1 /* 2 * Copyright (c) 2009-2012 Niels Provos and 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 /** 28 @file buffer_iocp.c 29 30 This module implements overlapped read and write functions for evbuffer 31 objects on Windows. 32 */ 33 #include "event2/event-config.h" 34 #include "evconfig-private.h" 35 36 #include "event2/buffer.h" 37 #include "event2/buffer_compat.h" 38 #include "event2/util.h" 39 #include "event2/thread.h" 40 #include "util-internal.h" 41 #include "evthread-internal.h" 42 #include "evbuffer-internal.h" 43 #include "iocp-internal.h" 44 #include "mm-internal.h" 45 46 #include <winsock2.h> 47 #include <windows.h> 48 #include <stdio.h> 49 50 #define MAX_WSABUFS 16 51 52 /** An evbuffer that can handle overlapped IO. */ 53 struct evbuffer_overlapped { 54 struct evbuffer buffer; 55 /** The socket that we're doing overlapped IO on. */ 56 evutil_socket_t fd; 57 58 /** pending I/O type */ 59 unsigned read_in_progress : 1; 60 unsigned write_in_progress : 1; 61 62 /** The first pinned chain in the buffer. */ 63 struct evbuffer_chain *first_pinned; 64 65 /** How many chains are pinned; how many of the fields in buffers 66 * are we using. */ 67 int n_buffers; 68 WSABUF buffers[MAX_WSABUFS]; 69 }; 70 71 /** Given an evbuffer, return the correponding evbuffer structure, or NULL if 72 * the evbuffer isn't overlapped. */ 73 static inline struct evbuffer_overlapped * 74 upcast_evbuffer(struct evbuffer *buf) 75 { 76 if (!buf || !buf->is_overlapped) 77 return NULL; 78 return EVUTIL_UPCAST(buf, struct evbuffer_overlapped, buffer); 79 } 80 81 /** Unpin all the chains noted as pinned in 'eo'. */ 82 static void 83 pin_release(struct evbuffer_overlapped *eo, unsigned flag) 84 { 85 int i; 86 struct evbuffer_chain *next, *chain = eo->first_pinned; 87 88 for (i = 0; i < eo->n_buffers; ++i) { 89 EVUTIL_ASSERT(chain); 90 next = chain->next; 91 evbuffer_chain_unpin_(chain, flag); 92 chain = next; 93 } 94 } 95 96 void 97 evbuffer_commit_read_(struct evbuffer *evbuf, ev_ssize_t nBytes) 98 { 99 struct evbuffer_overlapped *buf = upcast_evbuffer(evbuf); 100 struct evbuffer_chain **chainp; 101 size_t remaining, len; 102 unsigned i; 103 104 EVBUFFER_LOCK(evbuf); 105 EVUTIL_ASSERT(buf->read_in_progress && !buf->write_in_progress); 106 EVUTIL_ASSERT(nBytes >= 0); /* XXXX Can this be false? */ 107 108 evbuffer_unfreeze(evbuf, 0); 109 110 chainp = evbuf->last_with_datap; 111 if (!((*chainp)->flags & EVBUFFER_MEM_PINNED_R)) 112 chainp = &(*chainp)->next; 113 remaining = nBytes; 114 for (i = 0; remaining > 0 && i < (unsigned)buf->n_buffers; ++i) { 115 EVUTIL_ASSERT(*chainp); 116 len = buf->buffers[i].len; 117 if (remaining < len) 118 len = remaining; 119 (*chainp)->off += len; 120 evbuf->last_with_datap = chainp; 121 remaining -= len; 122 chainp = &(*chainp)->next; 123 } 124 125 pin_release(buf, EVBUFFER_MEM_PINNED_R); 126 127 buf->read_in_progress = 0; 128 129 evbuf->total_len += nBytes; 130 evbuf->n_add_for_cb += nBytes; 131 132 evbuffer_invoke_callbacks_(evbuf); 133 134 evbuffer_decref_and_unlock_(evbuf); 135 } 136 137 void 138 evbuffer_commit_write_(struct evbuffer *evbuf, ev_ssize_t nBytes) 139 { 140 struct evbuffer_overlapped *buf = upcast_evbuffer(evbuf); 141 142 EVBUFFER_LOCK(evbuf); 143 EVUTIL_ASSERT(buf->write_in_progress && !buf->read_in_progress); 144 evbuffer_unfreeze(evbuf, 1); 145 evbuffer_drain(evbuf, nBytes); 146 pin_release(buf,EVBUFFER_MEM_PINNED_W); 147 buf->write_in_progress = 0; 148 evbuffer_decref_and_unlock_(evbuf); 149 } 150 151 struct evbuffer * 152 evbuffer_overlapped_new_(evutil_socket_t fd) 153 { 154 struct evbuffer_overlapped *evo; 155 156 evo = mm_calloc(1, sizeof(struct evbuffer_overlapped)); 157 if (!evo) 158 return NULL; 159 160 LIST_INIT(&evo->buffer.callbacks); 161 evo->buffer.refcnt = 1; 162 evo->buffer.last_with_datap = &evo->buffer.first; 163 164 evo->buffer.is_overlapped = 1; 165 evo->fd = fd; 166 167 return &evo->buffer; 168 } 169 170 int 171 evbuffer_launch_write_(struct evbuffer *buf, ev_ssize_t at_most, 172 struct event_overlapped *ol) 173 { 174 struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf); 175 int r = -1; 176 int i; 177 struct evbuffer_chain *chain; 178 DWORD bytesSent; 179 180 if (!buf) { 181 /* No buffer, or it isn't overlapped */ 182 return -1; 183 } 184 185 EVBUFFER_LOCK(buf); 186 EVUTIL_ASSERT(!buf_o->read_in_progress); 187 if (buf->freeze_start || buf_o->write_in_progress) 188 goto done; 189 if (!buf->total_len) { 190 /* Nothing to write */ 191 r = 0; 192 goto done; 193 } else if (at_most < 0 || (size_t)at_most > buf->total_len) { 194 at_most = buf->total_len; 195 } 196 evbuffer_freeze(buf, 1); 197 198 buf_o->first_pinned = NULL; 199 buf_o->n_buffers = 0; 200 memset(buf_o->buffers, 0, sizeof(buf_o->buffers)); 201 202 chain = buf_o->first_pinned = buf->first; 203 204 for (i=0; i < MAX_WSABUFS && chain; ++i, chain=chain->next) { 205 WSABUF *b = &buf_o->buffers[i]; 206 b->buf = (char*)( chain->buffer + chain->misalign ); 207 evbuffer_chain_pin_(chain, EVBUFFER_MEM_PINNED_W); 208 209 if ((size_t)at_most > chain->off) { 210 /* XXXX Cast is safe for now, since win32 has no 211 mmaped chains. But later, we need to have this 212 add more WSAbufs if chain->off is greater than 213 ULONG_MAX */ 214 b->len = (unsigned long)chain->off; 215 at_most -= chain->off; 216 } else { 217 b->len = (unsigned long)at_most; 218 ++i; 219 break; 220 } 221 } 222 223 buf_o->n_buffers = i; 224 evbuffer_incref_(buf); 225 if (WSASend(buf_o->fd, buf_o->buffers, i, &bytesSent, 0, 226 &ol->overlapped, NULL)) { 227 int error = WSAGetLastError(); 228 if (error != WSA_IO_PENDING) { 229 /* An actual error. */ 230 pin_release(buf_o, EVBUFFER_MEM_PINNED_W); 231 evbuffer_unfreeze(buf, 1); 232 evbuffer_free(buf); /* decref */ 233 goto done; 234 } 235 } 236 237 buf_o->write_in_progress = 1; 238 r = 0; 239 done: 240 EVBUFFER_UNLOCK(buf); 241 return r; 242 } 243 244 int 245 evbuffer_launch_read_(struct evbuffer *buf, size_t at_most, 246 struct event_overlapped *ol) 247 { 248 struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf); 249 int r = -1, i; 250 int nvecs; 251 int npin=0; 252 struct evbuffer_chain *chain=NULL, **chainp; 253 DWORD bytesRead; 254 DWORD flags = 0; 255 struct evbuffer_iovec vecs[MAX_WSABUFS]; 256 257 if (!buf_o) 258 return -1; 259 EVBUFFER_LOCK(buf); 260 EVUTIL_ASSERT(!buf_o->write_in_progress); 261 if (buf->freeze_end || buf_o->read_in_progress) 262 goto done; 263 264 buf_o->first_pinned = NULL; 265 buf_o->n_buffers = 0; 266 memset(buf_o->buffers, 0, sizeof(buf_o->buffers)); 267 268 if (evbuffer_expand_fast_(buf, at_most, MAX_WSABUFS) == -1) 269 goto done; 270 evbuffer_freeze(buf, 0); 271 272 nvecs = evbuffer_read_setup_vecs_(buf, at_most, 273 vecs, MAX_WSABUFS, &chainp, 1); 274 for (i=0;i<nvecs;++i) { 275 WSABUF_FROM_EVBUFFER_IOV( 276 &buf_o->buffers[i], 277 &vecs[i]); 278 } 279 280 buf_o->n_buffers = nvecs; 281 buf_o->first_pinned = chain = *chainp; 282 283 npin=0; 284 for ( ; chain; chain = chain->next) { 285 evbuffer_chain_pin_(chain, EVBUFFER_MEM_PINNED_R); 286 ++npin; 287 } 288 EVUTIL_ASSERT(npin == nvecs); 289 290 evbuffer_incref_(buf); 291 if (WSARecv(buf_o->fd, buf_o->buffers, nvecs, &bytesRead, &flags, 292 &ol->overlapped, NULL)) { 293 int error = WSAGetLastError(); 294 if (error != WSA_IO_PENDING) { 295 /* An actual error. */ 296 pin_release(buf_o, EVBUFFER_MEM_PINNED_R); 297 evbuffer_unfreeze(buf, 0); 298 evbuffer_free(buf); /* decref */ 299 goto done; 300 } 301 } 302 303 buf_o->read_in_progress = 1; 304 r = 0; 305 done: 306 EVBUFFER_UNLOCK(buf); 307 return r; 308 } 309 310 evutil_socket_t 311 evbuffer_overlapped_get_fd_(struct evbuffer *buf) 312 { 313 struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf); 314 return buf_o ? buf_o->fd : -1; 315 } 316 317 void 318 evbuffer_overlapped_set_fd_(struct evbuffer *buf, evutil_socket_t fd) 319 { 320 struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf); 321 EVBUFFER_LOCK(buf); 322 /* XXX is this right?, should it cancel current I/O operations? */ 323 if (buf_o) 324 buf_o->fd = fd; 325 EVBUFFER_UNLOCK(buf); 326 } 327
