Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 1 | /* |
| 2 | * |
Jan Tattermusch | 7897ae9 | 2017-06-07 22:57:36 +0200 | [diff] [blame] | 3 | * Copyright 2017 gRPC authors. |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 4 | * |
Jan Tattermusch | 7897ae9 | 2017-06-07 22:57:36 +0200 | [diff] [blame] | 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain a copy of the License at |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 8 | * |
Jan Tattermusch | 7897ae9 | 2017-06-07 22:57:36 +0200 | [diff] [blame] | 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 10 | * |
Jan Tattermusch | 7897ae9 | 2017-06-07 22:57:36 +0200 | [diff] [blame] | 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 16 | * |
| 17 | */ |
| 18 | |
| 19 | #include "src/core/lib/iomgr/port.h" |
| 20 | |
| 21 | /* This polling engine is only relevant on linux kernels supporting epoll() */ |
| 22 | #ifdef GRPC_LINUX_EPOLL |
| 23 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 24 | #include "src/core/lib/iomgr/ev_epoll1_linux.h" |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 25 | |
| 26 | #include <assert.h> |
| 27 | #include <errno.h> |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 28 | #include <limits.h> |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 29 | #include <poll.h> |
| 30 | #include <pthread.h> |
| 31 | #include <string.h> |
| 32 | #include <sys/epoll.h> |
| 33 | #include <sys/socket.h> |
| 34 | #include <unistd.h> |
| 35 | |
| 36 | #include <grpc/support/alloc.h> |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 37 | #include <grpc/support/cpu.h> |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 38 | #include <grpc/support/log.h> |
| 39 | #include <grpc/support/string_util.h> |
| 40 | #include <grpc/support/tls.h> |
| 41 | #include <grpc/support/useful.h> |
| 42 | |
| 43 | #include "src/core/lib/iomgr/ev_posix.h" |
| 44 | #include "src/core/lib/iomgr/iomgr_internal.h" |
| 45 | #include "src/core/lib/iomgr/lockfree_event.h" |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 46 | #include "src/core/lib/iomgr/wakeup_fd_posix.h" |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 47 | #include "src/core/lib/profiling/timers.h" |
| 48 | #include "src/core/lib/support/block_annotate.h" |
| 49 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 50 | static grpc_wakeup_fd global_wakeup_fd; |
| 51 | static int g_epfd; |
| 52 | |
| 53 | /******************************************************************************* |
| 54 | * Fd Declarations |
| 55 | */ |
| 56 | |
| 57 | struct grpc_fd { |
| 58 | int fd; |
| 59 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 60 | gpr_atm read_closure; |
| 61 | gpr_atm write_closure; |
| 62 | |
| 63 | struct grpc_fd *freelist_next; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 64 | |
| 65 | /* The pollset that last noticed that the fd is readable. The actual type |
| 66 | * stored in this is (grpc_pollset *) */ |
| 67 | gpr_atm read_notifier_pollset; |
| 68 | |
| 69 | grpc_iomgr_object iomgr_object; |
| 70 | }; |
| 71 | |
| 72 | static void fd_global_init(void); |
| 73 | static void fd_global_shutdown(void); |
| 74 | |
| 75 | /******************************************************************************* |
| 76 | * Pollset Declarations |
| 77 | */ |
| 78 | |
Craig Tiller | 43bf259 | 2017-04-28 23:21:01 +0000 | [diff] [blame] | 79 | typedef enum { UNKICKED, KICKED, DESIGNATED_POLLER } kick_state; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 80 | |
| 81 | struct grpc_pollset_worker { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 82 | kick_state kick_state; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 83 | bool initialized_cv; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 84 | grpc_pollset_worker *next; |
| 85 | grpc_pollset_worker *prev; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 86 | gpr_cv cv; |
Craig Tiller | 50da5ec | 2017-05-01 13:51:14 -0700 | [diff] [blame] | 87 | grpc_closure_list schedule_on_end_work; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 88 | }; |
| 89 | |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 90 | #define MAX_NEIGHBOURHOODS 1024 |
| 91 | |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 92 | typedef struct pollset_neighbourhood { |
| 93 | gpr_mu mu; |
| 94 | grpc_pollset *active_root; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 95 | char pad[GPR_CACHELINE_SIZE]; |
| 96 | } pollset_neighbourhood; |
| 97 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 98 | struct grpc_pollset { |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 99 | gpr_mu mu; |
| 100 | pollset_neighbourhood *neighbourhood; |
Craig Tiller | e00d733 | 2017-05-01 15:43:51 +0000 | [diff] [blame] | 101 | bool reassigning_neighbourhood; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 102 | grpc_pollset_worker *root_worker; |
| 103 | bool kicked_without_poller; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 104 | bool seen_inactive; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 105 | bool shutting_down; /* Is the pollset shutting down ? */ |
| 106 | bool finish_shutdown_called; /* Is the 'finish_shutdown_locked()' called ? */ |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 107 | grpc_closure *shutdown_closure; /* Called after after shutdown is complete */ |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 108 | int begin_refs; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 109 | |
| 110 | grpc_pollset *next; |
| 111 | grpc_pollset *prev; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 112 | }; |
| 113 | |
| 114 | /******************************************************************************* |
| 115 | * Pollset-set Declarations |
| 116 | */ |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 117 | |
Craig Tiller | 61f96c1 | 2017-05-12 13:36:39 -0700 | [diff] [blame] | 118 | struct grpc_pollset_set { |
| 119 | char unused; |
| 120 | }; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 121 | |
| 122 | /******************************************************************************* |
