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00025 #include <config.h>
00026 #include "dbus-socket-set.h"
00027
00028 #include <dbus/dbus-internals.h>
00029 #include <dbus/dbus-sysdeps.h>
00030
00031 #ifndef __linux__
00032 # error This file is for Linux epoll(4)
00033 #endif
00034
00035 #include <errno.h>
00036 #include <fcntl.h>
00037 #include <sys/epoll.h>
00038 #include <unistd.h>
00039
00040 #ifndef DOXYGEN_SHOULD_SKIP_THIS
00041
00042 typedef struct {
00043 DBusSocketSet parent;
00044 int epfd;
00045 } DBusSocketSetEpoll;
00046
00047 static inline DBusSocketSetEpoll *
00048 socket_set_epoll_cast (DBusSocketSet *set)
00049 {
00050 _dbus_assert (set->cls == &_dbus_socket_set_epoll_class);
00051 return (DBusSocketSetEpoll *) set;
00052 }
00053
00054
00055 static void
00056 socket_set_epoll_free (DBusSocketSet *set)
00057 {
00058 DBusSocketSetEpoll *self = socket_set_epoll_cast (set);
00059
00060 if (self == NULL)
00061 return;
00062
00063 if (self->epfd != -1)
00064 close (self->epfd);
00065
00066 dbus_free (self);
00067 }
00068
00069 DBusSocketSet *
00070 _dbus_socket_set_epoll_new (void)
00071 {
00072 DBusSocketSetEpoll *self;
00073
00074 self = dbus_new0 (DBusSocketSetEpoll, 1);
00075
00076 if (self == NULL)
00077 return NULL;
00078
00079 self->parent.cls = &_dbus_socket_set_epoll_class;
00080
00081 self->epfd = epoll_create1 (EPOLL_CLOEXEC);
00082
00083 if (self->epfd == -1)
00084 {
00085 int flags;
00086
00087
00088
00089
00090 self->epfd = epoll_create (42);
00091
00092 flags = fcntl (self->epfd, F_GETFD, 0);
00093
00094 if (flags != -1)
00095 fcntl (self->epfd, F_SETFD, flags | FD_CLOEXEC);
00096 }
00097
00098 if (self->epfd == -1)
00099 {
00100 socket_set_epoll_free ((DBusSocketSet *) self);
00101 return NULL;
00102 }
00103
00104 return (DBusSocketSet *) self;
00105 }
00106
00107 static uint32_t
00108 watch_flags_to_epoll_events (unsigned int flags)
00109 {
00110 uint32_t events = 0;
00111
00112 if (flags & DBUS_WATCH_READABLE)
00113 events |= EPOLLIN;
00114 if (flags & DBUS_WATCH_WRITABLE)
00115 events |= EPOLLOUT;
00116
00117 return events;
00118 }
00119
00120 static unsigned int
00121 epoll_events_to_watch_flags (uint32_t events)
00122 {
00123 short flags = 0;
00124
00125 if (events & EPOLLIN)
00126 flags |= DBUS_WATCH_READABLE;
00127 if (events & EPOLLOUT)
00128 flags |= DBUS_WATCH_WRITABLE;
00129 if (events & EPOLLHUP)
00130 flags |= DBUS_WATCH_HANGUP;
00131 if (events & EPOLLERR)
00132 flags |= DBUS_WATCH_ERROR;
00133
00134 return flags;
00135 }
00136
00137 static dbus_bool_t
00138 socket_set_epoll_add (DBusSocketSet *set,
00139 int fd,
00140 unsigned int flags,
00141 dbus_bool_t enabled)
00142 {
00143 DBusSocketSetEpoll *self = socket_set_epoll_cast (set);
00144 struct epoll_event event;
00145 int err;
00146
00147 event.data.fd = fd;
00148
00149 if (enabled)
00150 {
00151 event.events = watch_flags_to_epoll_events (flags);
00152 }
00153 else
00154 {
00155
00156
00157 event.events = EPOLLET;
00158 }
00159
00160 if (epoll_ctl (self->epfd, EPOLL_CTL_ADD, fd, &event) == 0)
00161 return TRUE;
00162
00163
00164 err = errno;
00165 switch (err)
00166 {
00167 case ENOMEM:
00168 case ENOSPC:
00169
00170
00171 break;
00172
00173 case EBADF:
00174 _dbus_warn ("Bad fd %d\n", fd);
00175 break;
00176
00177 case EEXIST:
00178 _dbus_warn ("fd %d added and then added again\n", fd);
00179 break;
00180
00181 default:
00182 _dbus_warn ("Misc error when trying to watch fd %d: %s\n", fd,
00183 strerror (err));
00184 break;
00185 }
00186
00187 return FALSE;
00188 }
00189
00190 static void
00191 socket_set_epoll_enable (DBusSocketSet *set,
00192 int fd,
00193 unsigned int flags)
00194 {
00195 DBusSocketSetEpoll *self = socket_set_epoll_cast (set);
00196 struct epoll_event event;
