Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 1 | /* |
| 2 | * |
Craig Tiller | d4838a9 | 2017-04-27 12:08:18 -0700 | [diff] [blame] | 3 | * Copyright 2017, Google Inc. |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions are |
| 8 | * met: |
| 9 | * |
| 10 | * * Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * * Redistributions in binary form must reproduce the above |
| 13 | * copyright notice, this list of conditions and the following disclaimer |
| 14 | * in the documentation and/or other materials provided with the |
| 15 | * distribution. |
| 16 | * * Neither the name of Google Inc. nor the names of its |
| 17 | * contributors may be used to endorse or promote products derived from |
| 18 | * this software without specific prior written permission. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 22 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 23 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 24 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 25 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 26 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 27 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 28 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 29 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 30 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 31 | * |
| 32 | */ |
| 33 | |
| 34 | #include "src/core/lib/iomgr/port.h" |
| 35 | |
| 36 | /* This polling engine is only relevant on linux kernels supporting epoll() */ |
| 37 | #ifdef GRPC_LINUX_EPOLL |
| 38 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 39 | #include "src/core/lib/iomgr/ev_epoll1_linux.h" |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 40 | |
| 41 | #include <assert.h> |
| 42 | #include <errno.h> |
| 43 | #include <poll.h> |
| 44 | #include <pthread.h> |
| 45 | #include <string.h> |
| 46 | #include <sys/epoll.h> |
| 47 | #include <sys/socket.h> |
| 48 | #include <unistd.h> |
| 49 | |
| 50 | #include <grpc/support/alloc.h> |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 51 | #include <grpc/support/cpu.h> |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 52 | #include <grpc/support/log.h> |
| 53 | #include <grpc/support/string_util.h> |
| 54 | #include <grpc/support/tls.h> |
| 55 | #include <grpc/support/useful.h> |
| 56 | |
| 57 | #include "src/core/lib/iomgr/ev_posix.h" |
| 58 | #include "src/core/lib/iomgr/iomgr_internal.h" |
| 59 | #include "src/core/lib/iomgr/lockfree_event.h" |
| 60 | #include "src/core/lib/iomgr/timer.h" |
| 61 | #include "src/core/lib/iomgr/wakeup_fd_posix.h" |
| 62 | #include "src/core/lib/iomgr/workqueue.h" |
| 63 | #include "src/core/lib/profiling/timers.h" |
| 64 | #include "src/core/lib/support/block_annotate.h" |
| 65 | |
| 66 | /* TODO: sreek: Right now, this wakes up all pollers. In future we should make |
| 67 | * sure to wake up one polling thread (which can wake up other threads if |
| 68 | * needed) */ |
| 69 | static grpc_wakeup_fd global_wakeup_fd; |
| 70 | static int g_epfd; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 71 | static gpr_atm g_timer_kick; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 72 | |
| 73 | /******************************************************************************* |
| 74 | * Fd Declarations |
| 75 | */ |
| 76 | |
| 77 | struct grpc_fd { |
| 78 | int fd; |
| 79 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 80 | gpr_atm read_closure; |
| 81 | gpr_atm write_closure; |
| 82 | |
| 83 | struct grpc_fd *freelist_next; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 84 | |
| 85 | /* The pollset that last noticed that the fd is readable. The actual type |
| 86 | * stored in this is (grpc_pollset *) */ |
| 87 | gpr_atm read_notifier_pollset; |
| 88 | |
| 89 | grpc_iomgr_object iomgr_object; |
| 90 | }; |
| 91 | |
| 92 | static void fd_global_init(void); |
| 93 | static void fd_global_shutdown(void); |
| 94 | |
| 95 | /******************************************************************************* |
| 96 | * Pollset Declarations |
| 97 | */ |
| 98 | |
Craig Tiller | 43bf259 | 2017-04-28 23:21:01 +0000 | [diff] [blame] | 99 | typedef enum { UNKICKED, KICKED, DESIGNATED_POLLER } kick_state; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 100 | |
| 101 | struct grpc_pollset_worker { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 102 | kick_state kick_state; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 103 | bool initialized_cv; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 104 | grpc_pollset_worker *next; |
| 105 | grpc_pollset_worker *prev; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 106 | gpr_cv cv; |
| 107 | }; |
| 108 | |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 109 | #define MAX_NEIGHBOURHOODS 1024 |
| 110 | |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 111 | typedef struct pollset_neighbourhood { |
| 112 | gpr_mu mu; |
| 113 | grpc_pollset *active_root; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 114 | char pad[GPR_CACHELINE_SIZE]; |
| 115 | } pollset_neighbourhood; |
| 116 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 117 | struct grpc_pollset { |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 118 | gpr_mu mu; |
| 119 | pollset_neighbourhood *neighbourhood; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 120 | grpc_pollset_worker *root_worker; |
| 121 | bool kicked_without_poller; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 122 | bool seen_inactive; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 123 | bool shutting_down; /* Is the pollset shutting down ? */ |
| 124 | bool finish_shutdown_called; /* Is the 'finish_shutdown_locked()' called ? */ |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 125 | grpc_closure *shutdown_closure; /* Called after after shutdown is complete */ |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 126 | int begin_refs; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 127 | |
| 128 | grpc_pollset *next; |
