/* * Copyright (c) 2015 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* * input.c: Unix file input * * Copyright (c) 2008 Eliot Dresselhaus * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include <vlib/vlib.h> #include <vlib/unix/unix.h> #include <signal.h> /* FIXME autoconf */ #define HAVE_LINUX_EPOLL #ifdef HAVE_LINUX_EPOLL #include <sys/epoll.h> typedef struct { int epoll_fd; struct epoll_event *epoll_events; /* Statistics. */ u64 epoll_files_ready; u64 epoll_waits; } linux_epoll_main_t; static linux_epoll_main_t linux_epoll_main; static void linux_epoll_file_update (unix_file_t * f, unix_file_update_type_t update_type) { unix_main_t *um = &unix_main; linux_epoll_main_t *em = &linux_epoll_main; struct epoll_event e; memset (&e, 0, sizeof (e)); e.events = EPOLLIN; if (f->flags & UNIX_FILE_DATA_AVAILABLE_TO_WRITE) e.events |= EPOLLOUT; if (f->flags & UNIX_FILE_EVENT_EDGE_TRIGGERED) e.events |= EPOLLET; e.data.u32 = f - um->file_pool; if (epoll_ctl (em->epoll_fd, (update_type == UNIX_FILE_UPDATE_ADD ? EPOLL_CTL_ADD : (update_type == UNIX_FILE_UPDATE_MODIFY ? EPOLL_CTL_MOD : EPOLL_CTL_DEL)), f->file_descriptor, &e) < 0) clib_warning ("epoll_ctl"); } static uword linux_epoll_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { unix_main_t *um = &unix_main; linux_epoll_main_t *em = &linux_epoll_main; struct epoll_event *e; int n_fds_ready; { vlib_node_main_t *nm = &vm->node_main; u64 t = nm->cpu_time_next_process_ready; f64 timeout; int timeout_ms, max_timeout_ms = 10; f64 vector_rate = vlib_last_vectors_per_main_loop (vm); if (t == ~0ULL) { timeout = 10e-3; timeout_ms = max_timeout_ms; } else { timeout = (((i64) t - (i64) clib_cpu_time_now ()) * vm->clib_time.seconds_per_clock) /* subtract off some slop time */ - 50e-6; if (timeout < 1e3) { /* We have event happenning in less than 1 ms so don't allow epoll to wait */ timeout_ms = 0; } else { timeout_ms = timeout * 1e3; /* Must be between 1 and 10 ms. */ timeout_ms = clib_max (1, timeout_ms); timeout_ms = clib_min (max_timeout_ms, timeout_ms); } } /* If we still have input nodes polling (e.g. vnet packet generator) don't sleep. */ if (nm->input_node_counts_by_state[VLIB_NODE_STATE_POLLING] > 0) timeout_ms = 0; /* * When busy: don't wait & only epoll for input * every 1024 times through main loop. */ if (vector_rate > 1 || vm->api_queue_nonempty) { timeout_ms = 0; node->input_main_loops_per_call = 1024; } else /* We're not busy; go to sleep for a while. */ node->input_main_loops_per_call = 0; /* Allow any signal to wakeup our sleep. */ { static sigset_t unblock_all_signals; n_fds_ready = epoll_pwait (em->epoll_fd, em->epoll_events, vec_len (em->epoll_events), timeout_ms, &unblock_all_signals); /* This kludge is necessary to run over absurdly old kernels */ if (n_fds_ready < 0 && errno == ENOSYS) { n_fds_ready = epoll_wait (em->epoll_fd, em->epoll_events, vec_len (em->epoll_events), timeout_ms); } } } if (n_fds_ready < 0) { if (unix_error_is_fatal (errno)) vlib_panic_with_error (vm, clib_error_return_unix (0, "epoll_wait")); /* non fatal error (e.g. EINTR). */ return 0; } em->epoll_waits += 1; em->epoll_files_ready += n_fds_ready; for (e = em->epoll_events; e < em->epoll_events + n_fds_ready; e++) { u32 i = e->data.u32; unix_file_t *f = pool_elt_at_index (um->file_pool, i); clib_error_t *errors[4]; int n_errors = 0; if (PREDICT_TRUE (!(e->events & EPOLLERR))) { if (e->events & EPOLLIN) { errors[n_errors] = f->read_function (f); n_errors += errors[n_errors] != 0; } if (e->events & EPOLLOUT) { errors[n_errors] = f->write_function (f); n_errors += errors[n_errors] != 0; } } else { if (f->error_function) { errors[n_errors] = f->error_function (f); n_errors += errors[n_errors] != 0; } else close (f->file_descriptor); } ASSERT (n_errors < ARRAY_LEN (errors)); for (i = 0; i < n_errors; i++) { unix_save_error (um, errors[i]); } } return 0; } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (linux_epoll_input_node,static) = { .function = linux_epoll_input, .type = VLIB_NODE_TYPE_PRE_INPUT, .name = "unix-epoll-input", }; /* *INDENT-ON* */ clib_error_t * linux_epoll_input_init (vlib_main_t * vm) { linux_epoll_main_t *em = &linux_epoll_main; unix_main_t *um = &unix_main; /* Allocate some events. */ vec_resize (em->epoll_events, VLIB_FRAME_SIZE); em->epoll_fd = epoll_create (vec_len (em->epoll_events)); if (em->epoll_fd < 0) return clib_error_return_unix (0, "epoll_create"); um->file_update = linux_epoll_file_update; return 0; } VLIB_INIT_FUNCTION (linux_epoll_input_init); #endif /* HAVE_LINUX_EPOLL */ static clib_error_t * unix_input_init (vlib_main_t * vm) { return vlib_call_init_function (vm, linux_epoll_input_init); } VLIB_INIT_FUNCTION (unix_input_init); /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */