added resubmit example

examples/resubmit/p4src/resubmit.p4

@@ -0,0 +1,101 @@
+/*
+Copyright 2013-present Barefoot Networks, Inc. 
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+header_type ethernet_t {
+    fields {
+        dstAddr : 48;
+        srcAddr : 48;
+        etherType : 16;
+    }
+}
+
+header_type intrinsic_metadata_t {
+    fields {
+        mcast_grp : 4;
+        egress_rid : 4;
+        mcast_hash : 16;
+        lf_field_list : 32;
+        resubmit_flag : 16;
+    }
+}
+
+header_type mymeta_t {
+    fields {
+        f1 : 8;
+    }
+}
+
+header ethernet_t ethernet;
+metadata intrinsic_metadata_t intrinsic_metadata;
+metadata mymeta_t mymeta;
+
+parser start {
+    return parse_ethernet;
+}
+
+parser parse_ethernet {
+    extract(ethernet);
+    return ingress;
+}
+
+action _drop() {
+    drop();
+}
+
+action _nop() {
+}
+
+action set_port(port) {
+    modify_field(standard_metadata.egress_spec, port);
+}
+
+field_list resubmit_FL {
+    standard_metadata;
+    mymeta;
+}
+
+action _resubmit() {
+    modify_field(mymeta.f1, 1);
+    resubmit(resubmit_FL);
+}
+
+table t_ingress_1 {
+    reads {
+        mymeta.f1 : exact;
+    }
+    actions {
+        _nop; set_port;
+    }
+    size : 128;
+}
+
+table t_ingress_2 {
+    reads {
+        mymeta.f1 : exact;
+    }
+    actions {
+        _nop; _resubmit;
+    }
+    size : 128;
+}
+
+control ingress {
+    apply(t_ingress_1);
+    apply(t_ingress_2);
+}
+
+control egress {
+}