| 129 | grpc_pollset *prev; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 130 | }; |
| 131 | |
| 132 | /******************************************************************************* |
| 133 | * Pollset-set Declarations |
| 134 | */ |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 135 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 136 | struct grpc_pollset_set {}; |
| 137 | |
| 138 | /******************************************************************************* |
| 139 | * Common helpers |
| 140 | */ |
| 141 | |
| 142 | static bool append_error(grpc_error **composite, grpc_error *error, |
| 143 | const char *desc) { |
| 144 | if (error == GRPC_ERROR_NONE) return true; |
| 145 | if (*composite == GRPC_ERROR_NONE) { |
| 146 | *composite = GRPC_ERROR_CREATE_FROM_COPIED_STRING(desc); |
| 147 | } |
| 148 | *composite = grpc_error_add_child(*composite, error); |
| 149 | return false; |
| 150 | } |
| 151 | |
| 152 | /******************************************************************************* |
| 153 | * Fd Definitions |
| 154 | */ |
| 155 | |
| 156 | /* We need to keep a freelist not because of any concerns of malloc performance |
| 157 | * but instead so that implementations with multiple threads in (for example) |
| 158 | * epoll_wait deal with the race between pollset removal and incoming poll |
| 159 | * notifications. |
| 160 | * |
| 161 | * The problem is that the poller ultimately holds a reference to this |
| 162 | * object, so it is very difficult to know when is safe to free it, at least |
| 163 | * without some expensive synchronization. |
| 164 | * |
| 165 | * If we keep the object freelisted, in the worst case losing this race just |
| 166 | * becomes a spurious read notification on a reused fd. |
| 167 | */ |
| 168 | |
| 169 | /* The alarm system needs to be able to wakeup 'some poller' sometimes |
| 170 | * (specifically when a new alarm needs to be triggered earlier than the next |
| 171 | * alarm 'epoch'). This wakeup_fd gives us something to alert on when such a |
| 172 | * case occurs. */ |
| 173 | |
| 174 | static grpc_fd *fd_freelist = NULL; |
| 175 | static gpr_mu fd_freelist_mu; |
| 176 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 177 | static void fd_global_init(void) { gpr_mu_init(&fd_freelist_mu); } |
| 178 | |
| 179 | static void fd_global_shutdown(void) { |
| 180 | gpr_mu_lock(&fd_freelist_mu); |
| 181 | gpr_mu_unlock(&fd_freelist_mu); |
| 182 | while (fd_freelist != NULL) { |
| 183 | grpc_fd *fd = fd_freelist; |
| 184 | fd_freelist = fd_freelist->freelist_next; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 185 | gpr_free(fd); |
| 186 | } |
| 187 | gpr_mu_destroy(&fd_freelist_mu); |
| 188 | } |
| 189 | |
| 190 | static grpc_fd *fd_create(int fd, const char *name) { |
| 191 | grpc_fd *new_fd = NULL; |
| 192 | |
| 193 | gpr_mu_lock(&fd_freelist_mu); |
| 194 | if (fd_freelist != NULL) { |
| 195 | new_fd = fd_freelist; |
| 196 | fd_freelist = fd_freelist->freelist_next; |
| 197 | } |
| 198 | gpr_mu_unlock(&fd_freelist_mu); |
| 199 | |
| 200 | if (new_fd == NULL) { |
| 201 | new_fd = gpr_malloc(sizeof(grpc_fd)); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 202 | } |
| 203 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 204 | new_fd->fd = fd; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 205 | grpc_lfev_init(&new_fd->read_closure); |
| 206 | grpc_lfev_init(&new_fd->write_closure); |
| 207 | gpr_atm_no_barrier_store(&new_fd->read_notifier_pollset, (gpr_atm)NULL); |
| 208 | |
| 209 | new_fd->freelist_next = NULL; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 210 | |
| 211 | char *fd_name; |
| 212 | gpr_asprintf(&fd_name, "%s fd=%d", name, fd); |
| 213 | grpc_iomgr_register_object(&new_fd->iomgr_object, fd_name); |
| 214 | #ifdef GRPC_FD_REF_COUNT_DEBUG |
| 215 | gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, (void *)new_fd, fd_name); |
| 216 | #endif |
| 217 | gpr_free(fd_name); |
Craig Tiller | 9ddb315 | 2017-04-27 21:32:56 +0000 | [diff] [blame] | 218 | |
| 219 | struct epoll_event ev = {.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET), |
| 220 | .data.ptr = new_fd}; |
| 221 | if (epoll_ctl(g_epfd, EPOLL_CTL_ADD, fd, &ev) != 0) { |
| 222 | gpr_log(GPR_ERROR, "epoll_ctl failed: %s", strerror(errno)); |
| 223 | } |
| 224 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 225 | return new_fd; |
| 226 | } |
| 227 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 228 | static int fd_wrapped_fd(grpc_fd *fd) { return fd->fd; } |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 229 | |
Craig Tiller | 9ddb315 | 2017-04-27 21:32:56 +0000 | [diff] [blame] | 230 | /* Might be called multiple times */ |
| 231 | static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_error *why) { |
| 232 | if (grpc_lfev_set_shutdown(exec_ctx, &fd->read_closure, |
| 233 | GRPC_ERROR_REF(why))) { |
| 234 | shutdown(fd->fd, SHUT_RDWR); |
| 235 | grpc_lfev_set_shutdown(exec_ctx, &fd->write_closure, GRPC_ERROR_REF(why)); |
| 236 | } |
| 237 | GRPC_ERROR_UNREF(why); |
| 238 | } |
| 239 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 240 | static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 241 | grpc_closure *on_done, int *release_fd, |
| 242 | const char *reason) { |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 243 | grpc_error *error = GRPC_ERROR_NONE; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 244 | |
Craig Tiller | 9ddb315 | 2017-04-27 21:32:56 +0000 | [diff] [blame] | 245 | if (!grpc_lfev_is_shutdown(&fd->read_closure)) { |
| 246 | fd_shutdown(exec_ctx, fd, GRPC_ERROR_CREATE_FROM_COPIED_STRING(reason)); |
| 247 | } |
| 248 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 249 | /* If release_fd is not NULL, we should be relinquishing control of the file |
| 250 | descriptor fd->fd (but we still own the grpc_fd structure). */ |
| 251 | if (release_fd != NULL) { |
| 252 | *release_fd = fd->fd; |
| 253 | } else { |
| 254 | close(fd->fd); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 255 | } |
