Adding MOJO_HANDLE_SIGNAL_PEER_CLOSED to be notified when a peer is closed.

mojo/edk/system/local_data_pipe.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // TODO(vtl): I currently potentially overflow in doing index calculations.
 // E.g., |start_index_| and |current_num_bytes_| fit into a |uint32_t|, but
 // their sum may not. This is bad and poses a security risk. (We're currently
 // saved by the limit on capacity -- the maximum size of the buffer, checked in
 // |DataPipe::ValidateOptions()|, is currently sufficiently small.)
 
@@ skipping 142 matching lines @@
 }
 
 HandleSignalsState LocalDataPipe::ProducerGetHandleSignalsStateImplNoLock()
     const {
   HandleSignalsState rv;
   if (consumer_open_no_lock()) {
     if ((may_discard() || current_num_bytes_ < capacity_num_bytes()) &&
         !producer_in_two_phase_write_no_lock())
       rv.satisfied_signals |= MOJO_HANDLE_SIGNAL_WRITABLE;
     rv.satisfiable_signals |= MOJO_HANDLE_SIGNAL_WRITABLE;
+  } else {
+    rv.satisfied_signals |= MOJO_HANDLE_SIGNAL_PEER_CLOSED;
   }
+  rv.satisfiable_signals |= MOJO_HANDLE_SIGNAL_PEER_CLOSED;
   return rv;
 }
 
 void LocalDataPipe::ConsumerCloseImplNoLock() {
   // If the producer is around and in a two-phase write, we have to keep the
   // buffer around. (We then don't free it until the producer is closed. This
   // could be rectified, but again seems like optimizing for the uncommon case.)
   if (!producer_open_no_lock() || !producer_in_two_phase_write_no_lock())
     DestroyBufferNoLock();
   current_num_bytes_ = 0;
@@ skipping 112 matching lines @@
 HandleSignalsState LocalDataPipe::ConsumerGetHandleSignalsStateImplNoLock()
     const {
   HandleSignalsState rv;
   if (current_num_bytes_ > 0) {
     if (!consumer_in_two_phase_read_no_lock())
       rv.satisfied_signals |= MOJO_HANDLE_SIGNAL_READABLE;
     rv.satisfiable_signals |= MOJO_HANDLE_SIGNAL_READABLE;
   } else if (producer_open_no_lock()) {
     rv.satisfiable_signals |= MOJO_HANDLE_SIGNAL_READABLE;
   }
+  if (!producer_open_no_lock())
+    rv.satisfied_signals |= MOJO_HANDLE_SIGNAL_PEER_CLOSED;
+  rv.satisfiable_signals |= MOJO_HANDLE_SIGNAL_PEER_CLOSED;
   return rv;
 }
 
 void LocalDataPipe::EnsureBufferNoLock() {
   DCHECK(producer_open_no_lock());
   if (buffer_)
     return;
   buffer_.reset(static_cast<char*>(
       base::AlignedAlloc(capacity_num_bytes(),
                          GetConfiguration().data_pipe_buffer_alignment_bytes)));
@@ skipping 29 matching lines @@
 
 void LocalDataPipe::MarkDataAsConsumedNoLock(size_t num_bytes) {
   DCHECK_LE(num_bytes, current_num_bytes_);
   start_index_ += num_bytes;
   start_index_ %= capacity_num_bytes();
   current_num_bytes_ -= num_bytes;
 }
 
 }  // namespace system
 }  // namespace mojo