[SPDY] Refactor SpdySession's write queue

net/spdy/spdy_stream.cc

Index: net/spdy/spdy_stream.cc
diff --git a/net/spdy/spdy_stream.cc b/net/spdy/spdy_stream.cc
index e20fb8d73125baa10d1316d87830d6663f87fae9..4bf4e74ecbf484df853983b5e3c1706c8e489d0d 100644
--- a/net/spdy/spdy_stream.cc
+++ b/net/spdy/spdy_stream.cc
@@ -12,6 +12,7 @@
 #include "base/values.h"
 #include "net/spdy/spdy_http_utils.h"
 #include "net/spdy/spdy_session.h"
+#include "net/spdy/spdy_write_queue.h"
 
 namespace net {
 
@@ -50,6 +51,57 @@ bool ContainsUpperAscii(const std::string& str) {
 
 }  // namespace
 
+// A wrapper around a stream that calls into ProduceSynStreamFrame().
+class SpdyStream::SynStreamFrameProducer : public SpdyFrameProducer {
+ public:
+  SynStreamFrameProducer(const base::WeakPtr<SpdyStream>& stream)
+      : stream_(stream) {
+    DCHECK(stream_);
+  }
+
+  virtual ~SynStreamFrameProducer() {}
+
+  virtual scoped_ptr<SpdyFrame> ProduceFrame() OVERRIDE {
+    if (!stream_) {
+      NOTREACHED();
+      return scoped_ptr<SpdyFrame>();
+    }
+    DCHECK_GT(stream_->stream_id(), 0u);
+    return stream_->ProduceSynStreamFrame();
+  }
+
+ private:
+  const base::WeakPtr<SpdyStream> stream_;
+};
+
+// A wrapper around a stream that calls into ProduceHeaderFrame() with
+// a given header block.
+class SpdyStream::HeaderFrameProducer : public SpdyFrameProducer {
+ public:
+  HeaderFrameProducer(const base::WeakPtr<SpdyStream>& stream,
+                      scoped_ptr<SpdyHeaderBlock> headers)
+      : stream_(stream),
+        headers_(headers.Pass()) {
+    DCHECK(stream_);
+    DCHECK(headers_);
+  }
+
+  virtual ~HeaderFrameProducer() {}
+
+  virtual scoped_ptr<SpdyFrame> ProduceFrame() OVERRIDE {
+    if (!stream_) {
+      NOTREACHED();
+      return scoped_ptr<SpdyFrame>();
+    }
+    DCHECK_GT(stream_->stream_id(), 0u);
+    return stream_->ProduceHeaderFrame(headers_.Pass());
+  }
+
+ private:
+  const base::WeakPtr<SpdyStream> stream_;
+  scoped_ptr<SpdyHeaderBlock> headers_;
+};
+
 SpdyStream::SpdyStream(SpdySession* session,
                        const std::string& path,
                        RequestPriority priority,
@@ -83,99 +135,8 @@ SpdyStream::SpdyStream(SpdySession* session,
       domain_bound_cert_type_(CLIENT_CERT_INVALID_TYPE) {
 }
 