| 123 | * Common helpers |
| 124 | */ |
| 125 | |
| 126 | static bool append_error(grpc_error **composite, grpc_error *error, |
| 127 | const char *desc) { |
| 128 | if (error == GRPC_ERROR_NONE) return true; |
| 129 | if (*composite == GRPC_ERROR_NONE) { |
| 130 | *composite = GRPC_ERROR_CREATE_FROM_COPIED_STRING(desc); |
| 131 | } |
| 132 | *composite = grpc_error_add_child(*composite, error); |
| 133 | return false; |
| 134 | } |
| 135 | |
| 136 | /******************************************************************************* |
| 137 | * Fd Definitions |
| 138 | */ |
| 139 | |
| 140 | /* We need to keep a freelist not because of any concerns of malloc performance |
| 141 | * but instead so that implementations with multiple threads in (for example) |
| 142 | * epoll_wait deal with the race between pollset removal and incoming poll |
| 143 | * notifications. |
| 144 | * |
| 145 | * The problem is that the poller ultimately holds a reference to this |
| 146 | * object, so it is very difficult to know when is safe to free it, at least |
| 147 | * without some expensive synchronization. |
| 148 | * |
| 149 | * If we keep the object freelisted, in the worst case losing this race just |
| 150 | * becomes a spurious read notification on a reused fd. |
| 151 | */ |
| 152 | |
| 153 | /* The alarm system needs to be able to wakeup 'some poller' sometimes |
| 154 | * (specifically when a new alarm needs to be triggered earlier than the next |
| 155 | * alarm 'epoch'). This wakeup_fd gives us something to alert on when such a |
| 156 | * case occurs. */ |
| 157 | |
| 158 | static grpc_fd *fd_freelist = NULL; |
| 159 | static gpr_mu fd_freelist_mu; |
| 160 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 161 | static void fd_global_init(void) { gpr_mu_init(&fd_freelist_mu); } |
| 162 | |
| 163 | static void fd_global_shutdown(void) { |
| 164 | gpr_mu_lock(&fd_freelist_mu); |
| 165 | gpr_mu_unlock(&fd_freelist_mu); |
| 166 | while (fd_freelist != NULL) { |
| 167 | grpc_fd *fd = fd_freelist; |
| 168 | fd_freelist = fd_freelist->freelist_next; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 169 | gpr_free(fd); |
| 170 | } |
| 171 | gpr_mu_destroy(&fd_freelist_mu); |
| 172 | } |
| 173 | |
| 174 | static grpc_fd *fd_create(int fd, const char *name) { |
| 175 | grpc_fd *new_fd = NULL; |
| 176 | |
| 177 | gpr_mu_lock(&fd_freelist_mu); |
| 178 | if (fd_freelist != NULL) { |
| 179 | new_fd = fd_freelist; |
| 180 | fd_freelist = fd_freelist->freelist_next; |
| 181 | } |
| 182 | gpr_mu_unlock(&fd_freelist_mu); |
| 183 | |
| 184 | if (new_fd == NULL) { |
| 185 | new_fd = gpr_malloc(sizeof(grpc_fd)); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 186 | } |
| 187 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 188 | new_fd->fd = fd; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 189 | grpc_lfev_init(&new_fd->read_closure); |
| 190 | grpc_lfev_init(&new_fd->write_closure); |
| 191 | gpr_atm_no_barrier_store(&new_fd->read_notifier_pollset, (gpr_atm)NULL); |
| 192 | |
| 193 | new_fd->freelist_next = NULL; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 194 | |
| 195 | char *fd_name; |
| 196 | gpr_asprintf(&fd_name, "%s fd=%d", name, fd); |
| 197 | grpc_iomgr_register_object(&new_fd->iomgr_object, fd_name); |
Noah Eisen | 264879f | 2017-06-20 17:14:47 -0700 | [diff] [blame] | 198 | #ifndef NDEBUG |
| 199 | if (GRPC_TRACER_ON(grpc_trace_fd_refcount)) { |
| 200 | gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, new_fd, fd_name); |
| 201 | } |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 202 | #endif |
| 203 | gpr_free(fd_name); |
Craig Tiller | 9ddb315 | 2017-04-27 21:32:56 +0000 | [diff] [blame] | 204 | |
| 205 | struct epoll_event ev = {.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET), |
| 206 | .data.ptr = new_fd}; |
| 207 | if (epoll_ctl(g_epfd, EPOLL_CTL_ADD, fd, &ev) != 0) { |
| 208 | gpr_log(GPR_ERROR, "epoll_ctl failed: %s", strerror(errno)); |
| 209 | } |
| 210 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 211 | return new_fd; |
| 212 | } |
| 213 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 214 | static int fd_wrapped_fd(grpc_fd *fd) { return fd->fd; } |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 215 | |
Craig Tiller | 9ddb315 | 2017-04-27 21:32:56 +0000 | [diff] [blame] | 216 | /* Might be called multiple times */ |
| 217 | static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_error *why) { |
| 218 | if (grpc_lfev_set_shutdown(exec_ctx, &fd->read_closure, |
| 219 | GRPC_ERROR_REF(why))) { |
| 220 | shutdown(fd->fd, SHUT_RDWR); |
| 221 | grpc_lfev_set_shutdown(exec_ctx, &fd->write_closure, GRPC_ERROR_REF(why)); |
| 222 | } |
| 223 | GRPC_ERROR_UNREF(why); |
| 224 | } |
| 225 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 226 | static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 227 | grpc_closure *on_done, int *release_fd, |
| 228 | const char *reason) { |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 229 | grpc_error *error = GRPC_ERROR_NONE; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 230 | |
Craig Tiller | 9ddb315 | 2017-04-27 21:32:56 +0000 | [diff] [blame] | 231 | if (!grpc_lfev_is_shutdown(&fd->read_closure)) { |
| 232 | fd_shutdown(exec_ctx, fd, GRPC_ERROR_CREATE_FROM_COPIED_STRING(reason)); |
| 233 | } |
| 234 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 235 | /* If release_fd is not NULL, we should be relinquishing control of the file |
| 236 | descriptor fd->fd (but we still own the grpc_fd structure). */ |
| 237 | if (release_fd != NULL) { |
| 238 | *release_fd = fd->fd; |
| 239 | } else { |
| 240 | close(fd->fd); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 241 | } |
| 242 | |
ncteisen | 969b46e | 2017-06-08 14:57:11 -0700 | [diff] [blame] | 243 | GRPC_CLOSURE_SCHED(exec_ctx, on_done, GRPC_ERROR_REF(error)); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 244 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 245 | grpc_iomgr_unregister_object(&fd->iomgr_object); |
