Fix WebSocket{Read,Write}Queue.

This CL fixes:
- WebSocketReadQueue may discard data unexpectedly.
- WebSocket{Read,Write}Queue: may stop processing queued operations.

BUG=490196,490200
TEST=None

Review URL: https://codereview.chromium.org/1148913002

Cr-Commit-Position: refs/heads/master@{#330846}

5 files changed, 101 insertions, 56 deletions

diff --git a/mojo/services/network/public/DEPS b/mojo/services/network/public/DEPS
index b8b14d2..86a3623 100644
--- a/mojo/services/network/public/DEPS
+++ b/mojo/services/network/public/DEPS
@@ -4,7 +4,6 @@ include_rules = [
   "-net",
   "-services",
   "-testing",
-  "!base",
   "!mojo/common",
   "+mojo/services/network/public",
   "+third_party/mojo/src/mojo/public",
diff --git a/mojo/services/network/public/cpp/web_socket_read_queue.cc b/mojo/services/network/public/cpp/web_socket_read_queue.cc
index 1bcf503..2d3499c 100644
--- a/mojo/services/network/public/cpp/web_socket_read_queue.cc
+++ b/mojo/services/network/public/cpp/web_socket_read_queue.cc
@@ -5,6 +5,7 @@
 #include "network/public/cpp/web_socket_read_queue.h"
 
 #include "base/bind.h"
+#include "base/logging.h"
 
 namespace mojo {
 
@@ -14,7 +15,7 @@ struct WebSocketReadQueue::Operation {
 };
 
 WebSocketReadQueue::WebSocketReadQueue(DataPipeConsumerHandle handle)
-    : handle_(handle), is_waiting_(false) {
+    : handle_(handle), is_busy_(false), weak_factory_(this) {
 }
 
 WebSocketReadQueue::~WebSocketReadQueue() {
@@ -27,34 +28,57 @@ void WebSocketReadQueue::Read(uint32_t num_bytes,
   op->callback_ = callback;
   queue_.push_back(op);
 
-  if (!is_waiting_)
-    TryToRead();
+  if (is_busy_)
+    return;
+
+  is_busy_ = true;
+  TryToRead();
 }
 
 void WebSocketReadQueue::TryToRead() {
-  Operation* op = queue_[0];
-  const void* buffer = NULL;
-  uint32_t bytes_read = op->num_bytes_;
-  MojoResult result = BeginReadDataRaw(
-      handle_, &buffer, &bytes_read, MOJO_READ_DATA_FLAG_ALL_OR_NONE);
-  if (result == MOJO_RESULT_SHOULD_WAIT) {
-    EndReadDataRaw(handle_, bytes_read);
-    Wait();
-    return;
-  }
+  DCHECK(is_busy_);
+  DCHECK(!queue_.empty());
+  do {
+    Operation* op = queue_[0];
+    const void* buffer = NULL;
+    uint32_t bytes_read = op->num_bytes_;
+    MojoResult result = BeginReadDataRaw(
+        handle_, &buffer, &bytes_read, MOJO_READ_DATA_FLAG_ALL_OR_NONE);
+    if (result == MOJO_RESULT_SHOULD_WAIT) {
+      Wait();
+      return;
+    }
 
-  // Ensure |op| is deleted, whether or not |this| goes away.
-  scoped_ptr<Operation> op_deleter(op);
-  queue_.weak_erase(queue_.begin());
-  if (result != MOJO_RESULT_OK)
-    return;
-  DataPipeConsumerHandle handle = handle_;
-  op->callback_.Run(static_cast<const char*>(buffer));  // may delete |this|
-  EndReadDataRaw(handle, bytes_read);
+    // Ensure |op| is deleted, whether or not |this| goes away.
+    scoped_ptr<Operation> op_deleter(op);
+    queue_.weak_erase(queue_.begin());
+
+    // http://crbug.com/490193 This should run callback as well. May need to
+    // change the callback signature.
+    if (result != MOJO_RESULT_OK)
+      return;
+
+    uint32_t num_bytes = op_deleter->num_bytes_;
+    DCHECK_LE(num_bytes, bytes_read);
+    DataPipeConsumerHandle handle = handle_;
+
+    base::WeakPtr<WebSocketReadQueue> self(weak_factory_.GetWeakPtr());
+
+    // This call may delete |this|. In that case, |self| will be invalidated.
+    // It may re-enter Read() too. Because |is_busy_| is true during the whole
+    // process, TryToRead() won't be re-entered.
+    op->callback_.Run(static_cast<const char*>(buffer));
+
+    EndReadDataRaw(handle, num_bytes);
+
+    if (!self)
+      return;
+  } while (!queue_.empty());
+  is_busy_ = false;
 }
 
