Sree Kuchibhotla | f448c34 | 2016-05-19 10:51:24 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * |
| 3 | * Copyright 2016, Google Inc. |
| 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 <grpc/support/port_platform.h> |
| 35 | |
| 36 | #ifdef GPR_POSIX_SOCKET |
| 37 | |
| 38 | #include "src/core/lib/iomgr/ev_epoll_posix.h" |
| 39 | |
| 40 | #include <assert.h> |
| 41 | #include <errno.h> |
| 42 | #include <poll.h> |
| 43 | #include <signal.h> |
| 44 | #include <string.h> |
| 45 | #include <sys/epoll.h> |
| 46 | #include <sys/socket.h> |
| 47 | #include <unistd.h> |
| 48 | |
| 49 | #include <grpc/support/alloc.h> |
| 50 | #include <grpc/support/log.h> |
| 51 | #include <grpc/support/string_util.h> |
| 52 | #include <grpc/support/tls.h> |
| 53 | #include <grpc/support/useful.h> |
| 54 | |
| 55 | #include "src/core/lib/iomgr/ev_posix.h" |
| 56 | #include "src/core/lib/iomgr/iomgr_internal.h" |
| 57 | #include "src/core/lib/iomgr/wakeup_fd_posix.h" |
| 58 | #include "src/core/lib/profiling/timers.h" |
| 59 | #include "src/core/lib/support/block_annotate.h" |
| 60 | |
| 61 | struct polling_island; |
| 62 | |
| 63 | /******************************************************************************* |
| 64 | * FD declarations |
| 65 | */ |
| 66 | |
| 67 | struct grpc_fd { |
| 68 | int fd; |
| 69 | /* refst format: |
| 70 | bit0: 1=active/0=orphaned |
| 71 | bit1-n: refcount |
| 72 | meaning that mostly we ref by two to avoid altering the orphaned bit, |
| 73 | and just unref by 1 when we're ready to flag the object as orphaned */ |
| 74 | gpr_atm refst; |
| 75 | |
| 76 | gpr_mu mu; |
| 77 | int shutdown; |
| 78 | int closed; |
| 79 | int released; |
| 80 | |
| 81 | grpc_closure *read_closure; |
| 82 | grpc_closure *write_closure; |
| 83 | |
| 84 | /* Mutex protecting the 'polling_island' field */ |
| 85 | gpr_mu pi_mu; |
| 86 | |
| 87 | /* The polling island to which this fd belongs to. An fd belongs to exactly |
| 88 | one polling island */ |
| 89 | struct polling_island *polling_island; |
| 90 | |
| 91 | struct grpc_fd *freelist_next; |
| 92 | |
| 93 | grpc_closure *on_done_closure; |
| 94 | |
| 95 | grpc_iomgr_object iomgr_object; |
| 96 | }; |
| 97 | |
| 98 | /* Return 1 if this fd is orphaned, 0 otherwise */ |
| 99 | static bool fd_is_orphaned(grpc_fd *fd); |
| 100 | |
| 101 | /* Reference counting for fds */ |
| 102 | /*#define GRPC_FD_REF_COUNT_DEBUG*/ |
| 103 | #ifdef GRPC_FD_REF_COUNT_DEBUG |
| 104 | static void fd_ref(grpc_fd *fd, const char *reason, const char *file, int line); |
| 105 | static void fd_unref(grpc_fd *fd, const char *reason, const char *file, |
| 106 | int line); |
| 107 | #define GRPC_FD_REF(fd, reason) fd_ref(fd, reason, __FILE__, __LINE__) |
| 108 | #define GRPC_FD_UNREF(fd, reason) fd_unref(fd, reason, __FILE__, __LINE__) |
| 109 | #else |
| 110 | static void fd_ref(grpc_fd *fd); |
| 111 | static void fd_unref(grpc_fd *fd); |
| 112 | #define GRPC_FD_REF(fd, reason) fd_ref(fd) |
| 113 | #define GRPC_FD_UNREF(fd, reason) fd_unref(fd) |
| 114 | #endif |
| 115 | |
| 116 | static void fd_global_init(void); |
| 117 | static void fd_global_shutdown(void); |
| 118 | |
| 119 | #define CLOSURE_NOT_READY ((grpc_closure *)0) |
| 120 | #define CLOSURE_READY ((grpc_closure *)1) |
| 121 | |
| 122 | /******************************************************************************* |
| 123 | * Polling Island |
| 124 | */ |
| 125 | typedef struct polling_island { |
| 126 | gpr_mu mu; |
| 127 | int ref_cnt; |
| 128 | |
| 129 | /* Pointer to the polling_island this merged into. If this is not NULL, all |
| 130 | the remaining fields in this pollset (i.e all fields except mu and ref_cnt) |
| 131 | are considered invalid and must be ignored */ |
| 132 | struct polling_island *merged_to; |
| 133 | |
| 134 | /* The fd of the underlying epoll set */ |
| 135 | int epoll_fd; |
| 136 | |
