1 | /* |
1 | /* |
2 | * libev epoll fd activity backend |
2 | * libev epoll fd activity backend |
3 | * |
3 | * |
4 | * Copyright (c) 2007,2008 Marc Alexander Lehmann <libev@schmorp.de> |
4 | * Copyright (c) 2007,2008,2009 Marc Alexander Lehmann <libev@schmorp.de> |
5 | * All rights reserved. |
5 | * All rights reserved. |
6 | * |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without modifica- |
7 | * Redistribution and use in source and binary forms, with or without modifica- |
8 | * tion, are permitted provided that the following conditions are met: |
8 | * tion, are permitted provided that the following conditions are met: |
9 | * |
9 | * |
… | |
… | |
68 | /* |
68 | /* |
69 | * we handle EPOLL_CTL_DEL by ignoring it here |
69 | * we handle EPOLL_CTL_DEL by ignoring it here |
70 | * on the assumption that the fd is gone anyways |
70 | * on the assumption that the fd is gone anyways |
71 | * if that is wrong, we have to handle the spurious |
71 | * if that is wrong, we have to handle the spurious |
72 | * event in epoll_poll. |
72 | * event in epoll_poll. |
73 | * the fd is later added, we try to ADD it, and, if that |
73 | * if the fd is added again, we try to ADD it, and, if that |
74 | * fails, we assume it still has the same eventmask. |
74 | * fails, we assume it still has the same eventmask. |
75 | */ |
75 | */ |
76 | if (!nev) |
76 | if (!nev) |
77 | return; |
77 | return; |
78 | |
78 | |
79 | oldmask = anfds [fd].emask; |
79 | oldmask = anfds [fd].emask; |
80 | anfds [fd].emask = nev; |
80 | anfds [fd].emask = nev; |
81 | |
81 | |
82 | /* store the generation counter in the upper 32 bits */ |
82 | /* store the generation counter in the upper 32 bits, the fd in the lower 32 bits */ |
83 | ev.data.u64 = (uint64_t)(uint32_t)fd | ((uint64_t)(uint32_t)++anfds [fd].egen << 32); |
83 | ev.data.u64 = (uint64_t)(uint32_t)fd |
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84 | | ((uint64_t)(uint32_t)++anfds [fd].egen << 32); |
84 | ev.events = (nev & EV_READ ? EPOLLIN : 0) |
85 | ev.events = (nev & EV_READ ? EPOLLIN : 0) |
85 | | (nev & EV_WRITE ? EPOLLOUT : 0); |
86 | | (nev & EV_WRITE ? EPOLLOUT : 0); |
86 | |
87 | |
87 | if (expect_true (!epoll_ctl (backend_fd, oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &ev))) |
88 | if (expect_true (!epoll_ctl (backend_fd, oev ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &ev))) |
88 | return; |
89 | return; |
… | |
… | |
116 | |
117 | |
117 | static void |
118 | static void |
118 | epoll_poll (EV_P_ ev_tstamp timeout) |
119 | epoll_poll (EV_P_ ev_tstamp timeout) |
119 | { |
120 | { |
120 | int i; |
121 | int i; |
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122 | int eventcnt; |
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123 | |
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124 | /* epoll wait times cannot be larger than (LONG_MAX - 999UL) / HZ msecs, which is below */ |
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125 | /* the default libev max wait time, however. */ |
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126 | EV_RELEASE_CB; |
121 | int eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, (int)ceil (timeout * 1000.)); |
127 | eventcnt = epoll_wait (backend_fd, epoll_events, epoll_eventmax, (int)ceil (timeout * 1000.)); |
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128 | EV_ACQUIRE_CB; |
122 | |
129 | |
123 | if (expect_false (eventcnt < 0)) |
130 | if (expect_false (eventcnt < 0)) |
124 | { |
131 | { |
125 | if (errno != EINTR) |
132 | if (errno != EINTR) |
126 | ev_syserr ("(libev) epoll_wait"); |
133 | ev_syserr ("(libev) epoll_wait"); |
… | |
… | |
152 | /* we received an event but are not interested in it, try mod or del */ |
159 | /* we received an event but are not interested in it, try mod or del */ |
153 | /* I don't think we ever need MOD, but let's handle it anyways */ |
160 | /* I don't think we ever need MOD, but let's handle it anyways */ |
154 | ev->events = (want & EV_READ ? EPOLLIN : 0) |
161 | ev->events = (want & EV_READ ? EPOLLIN : 0) |
155 | | (want & EV_WRITE ? EPOLLOUT : 0); |
162 | | (want & EV_WRITE ? EPOLLOUT : 0); |
156 | |
163 | |
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164 | /* pre-2.6.9 kernels require a non-null pointer with EPOLL_CTL_DEL, */ |
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165 | /* which is fortunately easy to do for us. */ |
157 | if (epoll_ctl (backend_fd, want ? EPOLL_CTL_MOD : EPOLL_CTL_DEL, fd, ev)) |
166 | if (epoll_ctl (backend_fd, want ? EPOLL_CTL_MOD : EPOLL_CTL_DEL, fd, ev)) |
158 | { |
167 | { |
159 | postfork = 1; /* an error occured, recreate kernel state */ |
168 | postfork = 1; /* an error occured, recreate kernel state */ |
160 | continue; |
169 | continue; |
161 | } |
170 | } |
… | |
… | |
174 | } |
183 | } |
175 | |
184 | |
176 | int inline_size |
185 | int inline_size |
177 | epoll_init (EV_P_ int flags) |
186 | epoll_init (EV_P_ int flags) |
178 | { |
187 | { |
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188 | #ifdef EPOLL_CLOEXEC |
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189 | backend_fd = epoll_create1 (EPOLL_CLOEXEC); |
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190 | |
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191 | if (backend_fd <= 0) |
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192 | #endif |
179 | backend_fd = epoll_create (256); |
193 | backend_fd = epoll_create (256); |
180 | |
194 | |
181 | if (backend_fd < 0) |
195 | if (backend_fd < 0) |
182 | return 0; |
196 | return 0; |
183 | |
197 | |
184 | fcntl (backend_fd, F_SETFD, FD_CLOEXEC); |
198 | fcntl (backend_fd, F_SETFD, FD_CLOEXEC); |