&g_throttle_sem));
+          g_throttle_sem.semcount--;
+          DEBUGASSERT(g_throttle_sem.semcount >= -CONFIG_IOB_THROTTLE);
 #endif
           irqrestore(flags);
 
@@ -161,7 +163,7 @@ static FAR struct iob_s *iob_allocwait(bool throttled)
 #if CONFIG_IOB_THROTTLE > 0
   /* Select the semaphore count to check. */
 
-  sem = (throttled ? : &g_throttled_sem, &g_iob_sem);
+  sem = (throttled ? &g_throttle_sem : &g_iob_sem);
 #else
   sem = &g_iob_sem;
 #endif
diff --git a/nuttx/net/iob/iob_alloc_qentry.c b/nuttx/net/iob/iob_alloc_qentry.c
index f75d21009..8f425adb0 100644
--- a/nuttx/net/iob/iob_alloc_qentry.c
+++ b/nuttx/net/iob/iob_alloc_qentry.c
@@ -105,7 +105,7 @@ static FAR struct iob_qentry_s *iob_tryalloc_qentry(void)
        */
 
       g_iob_freeqlist = iobq->qe_flink;
-      DEBVERIFY(sem_trywait(&g_qentry_sem));
+      DEBUGVERIFY(sem_trywait(&g_qentry_sem));
 
       /* Put the I/O buffer in a known state */
 
@@ -186,32 +186,20 @@ static FAR struct iob_qentry_s *iob_allocwait_qentry(void)
 
 FAR struct iob_qentry_s *iob_alloc_qentry(void)
 {
-  FAR struct iob_qentry_s *iobq;
-  irqstate_t flags;
-
-  /* We don't know what context we are called from so we use extreme measures
-   * to protect the free list:  We disable interrupts very briefly.
-   */
+  /* Were we called from the interrupt level? */
 
-  flags = irqsave();
-  iobq  = g_iob_freeqlist;
-  if (iobq)
+  if (up_interrupt_context())
     {
-      /* Remove the I/O buffer chain container from the free list and
-       * decrement the counting semaphore that tracks the number of free
-       * containers.
-       */
-
-      g_iob_freeqlist = iobq->qe_flink;
-      DEBVERIFY(sem_trywait(&g_qentry_sem));
-
-      /* Put the I/O buffer in a known state */
+      /* Yes, then try to allocate an I/O buffer without waiting */
 
-      iobq->qe_head = NULL; /* Nothing is contained */
+      return iob_tryalloc_qentry();
     }
+  else
+    {
+      /* Then allocate an I/O buffer, waiting as necessary */
 
-  irqrestore(flags);
-  return iobq;
+      return iob_allocwait_qentry();
+    }
 }
 
 #endif /* CONFIG_IOB_NCHAINS > 0 */
diff --git a/nuttx/net/iob/iob_copyin.c b/nuttx/net/iob/iob_copyin.c
index 1cfd1f697..75d82023c 100644
--- a/nuttx/net/iob/iob_copyin.c
+++ b/nuttx/net/iob/iob_copyin.c
@@ -223,5 +223,5 @@ int iob_copyin(FAR struct iob_s *iob, FAR const uint8_t *src,
       offset = 0;
     }
 
-  return 0;
+  return OK;
 }
diff --git a/nuttx/net/iob/iob_free.c b/nuttx/net/iob/iob_free.c
index ada8a7fe6..984287600 100644
--- a/nuttx/net/iob/iob_free.c
+++ b/nuttx/net/iob/iob_free.c
@@ -135,6 +135,9 @@ FAR struct iob_s *iob_free(FAR struct iob_s *iob)
   /* Signal that an IOB is available */
 
   sem_post(&g_iob_sem);
+#if CONFIG_IOB_THROTTLE > 0
+  sem_post(&g_throttle_sem);
+#endif
   irqrestore(flags);
 
   /* And return the I/O buffer after the one that was freed */
diff --git a/nuttx/net/iob/iob_initialize.c b/nuttx/net/iob/iob_initialize.c
index 8971f8d63..647eb0649 100644
--- a/nuttx/net/iob/iob_initialize.c
+++ b/nuttx/net/iob/iob_initialize.c
@@ -131,6 +131,10 @@ void iob_initialize(void)
 
       sem_init(&g_iob_sem, 0, CONFIG_IOB_NBUFFERS);
 
+#if CONFIG_IOB_THROTTLE > 0
+      sem_init(&g_throttle_sem, 0, CONFIG_IOB_NBUFFERS - CONFIG_IOB_THROTTLE);
+#endif
+
 #if CONFIG_IOB_NCHAINS > 0
       /* Add each I/O buffer chain queue container to the free list */
 
diff --git a/nuttx/net/iob/iob_remove_queue.c b/nuttx/net/iob/iob_remove_queue.c
index f516ad047..e134bcd01 100644
--- a/nuttx/net/iob/iob_remove_queue.c
+++ b/nuttx/net/iob/iob_remove_queue.c
@@ -67,10 +67,13 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: iob_add_queue
+ * Name: iob_remove_queue
  *
  * Description:
- *   Remove one I/O buffer chain from the heaqd of a queue.
+ *   Remove and return one I/O buffer chain from the head of a queue.
+ *
+ * Returned Value:
+ *   Returns a reference to the I/O buffer chain at the head of the queue.
  *
  ****************************************************************************/