| 137 | /* The file descriptors in the epoll set */ |
| 138 | size_t fd_cnt; |
| 139 | size_t fd_capacity; |
| 140 | grpc_fd **fds; |
| 141 | |
| 142 | /* Polling islands that are no longer needed are kept in a freelist so that |
| 143 | they can be reused. This field points to the next polling island in the |
| 144 | free list. Note that this is only used if the polling island is in the |
| 145 | free list */ |
| 146 | struct polling_island *next_free; |
| 147 | } polling_island; |
| 148 | |
| 149 | /* Polling island freelist */ |
| 150 | static gpr_mu g_pi_freelist_mu; |
| 151 | static polling_island *g_pi_freelist = NULL; |
| 152 | |
| 153 | /* TODO: sreek - Should we hold a lock on fd or add a ref to the fd ? */ |
| 154 | static void add_fd_to_polling_island_locked(polling_island *pi, grpc_fd *fd) { |
| 155 | int err; |
| 156 | struct epoll_event ev; |
| 157 | |
| 158 | ev.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET); |
| 159 | ev.data.ptr = fd; |
| 160 | err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_ADD, fd->fd, &ev); |
| 161 | |
| 162 | if (err < 0 && errno != EEXIST) { |
| 163 | gpr_log(GPR_ERROR, "epoll_ctl add for fd: %d failed with error: %s", fd->fd, |
| 164 | strerror(errno)); |
| 165 | return; |
| 166 | } |
| 167 | |
| 168 | pi->fd_capacity = GPR_MAX(pi->fd_capacity + 8, pi->fd_cnt * 3 / 2); |
| 169 | pi->fds = gpr_realloc(pi->fds, sizeof(grpc_fd *) * pi->fd_capacity); |
| 170 | pi->fds[pi->fd_cnt++] = fd; |
| 171 | } |
| 172 | |
| 173 | static polling_island *polling_island_create(int initial_ref_cnt, |
| 174 | grpc_fd *initial_fd) { |
| 175 | polling_island *pi = NULL; |
| 176 | gpr_mu_lock(&g_pi_freelist_mu); |
| 177 | if (g_pi_freelist != NULL) { |
| 178 | pi = g_pi_freelist; |
| 179 | g_pi_freelist = g_pi_freelist->next_free; |
| 180 | pi->next_free = NULL; |
| 181 | } |
| 182 | gpr_mu_unlock(&g_pi_freelist_mu); |
| 183 | |
| 184 | /* Create new polling island if we could not get one from the free list */ |
| 185 | if (pi == NULL) { |
| 186 | pi = gpr_malloc(sizeof(*pi)); |
| 187 | gpr_mu_init(&pi->mu); |
| 188 | pi->fd_cnt = 0; |
| 189 | pi->fd_capacity = 0; |
| 190 | pi->fds = NULL; |
| 191 | |
| 192 | pi->epoll_fd = epoll_create1(EPOLL_CLOEXEC); |
| 193 | if (pi->epoll_fd < 0) { |
| 194 | gpr_log(GPR_ERROR, "epoll_create1() failed with error: %s", |
| 195 | strerror(errno)); |
| 196 | } |
| 197 | GPR_ASSERT(pi->epoll_fd >= 0); |
| 198 | } |
| 199 | |
| 200 | pi->ref_cnt = initial_ref_cnt; |
| 201 | pi->merged_to = NULL; |
| 202 | pi->next_free = NULL; |
| 203 | |
| 204 | if (initial_fd != NULL) { |
| 205 | /* add_fd_to_polling_island_locked() expects the caller to hold a pi->mu |
| 206 | * lock. However, since this is a new polling island (and no one has a |
| 207 | * reference to it yet), it is okay to not acquire pi->mu here */ |
| 208 | add_fd_to_polling_island_locked(pi, initial_fd); |
| 209 | } |
| 210 | |
| 211 | return pi; |
| 212 | } |
| 213 | |
| 214 | static void polling_island_global_init() { |
| 215 | polling_island_create(0, NULL); /* TODO(sreek): Delete this line */ |
| 216 | gpr_mu_init(&g_pi_freelist_mu); |
| 217 | g_pi_freelist = NULL; |
| 218 | } |
| 219 | |
| 220 | /******************************************************************************* |
| 221 | * pollset declarations |
| 222 | */ |
| 223 | |
| 224 | typedef struct grpc_cached_wakeup_fd { |
| 225 | grpc_wakeup_fd fd; |
| 226 | struct grpc_cached_wakeup_fd *next; |
| 227 | } grpc_cached_wakeup_fd; |
| 228 | |
| 229 | struct grpc_pollset_worker { |
| 230 | grpc_cached_wakeup_fd *wakeup_fd; |
| 231 | int reevaluate_polling_on_wakeup; |
| 232 | int kicked_specifically; |
| 233 | pthread_t pt_id; |
| 234 | struct grpc_pollset_worker *next; |
| 235 | struct grpc_pollset_worker *prev; |
| 236 | }; |
| 237 | |
| 238 | struct grpc_pollset { |
| 239 | gpr_mu mu; |
| 240 | grpc_pollset_worker root_worker; |