 void WebSocketReadQueue::Wait() {
-  is_waiting_ = true;
+  DCHECK(is_busy_);
   handle_watcher_.Start(
       handle_,
       MOJO_HANDLE_SIGNAL_READABLE,
@@ -63,7 +87,7 @@ void WebSocketReadQueue::Wait() {
 }
 
 void WebSocketReadQueue::OnHandleReady(MojoResult result) {
-  is_waiting_ = false;
+  DCHECK(is_busy_);
   TryToRead();
 }
 
diff --git a/mojo/services/network/public/cpp/web_socket_read_queue.h b/mojo/services/network/public/cpp/web_socket_read_queue.h
index 2731510..287e91c 100644
--- a/mojo/services/network/public/cpp/web_socket_read_queue.h
+++ b/mojo/services/network/public/cpp/web_socket_read_queue.h
@@ -7,6 +7,7 @@
 
 #include "base/callback.h"
 #include "base/memory/scoped_vector.h"
+#include "base/memory/weak_ptr.h"
 #include "mojo/common/handle_watcher.h"
 #include "third_party/mojo/src/mojo/public/cpp/system/data_pipe.h"
 
@@ -19,7 +20,7 @@ namespace mojo {
 // See also: WebSocketWriteQueue
 class WebSocketReadQueue {
  public:
-  WebSocketReadQueue(DataPipeConsumerHandle handle);
+  explicit WebSocketReadQueue(DataPipeConsumerHandle handle);
   ~WebSocketReadQueue();
 
   void Read(uint32_t num_bytes, base::Callback<void(const char*)> callback);
@@ -34,7 +35,8 @@ class WebSocketReadQueue {
   DataPipeConsumerHandle handle_;
   common::HandleWatcher handle_watcher_;
   ScopedVector<Operation> queue_;
-  bool is_waiting_;
+  bool is_busy_;
+  base::WeakPtrFactory<WebSocketReadQueue> weak_factory_;
 };
 
 }  // namespace mojo
diff --git a/mojo/services/network/public/cpp/web_socket_write_queue.cc b/mojo/services/network/public/cpp/web_socket_write_queue.cc
index 9f2d132..9a0079c 100644
--- a/mojo/services/network/public/cpp/web_socket_write_queue.cc
+++ b/mojo/services/network/public/cpp/web_socket_write_queue.cc
@@ -5,6 +5,7 @@
 #include "network/public/cpp/web_socket_write_queue.h"
 
 #include "base/bind.h"
+#include "base/logging.h"
 
 namespace mojo {
 
@@ -19,7 +20,7 @@ struct WebSocketWriteQueue::Operation {
 };
 
 WebSocketWriteQueue::WebSocketWriteQueue(DataPipeProducerHandle handle)
-    : handle_(handle), is_waiting_(false) {
+    : handle_(handle), is_busy_(false), weak_factory_(this) {
 }
 
 WebSocketWriteQueue::~WebSocketWriteQueue() {
@@ -34,41 +35,58 @@ void WebSocketWriteQueue::Write(const char* data,
   op->data_ = data;
   queue_.push_back(op);
 
-  MojoResult result = MOJO_RESULT_SHOULD_WAIT;
-  if (!is_waiting_)
-    result = TryToWrite();
+  if (!is_busy_) {
+    is_busy_ = true;
+    // This call may reset |is_busy_| to false.
+    TryToWrite();
+  }
 
-  // If we have to wait, make a local copy of the data so we know it will
-  // live until we need it.
-  if (result == MOJO_RESULT_SHOULD_WAIT) {
+  if (is_busy_) {
+    // If we have to wait, make a local copy of the data so we know it will
+    // live until we need it.
     op->data_copy_.resize(num_bytes);
     memcpy(&op->data_copy_[0], data, num_bytes);
     op->data_ = &op->data_copy_[0];
   }
 }
 
