[NaCl SDK] Support non blocking TCP/UDP

native_client_sdk/src/libraries/nacl_io/mount_node_tcp.cc

 // Copyright (c) 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.
 
 
 #include "nacl_io/ossocket.h"
 #ifdef PROVIDES_SOCKET_API
 
 #include <errno.h>
 #include <string.h>
 #include <algorithm>
 
-#include "nacl_io/mount.h"
-#include "nacl_io/mount_node_socket.h"
 #include "nacl_io/mount_node_tcp.h"
+#include "nacl_io/mount_stream.h"
 #include "nacl_io/pepper_interface.h"
 
+namespace {
+  const size_t kMaxPacketSize = 65536;
+  const size_t kDefaultFifoSize = kMaxPacketSize * 8;
+}
+
 namespace nacl_io {
 
-MountNodeTCP::MountNodeTCP(Mount* mount) : MountNodeSocket(mount) {}
+class TCPWork : public MountStream::Work {
+ public:
+  explicit TCPWork(const ScopedEventEmitterTCP& emitter)
+      : MountStream::Work(emitter->stream()->mount_stream()),
+        emitter_(emitter),
+        data_(NULL) {
+  }
+
+  ~TCPWork() {
+    delete[] data_;
+  }
+
+  TCPSocketInterface* TCPInterface() {
+    return mount()->ppapi()->GetTCPSocketInterface();
+  }
+
+ protected:
+  ScopedEventEmitterTCP emitter_;
+  char* data_;
+};
 
 
-TCPSocketInterface* MountNodeTCP::TCPSocket() {
-  if (mount_->ppapi() == NULL)
-    return NULL;
+class TCPSendWork : public TCPWork {
+ public:
+  explicit TCPSendWork(const ScopedEventEmitterTCP& emitter)
+      : TCPWork(emitter) {}
 
-  return mount_->ppapi()->GetTCPSocketInterface();
+  virtual bool Start(int32_t val) {
+    AUTO_LOCK(emitter_->GetLock());
+    MountNodeTCP* stream = static_cast<MountNodeTCP*>(emitter_->stream());
+
+    // Does the stream exist, and can it send?
+    if (NULL == stream)
+      return false;
+
+    bool wth = stream->TestStreamFlags(SSF_CAN_SEND);

[binji, 2013/09/19 22:40:25]

wth?

[noelallen1, 2013/09/20 00:51:27]

Still debugging TCP. I take it you didn't notice the change title.  :)

+    if (!wth)
+      return false;
+
+    // If not currently sending...
+    if (!stream->TestStreamFlags(SSF_SENDING)) {
+      size_t tx_data_avail = emitter_->out_fifo()->ReadAvailable();
+      int capped_len =
+          static_cast<int32_t>(std::min(tx_data_avail, kMaxPacketSize));
+
+      if (capped_len == 0)
+        return false;
+
+      data_ = new char[capped_len];
+      emitter_->ReadOut_Locked(data_, capped_len);
+
+      stream->SetStreamFlags(SSF_SENDING);
+      int err = TCPInterface()->Write(stream->socket_resource(),
+                                      data_,
+                                      capped_len,
+                                      mount()->GetRunCompletion(this));
+      if (err == PP_OK_COMPLETIONPENDING)
+        return true;
+
+      // Anything else, we should assume the socket has gone bad.
+      stream->SetError(err);
+    }
+    return false;
+  }
+
+  virtual void Run(int32_t length_error) {
+    AUTO_LOCK(emitter_->GetLock());
+    MountNodeTCP* stream = static_cast<MountNodeTCP*>(emitter_->stream());
+
+    // If the stream is still there...
+    if (stream) {
+      // And we did send, then Q more work.
+      if (length_error >= 0) {
+        stream->ClearStreamFlags(SSF_SENDING);
+        stream->QueueOutput();

[binji, 2013/09/19 22:40:25]

why does TCPSendWork QueueOutput in the Run callback, but TCPRecvWork doesn't
QueueInput?

Doesn't the MountNodeSocket handle this now?

[noelallen1, 2013/09/20 00:51:27]

MountNodeSocket handles the foreground thread side (recv more because I just
added something to the Q), Work objs handle the background thread side (recv
again, I'm free to issue another completion request).