| 246 | grpc_lfev_destroy(&fd->read_closure); |
| 247 | grpc_lfev_destroy(&fd->write_closure); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 248 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 249 | gpr_mu_lock(&fd_freelist_mu); |
| 250 | fd->freelist_next = fd_freelist; |
| 251 | fd_freelist = fd; |
| 252 | gpr_mu_unlock(&fd_freelist_mu); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 253 | } |
| 254 | |
| 255 | static grpc_pollset *fd_get_read_notifier_pollset(grpc_exec_ctx *exec_ctx, |
| 256 | grpc_fd *fd) { |
| 257 | gpr_atm notifier = gpr_atm_acq_load(&fd->read_notifier_pollset); |
| 258 | return (grpc_pollset *)notifier; |
| 259 | } |
| 260 | |
| 261 | static bool fd_is_shutdown(grpc_fd *fd) { |
| 262 | return grpc_lfev_is_shutdown(&fd->read_closure); |
| 263 | } |
| 264 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 265 | static void fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 266 | grpc_closure *closure) { |
| 267 | grpc_lfev_notify_on(exec_ctx, &fd->read_closure, closure); |
| 268 | } |
| 269 | |
| 270 | static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 271 | grpc_closure *closure) { |
| 272 | grpc_lfev_notify_on(exec_ctx, &fd->write_closure, closure); |
| 273 | } |
| 274 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 275 | static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 276 | grpc_pollset *notifier) { |
| 277 | grpc_lfev_set_ready(exec_ctx, &fd->read_closure); |
| 278 | |
| 279 | /* Note, it is possible that fd_become_readable might be called twice with |
| 280 | different 'notifier's when an fd becomes readable and it is in two epoll |
| 281 | sets (This can happen briefly during polling island merges). In such cases |
| 282 | it does not really matter which notifer is set as the read_notifier_pollset |
| 283 | (They would both point to the same polling island anyway) */ |
| 284 | /* Use release store to match with acquire load in fd_get_read_notifier */ |
| 285 | gpr_atm_rel_store(&fd->read_notifier_pollset, (gpr_atm)notifier); |
| 286 | } |
| 287 | |
| 288 | static void fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) { |
| 289 | grpc_lfev_set_ready(exec_ctx, &fd->write_closure); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 290 | } |
| 291 | |
| 292 | /******************************************************************************* |
| 293 | * Pollset Definitions |
| 294 | */ |
| 295 | |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 296 | GPR_TLS_DECL(g_current_thread_pollset); |
| 297 | GPR_TLS_DECL(g_current_thread_worker); |
| 298 | static gpr_atm g_active_poller; |
| 299 | static pollset_neighbourhood *g_neighbourhoods; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 300 | static size_t g_num_neighbourhoods; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 301 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 302 | /* Return true if first in list */ |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 303 | static bool worker_insert(grpc_pollset *pollset, grpc_pollset_worker *worker) { |
| 304 | if (pollset->root_worker == NULL) { |
| 305 | pollset->root_worker = worker; |
| 306 | worker->next = worker->prev = worker; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 307 | return true; |
| 308 | } else { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 309 | worker->next = pollset->root_worker; |
| 310 | worker->prev = worker->next->prev; |
| 311 | worker->next->prev = worker; |
| 312 | worker->prev->next = worker; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 313 | return false; |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | /* Return true if last in list */ |
| 318 | typedef enum { EMPTIED, NEW_ROOT, REMOVED } worker_remove_result; |
| 319 | |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 320 | static worker_remove_result worker_remove(grpc_pollset *pollset, |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 321 | grpc_pollset_worker *worker) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 322 | if (worker == pollset->root_worker) { |
| 323 | if (worker == worker->next) { |
| 324 | pollset->root_worker = NULL; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 325 | return EMPTIED; |
| 326 | } else { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 327 | pollset->root_worker = worker->next; |
| 328 | worker->prev->next = worker->next; |
| 329 | worker->next->prev = worker->prev; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 330 | return NEW_ROOT; |
| 331 | } |
| 332 | } else { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 333 | worker->prev->next = worker->next; |
| 334 | worker->next->prev = worker->prev; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 335 | return REMOVED; |
| 336 | } |
| 337 | } |
| 338 | |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 339 | static size_t choose_neighbourhood(void) { |
| 340 | return (size_t)gpr_cpu_current_cpu() % g_num_neighbourhoods; |
| 341 | } |
| 342 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 343 | static grpc_error *pollset_global_init(void) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 344 | gpr_tls_init(&g_current_thread_pollset); |
| 345 | gpr_tls_init(&g_current_thread_worker); |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 346 | gpr_atm_no_barrier_store(&g_active_poller, 0); |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 347 | global_wakeup_fd.read_fd = -1; |
| 348 | grpc_error *err = grpc_wakeup_fd_init(&global_wakeup_fd); |
| 349 | if (err != GRPC_ERROR_NONE) return err; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 350 | struct epoll_event ev = {.events = (uint32_t)(EPOLLIN | EPOLLET), |
| 351 | .data.ptr = &global_wakeup_fd}; |
| 352 | if (epoll_ctl(g_epfd, EPOLL_CTL_ADD, global_wakeup_fd.read_fd, &ev) != 0) { |
| 353 | return GRPC_OS_ERROR(errno, "epoll_ctl"); |
| 354 | } |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 355 | g_num_neighbourhoods = GPR_CLAMP(gpr_cpu_num_cores(), 1, MAX_NEIGHBOURHOODS); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 356 | g_neighbourhoods = |
