release/src/router/dnscrypt/src/libevent/event_iocp.c

   1 /*
   2  * Copyright (c) 2009-2012 Niels Provos, Nick Mathewson
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  * 3. The name of the author may not be used to endorse or promote products
  13  *    derived from this software without specific prior written permission.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef _WIN32_WINNT
  28 /* Minimum required for InitializeCriticalSectionAndSpinCount */
  29 #define _WIN32_WINNT 0x0403
  30 #endif
  31 #include <winsock2.h>
  32 #include <windows.h>
  33 #include <process.h>
  34 #include <stdio.h>
  35 #include <mswsock.h>
  36
  37 #include "event2/util.h"
  38 #include "util-internal.h"
  39 #include "iocp-internal.h"
  40 #include "log-internal.h"
  41 #include "mm-internal.h"
  42 #include "event-internal.h"
  43 #include "evthread-internal.h"
  44
  45 #define NOTIFICATION_KEY ((ULONG_PTR)-1)
  46
  47 void
  48 event_overlapped_init(struct event_overlapped *o, iocp_callback cb)
  49 {
  50         memset(o, 0, sizeof(struct event_overlapped));
  51         o->cb = cb;
  52 }
  53
  54 static void
  55 handle_entry(OVERLAPPED *o, ULONG_PTR completion_key, DWORD nBytes, int ok)
  56 {
  57         struct event_overlapped *eo =
  58             EVUTIL_UPCAST(o, struct event_overlapped, overlapped);
  59         eo->cb(eo, completion_key, nBytes, ok);
  60 }
  61
  62 static void
  63 loop(void *_port)
  64 {
  65         struct event_iocp_port *port = _port;
  66         long ms = port->ms;
  67         HANDLE p = port->port;
  68
  69         if (ms <= 0)
  70                 ms = INFINITE;
  71
  72         while (1) {
  73                 OVERLAPPED *overlapped=NULL;
  74                 ULONG_PTR key=0;
  75                 DWORD bytes=0;
  76                 int ok = GetQueuedCompletionStatus(p, &bytes, &key,
  77                         &overlapped, ms);
  78                 EnterCriticalSection(&port->lock);
  79                 if (port->shutdown) {
  80                         if (--port->n_live_threads == 0)
  81                                 ReleaseSemaphore(port->shutdownSemaphore, 1,
  82                                                 NULL);
  83                         LeaveCriticalSection(&port->lock);
  84                         return;
  85                 }
  86                 LeaveCriticalSection(&port->lock);
  87
  88                 if (key != NOTIFICATION_KEY && overlapped)
  89                         handle_entry(overlapped, key, bytes, ok);
  90                 else if (!overlapped)
  91                         break;
  92         }
  93         event_warnx("GetQueuedCompletionStatus exited with no event.");
  94         EnterCriticalSection(&port->lock);
  95         if (--port->n_live_threads == 0)
  96                 ReleaseSemaphore(port->shutdownSemaphore, 1, NULL);
  97         LeaveCriticalSection(&port->lock);
  98 }
  99
 100 int
 101 event_iocp_port_associate(struct event_iocp_port *port, evutil_socket_t fd,
 102     ev_uintptr_t key)
 103 {
 104         HANDLE h;
 105         h = CreateIoCompletionPort((HANDLE)fd, port->port, key, port->n_threads);
 106         if (!h)
 107                 return -1;
 108         return 0;
 109 }
 110
 111 static void *
 112 get_extension_function(SOCKET s, const GUID *which_fn)
 113 {
 114         void *ptr = NULL;
 115         DWORD bytes=0;
 116         WSAIoctl(s, SIO_GET_EXTENSION_FUNCTION_POINTER,
 117             (GUID*)which_fn, sizeof(*which_fn),
 118             &ptr, sizeof(ptr),
 119             &bytes, NULL, NULL);
 120
 121         /* No need to detect errors here: if ptr is set, then we have a good
 122            function pointer.  Otherwise, we should behave as if we had no
 123            function pointer.
 124         */
 125         return ptr;
 126 }
 127
 128 /* Mingw doesn't have these in its mswsock.h.  The values are copied from
 129    wine.h.   Perhaps if we copy them exactly, the cargo will come again.