+      } else {
+        // Otherwise this socket has gone bad.
+        stream->SetError(length_error);
+      }
+    }
+  }
+};
+
+class TCPRecvWork : public TCPWork {
+ public:
+  explicit TCPRecvWork(const ScopedEventEmitterTCP& emitter)
+      : TCPWork(emitter) {}
+
+  virtual bool Start(int32_t val) {
+    AUTO_LOCK(emitter_->GetLock());
+    MountNodeTCP* stream = static_cast<MountNodeTCP*>(emitter_->stream());
+
+    // Does the stream exist, and can it recv?
+    if (NULL == stream || !stream->TestStreamFlags(SSF_CAN_RECV))
+      return false;
+
+    // If the stream is valid and we are not currently receiving

[binji, 2013/09/19 22:40:25]

bad comment, just "if not currently receiving"

[noelallen1, 2013/09/20 00:51:27]

Done.

+    if (!stream->TestStreamFlags(SSF_RECVING)) {
+      size_t rx_space_avail = emitter_->in_fifo()->WriteAvailable();
+      int capped_len =
+          static_cast<int32_t>(std::min(rx_space_avail, kMaxPacketSize));
+
+      if (capped_len > 0) {

[binji, 2013/09/19 22:40:25]

why did you flip this if? (TCPSendWork uses an if-guard like before)

[noelallen1, 2013/09/20 00:51:27]

Done.

+        stream->SetStreamFlags(SSF_RECVING);
+        data_ = new char[capped_len];
+        int err = TCPInterface()->Read(stream->socket_resource(),
+                                       data_,
+                                       capped_len,
+                                       mount()->GetRunCompletion(this));
+        if (err == PP_OK_COMPLETIONPENDING)
+          return true;
+
+        stream->SetError(err);
+      }
+    }
+    return false;
+  }
+
+  virtual void Run(int32_t length_error) {
+    AUTO_LOCK(emitter_->GetLock());
+    MountNodeTCP* stream = static_cast<MountNodeTCP*>(emitter_->stream());
+
+    // If the stream is still there, see if we can queue more input
+    if (stream) {
+      if (length_error > 0) {
+        emitter_->WriteIn_Locked(data_, length_error);
+      } else {
+        stream->SetError(length_error);
+      }
+    }
+  }
+};
+
+
+MountNodeTCP::MountNodeTCP(Mount* mount)
+    : MountNodeSocket(mount),
+      emitter_(new EventEmitterTCP(kDefaultFifoSize, kDefaultFifoSize)) {
+  emitter_->AttachStream(this);
+}
+
+void MountNodeTCP::Destroy() {
+  emitter_->DetachStream();
+  MountNodeSocket::Destroy();
 }
 
 Error MountNodeTCP::Init(int flags) {
-  if (TCPSocket() == NULL)
+  if (TCPInterface() == NULL)
     return EACCES;
 
-  socket_resource_ = TCPSocket()->Create(mount_->ppapi()->GetInstance());
+  socket_resource_ = TCPInterface()->Create(mount_->ppapi()->GetInstance());
   if (0 == socket_resource_)
     return EACCES;
 
   return 0;
 }
 
+EventEmitterTCP* MountNodeTCP::GetEventEmitter() {
+  return emitter_.get();
+}
+
+void MountNodeTCP::QueueInput() {
+  TCPRecvWork* work = new TCPRecvWork(emitter_);
+  mount_stream()->EnqueueWork(work);
+}
+
+void MountNodeTCP::QueueOutput() {
+  TCPSendWork* work = new TCPSendWork(emitter_);
+  mount_stream()->EnqueueWork(work);
+}
+
+
+// We can not bind a client socket with PPAPI.  For now we ignore the
+// bind but report the correct address later, just in case someone is
+// binding without really caring what the address is (for example to
+// select a more optimized interface/route.)
 Error MountNodeTCP::Bind(const struct sockaddr* addr, socklen_t len) {
   AUTO_LOCK(node_lock_);
 
   if (0 == socket_resource_)
     return EBADF;
 
   /* Only bind once. */
   if (local_addr_ != 0)
     return EINVAL;
 
