Revert "Move mojo edk into mojo/edk"

mojo/edk/system/local_data_pipe.cc

Index: mojo/edk/system/local_data_pipe.cc
diff --git a/mojo/edk/system/local_data_pipe.cc b/mojo/edk/system/local_data_pipe.cc
deleted file mode 100644
index 8ee696cc8a1ac6f1fb5dc5e83350ba4211c2d151..0000000000000000000000000000000000000000
--- a/mojo/edk/system/local_data_pipe.cc
+++ /dev/null
@@ -1,341 +0,0 @@
-// 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.)
-
-#include "mojo/edk/system/local_data_pipe.h"
-
-#include <string.h>
-
-#include <algorithm>
-
-#include "base/logging.h"
-#include "mojo/edk/system/constants.h"
-
-namespace mojo {
-namespace system {
-
-LocalDataPipe::LocalDataPipe(const MojoCreateDataPipeOptions& options)
-    : DataPipe(true, true, options), start_index_(0), current_num_bytes_(0) {
-  // Note: |buffer_| is lazily allocated, since a common case will be that one
-  // of the handles is immediately passed off to another process.
-}
-
-LocalDataPipe::~LocalDataPipe() {
-}
-
-void LocalDataPipe::ProducerCloseImplNoLock() {
-  // If the consumer is still open and we still have data, we have to keep the
-  // buffer around. Currently, we won't free it even if it empties later. (We
-  // could do this -- requiring a check on every read -- but that seems to be
-  // optimizing for the uncommon case.)
-  if (!consumer_open_no_lock() || !current_num_bytes_) {
-    // Note: There can only be a two-phase *read* (by the consumer) if we still
-    // have data.
-    DCHECK(!consumer_in_two_phase_read_no_lock());
-    DestroyBufferNoLock();
-  }
-}
-
-MojoResult LocalDataPipe::ProducerWriteDataImplNoLock(
-    UserPointer<const void> elements,
-    UserPointer<uint32_t> num_bytes,
-    uint32_t max_num_bytes_to_write,
-    uint32_t min_num_bytes_to_write) {
-  DCHECK_EQ(max_num_bytes_to_write % element_num_bytes(), 0u);
-  DCHECK_EQ(min_num_bytes_to_write % element_num_bytes(), 0u);
-  DCHECK_GT(max_num_bytes_to_write, 0u);
-  DCHECK(consumer_open_no_lock());
-
-  size_t num_bytes_to_write = 0;
-  if (may_discard()) {
-    if (min_num_bytes_to_write > capacity_num_bytes())
-      return MOJO_RESULT_OUT_OF_RANGE;
-
-    num_bytes_to_write = std::min(static_cast<size_t>(max_num_bytes_to_write),
-                                  capacity_num_bytes());
-    if (num_bytes_to_write > capacity_num_bytes() - current_num_bytes_) {
-      // Discard as much as needed (discard oldest first).
-      MarkDataAsConsumedNoLock(num_bytes_to_write -
-                               (capacity_num_bytes() - current_num_bytes_));
-      // No need to wake up write waiters, since we're definitely going to leave
-      // the buffer full.
-    }
-  } else {
-    if (min_num_bytes_to_write > capacity_num_bytes() - current_num_bytes_) {
-      // Don't return "should wait" since you can't wait for a specified amount
-      // of data.
-      return MOJO_RESULT_OUT_OF_RANGE;
-    }
-
-    num_bytes_to_write = std::min(static_cast<size_t>(max_num_bytes_to_write),
-                                  capacity_num_bytes() - current_num_bytes_);
-  }
-  if (num_bytes_to_write == 0)
-    return MOJO_RESULT_SHOULD_WAIT;
-
-  // The amount we can write in our first |memcpy()|.
-  size_t num_bytes_to_write_first =
-      std::min(num_bytes_to_write, GetMaxNumBytesToWriteNoLock());
-  // Do the first (and possibly only) |memcpy()|.
-  size_t first_write_index =
-      (start_index_ + current_num_bytes_) % capacity_num_bytes();
-  EnsureBufferNoLock();
-  elements.GetArray(buffer_.get() + first_write_index,
-                    num_bytes_to_write_first);
-
-  if (num_bytes_to_write_first < num_bytes_to_write) {
-    // The "second write index" is zero.