| 241 | int shutting_down; |
| 242 | int called_shutdown; |
| 243 | int kicked_without_pollers; |
| 244 | grpc_closure *shutdown_done; |
| 245 | |
| 246 | int epoll_fd; |
| 247 | |
| 248 | /* Mutex protecting the 'polling_island' field */ |
| 249 | gpr_mu pi_mu; |
| 250 | |
| 251 | /* The polling island to which this fd belongs to. An fd belongs to exactly |
| 252 | one polling island */ |
| 253 | struct polling_island *polling_island; |
| 254 | |
| 255 | /* Local cache of eventfds for workers */ |
| 256 | grpc_cached_wakeup_fd *local_wakeup_cache; |
| 257 | }; |
| 258 | |
| 259 | /* Add an fd to a pollset */ |
| 260 | static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 261 | struct grpc_fd *fd); |
| 262 | |
| 263 | static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx, |
| 264 | grpc_pollset_set *pollset_set, grpc_fd *fd); |
| 265 | |
| 266 | /* Convert a timespec to milliseconds: |
| 267 | - very small or negative poll times are clamped to zero to do a |
| 268 | non-blocking poll (which becomes spin polling) |
| 269 | - other small values are rounded up to one millisecond |
| 270 | - longer than a millisecond polls are rounded up to the next nearest |
| 271 | millisecond to avoid spinning |
| 272 | - infinite timeouts are converted to -1 */ |
| 273 | static int poll_deadline_to_millis_timeout(gpr_timespec deadline, |
| 274 | gpr_timespec now); |
| 275 | |
| 276 | /* Allow kick to wakeup the currently polling worker */ |
| 277 | #define GRPC_POLLSET_CAN_KICK_SELF 1 |
| 278 | /* Force the wakee to repoll when awoken */ |
| 279 | #define GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP 2 |
| 280 | /* As per pollset_kick, with an extended set of flags (defined above) |
| 281 | -- mostly for fd_posix's use. */ |
| 282 | static void pollset_kick_ext(grpc_pollset *p, |
| 283 | grpc_pollset_worker *specific_worker, |
| 284 | uint32_t flags); |
| 285 | |
| 286 | /* turn a pollset into a multipoller: platform specific */ |
| 287 | typedef void (*platform_become_multipoller_type)(grpc_exec_ctx *exec_ctx, |
| 288 | grpc_pollset *pollset, |
| 289 | struct grpc_fd **fds, |
| 290 | size_t fd_count); |
| 291 | |
| 292 | /* Return 1 if the pollset has active threads in pollset_work (pollset must |
| 293 | * be locked) */ |
| 294 | static int pollset_has_workers(grpc_pollset *pollset); |
| 295 | |
| 296 | static void remove_fd_from_all_epoll_sets(int fd); |
| 297 | |
| 298 | /******************************************************************************* |
| 299 | * pollset_set definitions |
| 300 | */ |
| 301 | |
| 302 | struct grpc_pollset_set { |
| 303 | gpr_mu mu; |
| 304 | |
| 305 | size_t pollset_count; |
| 306 | size_t pollset_capacity; |
| 307 | grpc_pollset **pollsets; |
| 308 | |
| 309 | size_t pollset_set_count; |
| 310 | size_t pollset_set_capacity; |
| 311 | struct grpc_pollset_set **pollset_sets; |
| 312 | |
| 313 | size_t fd_count; |
| 314 | size_t fd_capacity; |
| 315 | grpc_fd **fds; |
| 316 | }; |
| 317 | |
| 318 | /******************************************************************************* |
| 319 | * fd_posix.c |
| 320 | */ |
| 321 | |
| 322 | /* We need to keep a freelist not because of any concerns of malloc performance |
| 323 | * but instead so that implementations with multiple threads in (for example) |
| 324 | * epoll_wait deal with the race between pollset removal and incoming poll |
| 325 | * notifications. |
| 326 | * |
| 327 | * The problem is that the poller ultimately holds a reference to this |
| 328 | * object, so it is very difficult to know when is safe to free it, at least |
| 329 | * without some expensive synchronization. |
| 330 | * |
| 331 | * If we keep the object freelisted, in the worst case losing this race just |
| 332 | * becomes a spurious read notification on a reused fd. |
| 333 | */ |
| 334 | /* TODO(klempner): We could use some form of polling generation count to know |