-class SpdyStream::SpdyStreamIOBufferProducer
-    : public SpdySession::SpdyIOBufferProducer {
- public:
-  SpdyStreamIOBufferProducer(SpdyStream* stream) : stream_(stream) {}
-
-  // SpdyFrameProducer
-  virtual RequestPriority GetPriority() const OVERRIDE {
-    return stream_->priority();
-  }
-
-  virtual SpdyIOBuffer* ProduceNextBuffer(SpdySession* session) OVERRIDE {
-    if (stream_->cancelled())
-      return NULL;
-    if (stream_->stream_id() == 0)
-      SpdySession::SpdyIOBufferProducer::ActivateStream(session, stream_);
-    frame_ = stream_->ProduceNextFrame();
-    return frame_ == NULL ? NULL :
-        SpdySession::SpdyIOBufferProducer::CreateIOBuffer(
-            frame_.get(), GetPriority(), stream_);
-  }
-
- private:
-  scoped_refptr<SpdyStream> stream_;
-  scoped_ptr<SpdyFrame> frame_;
-};
-
-void SpdyStream::SetHasWriteAvailable() {
-  session_->SetStreamHasWriteAvailable(this,
-                                       new SpdyStreamIOBufferProducer(this));
-}
-
-scoped_ptr<SpdyFrame> SpdyStream::ProduceNextFrame() {
-  if (io_state_ == STATE_SEND_DOMAIN_BOUND_CERT_COMPLETE) {
-    CHECK(request_.get());
-    CHECK_GT(stream_id_, 0u);
-
-    std::string origin = GetUrl().GetOrigin().spec();
-    DCHECK(origin[origin.length() - 1] == '/');
-    origin.erase(origin.length() - 1);  // Trim trailing slash.
-    scoped_ptr<SpdyFrame> frame(session_->CreateCredentialFrame(
-        origin, domain_bound_cert_type_, domain_bound_private_key_,
-        domain_bound_cert_, priority_));
-    return frame.Pass();
-  } else if (io_state_ == STATE_SEND_HEADERS_COMPLETE) {
-    CHECK(request_.get());
-    CHECK_GT(stream_id_, 0u);
-
-    SpdyControlFlags flags =
-        has_upload_data_ ? CONTROL_FLAG_NONE : CONTROL_FLAG_FIN;
-    scoped_ptr<SpdyFrame> frame(session_->CreateSynStream(
-        stream_id_, priority_, slot_, flags, *request_));
-    send_time_ = base::TimeTicks::Now();
-    return frame.Pass();
-  } else {
-    CHECK(!cancelled());
-    // We must need to write stream data.
-    // Until the headers have been completely sent, we can not be sure
-    // that our stream_id is correct.
-    DCHECK_GT(io_state_, STATE_SEND_HEADERS_COMPLETE);
-    DCHECK_GT(stream_id_, 0u);
-    DCHECK(!pending_frames_.empty());
-
-    PendingFrame frame = pending_frames_.front();
-    pending_frames_.pop_front();
-
-    waiting_completions_.push_back(frame.type);
-
-    if (frame.type == TYPE_DATA) {
-      // Send queued data frame.
-      return scoped_ptr<SpdyFrame>(frame.data_frame);
-    } else {
-      DCHECK(frame.type == TYPE_HEADERS);
-      // Create actual HEADERS frame just in time because it depends on
-      // compression context and should not be reordered after the creation.
-      scoped_ptr<SpdyFrame> header_frame(session_->CreateHeadersFrame(
-          stream_id_, *frame.header_block, SpdyControlFlags()));
-      delete frame.header_block;
-      return header_frame.Pass();
-    }
-  }
-  NOTREACHED();
-}
-
 SpdyStream::~SpdyStream() {
   UpdateHistograms();
-  while (!pending_frames_.empty()) {
-    PendingFrame frame = pending_frames_.back();
-    pending_frames_.pop_back();
-    if (frame.type == TYPE_DATA)
-      delete frame.data_frame;
-    else
-      delete frame.header_block;
-  }
 }
 
 void SpdyStream::SetDelegate(Delegate* delegate) {
@@ -228,6 +189,35 @@ void SpdyStream::PushedStreamReplayData() {
   }
 }
 
+scoped_ptr<SpdyFrame> SpdyStream::ProduceSynStreamFrame() {
+  CHECK_EQ(io_state_, STATE_SEND_HEADERS_COMPLETE);
+  CHECK(request_.get());
+  CHECK_GT(stream_id_, 0u);
+
+  SpdyControlFlags flags =
+      has_upload_data_ ? CONTROL_FLAG_NONE : CONTROL_FLAG_FIN;
+  scoped_ptr<SpdyFrame> frame(session_->CreateSynStream(
+      stream_id_, priority_, slot_, flags, *request_));
+  send_time_ = base::TimeTicks::Now();
+  return frame.Pass();
+}
+
+scoped_ptr<SpdyFrame> SpdyStream::ProduceHeaderFrame(
+    scoped_ptr<SpdyHeaderBlock> header_block) {
+  CHECK(!cancelled());
+  // We must need to write stream data.
+  // Until the headers have been completely sent, we can not be sure
+  // that our stream_id is correct.
+  DCHECK_GT(io_state_, STATE_SEND_HEADERS_COMPLETE);
+  DCHECK_GT(stream_id_, 0u);
+
+  // Create actual HEADERS frame just in time because it depends on
+  // compression context and should not be reordered after the creation.
+  scoped_ptr<SpdyFrame> header_frame(session_->CreateHeadersFrame(
+      stream_id_, *header_block, SpdyControlFlags()));
+  return header_frame.Pass();
+}
+
 void SpdyStream::DetachDelegate() {
   delegate_ = NULL;
   if (!closed())
@@ -578,14 +568,13 @@ void SpdyStream::QueueHeaders(scoped_ptr<SpdyHeaderBlock> headers) {
   DCHECK_GT(io_state_, STATE_SEND_HEADERS_COMPLETE);
   CHECK_GT(stream_id_, 0u);
 