-    elements.At(num_bytes_to_write_first)
-        .GetArray(buffer_.get(), num_bytes_to_write - num_bytes_to_write_first);
-  }
-
-  current_num_bytes_ += num_bytes_to_write;
-  DCHECK_LE(current_num_bytes_, capacity_num_bytes());
-  num_bytes.Put(static_cast<uint32_t>(num_bytes_to_write));
-  return MOJO_RESULT_OK;
-}
-
-MojoResult LocalDataPipe::ProducerBeginWriteDataImplNoLock(
-    UserPointer<void*> buffer,
-    UserPointer<uint32_t> buffer_num_bytes,
-    uint32_t min_num_bytes_to_write) {
-  DCHECK(consumer_open_no_lock());
-
-  // The index we need to start writing at.
-  size_t write_index =
-      (start_index_ + current_num_bytes_) % capacity_num_bytes();
-
-  size_t max_num_bytes_to_write = GetMaxNumBytesToWriteNoLock();
-  if (min_num_bytes_to_write > max_num_bytes_to_write) {
-    // In "may discard" mode, we can always write from the write index to the
-    // end of the buffer.
-    if (may_discard() &&
-        min_num_bytes_to_write <= capacity_num_bytes() - write_index) {
-      // To do so, we need to discard an appropriate amount of data.
-      // We should only reach here if the start index is after the write index!
-      DCHECK_GE(start_index_, write_index);
-      DCHECK_GT(min_num_bytes_to_write - max_num_bytes_to_write, 0u);
-      MarkDataAsConsumedNoLock(min_num_bytes_to_write - max_num_bytes_to_write);
-      max_num_bytes_to_write = min_num_bytes_to_write;
-    } else {
-      // Don't return "should wait" since you can't wait for a specified amount
-      // of data.
-      return MOJO_RESULT_OUT_OF_RANGE;
-    }
-  }
-
-  // Don't go into a two-phase write if there's no room.
-  if (max_num_bytes_to_write == 0)
-    return MOJO_RESULT_SHOULD_WAIT;
-
-  EnsureBufferNoLock();
-  buffer.Put(buffer_.get() + write_index);
-  buffer_num_bytes.Put(static_cast<uint32_t>(max_num_bytes_to_write));
-  set_producer_two_phase_max_num_bytes_written_no_lock(
-      static_cast<uint32_t>(max_num_bytes_to_write));
-  return MOJO_RESULT_OK;
-}
-
-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;
-}
-
-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;
-  }
-  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(
-    UserPointer<void> elements,
-    UserPointer<uint32_t> num_bytes,
-    uint32_t max_num_bytes_to_read,
-    uint32_t min_num_bytes_to_read) {
-  DCHECK_EQ(max_num_bytes_to_read % element_num_bytes(), 0u);
-  DCHECK_EQ(min_num_bytes_to_read % element_num_bytes(), 0u);
-  DCHECK_GT(max_num_bytes_to_read, 0u);
-
-  if (min_num_bytes_to_read > current_num_bytes_) {
-    // Don't return "should wait" since you can't wait for a specified amount of
-    // data.
-    return producer_open_no_lock() ? MOJO_RESULT_OUT_OF_RANGE
-                                   : MOJO_RESULT_FAILED_PRECONDITION;
-  }
-
-  size_t num_bytes_to_read =
-      std::min(static_cast<size_t>(max_num_bytes_to_read), current_num_bytes_);
-  if (num_bytes_to_read == 0) {
-    return producer_open_no_lock() ? MOJO_RESULT_SHOULD_WAIT
-                                   : MOJO_RESULT_FAILED_PRECONDITION;
-  }
-
-  // The amount we can read in our first |memcpy()|.
-  size_t num_bytes_to_read_first =
-      std::min(num_bytes_to_read, GetMaxNumBytesToReadNoLock());
-  elements.PutArray(buffer_.get() + start_index_, num_bytes_to_read_first);
-
-  if (num_bytes_to_read_first < num_bytes_to_read) {
-    // The "second read index" is zero.
-    elements.At(num_bytes_to_read_first)
-        .PutArray(buffer_.get(), num_bytes_to_read - num_bytes_to_read_first);
-  }
-
-  MarkDataAsConsumedNoLock(num_bytes_to_read);
-  num_bytes.Put(static_cast<uint32_t>(num_bytes_to_read));
-  return MOJO_RESULT_OK;
-}
-
-MojoResult LocalDataPipe::ConsumerDiscardDataImplNoLock(
-    UserPointer<uint32_t> num_bytes,
-    uint32_t max_num_bytes_to_discard,
-    uint32_t min_num_bytes_to_discard) {
-  DCHECK_EQ(max_num_bytes_to_discard % element_num_bytes(), 0u);
-  DCHECK_EQ(min_num_bytes_to_discard % element_num_bytes(), 0u);
-  DCHECK_GT(max_num_bytes_to_discard, 0u);
-
-  if (min_num_bytes_to_discard > current_num_bytes_) {
-    // Don't return "should wait" since you can't wait for a specified amount of
-    // data.
