add matching logic that assumes in-order delivery with no

dropped packets (shared memory, for example).  Reviewed by Tim W.

This commit was SVN r2999.

src/mca/ptl/base/ptl_base_match.c

@@ -600,3 +600,79 @@ static void mca_ptl_base_check_cantmatch_for_match(ompi_list_t *additional_match
     return;
 }
 
+/**
+ * RCS/CTS receive side matching
+ *
+ * @param frag_header list of parameters needed for matching
+ *                    This list is also embeded in frag_desc,
+ *                    but this allows to save a memory copy when
+ *                    a match is made in this routine. (IN)
+ * @param frag_desc   pointer to receive fragment which we want
+ *                    to match (IN/OUT).  If a match is not made,
+ *                    frag_header is copied to frag_desc.
+ * @param match_made  parameter indicating if we matched frag_desc/
+ *                    frag_header (OUT)
+ * @return indication if match was made or not.
+ *
+ * This routine is used to try and match a newly arrived message fragment
+ *   to pre-posted receives.  The following assumptions are made
+ *   - fragments are received in order, so no explicit sequence
+ *     tracking is needed.
+ *   - for long messages, e.g. more than one fragment, a RTS/CTS algorithm
+ *       is used.
+ *   - 2nd and greater fragments include a receive descriptor pointer
+ *   - this routine may be called simoultaneously by more than one thread
+ */
+bool mca_ptl_base_match_in_order_network_delivery(
+    mca_ptl_base_match_header_t *frag_header,
+    struct mca_ptl_base_recv_frag_t *frag_desc)
+{
+    /* local variables */
+    mca_ptl_sequence_t frag_msg_seq,next_msg_seq_expected;
+    ompi_communicator_t *comm_ptr;
+    mca_pml_base_recv_request_t *matched_receive;
+    mca_pml_ptl_comm_t *pml_comm;
+    int frag_src;
+
+    bool match_made=false;
+
+    /* communicator pointer */
+    comm_ptr=ompi_comm_lookup(frag_header->hdr_contextid);
+    pml_comm=(mca_pml_ptl_comm_t *)comm_ptr->c_pml_comm;
+
+    /* source sequence number */
+    frag_msg_seq = frag_header->hdr_msg_seq;
+
+    /* get fragment communicator source rank */
+    frag_src = frag_header->hdr_src;
+
+    /* get next expected message sequence number - if threaded
+     * run, lock to make sure that if another thread is processing 
+     * a frag from the same message a match is made only once.
+     * Also, this prevents other posted receives (for a pair of
+     * end points) from being processed, and potentially "loosing"
+     * the fragment.
+     */
+    OMPI_THREAD_LOCK(&pml_comm->c_matching_lock);
+
+    /* see if receive has already been posted */
+    matched_receive = mca_ptl_base_check_receives_for_match(frag_header,
+            pml_comm);
+
+    /* if match found, process data */
+    if (matched_receive) {
+        /* set flag indicating the input fragment was matched */
+        match_made=true;
+
+        /* associate the receive descriptor with the fragment descriptor */
+        frag_desc->frag_request=matched_receive;
+    } else {
+        /* if no match found, place on unexpected queue */
+        ompi_list_append( ((pml_comm->c_unexpected_frags)+frag_src),
+                (ompi_list_item_t *)frag_desc);
+    }
+
+
+    OMPI_THREAD_UNLOCK(&pml_comm->c_matching_lock);
+    return match_made;
+}

src/mca/ptl/base/ptl_base_match.h

@@ -10,7 +10,9 @@
 struct mca_ptl_base_recv_frag_t;
 
 /**
- * Match incoming fragments against posted receives.
+ * RCS/CTS receive side matching
+ * Match incoming fragments against posted receives.  Out of order
+ * delivery.
  * 
  * @param frag_header (IN)          Header of received fragment.
  * @param frag_desc (IN)            Received fragment descriptor.
@@ -21,5 +23,32 @@ struct mca_ptl_base_recv_frag_t;
 bool mca_ptl_base_match(mca_ptl_base_match_header_t *frag_header,
     struct mca_ptl_base_recv_frag_t *frag_desc, ompi_list_t *additional_matches);
 
+/**
+ * RCS/CTS receive side matching
+ *
+ * @param frag_header list of parameters needed for matching
+ *                    This list is also embeded in frag_desc,
+ *                    but this allows to save a memory copy when
+ *                    a match is made in this routine. (IN)
+ * @param frag_desc   pointer to receive fragment which we want
+ *                    to match (IN/OUT).  If a match is not made,
+ *                    frag_header is copied to frag_desc.
+ * @param match_made  parameter indicating if we matched frag_desc/
+ *                    frag_header (OUT)
+ * @return indication if match was made or not.
+ *
+ * This routine is used to try and match a newly arrived message fragment
+ *   to pre-posted receives.  The following assumptions are made
+ *   - fragments are received in order, so no explicit sequence
+ *     tracking is needed.
+ *   - for long messages, e.g. more than one fragment, a RTS/CTS algorithm
+ *       is used.
+ *   - 2nd and greater fragments include a receive descriptor pointer
+ *   - this routine may be called simoultaneously by more than one thread
+ */
+bool mca_ptl_base_match_in_order_network_delivery(
+        mca_ptl_base_match_header_t *frag_header,
+        struct mca_ptl_base_recv_frag_t *frag_desc);
+
 #endif /* MCA_PTL_BASE_MATCH_H */