| 357 | gpr_zalloc(sizeof(*g_neighbourhoods) * g_num_neighbourhoods); |
| 358 | for (size_t i = 0; i < g_num_neighbourhoods; i++) { |
| 359 | gpr_mu_init(&g_neighbourhoods[i].mu); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 360 | } |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 361 | return GRPC_ERROR_NONE; |
| 362 | } |
| 363 | |
| 364 | static void pollset_global_shutdown(void) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 365 | gpr_tls_destroy(&g_current_thread_pollset); |
| 366 | gpr_tls_destroy(&g_current_thread_worker); |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 367 | if (global_wakeup_fd.read_fd != -1) grpc_wakeup_fd_destroy(&global_wakeup_fd); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 368 | for (size_t i = 0; i < g_num_neighbourhoods; i++) { |
| 369 | gpr_mu_destroy(&g_neighbourhoods[i].mu); |
| 370 | } |
| 371 | gpr_free(g_neighbourhoods); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 372 | } |
| 373 | |
| 374 | static void pollset_init(grpc_pollset *pollset, gpr_mu **mu) { |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 375 | gpr_mu_init(&pollset->mu); |
| 376 | *mu = &pollset->mu; |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 377 | pollset->neighbourhood = &g_neighbourhoods[choose_neighbourhood()]; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 378 | pollset->seen_inactive = true; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 379 | } |
| 380 | |
Craig Tiller | c610985 | 2017-05-01 14:26:49 -0700 | [diff] [blame] | 381 | static void pollset_destroy(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) { |
Craig Tiller | e00d733 | 2017-05-01 15:43:51 +0000 | [diff] [blame] | 382 | gpr_mu_lock(&pollset->mu); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 383 | if (!pollset->seen_inactive) { |
Craig Tiller | e00d733 | 2017-05-01 15:43:51 +0000 | [diff] [blame] | 384 | pollset_neighbourhood *neighbourhood = pollset->neighbourhood; |
| 385 | gpr_mu_unlock(&pollset->mu); |
Craig Tiller | a95bacf | 2017-05-01 12:51:24 -0700 | [diff] [blame] | 386 | retry_lock_neighbourhood: |
Craig Tiller | e00d733 | 2017-05-01 15:43:51 +0000 | [diff] [blame] | 387 | gpr_mu_lock(&neighbourhood->mu); |
| 388 | gpr_mu_lock(&pollset->mu); |
| 389 | if (!pollset->seen_inactive) { |
| 390 | if (pollset->neighbourhood != neighbourhood) { |
| 391 | gpr_mu_unlock(&neighbourhood->mu); |
| 392 | neighbourhood = pollset->neighbourhood; |
| 393 | gpr_mu_unlock(&pollset->mu); |
| 394 | goto retry_lock_neighbourhood; |
| 395 | } |
| 396 | pollset->prev->next = pollset->next; |
| 397 | pollset->next->prev = pollset->prev; |
| 398 | if (pollset == pollset->neighbourhood->active_root) { |
| 399 | pollset->neighbourhood->active_root = |
| 400 | pollset->next == pollset ? NULL : pollset->next; |
| 401 | } |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 402 | } |
| 403 | gpr_mu_unlock(&pollset->neighbourhood->mu); |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 404 | } |
Craig Tiller | e00d733 | 2017-05-01 15:43:51 +0000 | [diff] [blame] | 405 | gpr_mu_unlock(&pollset->mu); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 406 | gpr_mu_destroy(&pollset->mu); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 407 | } |
| 408 | |
| 409 | static grpc_error *pollset_kick_all(grpc_pollset *pollset) { |
| 410 | grpc_error *error = GRPC_ERROR_NONE; |
| 411 | if (pollset->root_worker != NULL) { |
| 412 | grpc_pollset_worker *worker = pollset->root_worker; |
| 413 | do { |
| 414 | if (worker->initialized_cv) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 415 | worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 416 | gpr_cv_signal(&worker->cv); |
| 417 | } else { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 418 | worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 419 | append_error(&error, grpc_wakeup_fd_wakeup(&global_wakeup_fd), |
| 420 | "pollset_shutdown"); |
| 421 | } |
| 422 | |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 423 | worker = worker->next; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 424 | } while (worker != pollset->root_worker); |
| 425 | } |
| 426 | return error; |
| 427 | } |
| 428 | |
| 429 | static void pollset_maybe_finish_shutdown(grpc_exec_ctx *exec_ctx, |
| 430 | grpc_pollset *pollset) { |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 431 | if (pollset->shutdown_closure != NULL && pollset->root_worker == NULL && |
| 432 | pollset->begin_refs == 0) { |
ncteisen | 969b46e | 2017-06-08 14:57:11 -0700 | [diff] [blame] | 433 | GRPC_CLOSURE_SCHED(exec_ctx, pollset->shutdown_closure, GRPC_ERROR_NONE); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 434 | pollset->shutdown_closure = NULL; |
| 435 | } |
| 436 | } |
| 437 | |
| 438 | static void pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 439 | grpc_closure *closure) { |
| 440 | GPR_ASSERT(pollset->shutdown_closure == NULL); |
| 441 | pollset->shutdown_closure = closure; |
| 442 | GRPC_LOG_IF_ERROR("pollset_shutdown", pollset_kick_all(pollset)); |
| 443 | pollset_maybe_finish_shutdown(exec_ctx, pollset); |
| 444 | } |
| 445 | |
Craig Tiller | a95bacf | 2017-05-01 12:51:24 -0700 | [diff] [blame] | 446 | #define MAX_EPOLL_EVENTS 100 |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 447 | |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 448 | static int poll_deadline_to_millis_timeout(grpc_exec_ctx *exec_ctx, |
| 449 | grpc_millis millis) { |
| 450 | if (millis == GRPC_MILLIS_INF_FUTURE) return -1; |
| 451 | grpc_millis delta = millis - grpc_exec_ctx_now(exec_ctx); |
| 452 | if (delta > INT_MAX) |
| 453 | return INT_MAX; |
| 454 | else if (delta < 0) |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 455 | return 0; |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 456 | else |
| 457 | return (int)delta; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 458 | } |
| 459 | |
