From 01f5730a0d0103ebd7d4f05e5d3fd2eb359d6018 Mon Sep 17 00:00:00 2001
From: Yimin Jiang <jiangyimin@bytedance.com>
Date: Mon, 14 Oct 2019 18:45:05 +0800
Subject: [PATCH] zmq: fix exit hanging problem (#5)

---
 src/zmq_van.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/zmq_van.h b/src/zmq_van.h
index 58736165e..9be27bfe9 100644
--- a/src/zmq_van.h
+++ b/src/zmq_van.h
@@ -74,6 +74,7 @@ class ZMQVan : public Van {
     // join all threads
     should_stop_ = true;
     for (auto t : thread_list_) t->join();
+    PS_VLOG(1) << my_node_.ShortDebugString() << " all threads joined and destroyed";
     // close sockets
     int linger = 0;
     int rc = zmq_setsockopt(receiver_, ZMQ_LINGER, &linger, sizeof(linger));
@@ -285,7 +286,7 @@ class ZMQVan : public Van {
     CHECK(socket);
     LOG(INFO) << "Start ZMQ recv thread";
 
-    while (!should_stop_) {
+    while (true) {
       ZmqBufferContext *buf_ctx = new ZmqBufferContext();
 
       for (int i = 0;; ++i) {
@@ -295,7 +296,7 @@ class ZMQVan : public Van {
           std::lock_guard<std::mutex> lk(mu_);
           // the zmq_msg_recv should be non-blocking, otherwise deadlock will happen
           int tag = ZMQ_DONTWAIT;
-          if (zmq_msg_recv(zmsg, socket, tag) != -1) break;
+          if (should_stop_ || zmq_msg_recv(zmsg, socket, tag) != -1) break;
           if (errno == EINTR) {
             std::cout << "interrupted";
             continue;
@@ -305,6 +306,7 @@ class ZMQVan : public Van {
           CHECK(0) << "failed to receive message. errno: " << errno << " "
                        << zmq_strerror(errno);
         }
+        if (should_stop_) break;
         char* buf = CHECK_NOTNULL((char*)zmq_msg_data(zmsg));
         size_t size = zmq_msg_size(zmsg);
 
@@ -327,7 +329,7 @@ class ZMQVan : public Van {
           if (!more) break;
         }
       } // for
-
+      if (should_stop_) break;
       recv_buffers_.Push(*buf_ctx);
     } // while
   }