-  PendingFrame frame;
-  frame.type = TYPE_HEADERS;
-  // |frame.header_block| is deleted by either ProduceNextFrame() or
-  // the destructor.
-  frame.header_block = headers.release();
-  pending_frames_.push_back(frame);
+  waiting_completions_.push_back(TYPE_HEADERS);
 
-  SetHasWriteAvailable();
+  session_->EnqueueStreamWrite(
+      this,
+      scoped_ptr<SpdyFrameProducer>(
+          new HeaderFrameProducer(
+              weak_ptr_factory_.GetWeakPtr(), headers.Pass())));
 }
 
 void SpdyStream::QueueStreamData(IOBuffer* data,
@@ -595,20 +584,19 @@ void SpdyStream::QueueStreamData(IOBuffer* data,
   // that our stream_id is correct.
   DCHECK_GT(io_state_, STATE_SEND_HEADERS_COMPLETE);
   CHECK_GT(stream_id_, 0u);
+  CHECK(!cancelled());
 
   scoped_ptr<SpdyFrame> data_frame(session_->CreateDataFrame(
       stream_id_, data, length, flags));
   if (!data_frame)
     return;
 
-  PendingFrame frame;
-  frame.type = TYPE_DATA;
-  // |frame.data_frame| is either returned by ProduceNextFrame() or
-  // deleted in the destructor.
-  frame.data_frame = data_frame.release();
-  pending_frames_.push_back(frame);
+  waiting_completions_.push_back(TYPE_DATA);
 
-  SetHasWriteAvailable();
+  session_->EnqueueStreamWrite(
+      this,
+      scoped_ptr<SpdyFrameProducer>(
+          new SimpleFrameProducer(data_frame.Pass())));
 }
 
 bool SpdyStream::GetSSLInfo(SSLInfo* ssl_info,
@@ -693,7 +681,7 @@ int SpdyStream::DoLoop(int result) {
         break;
       // State machine 2: connection is established.
       // In STATE_OPEN, OnResponseReceived has already been called.
-      // OnDataReceived, OnClose and OnWriteCompelte can be called.
+      // OnDataReceived, OnClose and OnWriteComplete can be called.
       // Only OnWriteComplete calls DoLoop(().
       //
       // For HTTP streams, no data is sent from the client while in the OPEN
@@ -763,7 +751,37 @@ int SpdyStream::DoGetDomainBoundCertComplete(int result) {
 int SpdyStream::DoSendDomainBoundCert() {
   io_state_ = STATE_SEND_DOMAIN_BOUND_CERT_COMPLETE;
   CHECK(request_.get());
-  SetHasWriteAvailable();
+
+  std::string origin = GetUrl().GetOrigin().spec();
+  DCHECK(origin[origin.length() - 1] == '/');
+  origin.erase(origin.length() - 1);  // Trim trailing slash.
+  scoped_ptr<SpdyFrame> frame;
+  int rv = session_->CreateCredentialFrame(
+      origin, domain_bound_cert_type_, domain_bound_private_key_,
+      domain_bound_cert_, priority_, &frame);
+  if (rv != OK) {
+    DCHECK_NE(rv, ERR_IO_PENDING);
+    return rv;
+  }
+
+  DCHECK(frame);
+  // TODO(akalin): Fix a couple of race conditions:
+  //
+  // 1) Since this counts as a write for this stream, the stream will
+  // be activated (and hence allocated a stream ID) before this frame
+  // is sent, even though the ID should only be activated for the
+  // SYN_STREAM frame. This can be solved by signalling to the session
+  // when we're sending a SYN_STREAM frame, and have it only activate
+  // the stream then.
+  //
+  // 2) Since this is decoupled from sending the SYN_STREAM frame, it
+  // is possible that other domain-bound cert frames will clobber ours
+  // before our SYN_STREAM frame gets sent. This can be solved by
+  // immediately enqueueing the SYN_STREAM frame here and adjusting
+  // the state machine appropriately.
+  session_->EnqueueStreamWrite(
+      this,
+      scoped_ptr<SpdyFrameProducer>(new SimpleFrameProducer(frame.Pass())));
   return ERR_IO_PENDING;
 }
 
@@ -777,9 +795,12 @@ int SpdyStream::DoSendDomainBoundCertComplete(int result) {
 
 int SpdyStream::DoSendHeaders() {
   CHECK(!cancelled_);
-
-  SetHasWriteAvailable();
   io_state_ = STATE_SEND_HEADERS_COMPLETE;
+
+  session_->EnqueueStreamWrite(
+      this,
+      scoped_ptr<SpdyFrameProducer>(
+          new SynStreamFrameProducer(weak_ptr_factory_.GetWeakPtr())));
   return ERR_IO_PENDING;
 }