1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #ifndef GRPC_CORE_LIB_IOMGR_SOCKET_WINDOWS_H 20 #define GRPC_CORE_LIB_IOMGR_SOCKET_WINDOWS_H 21 22 #include <grpc/support/port_platform.h> 23 24 #include "src/core/lib/iomgr/port.h" 25 26 #ifdef GRPC_WINSOCK_SOCKET 27 #include <winsock2.h> 28 29 #include <grpc/support/atm.h> 30 #include <grpc/support/sync.h> 31 32 #include "src/core/lib/iomgr/closure.h" 33 #include "src/core/lib/iomgr/iomgr_internal.h" 34 35 #ifndef WSA_FLAG_NO_HANDLE_INHERIT 36 #define WSA_FLAG_NO_HANDLE_INHERIT 0x80 37 #endif 38 39 /* This holds the data for an outstanding read or write on a socket. 40 The mutex to protect the concurrent access to that data is the one 41 inside the winsocket wrapper. */ 42 typedef struct grpc_winsocket_callback_info { 43 /* This is supposed to be a WSAOVERLAPPED, but in order to get that 44 definition, we need to include ws2tcpip.h, which needs to be included 45 from the top, otherwise it'll clash with a previous inclusion of 46 windows.h that in turns includes winsock.h. If anyone knows a way 47 to do it properly, feel free to send a patch. */ 48 OVERLAPPED overlapped; 49 /* The callback information for the pending operation. May be empty if the 50 caller hasn't registered a callback yet. */ 51 grpc_closure* closure; 52 /* A boolean to describe if the IO Completion Port got a notification for 53 that operation. This will happen if the operation completed before the 54 called had time to register a callback. We could avoid that behavior 55 altogether by forcing the caller to always register its callback before 56 proceeding queue an operation, but it is frequent for an IO Completion 57 Port to trigger quickly. This way we avoid a context switch for calling 58 the callback. We also simplify the read / write operations to avoid having 59 to hold a mutex for a long amount of time. */ 60 int has_pending_iocp; 61 /* The results of the overlapped operation. */ 62 DWORD bytes_transferred; 63 int wsa_error; 64 } grpc_winsocket_callback_info; 65 66 /* This is a wrapper to a Windows socket. A socket can have one outstanding 67 read, and one outstanding write. Doing an asynchronous accept means waiting 68 for a read operation. Doing an asynchronous connect means waiting for a 69 write operation. These are completely arbitrary ties between the operation 70 and the kind of event, because we can have one overlapped per pending 71 operation, whichever its nature is. So we could have more dedicated pending 72 operation callbacks for connect and listen. But given the scope of listen 73 and accept, we don't need to go to that extent and waste memory. Also, this 74 is closer to what happens in posix world. */ 75 typedef struct grpc_winsocket { 76 SOCKET socket; 77 bool destroy_called; 78 79 grpc_winsocket_callback_info write_info; 80 grpc_winsocket_callback_info read_info; 81 82 gpr_mu state_mu; 83 bool shutdown_called; 84 85 /* You can't add the same socket twice to the same IO Completion Port. 86 This prevents that. */ 87 int added_to_iocp; 88 89 grpc_closure shutdown_closure; 90 91 /* A label for iomgr to track outstanding objects */ 92 grpc_iomgr_object iomgr_object; 93 } grpc_winsocket; 94 95 /* Create a wrapped windows handle. This takes ownership of it, meaning that 96 it will be responsible for closing it. */ 97 grpc_winsocket* grpc_winsocket_create(SOCKET socket, const char* name); 98 99 SOCKET grpc_winsocket_wrapped_socket(grpc_winsocket* socket); 100 101 /* Initiate an asynchronous shutdown of the socket. Will call off any pending 102 operation to cancel them. */ 103 void grpc_winsocket_shutdown(grpc_winsocket* socket); 104 105 /* Destroy a socket. Should only be called if there's no pending operation. */ 106 void grpc_winsocket_destroy(grpc_winsocket* socket); 107 108 void grpc_socket_notify_on_write(grpc_winsocket* winsocket, 109 grpc_closure* closure); 110 111 void grpc_socket_notify_on_read(grpc_winsocket* winsocket, 112 grpc_closure* closure); 113 114 void grpc_socket_become_ready(grpc_winsocket* winsocket, 115 grpc_winsocket_callback_info* ci); 116 117 /* Returns true if this system can create AF_INET6 sockets bound to ::1. 118 The value is probed once, and cached for the life of the process. */ 119 int grpc_ipv6_loopback_available(void); 120 121 void grpc_wsa_socket_flags_init(); 122 123 DWORD grpc_get_default_wsa_socket_flags(); 124 125 #endif 126 127 #endif /* GRPC_CORE_LIB_IOMGR_SOCKET_WINDOWS_H */ 128