| 256 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 257 | grpc_closure_sched(exec_ctx, on_done, GRPC_ERROR_REF(error)); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 258 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 259 | grpc_iomgr_unregister_object(&fd->iomgr_object); |
| 260 | grpc_lfev_destroy(&fd->read_closure); |
| 261 | grpc_lfev_destroy(&fd->write_closure); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 262 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 263 | gpr_mu_lock(&fd_freelist_mu); |
| 264 | fd->freelist_next = fd_freelist; |
| 265 | fd_freelist = fd; |
| 266 | gpr_mu_unlock(&fd_freelist_mu); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 267 | } |
| 268 | |
| 269 | static grpc_pollset *fd_get_read_notifier_pollset(grpc_exec_ctx *exec_ctx, |
| 270 | grpc_fd *fd) { |
| 271 | gpr_atm notifier = gpr_atm_acq_load(&fd->read_notifier_pollset); |
| 272 | return (grpc_pollset *)notifier; |
| 273 | } |
| 274 | |
| 275 | static bool fd_is_shutdown(grpc_fd *fd) { |
| 276 | return grpc_lfev_is_shutdown(&fd->read_closure); |
| 277 | } |
| 278 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 279 | static void fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 280 | grpc_closure *closure) { |
| 281 | grpc_lfev_notify_on(exec_ctx, &fd->read_closure, closure); |
| 282 | } |
| 283 | |
| 284 | static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 285 | grpc_closure *closure) { |
| 286 | grpc_lfev_notify_on(exec_ctx, &fd->write_closure, closure); |
| 287 | } |
| 288 | |
| 289 | static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 290 | return NULL; /* TODO(ctiller): add a global workqueue */ |
| 291 | } |
| 292 | |
| 293 | static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 294 | grpc_pollset *notifier) { |
| 295 | grpc_lfev_set_ready(exec_ctx, &fd->read_closure); |
| 296 | |
| 297 | /* Note, it is possible that fd_become_readable might be called twice with |
| 298 | different 'notifier's when an fd becomes readable and it is in two epoll |
| 299 | sets (This can happen briefly during polling island merges). In such cases |
| 300 | it does not really matter which notifer is set as the read_notifier_pollset |
| 301 | (They would both point to the same polling island anyway) */ |
| 302 | /* Use release store to match with acquire load in fd_get_read_notifier */ |
| 303 | gpr_atm_rel_store(&fd->read_notifier_pollset, (gpr_atm)notifier); |
| 304 | } |
| 305 | |
| 306 | static void fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) { |
| 307 | grpc_lfev_set_ready(exec_ctx, &fd->write_closure); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 308 | } |
| 309 | |
| 310 | /******************************************************************************* |
| 311 | * Pollset Definitions |
| 312 | */ |
| 313 | |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 314 | GPR_TLS_DECL(g_current_thread_pollset); |
| 315 | GPR_TLS_DECL(g_current_thread_worker); |
| 316 | static gpr_atm g_active_poller; |
| 317 | static pollset_neighbourhood *g_neighbourhoods; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 318 | static size_t g_num_neighbourhoods; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 319 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 320 | /* Return true if first in list */ |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 321 | static bool worker_insert(grpc_pollset *pollset, grpc_pollset_worker *worker) { |
| 322 | if (pollset->root_worker == NULL) { |
| 323 | pollset->root_worker = worker; |
| 324 | worker->next = worker->prev = worker; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 325 | return true; |
| 326 | } else { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 327 | worker->next = pollset->root_worker; |
| 328 | worker->prev = worker->next->prev; |
| 329 | worker->next->prev = worker; |
| 330 | worker->prev->next = worker; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 331 | return false; |
| 332 | } |
| 333 | } |
| 334 | |
| 335 | /* Return true if last in list */ |
| 336 | typedef enum { EMPTIED, NEW_ROOT, REMOVED } worker_remove_result; |
| 337 | |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 338 | static worker_remove_result worker_remove(grpc_pollset *pollset, |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 339 | grpc_pollset_worker *worker) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 340 | if (worker == pollset->root_worker) { |
| 341 | if (worker == worker->next) { |
| 342 | pollset->root_worker = NULL; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 343 | return EMPTIED; |
| 344 | } else { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 345 | pollset->root_worker = worker->next; |
| 346 | worker->prev->next = worker->next; |
| 347 | worker->next->prev = worker->prev; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 348 | return NEW_ROOT; |
| 349 | } |
| 350 | } else { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 351 | worker->prev->next = worker->next; |
| 352 | worker->next->prev = worker->prev; |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 353 | return REMOVED; |
| 354 | } |
| 355 | } |
| 356 | |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 357 | static size_t choose_neighbourhood(void) { |
| 358 | return (size_t)gpr_cpu_current_cpu() % g_num_neighbourhoods; |
| 359 | } |
| 360 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 361 | static grpc_error *pollset_global_init(void) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 362 | gpr_tls_init(&g_current_thread_pollset); |
| 363 | gpr_tls_init(&g_current_thread_worker); |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 364 | gpr_atm_no_barrier_store(&g_active_poller, 0); |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 365 | global_wakeup_fd.read_fd = -1; |
| 366 | grpc_error *err = grpc_wakeup_fd_init(&global_wakeup_fd); |
| 367 | if (err != GRPC_ERROR_NONE) return err; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 368 | struct epoll_event ev = {.events = (uint32_t)(EPOLLIN | EPOLLET), |
