From 751b24abc525cae8956587991bd0fa19f53b69eb Mon Sep 17 00:00:00 2001
From: Masaori Koshiba <masaori@apache.org>
Date: Fri, 13 Sep 2019 09:16:33 +0900
Subject: [PATCH] Track scheduled events to (read|write)_vio.cont from
 Http2Stream

---
 proxy/http2/Http2Stream.cc | 30 ++++++++++++++++++++++++++----
 proxy/http2/Http2Stream.h  |  6 ++++--
 2 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/proxy/http2/Http2Stream.cc b/proxy/http2/Http2Stream.cc
index 0f80ad00fe2..e4d6542cb0b 100644
--- a/proxy/http2/Http2Stream.cc
+++ b/proxy/http2/Http2Stream.cc
@@ -99,14 +99,20 @@ Http2Stream::main_event_handler(int event, void *edata)
       if (lock.is_locked()) {
         read_vio.cont->handleEvent(event, &read_vio);
       } else {
-        this_ethread()->schedule_imm(read_vio.cont, event, &read_vio);
+        if (this->_read_vio_event) {
+          this->_read_vio_event->cancel();
+        }
+        this->_read_vio_event = this_ethread()->schedule_imm(read_vio.cont, event, &read_vio);
       }
     } else if (_sm && write_vio.ntodo() > 0) {
       MUTEX_TRY_LOCK(lock, write_vio.mutex, this_ethread());
       if (lock.is_locked()) {
         write_vio.cont->handleEvent(event, &write_vio);
       } else {
-        this_ethread()->schedule_imm(write_vio.cont, event, &write_vio);
+        if (this->_write_vio_event) {
+          this->_write_vio_event->cancel();
+        }
+        this->_write_vio_event = this_ethread()->schedule_imm(write_vio.cont, event, &write_vio);
       }
     }
     break;
@@ -119,7 +125,10 @@ Http2Stream::main_event_handler(int event, void *edata)
         if (lock.is_locked()) {
           write_vio.cont->handleEvent(event, &write_vio);
         } else {
-          this_ethread()->schedule_imm(write_vio.cont, event, &write_vio);
+          if (this->_write_vio_event) {
+            this->_write_vio_event->cancel();
+          }
+          this->_write_vio_event = this_ethread()->schedule_imm(write_vio.cont, event, &write_vio);
         }
       }
     } else {
@@ -135,7 +144,10 @@ Http2Stream::main_event_handler(int event, void *edata)
         if (lock.is_locked()) {
           read_vio.cont->handleEvent(event, &read_vio);
         } else {
-          this_ethread()->schedule_imm(read_vio.cont, event, &read_vio);
+          if (this->_read_vio_event) {
+            this->_read_vio_event->cancel();
+          }
+          this->_read_vio_event = this_ethread()->schedule_imm(read_vio.cont, event, &read_vio);
         }
       }
     } else {
@@ -937,6 +949,16 @@ Http2Stream::clear_io_events()
     buffer_full_write_event->cancel();
     buffer_full_write_event = nullptr;
   }
+
+  if (this->_read_vio_event) {
+    this->_read_vio_event->cancel();
+    this->_read_vio_event = nullptr;
+  }
+
+  if (this->_write_vio_event) {
+    this->_write_vio_event->cancel();
+    this->_write_vio_event = nullptr;
+  }
 }
 
 void
diff --git a/proxy/http2/Http2Stream.h b/proxy/http2/Http2Stream.h
index 471e4046b06..8b0489b0c7d 100644
--- a/proxy/http2/Http2Stream.h
+++ b/proxy/http2/Http2Stream.h
@@ -218,8 +218,10 @@ class Http2Stream : public ProxyTransaction
   ink_hrtime inactive_timeout_at = 0;
   Event *inactive_event          = nullptr;
 
-  Event *read_event  = nullptr;
-  Event *write_event = nullptr;
+  Event *read_event       = nullptr;
+  Event *write_event      = nullptr;
+  Event *_read_vio_event  = nullptr;
+  Event *_write_vio_event = nullptr;
 };
 
 extern ClassAllocator<Http2Stream> http2StreamAllocator;