diff options
Diffstat (limited to 'src/vlib/unix/input.c')
| -rw-r--r-- | src/vlib/unix/input.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/src/vlib/unix/input.c b/src/vlib/unix/input.c new file mode 100644 index 00000000000..07096ed27dc --- /dev/null +++ b/src/vlib/unix/input.c @@ -0,0 +1,265 @@ +/* + * 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: + */ |