| 335 | * when these are safe to free. */ |
| 336 | /* TODO(klempner): Consider disabling freelisting if we don't have multiple |
| 337 | * threads in poll on the same fd */ |
| 338 | /* TODO(klempner): Batch these allocations to reduce fragmentation */ |
| 339 | static grpc_fd *fd_freelist = NULL; |
| 340 | static gpr_mu fd_freelist_mu; |
| 341 | |
| 342 | static void freelist_fd(grpc_fd *fd) { |
| 343 | gpr_mu_lock(&fd_freelist_mu); |
| 344 | fd->freelist_next = fd_freelist; |
| 345 | fd_freelist = fd; |
| 346 | grpc_iomgr_unregister_object(&fd->iomgr_object); |
| 347 | gpr_mu_unlock(&fd_freelist_mu); |
| 348 | } |
| 349 | |
| 350 | static grpc_fd *alloc_fd(int fd) { |
| 351 | grpc_fd *r = NULL; |
| 352 | |
| 353 | gpr_mu_lock(&fd_freelist_mu); |
| 354 | if (fd_freelist != NULL) { |
| 355 | r = fd_freelist; |
| 356 | fd_freelist = fd_freelist->freelist_next; |
| 357 | } |
| 358 | gpr_mu_unlock(&fd_freelist_mu); |
| 359 | |
| 360 | if (r == NULL) { |
| 361 | r = gpr_malloc(sizeof(grpc_fd)); |
| 362 | gpr_mu_init(&r->mu); |
| 363 | gpr_mu_init(&r->pi_mu); |
| 364 | } |
| 365 | |
| 366 | /* TODO: sreek - check with ctiller on why we need to acquire a lock here */ |
| 367 | gpr_mu_lock(&r->mu); |
| 368 | gpr_atm_rel_store(&r->refst, 1); |
| 369 | r->shutdown = 0; |
| 370 | r->read_closure = CLOSURE_NOT_READY; |
| 371 | r->write_closure = CLOSURE_NOT_READY; |
| 372 | r->fd = fd; |
| 373 | r->polling_island = NULL; |
| 374 | r->freelist_next = NULL; |
| 375 | r->on_done_closure = NULL; |
| 376 | r->closed = 0; |
| 377 | r->released = 0; |
| 378 | gpr_mu_unlock(&r->mu); |
| 379 | return r; |
| 380 | } |
| 381 | |
| 382 | static void destroy(grpc_fd *fd) { |
| 383 | gpr_mu_destroy(&fd->mu); |
| 384 | gpr_free(fd); |
| 385 | } |
| 386 | |
| 387 | #ifdef GRPC_FD_REF_COUNT_DEBUG |
| 388 | #define REF_BY(fd, n, reason) ref_by(fd, n, reason, __FILE__, __LINE__) |
| 389 | #define UNREF_BY(fd, n, reason) unref_by(fd, n, reason, __FILE__, __LINE__) |
| 390 | static void ref_by(grpc_fd *fd, int n, const char *reason, const char *file, |
| 391 | int line) { |
| 392 | gpr_log(GPR_DEBUG, "FD %d %p ref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n, |
| 393 | gpr_atm_no_barrier_load(&fd->refst), |
| 394 | gpr_atm_no_barrier_load(&fd->refst) + n, reason, file, line); |
| 395 | #else |
| 396 | #define REF_BY(fd, n, reason) ref_by(fd, n) |
| 397 | #define UNREF_BY(fd, n, reason) unref_by(fd, n) |
| 398 | static void ref_by(grpc_fd *fd, int n) { |
| 399 | #endif |
| 400 | GPR_ASSERT(gpr_atm_no_barrier_fetch_add(&fd->refst, n) > 0); |
| 401 | } |
| 402 | |
| 403 | #ifdef GRPC_FD_REF_COUNT_DEBUG |
| 404 | static void unref_by(grpc_fd *fd, int n, const char *reason, const char *file, |
| 405 | int line) { |
| 406 | gpr_atm old; |
| 407 | gpr_log(GPR_DEBUG, "FD %d %p unref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n, |
| 408 | gpr_atm_no_barrier_load(&fd->refst), |
| 409 | gpr_atm_no_barrier_load(&fd->refst) - n, reason, file, line); |
| 410 | #else |
| 411 | static void unref_by(grpc_fd *fd, int n) { |
| 412 | gpr_atm old; |
| 413 | #endif |
| 414 | old = gpr_atm_full_fetch_add(&fd->refst, -n); |
| 415 | if (old == n) { |
| 416 | freelist_fd(fd); |
| 417 | } else { |
| 418 | GPR_ASSERT(old > n); |
| 419 | } |
| 420 | } |
| 421 | |
| 422 | static void fd_global_init(void) { gpr_mu_init(&fd_freelist_mu); } |
| 423 | |
| 424 | static void fd_global_shutdown(void) { |
| 425 | gpr_mu_lock(&fd_freelist_mu); |
| 426 | gpr_mu_unlock(&fd_freelist_mu); |
| 427 | while (fd_freelist != NULL) { |
| 428 | grpc_fd *fd = fd_freelist; |
| 429 | fd_freelist = fd_freelist->freelist_next; |
| 430 | destroy(fd); |
| 431 | } |
| 432 | gpr_mu_destroy(&fd_freelist_mu); |
| 433 | } |
| 434 | |
| 435 | static grpc_fd *fd_create(int fd, const char *name) { |
| 436 | grpc_fd *r = alloc_fd(fd); |