00197 int err;
00198
00199 event.data.fd = fd;
00200 event.events = watch_flags_to_epoll_events (flags);
00201
00202 if (epoll_ctl (self->epfd, EPOLL_CTL_MOD, fd, &event) == 0)
00203 return;
00204
00205 err = errno;
00206
00207
00208
00209 switch (err)
00210 {
00211 case EBADF:
00212 _dbus_warn ("Bad fd %d\n", fd);
00213 break;
00214
00215 case ENOENT:
00216 _dbus_warn ("fd %d modified before it was added\n", fd);
00217 break;
00218
00219 case ENOMEM:
00220 _dbus_warn ("Insufficient memory to change watch for fd %d\n", fd);
00221 break;
00222
00223 default:
00224 _dbus_warn ("Misc error when trying to watch fd %d: %s\n", fd,
00225 strerror (err));
00226 break;
00227 }
00228 }
00229
00230 static void
00231 socket_set_epoll_disable (DBusSocketSet *set,
00232 int fd)
00233 {
00234 DBusSocketSetEpoll *self = socket_set_epoll_cast (set);
00235 struct epoll_event event;
00236 int err;
00237
00238
00239
00240
00241
00242
00243
00244
00245
00246
00247
00248
00249
00250
00251
00252
00253
00254 event.data.fd = fd;
00255 event.events = EPOLLET;
00256
00257 if (epoll_ctl (self->epfd, EPOLL_CTL_MOD, fd, &event) == 0)
00258 return;
00259
00260 err = errno;
00261 _dbus_warn ("Error when trying to watch fd %d: %s\n", fd,
00262 strerror (err));
00263 }
00264
00265 static void
00266 socket_set_epoll_remove (DBusSocketSet *set,
00267 int fd)
00268 {
00269 DBusSocketSetEpoll *self = socket_set_epoll_cast (set);
00270 int err;
00271
00272
00273 struct epoll_event dummy = { 0 };
00274
00275 if (epoll_ctl (self->epfd, EPOLL_CTL_DEL, fd, &dummy) == 0)
00276 return;
00277
00278 err = errno;
00279 _dbus_warn ("Error when trying to remove fd %d: %s\n", fd, strerror (err));
00280 }
00281
00282
00283
00284 #define N_STACK_DESCRIPTORS 64
00285
00286 static int
00287 socket_set_epoll_poll (DBusSocketSet *set,
00288 DBusSocketEvent *revents,
00289 int max_events,
00290 int timeout_ms)
00291 {
00292 DBusSocketSetEpoll *self = socket_set_epoll_cast (set);
00293 struct epoll_event events[N_STACK_DESCRIPTORS];
00294 int n_ready;
00295 int i;
00296
00297 _dbus_assert (max_events > 0);
00298
00299 n_ready = epoll_wait (self->epfd, events,
00300 MIN (_DBUS_N_ELEMENTS (events), max_events),
00301 timeout_ms);
00302
00303 if (n_ready <= 0)
00304 return n_ready;
00305
00306 for (i = 0; i < n_ready; i++)
00307 {
00308 revents[i].fd = events[i].data.fd;
00309 revents[i].flags = epoll_events_to_watch_flags (events[i].events);
00310 }
00311
00312 return n_ready;
00313 }
00314
00315 DBusSocketSetClass _dbus_socket_set_epoll_class = {
00316 socket_set_epoll_free,
00317 socket_set_epoll_add,
00318 socket_set_epoll_remove,
00319 socket_set_epoll_enable,
00320 socket_set_epoll_disable,
00321 socket_set_epoll_poll
00322 };
00323
00324 #ifdef TEST_BEHAVIOUR_OF_EPOLLET
00325
00326
00327
00328
00329
00330
00331
00332
00333
00334
00335 #include <sys/epoll.h>
00336
00337 #include <stdio.h>
00338
00339 int
00340 main (void)
00341 {
00342 struct epoll_event input;
00343 struct epoll_event output;
00344 int epfd = epoll_create1 (EPOLL_CLOEXEC);
00345 int fd = 0;
00346 int ret;
00347
00348 input.events = EPOLLHUP | EPOLLET;
00349 ret = epoll_ctl (epfd, EPOLL_CTL_ADD, fd, &input);
00350 printf ("ctl ADD: %d\n", ret);
00351
00352 ret = epoll_wait (epfd, &output, 1, -1);
00353 printf ("wait for HUP, edge-triggered: %d\n", ret);
00354
00355 ret = epoll_wait (epfd, &output, 1, 1);
00356 printf ("wait for HUP again: %d\n", ret);
00357
00358 input.events = EPOLLHUP;
00359 ret = epoll_ctl (epfd, EPOLL_CTL_MOD, fd, &input);
00360 printf ("ctl MOD: %d\n", ret);
00361
00362 ret = epoll_wait (epfd, &output, 1, -1);
00363 printf ("wait for HUP: %d\n", ret);
00364
00365 return 0;
00366 }
00367
00368 #endif
00369
00370 #endif