| 460 | static grpc_error *pollset_epoll(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 461 | grpc_millis deadline) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 462 | struct epoll_event events[MAX_EPOLL_EVENTS]; |
| 463 | static const char *err_desc = "pollset_poll"; |
| 464 | |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 465 | int timeout = poll_deadline_to_millis_timeout(exec_ctx, deadline); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 466 | |
| 467 | if (timeout != 0) { |
| 468 | GRPC_SCHEDULING_START_BLOCKING_REGION; |
| 469 | } |
| 470 | int r; |
| 471 | do { |
| 472 | r = epoll_wait(g_epfd, events, MAX_EPOLL_EVENTS, timeout); |
| 473 | } while (r < 0 && errno == EINTR); |
| 474 | if (timeout != 0) { |
Craig Tiller | 781e91a | 2017-07-17 16:21:00 -0700 | [diff] [blame] | 475 | GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX(exec_ctx); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 476 | } |
| 477 | |
| 478 | if (r < 0) return GRPC_OS_ERROR(errno, "epoll_wait"); |
| 479 | |
| 480 | grpc_error *error = GRPC_ERROR_NONE; |
| 481 | for (int i = 0; i < r; i++) { |
| 482 | void *data_ptr = events[i].data.ptr; |
| 483 | if (data_ptr == &global_wakeup_fd) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 484 | append_error(&error, grpc_wakeup_fd_consume_wakeup(&global_wakeup_fd), |
| 485 | err_desc); |
| 486 | } else { |
| 487 | grpc_fd *fd = (grpc_fd *)(data_ptr); |
| 488 | bool cancel = (events[i].events & (EPOLLERR | EPOLLHUP)) != 0; |
| 489 | bool read_ev = (events[i].events & (EPOLLIN | EPOLLPRI)) != 0; |
| 490 | bool write_ev = (events[i].events & EPOLLOUT) != 0; |
| 491 | if (read_ev || cancel) { |
| 492 | fd_become_readable(exec_ctx, fd, pollset); |
| 493 | } |
| 494 | if (write_ev || cancel) { |
| 495 | fd_become_writable(exec_ctx, fd); |
| 496 | } |
| 497 | } |
| 498 | } |
| 499 | |
| 500 | return error; |
| 501 | } |
| 502 | |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 503 | static bool begin_worker(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 504 | grpc_pollset_worker *worker, |
| 505 | grpc_pollset_worker **worker_hdl, |
| 506 | grpc_millis deadline) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 507 | if (worker_hdl != NULL) *worker_hdl = worker; |
| 508 | worker->initialized_cv = false; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 509 | worker->kick_state = UNKICKED; |
Craig Tiller | 50da5ec | 2017-05-01 13:51:14 -0700 | [diff] [blame] | 510 | worker->schedule_on_end_work = (grpc_closure_list)GRPC_CLOSURE_LIST_INIT; |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 511 | pollset->begin_refs++; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 512 | |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 513 | if (pollset->seen_inactive) { |
| 514 | // pollset has been observed to be inactive, we need to move back to the |
| 515 | // active list |
Craig Tiller | e00d733 | 2017-05-01 15:43:51 +0000 | [diff] [blame] | 516 | bool is_reassigning = false; |
| 517 | if (!pollset->reassigning_neighbourhood) { |
| 518 | is_reassigning = true; |
| 519 | pollset->reassigning_neighbourhood = true; |
| 520 | pollset->neighbourhood = &g_neighbourhoods[choose_neighbourhood()]; |
| 521 | } |
| 522 | pollset_neighbourhood *neighbourhood = pollset->neighbourhood; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 523 | gpr_mu_unlock(&pollset->mu); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 524 | // pollset unlocked: state may change (even worker->kick_state) |
| 525 | retry_lock_neighbourhood: |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 526 | gpr_mu_lock(&neighbourhood->mu); |
| 527 | gpr_mu_lock(&pollset->mu); |
| 528 | if (pollset->seen_inactive) { |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 529 | if (neighbourhood != pollset->neighbourhood) { |
| 530 | gpr_mu_unlock(&neighbourhood->mu); |
| 531 | neighbourhood = pollset->neighbourhood; |
| 532 | gpr_mu_unlock(&pollset->mu); |
| 533 | goto retry_lock_neighbourhood; |
| 534 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 535 | pollset->seen_inactive = false; |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 536 | if (neighbourhood->active_root == NULL) { |
| 537 | neighbourhood->active_root = pollset->next = pollset->prev = pollset; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 538 | if (gpr_atm_no_barrier_cas(&g_active_poller, 0, (gpr_atm)worker)) { |
Craig Tiller | 43bf259 | 2017-04-28 23:21:01 +0000 | [diff] [blame] | 539 | worker->kick_state = DESIGNATED_POLLER; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 540 | } |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 541 | } else { |
| 542 | pollset->next = neighbourhood->active_root; |
| 543 | pollset->prev = pollset->next->prev; |
| 544 | pollset->next->prev = pollset->prev->next = pollset; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 545 | } |
| 546 | } |
Craig Tiller | e00d733 | 2017-05-01 15:43:51 +0000 | [diff] [blame] | 547 | if (is_reassigning) { |
| 548 | GPR_ASSERT(pollset->reassigning_neighbourhood); |
| 549 | pollset->reassigning_neighbourhood = false; |
| 550 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 551 | gpr_mu_unlock(&neighbourhood->mu); |
| 552 | } |
| 553 | worker_insert(pollset, worker); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 554 | pollset->begin_refs--; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 555 | if (worker->kick_state == UNKICKED) { |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 556 | GPR_ASSERT(gpr_atm_no_barrier_load(&g_active_poller) != (gpr_atm)worker); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 557 | worker->initialized_cv = true; |
| 558 | gpr_cv_init(&worker->cv); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 559 | while (worker->kick_state == UNKICKED && |
| 560 | pollset->shutdown_closure == NULL) { |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 561 | if (gpr_cv_wait(&worker->cv, &pollset->mu, |
| 562 | grpc_millis_to_timespec(deadline, GPR_CLOCK_REALTIME)) && |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 563 | worker->kick_state == UNKICKED) { |