| 437 | char *name2; |
| 438 | gpr_asprintf(&name2, "%s fd=%d", name, fd); |
| 439 | grpc_iomgr_register_object(&r->iomgr_object, name2); |
| 440 | gpr_free(name2); |
| 441 | #ifdef GRPC_FD_REF_COUNT_DEBUG |
| 442 | gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, r, name); |
| 443 | #endif |
| 444 | return r; |
| 445 | } |
| 446 | |
| 447 | static bool fd_is_orphaned(grpc_fd *fd) { |
| 448 | return (gpr_atm_acq_load(&fd->refst) & 1) == 0; |
| 449 | } |
| 450 | |
| 451 | static void close_fd_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd) { |
| 452 | fd->closed = 1; |
| 453 | if (!fd->released) { |
| 454 | close(fd->fd); |
| 455 | } else { |
| 456 | remove_fd_from_all_epoll_sets(fd->fd); |
| 457 | } |
| 458 | grpc_exec_ctx_enqueue(exec_ctx, fd->on_done_closure, true, NULL); |
| 459 | } |
| 460 | |
| 461 | static int fd_wrapped_fd(grpc_fd *fd) { |
| 462 | if (fd->released || fd->closed) { |
| 463 | return -1; |
| 464 | } else { |
| 465 | return fd->fd; |
| 466 | } |
| 467 | } |
| 468 | |
| 469 | /* TODO: sreek - do something here with the pollset island link */ |
| 470 | static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 471 | grpc_closure *on_done, int *release_fd, |
| 472 | const char *reason) { |
| 473 | fd->on_done_closure = on_done; |
| 474 | fd->released = release_fd != NULL; |
| 475 | if (!fd->released) { |
| 476 | shutdown(fd->fd, SHUT_RDWR); |
| 477 | } else { |
| 478 | *release_fd = fd->fd; |
| 479 | } |
| 480 | gpr_mu_lock(&fd->mu); |
| 481 | REF_BY(fd, 1, reason); /* remove active status, but keep referenced */ |
| 482 | close_fd_locked(exec_ctx, fd); |
| 483 | gpr_mu_unlock(&fd->mu); |
| 484 | UNREF_BY(fd, 2, reason); /* drop the reference */ |
| 485 | } |
| 486 | |
| 487 | /* increment refcount by two to avoid changing the orphan bit */ |
| 488 | #ifdef GRPC_FD_REF_COUNT_DEBUG |
| 489 | static void fd_ref(grpc_fd *fd, const char *reason, const char *file, |
| 490 | int line) { |
| 491 | ref_by(fd, 2, reason, file, line); |
| 492 | } |
| 493 | |
| 494 | static void fd_unref(grpc_fd *fd, const char *reason, const char *file, |
| 495 | int line) { |
| 496 | unref_by(fd, 2, reason, file, line); |
| 497 | } |
| 498 | #else |
| 499 | static void fd_ref(grpc_fd *fd) { ref_by(fd, 2); } |
| 500 | |
| 501 | static void fd_unref(grpc_fd *fd) { unref_by(fd, 2); } |
| 502 | #endif |
| 503 | |
| 504 | static void notify_on_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 505 | grpc_closure **st, grpc_closure *closure) { |
| 506 | if (*st == CLOSURE_NOT_READY) { |
| 507 | /* not ready ==> switch to a waiting state by setting the closure */ |
| 508 | *st = closure; |
| 509 | } else if (*st == CLOSURE_READY) { |
| 510 | /* already ready ==> queue the closure to run immediately */ |
| 511 | *st = CLOSURE_NOT_READY; |
| 512 | grpc_exec_ctx_enqueue(exec_ctx, closure, !fd->shutdown, NULL); |
| 513 | } else { |
| 514 | /* upcallptr was set to a different closure. This is an error! */ |
| 515 | gpr_log(GPR_ERROR, |
| 516 | "User called a notify_on function with a previous callback still " |
| 517 | "pending"); |
| 518 | abort(); |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | /* returns 1 if state becomes not ready */ |
| 523 | static int set_ready_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 524 | grpc_closure **st) { |
| 525 | if (*st == CLOSURE_READY) { |
| 526 | /* duplicate ready ==> ignore */ |
| 527 | return 0; |
| 528 | } else if (*st == CLOSURE_NOT_READY) { |
| 529 | /* not ready, and not waiting ==> flag ready */ |
| 530 | *st = CLOSURE_READY; |
| 531 | return 0; |
| 532 | } else { |
| 533 | /* waiting ==> queue closure */ |
| 534 | grpc_exec_ctx_enqueue(exec_ctx, *st, !fd->shutdown, NULL); |
| 535 | *st = CLOSURE_NOT_READY; |
| 536 | return 1; |
| 537 | } |
| 538 | } |
| 539 | |
| 540 | /* Do something here with the pollset island link (?) */ |
