Merge pull request #1108 from yang-g/overflowfix

Time point conversion fix

2 files changed, 15 insertions, 8 deletions

diff --git a/src/cpp/common/completion_queue.cc b/src/cpp/common/completion_queue.cc
index fede2da016..cea2d24831 100644
--- a/src/cpp/common/completion_queue.cc
+++ b/src/cpp/common/completion_queue.cc
@@ -36,7 +36,6 @@
 
 #include <grpc/grpc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/time.h>
 #include "src/cpp/util/time.h"
 
 namespace grpc {
@@ -57,15 +56,12 @@ class EventDeleter {
   }
 };
 
-CompletionQueue::NextStatus
-CompletionQueue::AsyncNext(void** tag, bool* ok,
-			   std::chrono::system_clock::time_point deadline) {
+CompletionQueue::NextStatus CompletionQueue::AsyncNextInternal(
+    void** tag, bool* ok, gpr_timespec deadline) {
   std::unique_ptr<grpc_event, EventDeleter> ev;
 
-  gpr_timespec gpr_deadline;
-  Timepoint2Timespec(deadline, &gpr_deadline);
   for (;;) {
-    ev.reset(grpc_completion_queue_next(cq_, gpr_deadline));
+    ev.reset(grpc_completion_queue_next(cq_, deadline));
     if (!ev) { /* got a NULL back because deadline passed */
       return TIMEOUT;
     }
@@ -81,6 +77,13 @@ CompletionQueue::AsyncNext(void** tag, bool* ok,
   }
 }
 
+CompletionQueue::NextStatus CompletionQueue::AsyncNext(
+    void** tag, bool* ok, std::chrono::system_clock::time_point deadline) {
+  gpr_timespec gpr_deadline;
+  Timepoint2Timespec(deadline, &gpr_deadline);
+  return AsyncNextInternal(tag, ok, gpr_deadline);
+}
+
 bool CompletionQueue::Pluck(CompletionQueueTag* tag) {
   std::unique_ptr<grpc_event, EventDeleter> ev;
 
diff --git a/src/cpp/util/time.cc b/src/cpp/util/time.cc
index 44d2283e76..059ea72abf 100644
--- a/src/cpp/util/time.cc
+++ b/src/cpp/util/time.cc
@@ -42,11 +42,15 @@ using std::chrono::system_clock;
 
 namespace grpc {
 
-// TODO(yangg) prevent potential overflow.
 void Timepoint2Timespec(const system_clock::time_point& from,
                         gpr_timespec* to) {
   system_clock::duration deadline = from.time_since_epoch();
   seconds secs = duration_cast<seconds>(deadline);
+  if (from == system_clock::time_point::max() ||
+      secs.count() >= gpr_inf_future.tv_sec || secs.count() < 0) {
+    *to = gpr_inf_future;
+    return;
+  }
   nanoseconds nsecs = duration_cast<nanoseconds>(deadline - secs);
   to->tv_sec = secs.count();
   to->tv_nsec = nsecs.count();