| 564 | worker->kick_state = KICKED; |
| 565 | } |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 566 | } |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 567 | grpc_exec_ctx_invalidate_now(exec_ctx); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 568 | } |
| 569 | |
Craig Tiller | 43bf259 | 2017-04-28 23:21:01 +0000 | [diff] [blame] | 570 | return worker->kick_state == DESIGNATED_POLLER && |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 571 | pollset->shutdown_closure == NULL; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 572 | } |
| 573 | |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 574 | static bool check_neighbourhood_for_available_poller( |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 575 | pollset_neighbourhood *neighbourhood) { |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 576 | bool found_worker = false; |
| 577 | do { |
| 578 | grpc_pollset *inspect = neighbourhood->active_root; |
| 579 | if (inspect == NULL) { |
| 580 | break; |
| 581 | } |
| 582 | gpr_mu_lock(&inspect->mu); |
| 583 | GPR_ASSERT(!inspect->seen_inactive); |
| 584 | grpc_pollset_worker *inspect_worker = inspect->root_worker; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 585 | if (inspect_worker != NULL) { |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 586 | do { |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 587 | switch (inspect_worker->kick_state) { |
| 588 | case UNKICKED: |
| 589 | if (gpr_atm_no_barrier_cas(&g_active_poller, 0, |
| 590 | (gpr_atm)inspect_worker)) { |
| 591 | inspect_worker->kick_state = DESIGNATED_POLLER; |
| 592 | if (inspect_worker->initialized_cv) { |
| 593 | gpr_cv_signal(&inspect_worker->cv); |
| 594 | } |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 595 | } |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 596 | // even if we didn't win the cas, there's a worker, we can stop |
| 597 | found_worker = true; |
| 598 | break; |
| 599 | case KICKED: |
| 600 | break; |
| 601 | case DESIGNATED_POLLER: |
| 602 | found_worker = true; // ok, so someone else found the worker, but |
| 603 | // we'll accept that |
| 604 | break; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 605 | } |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 606 | inspect_worker = inspect_worker->next; |
| 607 | } while (inspect_worker != inspect->root_worker); |
| 608 | } |
| 609 | if (!found_worker) { |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 610 | inspect->seen_inactive = true; |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 611 | if (inspect == neighbourhood->active_root) { |
Craig Tiller | a95bacf | 2017-05-01 12:51:24 -0700 | [diff] [blame] | 612 | neighbourhood->active_root = |
| 613 | inspect->next == inspect ? NULL : inspect->next; |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 614 | } |
| 615 | inspect->next->prev = inspect->prev; |
| 616 | inspect->prev->next = inspect->next; |
Craig Tiller | e00d733 | 2017-05-01 15:43:51 +0000 | [diff] [blame] | 617 | inspect->next = inspect->prev = NULL; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 618 | } |
| 619 | gpr_mu_unlock(&inspect->mu); |
| 620 | } while (!found_worker); |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 621 | return found_worker; |
| 622 | } |
| 623 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 624 | static void end_worker(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 625 | grpc_pollset_worker *worker, |
| 626 | grpc_pollset_worker **worker_hdl) { |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 627 | if (worker_hdl != NULL) *worker_hdl = NULL; |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 628 | worker->kick_state = KICKED; |
Craig Tiller | 50da5ec | 2017-05-01 13:51:14 -0700 | [diff] [blame] | 629 | grpc_closure_list_move(&worker->schedule_on_end_work, |
| 630 | &exec_ctx->closure_list); |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 631 | if (gpr_atm_no_barrier_load(&g_active_poller) == (gpr_atm)worker) { |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 632 | if (worker->next != worker && worker->next->kick_state == UNKICKED) { |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 633 | GPR_ASSERT(worker->next->initialized_cv); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 634 | gpr_atm_no_barrier_store(&g_active_poller, (gpr_atm)worker->next); |
Craig Tiller | 43bf259 | 2017-04-28 23:21:01 +0000 | [diff] [blame] | 635 | worker->next->kick_state = DESIGNATED_POLLER; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 636 | gpr_cv_signal(&worker->next->cv); |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 637 | if (grpc_exec_ctx_has_work(exec_ctx)) { |
| 638 | gpr_mu_unlock(&pollset->mu); |
| 639 | grpc_exec_ctx_flush(exec_ctx); |
| 640 | gpr_mu_lock(&pollset->mu); |
| 641 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 642 | } else { |
| 643 | gpr_atm_no_barrier_store(&g_active_poller, 0); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 644 | gpr_mu_unlock(&pollset->mu); |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 645 | size_t poller_neighbourhood_idx = |
| 646 | (size_t)(pollset->neighbourhood - g_neighbourhoods); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 647 | bool found_worker = false; |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 648 | bool scan_state[MAX_NEIGHBOURHOODS]; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 649 | for (size_t i = 0; !found_worker && i < g_num_neighbourhoods; i++) { |
| 650 | pollset_neighbourhood *neighbourhood = |
| 651 | &g_neighbourhoods[(poller_neighbourhood_idx + i) % |
| 652 | g_num_neighbourhoods]; |
| 653 | if (gpr_mu_trylock(&neighbourhood->mu)) { |