| 541 | static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd) { |
| 542 | gpr_mu_lock(&fd->mu); |
| 543 | GPR_ASSERT(!fd->shutdown); |
| 544 | fd->shutdown = 1; |
| 545 | set_ready_locked(exec_ctx, fd, &fd->read_closure); |
| 546 | set_ready_locked(exec_ctx, fd, &fd->write_closure); |
| 547 | gpr_mu_unlock(&fd->mu); |
| 548 | } |
| 549 | |
| 550 | static void fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 551 | grpc_closure *closure) { |
| 552 | gpr_mu_lock(&fd->mu); |
| 553 | notify_on_locked(exec_ctx, fd, &fd->read_closure, closure); |
| 554 | gpr_mu_unlock(&fd->mu); |
| 555 | } |
| 556 | |
| 557 | static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd, |
| 558 | grpc_closure *closure) { |
| 559 | gpr_mu_lock(&fd->mu); |
| 560 | notify_on_locked(exec_ctx, fd, &fd->write_closure, closure); |
| 561 | gpr_mu_unlock(&fd->mu); |
| 562 | } |
| 563 | |
| 564 | /******************************************************************************* |
| 565 | * pollset_posix.c |
| 566 | */ |
| 567 | |
| 568 | GPR_TLS_DECL(g_current_thread_poller); |
| 569 | GPR_TLS_DECL(g_current_thread_worker); |
| 570 | |
| 571 | /** The alarm system needs to be able to wakeup 'some poller' sometimes |
| 572 | * (specifically when a new alarm needs to be triggered earlier than the next |
| 573 | * alarm 'epoch'). |
| 574 | * This wakeup_fd gives us something to alert on when such a case occurs. */ |
| 575 | grpc_wakeup_fd grpc_global_wakeup_fd; |
| 576 | |
| 577 | static void remove_worker(grpc_pollset *p, grpc_pollset_worker *worker) { |
| 578 | worker->prev->next = worker->next; |
| 579 | worker->next->prev = worker->prev; |
| 580 | } |
| 581 | |
| 582 | static int pollset_has_workers(grpc_pollset *p) { |
| 583 | return p->root_worker.next != &p->root_worker; |
| 584 | } |
| 585 | |
| 586 | static grpc_pollset_worker *pop_front_worker(grpc_pollset *p) { |
| 587 | if (pollset_has_workers(p)) { |
| 588 | grpc_pollset_worker *w = p->root_worker.next; |
| 589 | remove_worker(p, w); |
| 590 | return w; |
| 591 | } else { |
| 592 | return NULL; |
| 593 | } |
| 594 | } |
| 595 | |
| 596 | static void push_back_worker(grpc_pollset *p, grpc_pollset_worker *worker) { |
| 597 | worker->next = &p->root_worker; |
| 598 | worker->prev = worker->next->prev; |
| 599 | worker->prev->next = worker->next->prev = worker; |
| 600 | } |
| 601 | |
| 602 | static void push_front_worker(grpc_pollset *p, grpc_pollset_worker *worker) { |
| 603 | worker->prev = &p->root_worker; |
| 604 | worker->next = worker->prev->next; |
| 605 | worker->prev->next = worker->next->prev = worker; |
| 606 | } |
| 607 | |
| 608 | static void pollset_kick_ext(grpc_pollset *p, |
| 609 | grpc_pollset_worker *specific_worker, |
| 610 | uint32_t flags) { |
| 611 | GPR_TIMER_BEGIN("pollset_kick_ext", 0); |
| 612 | |
| 613 | /* pollset->mu already held */ |
| 614 | if (specific_worker != NULL) { |
| 615 | if (specific_worker == GRPC_POLLSET_KICK_BROADCAST) { |
| 616 | GPR_TIMER_BEGIN("pollset_kick_ext.broadcast", 0); |
| 617 | GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0); |
| 618 | for (specific_worker = p->root_worker.next; |
| 619 | specific_worker != &p->root_worker; |
| 620 | specific_worker = specific_worker->next) { |
| 621 | grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd); |
| 622 | } |
| 623 | p->kicked_without_pollers = 1; |
| 624 | GPR_TIMER_END("pollset_kick_ext.broadcast", 0); |
| 625 | } else if (gpr_tls_get(&g_current_thread_worker) != |
| 626 | (intptr_t)specific_worker) { |
| 627 | GPR_TIMER_MARK("different_thread_worker", 0); |
| 628 | if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) { |
| 629 | specific_worker->reevaluate_polling_on_wakeup = 1; |
| 630 | } |
| 631 | specific_worker->kicked_specifically = 1; |
| 632 | grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd); |
| 633 | /* TODO (sreek): Refactor this into a separate file*/ |