-MojoResult WebSocketWriteQueue::TryToWrite() {
-  Operation* op = queue_[0];
-  uint32_t bytes_written = op->num_bytes_;
-  MojoResult result = WriteDataRaw(
-      handle_, op->data_, &bytes_written, MOJO_WRITE_DATA_FLAG_ALL_OR_NONE);
-  if (result == MOJO_RESULT_SHOULD_WAIT) {
-    Wait();
-    return result;
-  }
-
-  // Ensure |op| is deleted, whether or not |this| goes away.
-  scoped_ptr<Operation> op_deleter(op);
-  queue_.weak_erase(queue_.begin());
-  if (result != MOJO_RESULT_OK)
-    return result;
-
-  op->callback_.Run(op->data_);  // may delete |this|
-  return result;
+void WebSocketWriteQueue::TryToWrite() {
+  DCHECK(is_busy_);
+  DCHECK(!queue_.empty());
+  do {
+    Operation* op = queue_[0];
+    uint32_t bytes_written = op->num_bytes_;
+    MojoResult result = WriteDataRaw(
+        handle_, op->data_, &bytes_written, MOJO_WRITE_DATA_FLAG_ALL_OR_NONE);
+    if (result == MOJO_RESULT_SHOULD_WAIT) {
+      Wait();
+      return;
+    }
+
+    // Ensure |op| is deleted, whether or not |this| goes away.
+    scoped_ptr<Operation> op_deleter(op);
+    queue_.weak_erase(queue_.begin());
+
+    // http://crbug.com/490193 This should run callback as well. May need to
+    // change the callback signature.
+    if (result != MOJO_RESULT_OK)
+      return;
+
+    base::WeakPtr<WebSocketWriteQueue> self(weak_factory_.GetWeakPtr());
+
+    // This call may delete |this|. In that case, |self| will be invalidated.
+    // It may re-enter Write() too. Because |is_busy_| is true during the whole
+    // process, TryToWrite() won't be re-entered.
+    op->callback_.Run(op->data_);
+
+    if (!self)
+      return;
+  } while (!queue_.empty());
+  is_busy_ = false;
 }
 
 void WebSocketWriteQueue::Wait() {
-  is_waiting_ = true;
+  DCHECK(is_busy_);
   handle_watcher_.Start(handle_,
                         MOJO_HANDLE_SIGNAL_WRITABLE,
                         MOJO_DEADLINE_INDEFINITE,
@@ -77,7 +95,7 @@ void WebSocketWriteQueue::Wait() {
 }
 
 void WebSocketWriteQueue::OnHandleReady(MojoResult result) {
-  is_waiting_ = false;
+  DCHECK(is_busy_);
   TryToWrite();
 }
 
diff --git a/mojo/services/network/public/cpp/web_socket_write_queue.h b/mojo/services/network/public/cpp/web_socket_write_queue.h
index b2c48fc..91e7924 100644
--- a/mojo/services/network/public/cpp/web_socket_write_queue.h
+++ b/mojo/services/network/public/cpp/web_socket_write_queue.h
@@ -7,6 +7,7 @@
 
 #include "base/callback.h"
 #include "base/memory/scoped_vector.h"
+#include "base/memory/weak_ptr.h"
 #include "mojo/common/handle_watcher.h"
 #include "third_party/mojo/src/mojo/public/cpp/system/data_pipe.h"
 
@@ -19,7 +20,7 @@ namespace mojo {
 // See also: WebSocketReadQueue
 class WebSocketWriteQueue {
  public:
-  WebSocketWriteQueue(DataPipeProducerHandle handle);
+  explicit WebSocketWriteQueue(DataPipeProducerHandle handle);
   ~WebSocketWriteQueue();
 
   void Write(const char* data,
@@ -29,14 +30,15 @@ class WebSocketWriteQueue {
  private:
   struct Operation;
 
-  MojoResult TryToWrite();
+  void TryToWrite();
   void Wait();
   void OnHandleReady(MojoResult result);
 
   DataPipeProducerHandle handle_;
   common::HandleWatcher handle_watcher_;
   ScopedVector<Operation> queue_;
-  bool is_waiting_;
+  bool is_busy_;
+  base::WeakPtrFactory<WebSocketWriteQueue> weak_factory_;
 };
 
 }  // namespace mojo