| 369 | .data.ptr = &global_wakeup_fd}; |
| 370 | if (epoll_ctl(g_epfd, EPOLL_CTL_ADD, global_wakeup_fd.read_fd, &ev) != 0) { |
| 371 | return GRPC_OS_ERROR(errno, "epoll_ctl"); |
| 372 | } |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 373 | g_num_neighbourhoods = GPR_CLAMP(gpr_cpu_num_cores(), 1, MAX_NEIGHBOURHOODS); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 374 | g_neighbourhoods = |
| 375 | gpr_zalloc(sizeof(*g_neighbourhoods) * g_num_neighbourhoods); |
| 376 | for (size_t i = 0; i < g_num_neighbourhoods; i++) { |
| 377 | gpr_mu_init(&g_neighbourhoods[i].mu); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 378 | } |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 379 | return GRPC_ERROR_NONE; |
| 380 | } |
| 381 | |
| 382 | static void pollset_global_shutdown(void) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 383 | gpr_tls_destroy(&g_current_thread_pollset); |
| 384 | gpr_tls_destroy(&g_current_thread_worker); |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 385 | 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] | 386 | for (size_t i = 0; i < g_num_neighbourhoods; i++) { |
| 387 | gpr_mu_destroy(&g_neighbourhoods[i].mu); |
| 388 | } |
| 389 | gpr_free(g_neighbourhoods); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 390 | } |
| 391 | |
| 392 | static void pollset_init(grpc_pollset *pollset, gpr_mu **mu) { |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 393 | gpr_mu_init(&pollset->mu); |
| 394 | *mu = &pollset->mu; |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 395 | pollset->neighbourhood = &g_neighbourhoods[choose_neighbourhood()]; |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 396 | pollset->seen_inactive = true; |
| 397 | pollset->next = pollset->prev = pollset; |
| 398 | } |
| 399 | |
| 400 | static void pollset_destroy(grpc_pollset *pollset) { |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 401 | if (!pollset->seen_inactive) { |
| 402 | gpr_mu_lock(&pollset->neighbourhood->mu); |
| 403 | pollset->prev->next = pollset->next; |
| 404 | pollset->next->prev = pollset->prev; |
| 405 | if (pollset == pollset->neighbourhood->active_root) { |
| 406 | pollset->neighbourhood->active_root = |
| 407 | pollset->next == pollset ? NULL : pollset->next; |
| 408 | } |
| 409 | gpr_mu_unlock(&pollset->neighbourhood->mu); |
Craig Tiller | 6de0593 | 2017-04-28 09:17:38 -0700 | [diff] [blame] | 410 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 411 | gpr_mu_destroy(&pollset->mu); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 412 | } |
| 413 | |
| 414 | static grpc_error *pollset_kick_all(grpc_pollset *pollset) { |
| 415 | grpc_error *error = GRPC_ERROR_NONE; |
| 416 | if (pollset->root_worker != NULL) { |
| 417 | grpc_pollset_worker *worker = pollset->root_worker; |
| 418 | do { |
| 419 | if (worker->initialized_cv) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 420 | worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 421 | gpr_cv_signal(&worker->cv); |
| 422 | } else { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 423 | worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 424 | append_error(&error, grpc_wakeup_fd_wakeup(&global_wakeup_fd), |
| 425 | "pollset_shutdown"); |
| 426 | } |
| 427 | |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 428 | worker = worker->next; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 429 | } while (worker != pollset->root_worker); |
| 430 | } |
| 431 | return error; |
| 432 | } |
| 433 | |
| 434 | static void pollset_maybe_finish_shutdown(grpc_exec_ctx *exec_ctx, |
| 435 | grpc_pollset *pollset) { |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 436 | if (pollset->shutdown_closure != NULL && pollset->root_worker == NULL && |
| 437 | pollset->begin_refs == 0) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 438 | grpc_closure_sched(exec_ctx, pollset->shutdown_closure, GRPC_ERROR_NONE); |
| 439 | pollset->shutdown_closure = NULL; |
| 440 | } |
| 441 | } |
| 442 | |
| 443 | static void pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 444 | grpc_closure *closure) { |
| 445 | GPR_ASSERT(pollset->shutdown_closure == NULL); |
| 446 | pollset->shutdown_closure = closure; |
| 447 | GRPC_LOG_IF_ERROR("pollset_shutdown", pollset_kick_all(pollset)); |
| 448 | pollset_maybe_finish_shutdown(exec_ctx, pollset); |
| 449 | } |
| 450 | |
Craig Tiller | 7cb2698 | 2017-04-28 23:05:37 +0000 | [diff] [blame] | 451 | #define MAX_EPOLL_EVENTS 10 |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 452 | |
| 453 | static int poll_deadline_to_millis_timeout(gpr_timespec deadline, |
| 454 | gpr_timespec now) { |
| 455 | gpr_timespec timeout; |
| 456 | if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) { |
| 457 | return -1; |
| 458 | } |
| 459 | |
| 460 | if (gpr_time_cmp(deadline, now) <= 0) { |
| 461 | return 0; |
| 462 | } |
| 463 | |
| 464 | static const gpr_timespec round_up = { |
| 465 | .clock_type = GPR_TIMESPAN, .tv_sec = 0, .tv_nsec = GPR_NS_PER_MS - 1}; |
| 466 | timeout = gpr_time_sub(deadline, now); |
| 467 | int millis = gpr_time_to_millis(gpr_time_add(timeout, round_up)); |
| 468 | return millis >= 1 ? millis : 1; |
| 469 | } |
| 470 | |
| 471 | static grpc_error *pollset_epoll(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 472 | gpr_timespec now, gpr_timespec deadline) { |
| 473 | struct epoll_event events[MAX_EPOLL_EVENTS]; |
| 474 | static const char *err_desc = "pollset_poll"; |
| 475 | |
| 476 | int timeout = poll_deadline_to_millis_timeout(deadline, now); |
| 477 | |
| 478 | if (timeout != 0) { |
| 479 | GRPC_SCHEDULING_START_BLOCKING_REGION; |
| 480 | } |
| 481 | int r; |
| 482 | do { |
| 483 | r = epoll_wait(g_epfd, events, MAX_EPOLL_EVENTS, timeout); |
| 484 | } while (r < 0 && errno == EINTR); |
| 485 | if (timeout != 0) { |
| 486 | GRPC_SCHEDULING_END_BLOCKING_REGION; |
| 487 | } |
| 488 | |
| 489 | if (r < 0) return GRPC_OS_ERROR(errno, "epoll_wait"); |