   /* Lie, we won't know until we connect. */
   return 0;
 }
 
 Error MountNodeTCP::Connect(const struct sockaddr* addr, socklen_t len) {
   AUTO_LOCK(node_lock_);
 
   if (0 == socket_resource_)
     return EBADF;
 
   if (remote_addr_ != 0)
     return EISCONN;
 
   remote_addr_ = SockAddrToResource(addr, len);
   if (0 == remote_addr_)
     return EINVAL;
 
-  int err = TCPSocket()->Connect(socket_resource_,
-                                 remote_addr_,
-                                 PP_BlockUntilComplete());
+  int err = TCPInterface()->Connect(socket_resource_,
+                                    remote_addr_,
+                                    PP_BlockUntilComplete());
 
   // If we fail, release the dest addr resource
   if (err != PP_OK) {
     mount_->ppapi()->ReleaseResource(remote_addr_);
     remote_addr_ = 0;
     return PPErrorToErrno(err);
   }
 
-  local_addr_ = TCPSocket()->GetLocalAddress(socket_resource_);
+  local_addr_ = TCPInterface()->GetLocalAddress(socket_resource_);
   mount_->ppapi()->AddRefResource(local_addr_);
+
+  // Now that we are connected, we can start sending and receiving.
+  SetStreamFlags(SSF_CAN_SEND | SSF_CAN_RECV);
+
+  // Begin the input pump
+  QueueInput();
   return 0;
 }
 
-Error MountNodeTCP::Recv(void* buf, size_t len, int flags, int* out_len) {
-  AUTO_LOCK(node_lock_);
-  if (0 == socket_resource_)
-    return EBADF;
 
-  int capped_len = static_cast<int32_t>(std::min(len, MAX_SOCK_TRANSFER));
-  int err = TCPSocket()->Read(socket_resource_,
-                              static_cast<char*>(buf),
-                              capped_len,
-                              PP_BlockUntilComplete());
-  if (err < 0)
-    return PPErrorToErrno(err);
+Error MountNodeTCP::Recv_Locked(void* buf,
+                                size_t len,
+                                PP_Resource* addr,

[binji, 2013/09/19 22:40:25]

out_addr?

[noelallen1, 2013/09/20 00:51:27]

Done.

+                                int* out_len) {
+  *out_len = emitter_->in_fifo()->Read(buf, len);
+  *addr = remote_addr_;
 
-  *out_len = err;
+  mount_->ppapi()->AddRefResource(remote_addr_);
   return 0;
 }
 
-Error MountNodeTCP::RecvFrom(void* buf,
-                             size_t len,
-                             int flags,
-                             struct sockaddr* src_addr,
-                             socklen_t* addrlen,
-                             int* out_len) {
-  Error err = Recv(buf, len, flags, out_len);
-  if (err == 0)
-    GetPeerName(src_addr, addrlen);
-  return err;
-}
-
-
-Error MountNodeTCP::Send(const void* buf, size_t len, int flags, int* out_len) {
-  AUTO_LOCK(node_lock_);
-
-  if (0 == socket_resource_)
-    return EBADF;
-
-  if (0 == remote_addr_)
-    return ENOTCONN;
-
-  int capped_len = static_cast<int32_t>(std::min(len, MAX_SOCK_TRANSFER));
-  int err = TCPSocket()->Write(socket_resource_,
-                               static_cast<const char*>(buf),
-                               capped_len,
-                               PP_BlockUntilComplete());
-  if (err < 0)
-    return PPErrorToErrno(err);
-
-  *out_len = err;
+// TCP ignores dst addr passed to send_to, and always uses bound address
+Error MountNodeTCP::Send_Locked(const void* buf,
+                                size_t len,
+                                PP_Resource,
+                                int* out_len) {
+  *out_len = emitter_->in_fifo()->Write(buf, len);
   return 0;
 }
 
-Error MountNodeTCP::SendTo(const void* buf,
-                           size_t len,
-                           int flags,
-                           const struct sockaddr* dest_addr,
-                           socklen_t addrlen,
-                           int* out_len) {
-  return Send(buf, len, flags, out_len);
-}
 
 }  // namespace nacl_io
 
 #endif  // PROVIDES_SOCKET_API