From 0b5f8dd430abf196587b7b2c07d58651c36bbfac Mon Sep 17 00:00:00 2001
From: Bryan Call <bcall@apache.org>
Date: Fri, 12 Aug 2016 11:00:11 -0700
Subject: [PATCH] TS-4732: Changing the do_io_read API so it can be called with
 NULL and 0 byte values.  Allowing do_io_read and do_io_write to not warn on
 closed connection when we are only trying to disable the reads and writes for
 it. Removed some macros that were used in a few places (not all the time) and
 a couple that were not used at all.

(cherry picked from commit 1975d679663453348057bb7155bdd3c17ac73880)
---
 iocore/net/UnixNetVConnection.cc | 26 ++++++++++----------------
 proxy/http2/Http2ClientSession.h |  3 +--
 2 files changed, 11 insertions(+), 18 deletions(-)

diff --git a/iocore/net/UnixNetVConnection.cc b/iocore/net/UnixNetVConnection.cc
index 441d20ee9b9..c98662f47dd 100644
--- a/iocore/net/UnixNetVConnection.cc
+++ b/iocore/net/UnixNetVConnection.cc
@@ -29,11 +29,6 @@
 #define STATE_VIO_OFFSET ((uintptr_t) & ((NetState *)0)->vio)
 #define STATE_FROM_VIO(_x) ((NetState *)(((char *)(_x)) - STATE_VIO_OFFSET))
 
-#define disable_read(_vc) (_vc)->read.enabled   = 0
-#define disable_write(_vc) (_vc)->write.enabled = 0
-#define enable_read(_vc) (_vc)->read.enabled    = 1
-#define enable_write(_vc) (_vc)->write.enabled  = 1
-
 #ifndef UIO_MAXIOV
 #define NET_MAX_IOV 16 // UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1)
 #else
@@ -624,8 +619,7 @@ UnixNetVConnection::get_data(int id, void *data)
 VIO *
 UnixNetVConnection::do_io_read(Continuation *c, int64_t nbytes, MIOBuffer *buf)
 {
-  ink_assert(c || 0 == nbytes);
-  if (closed) {
+  if (closed && !(c == NULL && nbytes == 0 && buf == NULL)) {
     Error("do_io_read invoked on closed vc %p, cont %p, nbytes %" PRId64 ", buf %p", this, c, nbytes, buf);
     return NULL;
   }
@@ -641,7 +635,7 @@ UnixNetVConnection::do_io_read(Continuation *c, int64_t nbytes, MIOBuffer *buf)
       read.vio.reenable();
   } else {
     read.vio.buffer.clear();
-    disable_read(this);
+    read.enabled = 0;
   }
   return &read.vio;
 }
@@ -649,7 +643,7 @@ UnixNetVConnection::do_io_read(Continuation *c, int64_t nbytes, MIOBuffer *buf)
 VIO *
 UnixNetVConnection::do_io_write(Continuation *c, int64_t nbytes, IOBufferReader *reader, bool owner)
 {
-  if (closed) {
+  if (closed && !(c == NULL && nbytes == 0 && reader == NULL)) {
     Error("do_io_write invoked on closed vc %p, cont %p, nbytes %" PRId64 ", reader %p", this, c, nbytes, reader);
     return NULL;
   }
@@ -665,7 +659,7 @@ UnixNetVConnection::do_io_write(Continuation *c, int64_t nbytes, IOBufferReader
     if (nbytes && !write.enabled)
       write.vio.reenable();
   } else {
-    disable_write(this);
+    write.enabled = 0;
   }
   return &write.vio;
 }
@@ -673,8 +667,8 @@ UnixNetVConnection::do_io_write(Continuation *c, int64_t nbytes, IOBufferReader
 void
 UnixNetVConnection::do_io_close(int alerrno /* = -1 */)
 {
-  disable_read(this);
-  disable_write(this);
+  read.enabled  = 0;
+  write.enabled = 0;
   read.vio.buffer.clear();
   read.vio.nbytes = 0;
   read.vio.op     = VIO::NONE;
@@ -705,22 +699,22 @@ UnixNetVConnection::do_io_shutdown(ShutdownHowTo_t howto)
   switch (howto) {
   case IO_SHUTDOWN_READ:
     socketManager.shutdown(((UnixNetVConnection *)this)->con.fd, 0);
-    disable_read(this);
+    read.enabled = 0;
     read.vio.buffer.clear();
     read.vio.nbytes = 0;
     f.shutdown      = NET_VC_SHUTDOWN_READ;
     break;
   case IO_SHUTDOWN_WRITE:
     socketManager.shutdown(((UnixNetVConnection *)this)->con.fd, 1);
-    disable_write(this);
+    write.enabled = 0;
     write.vio.buffer.clear();
     write.vio.nbytes = 0;
     f.shutdown       = NET_VC_SHUTDOWN_WRITE;
     break;
   case IO_SHUTDOWN_READWRITE:
     socketManager.shutdown(((UnixNetVConnection *)this)->con.fd, 2);
-    disable_read(this);
-    disable_write(this);
+    read.enabled  = 0;
+    write.enabled = 0;
     read.vio.buffer.clear();
     read.vio.nbytes = 0;
     write.vio.buffer.clear();
diff --git a/proxy/http2/Http2ClientSession.h b/proxy/http2/Http2ClientSession.h
index a6a6d6991af..58d38595900 100644
--- a/proxy/http2/Http2ClientSession.h
+++ b/proxy/http2/Http2ClientSession.h
@@ -187,8 +187,7 @@ class Http2ClientSession : public ProxyClientSession, public PluginIdentity
   virtual void
   release_netvc()
   {
-    // Make sure the vio's are also released to avoid
-    // later surprises in inactivity timeout
+    // Make sure the vio's are also released to avoid later surprises in inactivity timeout
     if (client_vc) {
       client_vc->do_io_read(NULL, 0, NULL);
       client_vc->do_io_write(NULL, 0, NULL);