| 490 | |
| 491 | grpc_error *error = GRPC_ERROR_NONE; |
| 492 | for (int i = 0; i < r; i++) { |
| 493 | void *data_ptr = events[i].data.ptr; |
| 494 | if (data_ptr == &global_wakeup_fd) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 495 | if (gpr_atm_no_barrier_cas(&g_timer_kick, 1, 0)) { |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 496 | grpc_timer_consume_kick(); |
| 497 | } |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 498 | append_error(&error, grpc_wakeup_fd_consume_wakeup(&global_wakeup_fd), |
| 499 | err_desc); |
| 500 | } else { |
| 501 | grpc_fd *fd = (grpc_fd *)(data_ptr); |
| 502 | bool cancel = (events[i].events & (EPOLLERR | EPOLLHUP)) != 0; |
| 503 | bool read_ev = (events[i].events & (EPOLLIN | EPOLLPRI)) != 0; |
| 504 | bool write_ev = (events[i].events & EPOLLOUT) != 0; |
| 505 | if (read_ev || cancel) { |
| 506 | fd_become_readable(exec_ctx, fd, pollset); |
| 507 | } |
| 508 | if (write_ev || cancel) { |
| 509 | fd_become_writable(exec_ctx, fd); |
| 510 | } |
| 511 | } |
| 512 | } |
| 513 | |
| 514 | return error; |
| 515 | } |
| 516 | |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 517 | #if 0 |
| 518 | static void verify_all_entries_in_neighbourhood_list( |
| 519 | grpc_pollset *root, bool should_be_seen_inactive) { |
| 520 | if (root == NULL) return; |
| 521 | grpc_pollset *p = root; |
| 522 | do { |
| 523 | GPR_ASSERT(p->seen_inactive == should_be_seen_inactive); |
| 524 | p = p->next; |
| 525 | } while (p != root); |
| 526 | } |
| 527 | |
| 528 | static void verify_neighbourhood_lists(pollset_neighbourhood *neighbourhood) { |
| 529 | // assumes neighbourhood->mu locked |
| 530 | verify_all_entries_in_neighbourhood_list(neighbourhood->active_root, false); |
| 531 | verify_all_entries_in_neighbourhood_list(neighbourhood->inactive_root, true); |
| 532 | } |
| 533 | #endif |
| 534 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 535 | static bool begin_worker(grpc_pollset *pollset, grpc_pollset_worker *worker, |
| 536 | grpc_pollset_worker **worker_hdl, gpr_timespec *now, |
| 537 | gpr_timespec deadline) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 538 | if (worker_hdl != NULL) *worker_hdl = worker; |
| 539 | worker->initialized_cv = false; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 540 | worker->kick_state = UNKICKED; |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 541 | pollset->begin_refs++; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 542 | |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 543 | if (pollset->seen_inactive) { |
| 544 | // pollset has been observed to be inactive, we need to move back to the |
| 545 | // active list |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 546 | pollset_neighbourhood *neighbourhood = pollset->neighbourhood = |
| 547 | &g_neighbourhoods[choose_neighbourhood()]; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 548 | gpr_mu_unlock(&pollset->mu); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 549 | // pollset unlocked: state may change (even worker->kick_state) |
| 550 | retry_lock_neighbourhood: |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 551 | gpr_mu_lock(&neighbourhood->mu); |
| 552 | gpr_mu_lock(&pollset->mu); |
| 553 | if (pollset->seen_inactive) { |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 554 | if (neighbourhood != pollset->neighbourhood) { |
| 555 | gpr_mu_unlock(&neighbourhood->mu); |
| 556 | neighbourhood = pollset->neighbourhood; |
| 557 | gpr_mu_unlock(&pollset->mu); |
| 558 | goto retry_lock_neighbourhood; |
| 559 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 560 | pollset->seen_inactive = false; |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 561 | if (neighbourhood->active_root == NULL) { |
| 562 | neighbourhood->active_root = pollset->next = pollset->prev = pollset; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 563 | 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] | 564 | worker->kick_state = DESIGNATED_POLLER; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 565 | } |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 566 | } else { |
| 567 | pollset->next = neighbourhood->active_root; |
| 568 | pollset->prev = pollset->next->prev; |
| 569 | pollset->next->prev = pollset->prev->next = pollset; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 570 | } |
| 571 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 572 | gpr_mu_unlock(&neighbourhood->mu); |
| 573 | } |
| 574 | worker_insert(pollset, worker); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 575 | pollset->begin_refs--; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 576 | if (worker->kick_state == UNKICKED) { |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 577 | 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] | 578 | worker->initialized_cv = true; |
| 579 | gpr_cv_init(&worker->cv); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 580 | while (worker->kick_state == UNKICKED && |
| 581 | pollset->shutdown_closure == NULL) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 582 | if (gpr_cv_wait(&worker->cv, &pollset->mu, deadline) && |
| 583 | worker->kick_state == UNKICKED) { |
| 584 | worker->kick_state = KICKED; |
| 585 | } |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 586 | } |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 587 | *now = gpr_now(now->clock_type); |
| 588 | } |
| 589 | |
Craig Tiller | 43bf259 | 2017-04-28 23:21:01 +0000 | [diff] [blame] | 590 | return worker->kick_state == DESIGNATED_POLLER && |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 591 | pollset->shutdown_closure == NULL; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 592 | } |
| 593 | |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 594 | static bool check_neighbourhood_for_available_poller( |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 595 | pollset_neighbourhood *neighbourhood) { |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 596 | bool found_worker = false; |
