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Comparing libev/ev_epoll.c (file contents):
Revision 1.36 by root, Mon Oct 27 11:08:29 2008 UTC vs.
Revision 1.41 by root, Wed Oct 29 07:10:16 2008 UTC

… …
50 * limits the applicability over poll, so this is not a generic 50 * limits the applicability over poll, so this is not a generic
51 * poll replacement. 51 * poll replacement.
52 * 52 *
53 * lots of "weird code" and complication handling in this file is due 53 * lots of "weird code" and complication handling in this file is due
54 * to these design problems with epoll, as we try very hard to avoid 54 * to these design problems with epoll, as we try very hard to avoid
55 * epoll_ctl syscalls for common usage patterns. 55 * epoll_ctl syscalls for common usage patterns and handle the breakage
56 * ensuing from receiving events for closed and otherwise long gone
57 * file descriptors.
56 */ 58 */
57 59
58#include <sys/epoll.h> 60#include <sys/epoll.h>
59
60void inline_size
61unsigned_char_init (unsigned char *base, int count)
62{
63 /* memset might be overkill */
64 while (count--)
65 *base++ = 0;
66}
67 61
68static void 62static void
69epoll_modify (EV_P_ int fd, int oev, int nev) 63epoll_modify (EV_P_ int fd, int oev, int nev)
70{ 64{
71 struct epoll_event ev; 65 struct epoll_event ev;
… …
84 78
85 oldmask = anfds [fd].emask; 79 oldmask = anfds [fd].emask;
86 anfds [fd].emask = nev; 80 anfds [fd].emask = nev;
87 81
88 /* store the generation counter in the upper 32 bits */ 82 /* store the generation counter in the upper 32 bits */
89 ev.data.u64 = fd | ((uint64_t)++anfds [fd].egen << 32); 83 ev.data.u64 = (uint64_t)(uint32_t)fd | ((uint64_t)(uint32_t)++anfds [fd].egen << 32);
90 ev.events = (nev & EV_READ ? EPOLLIN : 0) 84 ev.events = (nev & EV_READ ? EPOLLIN : 0)
91 | (nev & EV_WRITE ? EPOLLOUT : 0); 85 | (nev & EV_WRITE ? EPOLLOUT : 0);
92 86
93 if (expect_true (!epoll_ctl (backend_fd, oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &ev))) 87 if (expect_true (!epoll_ctl (backend_fd, oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &ev)))
94 return; 88 return;
… …
127 int eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, (int)ceil (timeout * 1000.)); 121 int eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, (int)ceil (timeout * 1000.));
128 122
129 if (expect_false (eventcnt < 0)) 123 if (expect_false (eventcnt < 0))
130 { 124 {
131 if (errno != EINTR) 125 if (errno != EINTR)
132 syserr ("(libev) epoll_wait"); 126 ev_syserr ("(libev) epoll_wait");
133 127
134 return; 128 return;
135 } 129 }
136 130
137 for (i = 0; i < eventcnt; ++i) 131 for (i = 0; i < eventcnt; ++i)
138 { 132 {
139 struct epoll_event *ev = epoll_events + i; 133 struct epoll_event *ev = epoll_events + i;
140 134
141 int fd = (uint32_t)ev->data.u64; /* mask out the lower 32 bits */ 135 int fd = (uint32_t)ev->data.u64; /* mask out the lower 32 bits */
136 int want = anfds [fd].events;
142 int got = (ev->events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0) 137 int got = (ev->events & (EPOLLOUT | EPOLLERR | EPOLLHUP) ? EV_WRITE : 0)
143 | (ev->events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0); 138 | (ev->events & (EPOLLIN | EPOLLERR | EPOLLHUP) ? EV_READ : 0);
144 int want = anfds [fd].events;
145 139
146 if (anfds [fd].egen != (unsigned char)(ev->data.u64 >> 32)) 140 /* check for spurious notification */
147 /*fprintf (stderr, "spurious notification fd %d, %d vs %d\n", fd, (int)(ev->data.u64 >> 32), anfds [fd].egen);*/ 141 if (expect_false ((uint32_t)anfds [fd].egen != (uint32_t)(ev->data.u64 >> 32)))
142 {
143 /* recreate kernel state */
144 postfork = 1;
148 continue; 145 continue;
146 }
149 147
150 if (expect_false (got & ~want)) 148 if (expect_false (got & ~want))
151 { 149 {
152 anfds [fd].emask = want; 150 anfds [fd].emask = want;
153 151
154 /* we received an event but are not interested in it, try mod or del */ 152 /* we received an event but are not interested in it, try mod or del */
155 /* I don't think we ever need MOD, but let's handle it anyways */ 153 /* I don't think we ever need MOD, but let's handle it anyways */
156 ev->events = (want & EV_READ ? EPOLLIN : 0) 154 ev->events = (want & EV_READ ? EPOLLIN : 0)
157 | (want & EV_WRITE ? EPOLLOUT : 0); 155 | (want & EV_WRITE ? EPOLLOUT : 0);
158 156
159 epoll_ctl (backend_fd, want ? EPOLL_CTL_MOD : EPOLL_CTL_DEL, fd, ev); 157 if (epoll_ctl (backend_fd, want ? EPOLL_CTL_MOD : EPOLL_CTL_DEL, fd, ev))
158 {
159 postfork = 1; /* an error occured, recreate kernel state */
160 continue;
161 }
160 } 162 }
161 163
162 fd_event (EV_A_ fd, got); 164 fd_event (EV_A_ fd, got);
163 } 165 }
164 166
… …
183 185
184 backend_fudge = 0.; /* kernel sources seem to indicate this to be zero */ 186 backend_fudge = 0.; /* kernel sources seem to indicate this to be zero */
185 backend_modify = epoll_modify; 187 backend_modify = epoll_modify;
186 backend_poll = epoll_poll; 188 backend_poll = epoll_poll;
187 189
188 epoll_eventmax = 64; /* intiial number of events receivable per poll */ 190 epoll_eventmax = 64; /* initial number of events receivable per poll */
189 epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax); 191 epoll_events = (struct epoll_event *)ev_malloc (sizeof (struct epoll_event) * epoll_eventmax);
190 192
191 return EVBACKEND_EPOLL; 193 return EVBACKEND_EPOLL;
192} 194}
193 195
… …
201epoll_fork (EV_P) 203epoll_fork (EV_P)
202{ 204{
203 close (backend_fd); 205 close (backend_fd);
204 206
205 while ((backend_fd = epoll_create (256)) < 0) 207 while ((backend_fd = epoll_create (256)) < 0)
206 syserr ("(libev) epoll_create"); 208 ev_syserr ("(libev) epoll_create");
207 209
208 fcntl (backend_fd, F_SETFD, FD_CLOEXEC); 210 fcntl (backend_fd, F_SETFD, FD_CLOEXEC);
209 211
210 fd_rearm_all (EV_A); 212 fd_rearm_all (EV_A);
211} 213}

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