Mojo: Wrap the satisfied/unsatisfied wait flags state in a single object.

mojo/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 133 matching lines @@
 MojoResult LocalDataPipe::ProducerEndWriteDataImplNoLock(
     uint32_t num_bytes_written) {
   DCHECK_LE(num_bytes_written,
             producer_two_phase_max_num_bytes_written_no_lock());
   current_num_bytes_ += num_bytes_written;
   DCHECK_LE(current_num_bytes_, capacity_num_bytes());
   set_producer_two_phase_max_num_bytes_written_no_lock(0);
   return MOJO_RESULT_OK;
 }
 
-MojoWaitFlags LocalDataPipe::ProducerSatisfiedFlagsNoLock() {
-  MojoWaitFlags rv = MOJO_WAIT_FLAG_NONE;
-  if (consumer_open_no_lock() &&
-      (may_discard() || current_num_bytes_ < capacity_num_bytes()) &&
-      !producer_in_two_phase_write_no_lock())
-    rv |= MOJO_WAIT_FLAG_WRITABLE;
+WaitFlagsState LocalDataPipe::ProducerGetWaitFlagsStateNoLock() const {
+  WaitFlagsState rv;
+  if (consumer_open_no_lock()) {
+    if ((may_discard() || current_num_bytes_ < capacity_num_bytes()) &&
+        !producer_in_two_phase_write_no_lock())
+      rv.satisfied_flags |= MOJO_WAIT_FLAG_WRITABLE;
+    rv.satisfiable_flags |= MOJO_WAIT_FLAG_WRITABLE;
+  }
   return rv;
 }
 
-MojoWaitFlags LocalDataPipe::ProducerSatisfiableFlagsNoLock() {
-  MojoWaitFlags rv = MOJO_WAIT_FLAG_NONE;
-  if (consumer_open_no_lock())
-    rv |= MOJO_WAIT_FLAG_WRITABLE;
-  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;
 }
 
 MojoResult LocalDataPipe::ConsumerReadDataImplNoLock(void* elements,
@@ skipping 91 matching lines @@
 
 MojoResult LocalDataPipe::ConsumerEndReadDataImplNoLock(
     uint32_t num_bytes_read) {
   DCHECK_LE(num_bytes_read, consumer_two_phase_max_num_bytes_read_no_lock());
   DCHECK_LE(start_index_ + num_bytes_read, capacity_num_bytes());
   MarkDataAsConsumedNoLock(num_bytes_read);
   set_consumer_two_phase_max_num_bytes_read_no_lock(0);
   return MOJO_RESULT_OK;
 }
 
-MojoWaitFlags LocalDataPipe::ConsumerSatisfiedFlagsNoLock() {
-  MojoWaitFlags rv = MOJO_WAIT_FLAG_NONE;
-  if (current_num_bytes_ > 0 && !consumer_in_two_phase_read_no_lock())
-    rv |= MOJO_WAIT_FLAG_READABLE;
+WaitFlagsState LocalDataPipe::ConsumerGetWaitFlagsStateNoLock() const {
+  WaitFlagsState rv;
+  if (current_num_bytes_ > 0) {
+    if (!consumer_in_two_phase_read_no_lock())
+      rv.satisfied_flags |= MOJO_WAIT_FLAG_READABLE;
+    rv.satisfiable_flags |= MOJO_WAIT_FLAG_READABLE;
+  } else if (producer_open_no_lock()) {
+    rv.satisfiable_flags |= MOJO_WAIT_FLAG_READABLE;
+  }
   return rv;
 }
 
-MojoWaitFlags LocalDataPipe::ConsumerSatisfiableFlagsNoLock() {
-  MojoWaitFlags rv = MOJO_WAIT_FLAG_NONE;
-  if (current_num_bytes_ > 0 || producer_open_no_lock())
-    rv |= MOJO_WAIT_FLAG_READABLE;
-  return rv;
-}
-
 void LocalDataPipe::EnsureBufferNoLock() {
   DCHECK(producer_open_no_lock());
   if (buffer_.get())
     return;
   buffer_.reset(static_cast<char*>(
       base::AlignedAlloc(capacity_num_bytes(), kDataPipeBufferAlignmentBytes)));
 }
 
 void LocalDataPipe::DestroyBufferNoLock() {
 #ifndef NDEBUG
@@ skipping 25 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