| 597 | do { |
| 598 | grpc_pollset *inspect = neighbourhood->active_root; |
| 599 | if (inspect == NULL) { |
| 600 | break; |
| 601 | } |
| 602 | gpr_mu_lock(&inspect->mu); |
| 603 | GPR_ASSERT(!inspect->seen_inactive); |
| 604 | grpc_pollset_worker *inspect_worker = inspect->root_worker; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 605 | if (inspect_worker != NULL) { |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 606 | do { |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 607 | switch (inspect_worker->kick_state) { |
| 608 | case UNKICKED: |
| 609 | if (gpr_atm_no_barrier_cas(&g_active_poller, 0, |
| 610 | (gpr_atm)inspect_worker)) { |
| 611 | inspect_worker->kick_state = DESIGNATED_POLLER; |
| 612 | if (inspect_worker->initialized_cv) { |
| 613 | gpr_cv_signal(&inspect_worker->cv); |
| 614 | } |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 615 | } |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 616 | // even if we didn't win the cas, there's a worker, we can stop |
| 617 | found_worker = true; |
| 618 | break; |
| 619 | case KICKED: |
| 620 | break; |
| 621 | case DESIGNATED_POLLER: |
| 622 | found_worker = true; // ok, so someone else found the worker, but |
| 623 | // we'll accept that |
| 624 | break; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 625 | } |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 626 | inspect_worker = inspect_worker->next; |
| 627 | } while (inspect_worker != inspect->root_worker); |
| 628 | } |
| 629 | if (!found_worker) { |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 630 | inspect->seen_inactive = true; |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 631 | if (inspect == neighbourhood->active_root) { |
| 632 | if (inspect->next == neighbourhood->active_root) { |
| 633 | neighbourhood->active_root = NULL; |
| 634 | } else { |
| 635 | neighbourhood->active_root = inspect->next; |
| 636 | } |
| 637 | } |
| 638 | inspect->next->prev = inspect->prev; |
| 639 | inspect->prev->next = inspect->next; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 640 | } |
| 641 | gpr_mu_unlock(&inspect->mu); |
| 642 | } while (!found_worker); |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 643 | return found_worker; |
| 644 | } |
| 645 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 646 | static void end_worker(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 647 | grpc_pollset_worker *worker, |
| 648 | grpc_pollset_worker **worker_hdl) { |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 649 | if (worker_hdl != NULL) *worker_hdl = NULL; |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 650 | worker->kick_state = KICKED; |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 651 | if (gpr_atm_no_barrier_load(&g_active_poller) == (gpr_atm)worker) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 652 | GPR_ASSERT(!pollset->seen_inactive); |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 653 | if (worker->next != worker && worker->next->kick_state == UNKICKED) { |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 654 | GPR_ASSERT(worker->next->initialized_cv); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 655 | gpr_atm_no_barrier_store(&g_active_poller, (gpr_atm)worker->next); |
Craig Tiller | 43bf259 | 2017-04-28 23:21:01 +0000 | [diff] [blame] | 656 | worker->next->kick_state = DESIGNATED_POLLER; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 657 | gpr_cv_signal(&worker->next->cv); |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 658 | if (grpc_exec_ctx_has_work(exec_ctx)) { |
| 659 | gpr_mu_unlock(&pollset->mu); |
| 660 | grpc_exec_ctx_flush(exec_ctx); |
| 661 | gpr_mu_lock(&pollset->mu); |
| 662 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 663 | } else { |
| 664 | gpr_atm_no_barrier_store(&g_active_poller, 0); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 665 | gpr_mu_unlock(&pollset->mu); |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 666 | size_t poller_neighbourhood_idx = |
| 667 | (size_t)(pollset->neighbourhood - g_neighbourhoods); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 668 | bool found_worker = false; |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 669 | bool scan_state[MAX_NEIGHBOURHOODS]; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 670 | for (size_t i = 0; !found_worker && i < g_num_neighbourhoods; i++) { |
| 671 | pollset_neighbourhood *neighbourhood = |
| 672 | &g_neighbourhoods[(poller_neighbourhood_idx + i) % |
| 673 | g_num_neighbourhoods]; |
| 674 | if (gpr_mu_trylock(&neighbourhood->mu)) { |
| 675 | found_worker = |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 676 | check_neighbourhood_for_available_poller(neighbourhood); |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 677 | gpr_mu_unlock(&neighbourhood->mu); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 678 | scan_state[i] = true; |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 679 | } else { |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 680 | scan_state[i] = false; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 681 | } |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 682 | } |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 683 | for (size_t i = 0; !found_worker && i < g_num_neighbourhoods; i++) { |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 684 | if (scan_state[i]) continue; |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 685 | pollset_neighbourhood *neighbourhood = |
| 686 | &g_neighbourhoods[(poller_neighbourhood_idx + i) % |
| 687 | g_num_neighbourhoods]; |
| 688 | gpr_mu_lock(&neighbourhood->mu); |
Craig Tiller | ba550da | 2017-05-01 14:26:31 +0000 | [diff] [blame^] | 689 | found_worker = check_neighbourhood_for_available_poller(neighbourhood); |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 690 | gpr_mu_unlock(&neighbourhood->mu); |
