From 155794a671e2773237f5d7b57c83198fc4c4e33a Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Sun, 19 Jun 2016 19:29:46 +0800
Subject: [PATCH] runtime: save now on RPC

---
 artiq/runtime/ksupport.c | 1 +
 artiq/runtime/messages.h | 1 +
 artiq/runtime/session.c  | 6 ++++++
 3 files changed, 8 insertions(+)

diff --git a/artiq/runtime/ksupport.c b/artiq/runtime/ksupport.c
index 780818dc2..3fcedfba3 100644
--- a/artiq/runtime/ksupport.c
+++ b/artiq/runtime/ksupport.c
@@ -475,6 +475,7 @@ void send_rpc(int service, const char *tag, ...)
 {
     struct msg_rpc_send request;
 
+    request.now = now;
     if(service != 0)
         request.type = MESSAGE_TYPE_RPC_SEND;
     else
diff --git a/artiq/runtime/messages.h b/artiq/runtime/messages.h
index 1a297d630..a3aa0a819 100644
--- a/artiq/runtime/messages.h
+++ b/artiq/runtime/messages.h
@@ -87,6 +87,7 @@ struct msg_watchdog_clear {
 
 struct msg_rpc_send {
     int type;
+    long long int now;
     int service;
     const char *tag;
     va_list args;
diff --git a/artiq/runtime/session.c b/artiq/runtime/session.c
index 517614e90..201c79dee 100644
--- a/artiq/runtime/session.c
+++ b/artiq/runtime/session.c
@@ -983,6 +983,12 @@ static int process_kmsg(struct msg_base *umsg)
         case MESSAGE_TYPE_RPC_BATCH: {
             struct msg_rpc_send *msg = (struct msg_rpc_send *)umsg;
 
+            /*
+             * save now in case the RPC stops the kernel
+             * (e.g. pause with preemption)
+             */
+            now = msg->now;
+
             if(!send_rpc_request(msg->service, msg->tag, msg->args)) {
                 core_log("Failed to send RPC request (service %d, tag %s)\n",
                          msg->service, msg->tag);