| 654 | found_worker = |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 655 | check_neighbourhood_for_available_poller(neighbourhood); |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 656 | gpr_mu_unlock(&neighbourhood->mu); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 657 | scan_state[i] = true; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 658 | } else { |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 659 | scan_state[i] = false; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 660 | } |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 661 | } |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 662 | for (size_t i = 0; !found_worker && i < g_num_neighbourhoods; i++) { |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 663 | if (scan_state[i]) continue; |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 664 | pollset_neighbourhood *neighbourhood = |
| 665 | &g_neighbourhoods[(poller_neighbourhood_idx + i) % |
| 666 | g_num_neighbourhoods]; |
| 667 | gpr_mu_lock(&neighbourhood->mu); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame] | 668 | found_worker = check_neighbourhood_for_available_poller(neighbourhood); |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 669 | gpr_mu_unlock(&neighbourhood->mu); |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 670 | } |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 671 | grpc_exec_ctx_flush(exec_ctx); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 672 | gpr_mu_lock(&pollset->mu); |
| 673 | } |
Craig Tiller | 50da5ec | 2017-05-01 13:51:14 -0700 | [diff] [blame] | 674 | } else if (grpc_exec_ctx_has_work(exec_ctx)) { |
| 675 | gpr_mu_unlock(&pollset->mu); |
| 676 | grpc_exec_ctx_flush(exec_ctx); |
| 677 | gpr_mu_lock(&pollset->mu); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 678 | } |
| 679 | if (worker->initialized_cv) { |
| 680 | gpr_cv_destroy(&worker->cv); |
| 681 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 682 | if (EMPTIED == worker_remove(pollset, worker)) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 683 | pollset_maybe_finish_shutdown(exec_ctx, pollset); |
| 684 | } |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 685 | GPR_ASSERT(gpr_atm_no_barrier_load(&g_active_poller) != (gpr_atm)worker); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 686 | } |
| 687 | |
| 688 | /* pollset->po.mu lock must be held by the caller before calling this. |
| 689 | The function pollset_work() may temporarily release the lock (pollset->po.mu) |
| 690 | during the course of its execution but it will always re-acquire the lock and |
| 691 | ensure that it is held by the time the function returns */ |
| 692 | static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 693 | grpc_pollset_worker **worker_hdl, |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 694 | grpc_millis deadline) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 695 | grpc_pollset_worker worker; |
| 696 | grpc_error *error = GRPC_ERROR_NONE; |
| 697 | static const char *err_desc = "pollset_work"; |
| 698 | if (pollset->kicked_without_poller) { |
| 699 | pollset->kicked_without_poller = false; |
| 700 | return GRPC_ERROR_NONE; |
| 701 | } |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 702 | gpr_tls_set(&g_current_thread_pollset, (intptr_t)pollset); |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 703 | if (begin_worker(exec_ctx, pollset, &worker, worker_hdl, deadline)) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 704 | gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker); |
| 705 | GPR_ASSERT(!pollset->shutdown_closure); |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 706 | GPR_ASSERT(!pollset->seen_inactive); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 707 | gpr_mu_unlock(&pollset->mu); |
Craig Tiller | 2039779 | 2017-07-18 11:35:27 -0700 | [diff] [blame^] | 708 | append_error(&error, pollset_epoll(exec_ctx, pollset, deadline), err_desc); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 709 | gpr_mu_lock(&pollset->mu); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 710 | gpr_tls_set(&g_current_thread_worker, 0); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 711 | } |
| 712 | end_worker(exec_ctx, pollset, &worker, worker_hdl); |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 713 | gpr_tls_set(&g_current_thread_pollset, 0); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 714 | return error; |
| 715 | } |
| 716 | |
| 717 | static grpc_error *pollset_kick(grpc_pollset *pollset, |
| 718 | grpc_pollset_worker *specific_worker) { |
| 719 | if (specific_worker == NULL) { |
| 720 | if (gpr_tls_get(&g_current_thread_pollset) != (intptr_t)pollset) { |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 721 | grpc_pollset_worker *root_worker = pollset->root_worker; |
| 722 | if (root_worker == NULL) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 723 | pollset->kicked_without_poller = true; |
| 724 | return GRPC_ERROR_NONE; |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 725 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 726 | grpc_pollset_worker *next_worker = root_worker->next; |
| 727 | if (root_worker == next_worker && |
| 728 | root_worker == (grpc_pollset_worker *)gpr_atm_no_barrier_load( |
| 729 | &g_active_poller)) { |
| 730 | root_worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 731 | return grpc_wakeup_fd_wakeup(&global_wakeup_fd); |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 732 | } else if (next_worker->kick_state == UNKICKED) { |
| 733 | GPR_ASSERT(next_worker->initialized_cv); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 734 | next_worker->kick_state = KICKED; |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 735 | gpr_cv_signal(&next_worker->cv); |
| 736 | return GRPC_ERROR_NONE; |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 737 | } else { |
| 738 | return GRPC_ERROR_NONE; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 739 | } |
| 740 | } else { |
| 741 | return GRPC_ERROR_NONE; |
| 742 | } |
Craig Tiller | 43bf259 | 2017-04-28 23:21:01 +0000 | [diff] [blame] | 743 | } else if (specific_worker->kick_state == KICKED) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 744 | return GRPC_ERROR_NONE; |
| 745 | } else if (gpr_tls_get(&g_current_thread_worker) == |