Craig Tiller | bbf4c7a | 2017-04-28 15:12:10 -0700 | [diff] [blame] | 691 | } |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 692 | grpc_exec_ctx_flush(exec_ctx); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 693 | gpr_mu_lock(&pollset->mu); |
| 694 | } |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 695 | } |
| 696 | if (worker->initialized_cv) { |
| 697 | gpr_cv_destroy(&worker->cv); |
| 698 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 699 | if (EMPTIED == worker_remove(pollset, worker)) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 700 | pollset_maybe_finish_shutdown(exec_ctx, pollset); |
| 701 | } |
Craig Tiller | a4b8eb0 | 2017-04-29 00:13:52 +0000 | [diff] [blame] | 702 | 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] | 703 | } |
| 704 | |
| 705 | /* pollset->po.mu lock must be held by the caller before calling this. |
| 706 | The function pollset_work() may temporarily release the lock (pollset->po.mu) |
| 707 | during the course of its execution but it will always re-acquire the lock and |
| 708 | ensure that it is held by the time the function returns */ |
| 709 | static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 710 | grpc_pollset_worker **worker_hdl, |
| 711 | gpr_timespec now, gpr_timespec deadline) { |
| 712 | grpc_pollset_worker worker; |
| 713 | grpc_error *error = GRPC_ERROR_NONE; |
| 714 | static const char *err_desc = "pollset_work"; |
| 715 | if (pollset->kicked_without_poller) { |
| 716 | pollset->kicked_without_poller = false; |
| 717 | return GRPC_ERROR_NONE; |
| 718 | } |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 719 | gpr_tls_set(&g_current_thread_pollset, (intptr_t)pollset); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 720 | if (begin_worker(pollset, &worker, worker_hdl, &now, deadline)) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 721 | gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker); |
| 722 | GPR_ASSERT(!pollset->shutdown_closure); |
Craig Tiller | 2acab6e | 2017-04-30 23:06:33 +0000 | [diff] [blame] | 723 | GPR_ASSERT(!pollset->seen_inactive); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 724 | gpr_mu_unlock(&pollset->mu); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 725 | append_error(&error, pollset_epoll(exec_ctx, pollset, now, deadline), |
| 726 | err_desc); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 727 | gpr_mu_lock(&pollset->mu); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 728 | gpr_tls_set(&g_current_thread_worker, 0); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 729 | } |
| 730 | end_worker(exec_ctx, pollset, &worker, worker_hdl); |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 731 | gpr_tls_set(&g_current_thread_pollset, 0); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 732 | return error; |
| 733 | } |
| 734 | |
| 735 | static grpc_error *pollset_kick(grpc_pollset *pollset, |
| 736 | grpc_pollset_worker *specific_worker) { |
| 737 | if (specific_worker == NULL) { |
| 738 | if (gpr_tls_get(&g_current_thread_pollset) != (intptr_t)pollset) { |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 739 | grpc_pollset_worker *root_worker = pollset->root_worker; |
| 740 | if (root_worker == NULL) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 741 | pollset->kicked_without_poller = true; |
| 742 | return GRPC_ERROR_NONE; |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 743 | } |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 744 | grpc_pollset_worker *next_worker = root_worker->next; |
| 745 | if (root_worker == next_worker && |
| 746 | root_worker == (grpc_pollset_worker *)gpr_atm_no_barrier_load( |
| 747 | &g_active_poller)) { |
| 748 | root_worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 749 | return grpc_wakeup_fd_wakeup(&global_wakeup_fd); |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 750 | } else if (next_worker->kick_state == UNKICKED) { |
| 751 | GPR_ASSERT(next_worker->initialized_cv); |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 752 | next_worker->kick_state = KICKED; |
Craig Tiller | 375eb25 | 2017-04-27 23:29:12 +0000 | [diff] [blame] | 753 | gpr_cv_signal(&next_worker->cv); |
| 754 | return GRPC_ERROR_NONE; |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 755 | } else { |
| 756 | return GRPC_ERROR_NONE; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 757 | } |
| 758 | } else { |
| 759 | return GRPC_ERROR_NONE; |
| 760 | } |
Craig Tiller | 43bf259 | 2017-04-28 23:21:01 +0000 | [diff] [blame] | 761 | } else if (specific_worker->kick_state == KICKED) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 762 | return GRPC_ERROR_NONE; |
| 763 | } else if (gpr_tls_get(&g_current_thread_worker) == |
| 764 | (intptr_t)specific_worker) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 765 | specific_worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 766 | return GRPC_ERROR_NONE; |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 767 | } else if (specific_worker == |
| 768 | (grpc_pollset_worker *)gpr_atm_no_barrier_load(&g_active_poller)) { |
| 769 | specific_worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 770 | return grpc_wakeup_fd_wakeup(&global_wakeup_fd); |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 771 | } else if (specific_worker->initialized_cv) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 772 | specific_worker->kick_state = KICKED; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 773 | gpr_cv_signal(&specific_worker->cv); |
| 774 | return GRPC_ERROR_NONE; |
Craig Tiller | 8502ecb | 2017-04-28 14:22:01 -0700 | [diff] [blame] | 775 | } else { |
| 776 | specific_worker->kick_state = KICKED; |
| 777 | return GRPC_ERROR_NONE; |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 778 | } |
| 779 | } |
| 780 | |
| 781 | static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 782 | grpc_fd *fd) {} |
| 783 | |
| 784 | static grpc_error *kick_poller(void) { |
Craig Tiller | 32f90ee | 2017-04-28 12:46:41 -0700 | [diff] [blame] | 785 | gpr_atm_no_barrier_store(&g_timer_kick, 1); |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 786 | return grpc_wakeup_fd_wakeup(&global_wakeup_fd); |
