diff -r 000000000000 -r 6474c204b198 ipc/ipdl/test/cxx/PTestLatency.ipdl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/ipdl/test/cxx/PTestLatency.ipdl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,75 @@
+
+namespace mozilla {
+namespace _ipdltest {
+
+
+intr protocol PTestLatency {
+
+child:
+    __delete__();
+    Ping();
+    Ping5();
+    intr Rpc();
+    Spam();
+    intr Synchro();
+    CompressedSpam(uint32_t seqno) compress;
+    intr Synchro2() returns (uint32_t lastSeqno,
+                            uint32_t numMessagesDispatched);
+
+parent:
+    Pong();
+    Pong5();
+
+state START:
+    // if the timing resolution is too low, abort the test
+    send __delete__;
+    // otherwise, kick off the ping/pong trials
+    send Ping goto PONG;
+
+    // Trial 1: single ping/pong latency
+state PING:
+    send Ping goto PONG;
+    send Ping5 goto PING4;
+
+state PONG:
+    recv Pong goto PING;
+
+    // Trial 2: "overlapped" ping/pong latency
+state PING5:
+    send Ping5 goto PING4;
+    call Rpc goto RPC;
+
+state PING4: send Ping5 goto PING3;
+state PING3: send Ping5 goto PING2;
+state PING2: send Ping5 goto PING1;
+state PING1: send Ping5 goto PONG1;
+
+state PONG1: recv Pong5 goto PONG2;
+state PONG2: recv Pong5 goto PONG3;
+state PONG3: recv Pong5 goto PONG4;
+state PONG4: recv Pong5 goto PONG5;
+state PONG5: recv Pong5 goto PING5;
+
+    // Trial 3: lotsa RPC
+state RPC:
+    call Rpc goto RPC;
+    send Spam goto SPAM;
+
+    // Trial 4: lots of sequential asyn messages, which tests pipelining
+state SPAM:
+    send Spam goto SPAM;
+    call Synchro goto COMPRESSED_SPAM;
+
+    // Trial 5: lots of async spam, but compressed to cut down on
+    // dispatch overhead
+state COMPRESSED_SPAM:          // compressed spam, mmm
+    send CompressedSpam goto COMPRESSED_SPAM;
+    call Synchro2 goto DONE;
+
+state DONE:
+    send __delete__;
+};
+
+
+} // namespace mozilla
+} // namespace _ipdltest