 130 */
 131 #ifndef WSAID_ACCEPTEX
 132 #define WSAID_ACCEPTEX \
 133         {0xb5367df1,0xcbac,0x11cf,{0x95,0xca,0x00,0x80,0x5f,0x48,0xa1,0x92}}
 134 #endif
 135 #ifndef WSAID_CONNECTEX
 136 #define WSAID_CONNECTEX \
 137         {0x25a207b9,0xddf3,0x4660,{0x8e,0xe9,0x76,0xe5,0x8c,0x74,0x06,0x3e}}
 138 #endif
 139 #ifndef WSAID_GETACCEPTEXSOCKADDRS
 140 #define WSAID_GETACCEPTEXSOCKADDRS \
 141         {0xb5367df2,0xcbac,0x11cf,{0x95,0xca,0x00,0x80,0x5f,0x48,0xa1,0x92}}
 142 #endif
 143
 144 static void
 145 init_extension_functions(struct win32_extension_fns *ext)
 146 {
 147         const GUID acceptex = WSAID_ACCEPTEX;
 148         const GUID connectex = WSAID_CONNECTEX;
 149         const GUID getacceptexsockaddrs = WSAID_GETACCEPTEXSOCKADDRS;
 150         SOCKET s = socket(AF_INET, SOCK_STREAM, 0);
 151         if (s == INVALID_SOCKET)
 152                 return;
 153         ext->AcceptEx = get_extension_function(s, &acceptex);
 154         ext->ConnectEx = get_extension_function(s, &connectex);
 155         ext->GetAcceptExSockaddrs = get_extension_function(s,
 156             &getacceptexsockaddrs);
 157         closesocket(s);
 158 }
 159
 160 static struct win32_extension_fns the_extension_fns;
 161 static int extension_fns_initialized = 0;
 162
 163 const struct win32_extension_fns *
 164 event_get_win32_extension_fns(void)
 165 {
 166         return &the_extension_fns;
 167 }
 168
 169 #define N_CPUS_DEFAULT 2
 170
 171 struct event_iocp_port *
 172 event_iocp_port_launch(int n_cpus)
 173 {
 174         struct event_iocp_port *port;
 175         int i;
 176
 177         if (!extension_fns_initialized)
 178                 init_extension_functions(&the_extension_fns);
 179
 180         if (!(port = mm_calloc(1, sizeof(struct event_iocp_port))))
 181                 return NULL;
 182
 183         if (n_cpus <= 0)
 184                 n_cpus = N_CPUS_DEFAULT;
 185         port->n_threads = n_cpus * 2;
 186         port->threads = mm_calloc(port->n_threads, sizeof(HANDLE));
 187         if (!port->threads)
 188                 goto err;
 189
 190         port->port = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0,
 191                         n_cpus);
 192         port->ms = -1;
 193         if (!port->port)
 194                 goto err;
 195
 196         port->shutdownSemaphore = CreateSemaphore(NULL, 0, 1, NULL);
 197         if (!port->shutdownSemaphore)
 198                 goto err;
 199
 200         for (i=0; i<port->n_threads; ++i) {
 201                 ev_uintptr_t th = _beginthread(loop, 0, port);
 202                 if (th == (ev_uintptr_t)-1)
 203                         goto err;
 204                 port->threads[i] = (HANDLE)th;
 205                 ++port->n_live_threads;
 206         }
 207
 208         InitializeCriticalSectionAndSpinCount(&port->lock, 1000);
 209
 210         return port;
 211 err:
 212         if (port->port)
 213                 CloseHandle(port->port);
 214         if (port->threads)
 215                 mm_free(port->threads);
 216         if (port->shutdownSemaphore)
 217                 CloseHandle(port->shutdownSemaphore);
 218         mm_free(port);
 219         return NULL;
 220 }
 221
 222 static void
 223 _event_iocp_port_unlock_and_free(struct event_iocp_port *port)
 224 {
 225         DeleteCriticalSection(&port->lock);
 226         CloseHandle(port->port);
 227         CloseHandle(port->shutdownSemaphore);
 228         mm_free(port->threads);
 229         mm_free(port);
 230 }
 231
 232 static int
 233 event_iocp_notify_all(struct event_iocp_port *port)
 234 {
 235         int i, r, ok=1;
 236         for (i=0; i<port->n_threads; ++i) {
 237                 r = PostQueuedCompletionStatus(port->port, 0, NOTIFICATION_KEY,
 238                     NULL);
 239                 if (!r)
 240                         ok = 0;
 241         }
 242         return ok ? 0 : -1;
 243 }
 244
 245 int
 246 event_iocp_shutdown(struct event_iocp_port *port, long waitMsec)
 247 {
 248         DWORD ms = INFINITE;
 249         int n;
 250
 251         EnterCriticalSection(&port->lock);
 252         port->shutdown = 1;
 253         LeaveCriticalSection(&port->lock);
 254         event_iocp_notify_all(port);
 255
 256         if (waitMsec >= 0)
 257                 ms = waitMsec;
 258
 259         WaitForSingleObject(port->shutdownSemaphore, ms);
 260         EnterCriticalSection(&port->lock);
 261         n = port->n_live_threads;
 262         LeaveCriticalSection(&port->lock);
 263         if (n == 0) {
 264                 _event_iocp_port_unlock_and_free(port);
 265                 return 0;
 266         } else {
 267                 return -1;
 268         }
 269 }
 270
 271 int
 272 event_iocp_activate_overlapped(
 273     struct event_iocp_port *port, struct event_overlapped *o,
 274     ev_uintptr_t key, ev_uint32_t n)
 275 {
 276         BOOL r;
 277
 278         r = PostQueuedCompletionStatus(port->port, n, key, &o->overlapped);
 279         return (r==0) ? -1 : 0;
 280 }
 281
 282 struct event_iocp_port *
 283 event_base_get_iocp(struct event_base *base)
 284 {
 285 #ifdef WIN32
 286         return base->iocp;
 287 #else
 288         return NULL;
 289 #endif
 290 }