TCP/session improvements

- Added svm fifo flag for tracking fifo dequeue events (replaces event
  length). Updated all code to switch to the new scheme.
- More session debugging
- Fix peek index wrap
- Add a trivial socket test client
- Fast retransmit/cc fixes
- tx and rx SACK fixes and unit testing
- SRTT computation fix
- remove dupack/ack burst filters
- improve ack rx
- improved segment rx
- builtin client test code

Change-Id: Ic4eb2d5ca446eb2260ccd3ccbcdaa73c64e7f4e1
Signed-off-by: Florin Coras <fcoras@cisco.com>
Signed-off-by: Dave Barach <dbarach@cisco.com>

3 files changed, 47 insertions, 20 deletions

diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index e3f534b1..07b0d2df 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-#include "svm_fifo.h"
+#include <svm/svm_fifo.h>
 
 /** create an svm fifo, in the current heap. Fails vs blow up the process */
 svm_fifo_t *
@@ -362,18 +362,19 @@ svm_fifo_enqueue_nowait (svm_fifo_t * f,
   return svm_fifo_enqueue_internal (f, pid, max_bytes, copy_from_here);
 }
 
-/** Enqueue a future segment.
+/**
+ * Enqueue a future segment.
+ *
  * Two choices: either copies the entire segment, or copies nothing
  * Returns 0 of the entire segment was copied
  * Returns -1 if none of the segment was copied due to lack of space
  */
-
 static int
-svm_fifo_enqueue_with_offset_internal2 (svm_fifo_t * f,
-					int pid,
-					u32 offset,
-					u32 required_bytes,
-					u8 * copy_from_here)
+svm_fifo_enqueue_with_offset_internal (svm_fifo_t * f,
+				       int pid,
+				       u32 offset,
+				       u32 required_bytes,
+				       u8 * copy_from_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
   u32 cursize, nitems;
@@ -424,14 +425,14 @@ svm_fifo_enqueue_with_offset (svm_fifo_t * f,
 			      u32 offset,
 			      u32 required_bytes, u8 * copy_from_here)
 {
-  return svm_fifo_enqueue_with_offset_internal2
+  return svm_fifo_enqueue_with_offset_internal
     (f, pid, offset, required_bytes, copy_from_here);
 }
 
 
 static int
-svm_fifo_dequeue_internal2 (svm_fifo_t * f,
-			    int pid, u32 max_bytes, u8 * copy_here)
+svm_fifo_dequeue_internal (svm_fifo_t * f,
+			   int pid, u32 max_bytes, u8 * copy_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
   u32 cursize, nitems;
@@ -484,7 +485,7 @@ int
 svm_fifo_dequeue_nowait (svm_fifo_t * f,
 			 int pid, u32 max_bytes, u8 * copy_here)
 {
-  return svm_fifo_dequeue_internal2 (f, pid, max_bytes, copy_here);
+  return svm_fifo_dequeue_internal (f, pid, max_bytes, copy_here);
 }
 
 int
@@ -492,7 +493,7 @@ svm_fifo_peek (svm_fifo_t * f, int pid, u32 offset, u32 max_bytes,
 	       u8 * copy_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
-  u32 cursize, nitems;
+  u32 cursize, nitems, real_head;
 
   if (PREDICT_FALSE (f->cursize == 0))
     return -2;			/* nothing in the fifo */
@@ -500,6 +501,8 @@ svm_fifo_peek (svm_fifo_t * f, int pid, u32 offset, u32 max_bytes,
   /* read cursize, which can only increase while we're working */
   cursize = f->cursize;
   nitems = f->nitems;
+  real_head = f->head + offset;
+  real_head = real_head >= nitems ? real_head - nitems : real_head;
 
   /* Number of bytes we're going to copy */
   total_copy_bytes = (cursize < max_bytes) ? cursize : max_bytes;
@@ -508,9 +511,9 @@ svm_fifo_peek (svm_fifo_t * f, int pid, u32 offset, u32 max_bytes,
     {
       /* Number of bytes in first copy segment */
       first_copy_bytes =
-	((nitems - f->head + offset) < total_copy_bytes) ?
-	(nitems - f->head + offset) : total_copy_bytes;
-      clib_memcpy (copy_here, &f->data[f->head + offset], first_copy_bytes);
+	((nitems - real_head) < total_copy_bytes) ?
+	(nitems - real_head) : total_copy_bytes;
+      clib_memcpy (copy_here, &f->data[real_head], first_copy_bytes);
 
       /* Number of bytes in second copy segment, if any */
       second_copy_bytes = total_copy_bytes - first_copy_bytes;
diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h
index 70624b74..39556173 100644
--- a/src/svm/svm_fifo.h
+++ b/src/svm/svm_fifo.h
@@ -46,9 +46,11 @@ typedef struct
 {
   pthread_mutex_t mutex;	/* 8 bytes */
   pthread_cond_t condvar;	/* 8 bytes */
-  u32 owner_pid;
   svm_lock_tag_t tag;
-  volatile u32 cursize;
+
+  volatile u32 cursize;		/**< current fifo size */
+  volatile u8 has_event;	/**< non-zero if deq event exists */
+  u32 owner_pid;
   u32 nitems;
 
   /* Backpointers */
@@ -112,6 +114,28 @@ svm_fifo_has_ooo_data (svm_fifo_t * f)
   return f->ooos_list_head != OOO_SEGMENT_INVALID_INDEX;
 }
 
+/**
+ * Sets fifo event flag.
+ *
+ * @return 1 if flag was not set.
+ */
+always_inline u8
+svm_fifo_set_event (svm_fifo_t * f)
+{
+  /* Probably doesn't need to be atomic. Still, better avoid surprises */
+  return __sync_lock_test_and_set (&f->has_event, 1) == 0;
+}
+
+/**
+ * Unsets fifo event flag.
+ */
+always_inline void
+svm_fifo_unset_event (svm_fifo_t * f)
+{
+  /* Probably doesn't need to be atomic. Still, better avoid surprises */
+  __sync_lock_test_and_set (&f->has_event, 0);
+}
+
 svm_fifo_t *svm_fifo_create (u32 data_size_in_bytes);
 
 int svm_fifo_enqueue_nowait (svm_fifo_t * f, int pid, u32 max_bytes,
diff --git a/src/svm/svm_fifo_segment.h b/src/svm/svm_fifo_segment.h
index 793fa7c8..ecb5653a 100644
--- a/src/svm/svm_fifo_segment.h
+++ b/src/svm/svm_fifo_segment.h
@@ -15,8 +15,8 @@
 #ifndef __included_ssvm_fifo_segment_h__
 #define __included_ssvm_fifo_segment_h__
 
-#include "svm_fifo.h"
-#include "ssvm.h"
+#include <svm/svm_fifo.h>
+#include <svm/ssvm.h>
 
 typedef struct
 {