-    return producer_open_no_lock() ? MOJO_RESULT_OUT_OF_RANGE
-                                   : MOJO_RESULT_FAILED_PRECONDITION;
-  }
-
-  // Be consistent with other operations; error if no data available.
-  if (current_num_bytes_ == 0) {
-    return producer_open_no_lock() ? MOJO_RESULT_SHOULD_WAIT
-                                   : MOJO_RESULT_FAILED_PRECONDITION;
-  }
-
-  size_t num_bytes_to_discard = std::min(
-      static_cast<size_t>(max_num_bytes_to_discard), current_num_bytes_);
-  MarkDataAsConsumedNoLock(num_bytes_to_discard);
-  num_bytes.Put(static_cast<uint32_t>(num_bytes_to_discard));
-  return MOJO_RESULT_OK;
-}
-
-MojoResult LocalDataPipe::ConsumerQueryDataImplNoLock(
-    UserPointer<uint32_t> num_bytes) {
-  // Note: This cast is safe, since the capacity fits into a |uint32_t|.
-  num_bytes.Put(static_cast<uint32_t>(current_num_bytes_));
-  return MOJO_RESULT_OK;
-}
-
-MojoResult LocalDataPipe::ConsumerBeginReadDataImplNoLock(
-    UserPointer<const void*> buffer,
-    UserPointer<uint32_t> buffer_num_bytes,
-    uint32_t min_num_bytes_to_read) {
-  size_t max_num_bytes_to_read = GetMaxNumBytesToReadNoLock();
-  if (min_num_bytes_to_read > max_num_bytes_to_read) {
-    // Don't return "should wait" since you can't wait for a specified amount of
-    // data.
-    return producer_open_no_lock() ? MOJO_RESULT_OUT_OF_RANGE
-                                   : MOJO_RESULT_FAILED_PRECONDITION;
-  }
-
-  // Don't go into a two-phase read if there's no data.
-  if (max_num_bytes_to_read == 0) {
-    return producer_open_no_lock() ? MOJO_RESULT_SHOULD_WAIT
-                                   : MOJO_RESULT_FAILED_PRECONDITION;
-  }
-
-  buffer.Put(buffer_.get() + start_index_);
-  buffer_num_bytes.Put(static_cast<uint32_t>(max_num_bytes_to_read));
-  set_consumer_two_phase_max_num_bytes_read_no_lock(
-      static_cast<uint32_t>(max_num_bytes_to_read));
-  return MOJO_RESULT_OK;
-}
-
-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;
-}
-
-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;
-  }
-  return rv;
-}
-
-void LocalDataPipe::EnsureBufferNoLock() {
-  DCHECK(producer_open_no_lock());
-  if (buffer_)
-    return;
-  buffer_.reset(static_cast<char*>(
-      base::AlignedAlloc(capacity_num_bytes(), kDataPipeBufferAlignmentBytes)));
-}
-
-void LocalDataPipe::DestroyBufferNoLock() {
-#ifndef NDEBUG
-  // Scribble on the buffer to help detect use-after-frees. (This also helps the
-  // unit test detect certain bugs without needing ASAN or similar.)
-  if (buffer_)
-    memset(buffer_.get(), 0xcd, capacity_num_bytes());
-#endif
-  buffer_.reset();
-}
-
-size_t LocalDataPipe::GetMaxNumBytesToWriteNoLock() {
-  size_t next_index = start_index_ + current_num_bytes_;
-  if (next_index >= capacity_num_bytes()) {
-    next_index %= capacity_num_bytes();
-    DCHECK_GE(start_index_, next_index);
-    DCHECK_EQ(start_index_ - next_index,
-              capacity_num_bytes() - current_num_bytes_);
-    return start_index_ - next_index;
-  }
-  return capacity_num_bytes() - next_index;
-}
-
-size_t LocalDataPipe::GetMaxNumBytesToReadNoLock() {
-  if (start_index_ + current_num_bytes_ > capacity_num_bytes())
-    return capacity_num_bytes() - start_index_;
-  return current_num_bytes_;
-}
-
-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