| 634 | pthread_kill(specific_worker->pt_id, SIGUSR1); |
| 635 | } else if ((flags & GRPC_POLLSET_CAN_KICK_SELF) != 0) { |
| 636 | GPR_TIMER_MARK("kick_yoself", 0); |
| 637 | if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) { |
| 638 | specific_worker->reevaluate_polling_on_wakeup = 1; |
| 639 | } |
| 640 | specific_worker->kicked_specifically = 1; |
| 641 | grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd); |
| 642 | } |
| 643 | } else if (gpr_tls_get(&g_current_thread_poller) != (intptr_t)p) { |
| 644 | GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0); |
| 645 | GPR_TIMER_MARK("kick_anonymous", 0); |
| 646 | specific_worker = pop_front_worker(p); |
| 647 | if (specific_worker != NULL) { |
| 648 | if (gpr_tls_get(&g_current_thread_worker) == (intptr_t)specific_worker) { |
| 649 | GPR_TIMER_MARK("kick_anonymous_not_self", 0); |
| 650 | push_back_worker(p, specific_worker); |
| 651 | specific_worker = pop_front_worker(p); |
| 652 | if ((flags & GRPC_POLLSET_CAN_KICK_SELF) == 0 && |
| 653 | gpr_tls_get(&g_current_thread_worker) == |
| 654 | (intptr_t)specific_worker) { |
| 655 | push_back_worker(p, specific_worker); |
| 656 | specific_worker = NULL; |
| 657 | } |
| 658 | } |
| 659 | if (specific_worker != NULL) { |
| 660 | GPR_TIMER_MARK("finally_kick", 0); |
| 661 | push_back_worker(p, specific_worker); |
| 662 | grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd); |
| 663 | } |
| 664 | } else { |
| 665 | GPR_TIMER_MARK("kicked_no_pollers", 0); |
| 666 | p->kicked_without_pollers = 1; |
| 667 | } |
| 668 | } |
| 669 | |
| 670 | GPR_TIMER_END("pollset_kick_ext", 0); |
| 671 | } |
| 672 | |
| 673 | static void pollset_kick(grpc_pollset *p, |
| 674 | grpc_pollset_worker *specific_worker) { |
| 675 | pollset_kick_ext(p, specific_worker, 0); |
| 676 | } |
| 677 | |
| 678 | /* global state management */ |
| 679 | |
| 680 | static void sig_handler(int sig_num) { |
| 681 | gpr_log(GPR_INFO, "Received signal %d", sig_num); |
| 682 | } |
| 683 | |
| 684 | static void pollset_global_init(void) { |
| 685 | gpr_tls_init(&g_current_thread_poller); |
| 686 | gpr_tls_init(&g_current_thread_worker); |
| 687 | grpc_wakeup_fd_init(&grpc_global_wakeup_fd); |
| 688 | signal(SIGUSR1, sig_handler); |
| 689 | } |
| 690 | |
| 691 | static void pollset_global_shutdown(void) { |
| 692 | grpc_wakeup_fd_destroy(&grpc_global_wakeup_fd); |
| 693 | gpr_tls_destroy(&g_current_thread_poller); |
| 694 | gpr_tls_destroy(&g_current_thread_worker); |
| 695 | } |
| 696 | |
| 697 | static void kick_poller(void) { grpc_wakeup_fd_wakeup(&grpc_global_wakeup_fd); } |
| 698 | |
| 699 | /* TODO: sreek. Try to Remove this forward declaration*/ |
| 700 | static void multipoll_with_epoll_pollset_create_efd(grpc_pollset *pollset); |
| 701 | |
| 702 | /* main interface */ |
| 703 | |
| 704 | static void pollset_init(grpc_pollset *pollset, gpr_mu **mu) { |
| 705 | gpr_mu_init(&pollset->mu); |
| 706 | *mu = &pollset->mu; |
| 707 | pollset->root_worker.next = pollset->root_worker.prev = &pollset->root_worker; |
| 708 | gpr_mu_init(&pollset->pi_mu); |
| 709 | pollset->polling_island = NULL; |
| 710 | pollset->shutting_down = 0; |
| 711 | pollset->called_shutdown = 0; |
| 712 | pollset->kicked_without_pollers = 0; |
| 713 | pollset->local_wakeup_cache = NULL; |
| 714 | pollset->kicked_without_pollers = 0; |
| 715 | |
| 716 | multipoll_with_epoll_pollset_create_efd(pollset); |
| 717 | } |
| 718 | |
| 719 | /* TODO(sreek): Maybe merge multipoll_*_destroy() with pollset_destroy() |
| 720 | * function */ |
| 721 | static void multipoll_with_epoll_pollset_destroy(grpc_pollset *pollset); |
| 722 | |
| 723 | static void pollset_destroy(grpc_pollset *pollset) { |
| 724 | GPR_ASSERT(!pollset_has_workers(pollset)); |
| 725 | |
| 726 | multipoll_with_epoll_pollset_destroy(pollset); |
| 727 | |
| 728 | while (pollset->local_wakeup_cache) { |