| 787 | } |
| 788 | |
| 789 | /******************************************************************************* |
| 790 | * Workqueue Definitions |
| 791 | */ |
| 792 | |
| 793 | #ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG |
| 794 | static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue, |
| 795 | const char *file, int line, |
| 796 | const char *reason) { |
| 797 | return workqueue; |
| 798 | } |
| 799 | |
| 800 | static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue, |
| 801 | const char *file, int line, const char *reason) {} |
| 802 | #else |
| 803 | static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) { |
| 804 | return workqueue; |
| 805 | } |
| 806 | |
| 807 | static void workqueue_unref(grpc_exec_ctx *exec_ctx, |
| 808 | grpc_workqueue *workqueue) {} |
| 809 | #endif |
| 810 | |
| 811 | static grpc_closure_scheduler *workqueue_scheduler(grpc_workqueue *workqueue) { |
| 812 | return grpc_schedule_on_exec_ctx; |
| 813 | } |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 814 | |
| 815 | /******************************************************************************* |
| 816 | * Pollset-set Definitions |
| 817 | */ |
| 818 | |
| 819 | static grpc_pollset_set *pollset_set_create(void) { |
| 820 | return (grpc_pollset_set *)((intptr_t)0xdeafbeef); |
| 821 | } |
| 822 | |
| 823 | static void pollset_set_destroy(grpc_exec_ctx *exec_ctx, |
| 824 | grpc_pollset_set *pss) {} |
| 825 | |
| 826 | static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset_set *pss, |
| 827 | grpc_fd *fd) {} |
| 828 | |
| 829 | static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx, grpc_pollset_set *pss, |
| 830 | grpc_fd *fd) {} |
| 831 | |
| 832 | static void pollset_set_add_pollset(grpc_exec_ctx *exec_ctx, |
| 833 | grpc_pollset_set *pss, grpc_pollset *ps) {} |
| 834 | |
| 835 | static void pollset_set_del_pollset(grpc_exec_ctx *exec_ctx, |
| 836 | grpc_pollset_set *pss, grpc_pollset *ps) {} |
| 837 | |
| 838 | static void pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx, |
| 839 | grpc_pollset_set *bag, |
| 840 | grpc_pollset_set *item) {} |
| 841 | |
| 842 | static void pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx, |
| 843 | grpc_pollset_set *bag, |
| 844 | grpc_pollset_set *item) {} |
| 845 | |
| 846 | /******************************************************************************* |
| 847 | * Event engine binding |
| 848 | */ |
| 849 | |
| 850 | static void shutdown_engine(void) { |
| 851 | fd_global_shutdown(); |
| 852 | pollset_global_shutdown(); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 853 | } |
| 854 | |
| 855 | static const grpc_event_engine_vtable vtable = { |
| 856 | .pollset_size = sizeof(grpc_pollset), |
| 857 | |
| 858 | .fd_create = fd_create, |
| 859 | .fd_wrapped_fd = fd_wrapped_fd, |
| 860 | .fd_orphan = fd_orphan, |
| 861 | .fd_shutdown = fd_shutdown, |
| 862 | .fd_is_shutdown = fd_is_shutdown, |
| 863 | .fd_notify_on_read = fd_notify_on_read, |
| 864 | .fd_notify_on_write = fd_notify_on_write, |
| 865 | .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset, |
| 866 | .fd_get_workqueue = fd_get_workqueue, |
| 867 | |
| 868 | .pollset_init = pollset_init, |
| 869 | .pollset_shutdown = pollset_shutdown, |
| 870 | .pollset_destroy = pollset_destroy, |
| 871 | .pollset_work = pollset_work, |
| 872 | .pollset_kick = pollset_kick, |
| 873 | .pollset_add_fd = pollset_add_fd, |
| 874 | |
| 875 | .pollset_set_create = pollset_set_create, |
| 876 | .pollset_set_destroy = pollset_set_destroy, |
| 877 | .pollset_set_add_pollset = pollset_set_add_pollset, |
| 878 | .pollset_set_del_pollset = pollset_set_del_pollset, |
| 879 | .pollset_set_add_pollset_set = pollset_set_add_pollset_set, |
| 880 | .pollset_set_del_pollset_set = pollset_set_del_pollset_set, |
| 881 | .pollset_set_add_fd = pollset_set_add_fd, |
| 882 | .pollset_set_del_fd = pollset_set_del_fd, |
| 883 | |
| 884 | .kick_poller = kick_poller, |
| 885 | |
| 886 | .workqueue_ref = workqueue_ref, |
| 887 | .workqueue_unref = workqueue_unref, |
| 888 | .workqueue_scheduler = workqueue_scheduler, |
| 889 | |
| 890 | .shutdown_engine = shutdown_engine, |
| 891 | }; |
| 892 | |
| 893 | /* It is possible that GLIBC has epoll but the underlying kernel doesn't. |
| 894 | * Create a dummy epoll_fd to make sure epoll support is available */ |
Craig Tiller | 6f0af49 | 2017-04-27 19:26:16 +0000 | [diff] [blame] | 895 | const grpc_event_engine_vtable *grpc_init_epoll1_linux(bool explicit_request) { |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 896 | if (!grpc_has_wakeup_fd()) { |
| 897 | return NULL; |
| 898 | } |
| 899 | |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 900 | g_epfd = epoll_create1(EPOLL_CLOEXEC); |
| 901 | if (g_epfd < 0) { |
| 902 | gpr_log(GPR_ERROR, "epoll unavailable"); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 903 | return NULL; |
| 904 | } |
| 905 | |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 906 | fd_global_init(); |
| 907 | |
| 908 | if (!GRPC_LOG_IF_ERROR("pollset_global_init", pollset_global_init())) { |
Craig Tiller | 4509c47 | 2017-04-27 19:05:13 +0000 | [diff] [blame] | 909 | close(g_epfd); |
| 910 | fd_global_shutdown(); |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 911 | return NULL; |
| 912 | } |
| 913 | |
| 914 | return &vtable; |
| 915 | } |
| 916 | |
| 917 | #else /* defined(GRPC_LINUX_EPOLL) */ |
| 918 | #if defined(GRPC_POSIX_SOCKET) |
| 919 | #include "src/core/lib/iomgr/ev_posix.h" |
| 920 | /* If GRPC_LINUX_EPOLL is not defined, it means epoll is not available. Return |
| 921 | * NULL */ |
Craig Tiller | 9ddb315 | 2017-04-27 21:32:56 +0000 | [diff] [blame] | 922 | const grpc_event_engine_vtable *grpc_init_epoll1_linux(bool explicit_request) { |
| 923 | return NULL; |
| 924 | } |
Craig Tiller | c67cc99 | 2017-04-27 10:15:51 -0700 | [diff] [blame] | 925 | #endif /* defined(GRPC_POSIX_SOCKET) */ |
| 926 | #endif /* !defined(GRPC_LINUX_EPOLL) */ |