| 746 | (intptr_t)specific_worker) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 747 | specific_worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 748 | return GRPC_ERROR_NONE; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 749 | } else if (specific_worker == |
| 750 | (grpc_pollset_worker *)gpr_atm_no_barrier_load(&g_active_poller)) { |
| 751 | specific_worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 752 | return grpc_wakeup_fd_wakeup(&global_wakeup_fd); |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 753 | } else if (specific_worker->initialized_cv) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 754 | specific_worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 755 | gpr_cv_signal(&specific_worker->cv); |
| 756 | return GRPC_ERROR_NONE; |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 757 | } else { |
| 758 | specific_worker->kick_state = KICKED; |
| 759 | return GRPC_ERROR_NONE; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 760 | } |
| 761 | } |
| 762 | |
| 763 | static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 764 | grpc_fd *fd) {} |
| 765 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 766 | /******************************************************************************* |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 767 | * Pollset-set Definitions |
| 768 | */ |
| 769 | |
| 770 | static grpc_pollset_set *pollset_set_create(void) { |
| 771 | return (grpc_pollset_set *)((intptr_t)0xdeafbeef); |
| 772 | } |
| 773 | |
| 774 | static void pollset_set_destroy(grpc_exec_ctx *exec_ctx, |
| 775 | grpc_pollset_set *pss) {} |
| 776 | |
| 777 | static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset_set *pss, |
| 778 | grpc_fd *fd) {} |
| 779 | |
| 780 | static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx, grpc_pollset_set *pss, |
| 781 | grpc_fd *fd) {} |
| 782 | |
| 783 | static void pollset_set_add_pollset(grpc_exec_ctx *exec_ctx, |
| 784 | grpc_pollset_set *pss, grpc_pollset *ps) {} |
| 785 | |
| 786 | static void pollset_set_del_pollset(grpc_exec_ctx *exec_ctx, |
| 787 | grpc_pollset_set *pss, grpc_pollset *ps) {} |
| 788 | |
| 789 | static void pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx, |
| 790 | grpc_pollset_set *bag, |
| 791 | grpc_pollset_set *item) {} |
| 792 | |
| 793 | static void pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx, |
| 794 | grpc_pollset_set *bag, |
| 795 | grpc_pollset_set *item) {} |
| 796 | |
| 797 | /******************************************************************************* |
| 798 | * Event engine binding |
| 799 | */ |
| 800 | |
| 801 | static void shutdown_engine(void) { |
| 802 | fd_global_shutdown(); |
| 803 | pollset_global_shutdown(); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 804 | } |
| 805 | |
| 806 | static const grpc_event_engine_vtable vtable = { |
| 807 | .pollset_size = sizeof(grpc_pollset), |
| 808 | |
| 809 | .fd_create = fd_create, |
| 810 | .fd_wrapped_fd = fd_wrapped_fd, |
| 811 | .fd_orphan = fd_orphan, |
| 812 | .fd_shutdown = fd_shutdown, |
| 813 | .fd_is_shutdown = fd_is_shutdown, |
| 814 | .fd_notify_on_read = fd_notify_on_read, |
| 815 | .fd_notify_on_write = fd_notify_on_write, |
| 816 | .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset, |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 817 | |
| 818 | .pollset_init = pollset_init, |
| 819 | .pollset_shutdown = pollset_shutdown, |
| 820 | .pollset_destroy = pollset_destroy, |
| 821 | .pollset_work = pollset_work, |
| 822 | .pollset_kick = pollset_kick, |
| 823 | .pollset_add_fd = pollset_add_fd, |
| 824 | |
| 825 | .pollset_set_create = pollset_set_create, |
| 826 | .pollset_set_destroy = pollset_set_destroy, |
| 827 | .pollset_set_add_pollset = pollset_set_add_pollset, |
| 828 | .pollset_set_del_pollset = pollset_set_del_pollset, |
| 829 | .pollset_set_add_pollset_set = pollset_set_add_pollset_set, |
| 830 | .pollset_set_del_pollset_set = pollset_set_del_pollset_set, |
| 831 | .pollset_set_add_fd = pollset_set_add_fd, |
| 832 | .pollset_set_del_fd = pollset_set_del_fd, |
| 833 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 834 | .shutdown_engine = shutdown_engine, |
| 835 | }; |
| 836 | |
| 837 | /* It is possible that GLIBC has epoll but the underlying kernel doesn't. |
| 838 | * Create a dummy epoll_fd to make sure epoll support is available */ |
Craig Tiller | 6f0af49 | 2017-04-27 19:26:16 +0000 | [diff] [blame] | 839 | const grpc_event_engine_vtable *grpc_init_epoll1_linux(bool explicit_request) { |
Craig Tiller | 924353a | 2017-05-05 17:36:31 +0000 | [diff] [blame] | 840 | /* TODO(ctiller): temporary, until this stabilizes */ |
| 841 | if (!explicit_request) return NULL; |
| 842 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 843 | if (!grpc_has_wakeup_fd()) { |
| 844 | return NULL; |
| 845 | } |
| 846 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 847 | g_epfd = epoll_create1(EPOLL_CLOEXEC); |
| 848 | if (g_epfd < 0) { |
| 849 | gpr_log(GPR_ERROR, "epoll unavailable"); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 850 | return NULL; |
| 851 | } |
| 852 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 853 | fd_global_init(); |
| 854 | |
| 855 | if (!GRPC_LOG_IF_ERROR("pollset_global_init", pollset_global_init())) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 856 | close(g_epfd); |
| 857 | fd_global_shutdown(); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 858 | return NULL; |
| 859 | } |
| 860 | |
| 861 | return &vtable; |
| 862 | } |
| 863 | |
| 864 | #else /* defined(GRPC_LINUX_EPOLL) */ |
| 865 | #if defined(GRPC_POSIX_SOCKET) |
| 866 | #include "src/core/lib/iomgr/ev_posix.h" |
| 867 | /* If GRPC_LINUX_EPOLL is not defined, it means epoll is not available. Return |
| 868 | * NULL */ |
Craig Tiller | 9ddb315 | 2017-04-27 21:32:56 +0000 | [diff] [blame] | 869 | const grpc_event_engine_vtable *grpc_init_epoll1_linux(bool explicit_request) { |
| 870 | return NULL; |
| 871 | } |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 872 | #endif /* defined(GRPC_POSIX_SOCKET) */ |
| 873 | #endif /* !defined(GRPC_LINUX_EPOLL) */ |