Initial checkin of gRPC to third_party/

third_party/grpc/src/core/iomgr/socket_windows.h

+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_IOMGR_SOCKET_WINDOWS_H
+#define GRPC_INTERNAL_CORE_IOMGR_SOCKET_WINDOWS_H
+
+#include <grpc/support/port_platform.h>
+#include <winsock2.h>
+
+#include <grpc/support/sync.h>
+#include <grpc/support/atm.h>
+
+#include "src/core/iomgr/iomgr_internal.h"
+#include "src/core/iomgr/exec_ctx.h"
+
+/* This holds the data for an outstanding read or write on a socket.
+   The mutex to protect the concurrent access to that data is the one
+   inside the winsocket wrapper. */
+typedef struct grpc_winsocket_callback_info {
+  /* This is supposed to be a WSAOVERLAPPED, but in order to get that
+     definition, we need to include ws2tcpip.h, which needs to be included
+     from the top, otherwise it'll clash with a previous inclusion of
+     windows.h that in turns includes winsock.h. If anyone knows a way
+     to do it properly, feel free to send a patch. */
+  OVERLAPPED overlapped;
+  /* The callback information for the pending operation. May be empty if the
+     caller hasn't registered a callback yet. */
+  grpc_closure *closure;
+  /* A boolean to describe if the IO Completion Port got a notification for
+     that operation. This will happen if the operation completed before the
+     called had time to register a callback. We could avoid that behavior
+     altogether by forcing the caller to always register its callback before
+     proceeding queue an operation, but it is frequent for an IO Completion
+     Port to trigger quickly. This way we avoid a context switch for calling
+     the callback. We also simplify the read / write operations to avoid having
+     to hold a mutex for a long amount of time. */
+  int has_pending_iocp;
+  /* The results of the overlapped operation. */
+  DWORD bytes_transfered;
+  int wsa_error;
+} grpc_winsocket_callback_info;
+
+/* This is a wrapper to a Windows socket. A socket can have one outstanding
+   read, and one outstanding write. Doing an asynchronous accept means waiting
+   for a read operation. Doing an asynchronous connect means waiting for a
+   write operation. These are completely arbitrary ties between the operation
+   and the kind of event, because we can have one overlapped per pending
+   operation, whichever its nature is. So we could have more dedicated pending
+   operation callbacks for connect and listen. But given the scope of listen
+   and accept, we don't need to go to that extent and waste memory. Also, this
+   is closer to what happens in posix world. */
+typedef struct grpc_winsocket {
+  SOCKET socket;
+
+  grpc_winsocket_callback_info write_info;
+  grpc_winsocket_callback_info read_info;
+
+  gpr_mu state_mu;
+
+  /* You can't add the same socket twice to the same IO Completion Port.
+     This prevents that. */
+  int added_to_iocp;
+
+  grpc_closure shutdown_closure;
+
+  /* A label for iomgr to track outstanding objects */
+  grpc_iomgr_object iomgr_object;
+} grpc_winsocket;
+
+/* Create a wrapped windows handle. This takes ownership of it, meaning that
+   it will be responsible for closing it. */
+grpc_winsocket *grpc_winsocket_create(SOCKET socket, const char *name);
+
+/* Initiate an asynchronous shutdown of the socket. Will call off any pending
+   operation to cancel them. */
+void grpc_winsocket_shutdown(grpc_winsocket *socket);
+
+/* Destroy a socket. Should only be called if there's no pending operation. */
+void grpc_winsocket_destroy(grpc_winsocket *socket);
+
+#endif /* GRPC_INTERNAL_CORE_IOMGR_SOCKET_WINDOWS_H */