From 4401f697e5547e71f1ad0190140753d879305267 Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Wed, 11 Feb 2015 00:44:30 +0900
Subject: [PATCH] src: Try to write immediately after read

---
 src/h2load.cc               | 23 ++++++++++++++---------
 src/shrpx_client_handler.cc |  8 ++++++++
 src/shrpx_client_handler.h  |  1 +
 src/shrpx_http2_session.cc  |  8 ++++++++
 4 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/src/h2load.cc b/src/h2load.cc
index 6cbcd164..7478d503 100644
--- a/src/h2load.cc
+++ b/src/h2load.cc
@@ -104,15 +104,6 @@ Stats::Stats(size_t req_todo)
 
 Stream::Stream() : status_success(-1) {}
 
-namespace {
-void readcb(struct ev_loop *loop, ev_io *w, int revents) {
-  auto client = static_cast<Client *>(w->data);
-  if (client->do_read() != 0) {
-    client->fail();
-  }
-}
-} // namespace
-
 namespace {
 void writecb(struct ev_loop *loop, ev_io *w, int revents) {
   auto client = static_cast<Client *>(w->data);
@@ -132,6 +123,20 @@ void writecb(struct ev_loop *loop, ev_io *w, int revents) {
 }
 } // namespace
 
+namespace {
+void readcb(struct ev_loop *loop, ev_io *w, int revents) {
+  auto client = static_cast<Client *>(w->data);
+  if (client->do_read() != 0) {
+    client->fail();
+    return;
+  }
+  if (ev_is_active(&client->wev)) {
+    writecb(loop, &client->wev, revents);
+    // client->disconnect() and client->fail() may be called
+  }
+}
+} // namespace
+
 Client::Client(Worker *worker, size_t req_todo)
     : worker(worker), ssl(nullptr), next_addr(config.addrs), reqidx(0),
       state(CLIENT_IDLE), req_todo(req_todo), req_started(0), req_done(0),
diff --git a/src/shrpx_client_handler.cc b/src/shrpx_client_handler.cc
index a70d4669..5cdfd70a 100644
--- a/src/shrpx_client_handler.cc
+++ b/src/shrpx_client_handler.cc
@@ -82,6 +82,12 @@ void readcb(struct ev_loop *loop, ev_io *w, int revents) {
     delete handler;
     return;
   }
+  if (ev_is_active(handler->get_wev())) {
+    if (handler->do_write() != 0) {
+      delete handler;
+      return;
+    }
+  }
 }
 } // namespace
 
@@ -729,4 +735,6 @@ void ClientHandler::signal_write() { conn_.wlimit.startw(); }
 RateLimit *ClientHandler::get_rlimit() { return &conn_.rlimit; }
 RateLimit *ClientHandler::get_wlimit() { return &conn_.wlimit; }
 
+ev_io *ClientHandler::get_wev() { return &conn_.wev; }
+
 } // namespace shrpx
diff --git a/src/shrpx_client_handler.h b/src/shrpx_client_handler.h
index 7a6b8f65..44662c6a 100644
--- a/src/shrpx_client_handler.h
+++ b/src/shrpx_client_handler.h
@@ -129,6 +129,7 @@ public:
   RateLimit *get_wlimit();
 
   void signal_write();
+  ev_io *get_wev();
 
 private:
   Connection conn_;
diff --git a/src/shrpx_http2_session.cc b/src/shrpx_http2_session.cc
index 51e84f33..4e01d3e3 100644
--- a/src/shrpx_http2_session.cc
+++ b/src/shrpx_http2_session.cc
@@ -95,6 +95,14 @@ void readcb(struct ev_loop *loop, ev_io *w, int revents) {
   rv = http2session->do_read();
   if (rv != 0) {
     http2session->disconnect(http2session->should_hard_fail());
+    return;
+  }
+  if (ev_is_active(http2session->get_wev())) {
+    rv = http2session->do_write();
+    if (rv != 0) {
+      http2session->disconnect(http2session->should_hard_fail());
+      return;
+    }
   }
 }
 } // namespace