| 729 | grpc_cached_wakeup_fd *next = pollset->local_wakeup_cache->next; |
| 730 | grpc_wakeup_fd_destroy(&pollset->local_wakeup_cache->fd); |
| 731 | gpr_free(pollset->local_wakeup_cache); |
| 732 | pollset->local_wakeup_cache = next; |
| 733 | } |
| 734 | gpr_mu_destroy(&pollset->pi_mu); |
| 735 | gpr_mu_destroy(&pollset->mu); |
| 736 | } |
| 737 | |
| 738 | /* TODO(sreek) - Do something with the pollset island link (??) */ |
| 739 | static void pollset_reset(grpc_pollset *pollset) { |
| 740 | GPR_ASSERT(pollset->shutting_down); |
| 741 | GPR_ASSERT(!pollset_has_workers(pollset)); |
| 742 | pollset->shutting_down = 0; |
| 743 | pollset->called_shutdown = 0; |
| 744 | pollset->kicked_without_pollers = 0; |
| 745 | } |
| 746 | |
| 747 | /* TODO (sreek): Remove multipoll_with_epoll_finish_shutdown() declaration */ |
| 748 | static void multipoll_with_epoll_pollset_finish_shutdown(grpc_pollset *pollset); |
| 749 | |
| 750 | static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) { |
| 751 | multipoll_with_epoll_pollset_finish_shutdown(pollset); |
| 752 | grpc_exec_ctx_enqueue(exec_ctx, pollset->shutdown_done, true, NULL); |
| 753 | } |
| 754 | |
| 755 | /* TODO(sreek): Remove multipoll_with_epoll_*_maybe_work_and_unlock declaration |
| 756 | */ |
| 757 | static void multipoll_with_epoll_pollset_maybe_work_and_unlock( |
| 758 | grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker, |
| 759 | gpr_timespec deadline, gpr_timespec now); |
| 760 | |
| 761 | static void pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 762 | grpc_pollset_worker **worker_hdl, gpr_timespec now, |
| 763 | gpr_timespec deadline) { |
| 764 | grpc_pollset_worker worker; |
| 765 | *worker_hdl = &worker; |
| 766 | |
| 767 | /* pollset->mu already held */ |
| 768 | int added_worker = 0; |
| 769 | int locked = 1; |
| 770 | int queued_work = 0; |
| 771 | int keep_polling = 0; |
| 772 | GPR_TIMER_BEGIN("pollset_work", 0); |
| 773 | /* this must happen before we (potentially) drop pollset->mu */ |
| 774 | worker.next = worker.prev = NULL; |
| 775 | worker.reevaluate_polling_on_wakeup = 0; |
| 776 | if (pollset->local_wakeup_cache != NULL) { |
| 777 | worker.wakeup_fd = pollset->local_wakeup_cache; |
| 778 | pollset->local_wakeup_cache = worker.wakeup_fd->next; |
| 779 | } else { |
| 780 | worker.wakeup_fd = gpr_malloc(sizeof(*worker.wakeup_fd)); |
| 781 | grpc_wakeup_fd_init(&worker.wakeup_fd->fd); |
| 782 | } |
| 783 | worker.kicked_specifically = 0; |
| 784 | |
| 785 | /* TODO(sreek): Abstract this thread id stuff out into a separate file */ |
| 786 | worker.pt_id = pthread_self(); |
| 787 | /* If we're shutting down then we don't execute any extended work */ |
| 788 | if (pollset->shutting_down) { |
| 789 | GPR_TIMER_MARK("pollset_work.shutting_down", 0); |
| 790 | goto done; |
| 791 | } |
| 792 | /* Start polling, and keep doing so while we're being asked to |
| 793 | re-evaluate our pollers (this allows poll() based pollers to |
| 794 | ensure they don't miss wakeups) */ |
| 795 | keep_polling = 1; |
| 796 | while (keep_polling) { |
| 797 | keep_polling = 0; |
| 798 | if (!pollset->kicked_without_pollers) { |
| 799 | if (!added_worker) { |
| 800 | push_front_worker(pollset, &worker); |
| 801 | added_worker = 1; |
| 802 | gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker); |
| 803 | } |
| 804 | gpr_tls_set(&g_current_thread_poller, (intptr_t)pollset); |
| 805 | GPR_TIMER_BEGIN("maybe_work_and_unlock", 0); |
| 806 | |
| 807 | multipoll_with_epoll_pollset_maybe_work_and_unlock( |
| 808 | exec_ctx, pollset, &worker, deadline, now); |
| 809 | |
| 810 | GPR_TIMER_END("maybe_work_and_unlock", 0); |
| 811 | locked = 0; |
| 812 | gpr_tls_set(&g_current_thread_poller, 0); |
| 813 | } else { |
| 814 | GPR_TIMER_MARK("pollset_work.kicked_without_pollers", 0); |
| 815 | pollset->kicked_without_pollers = 0; |
| 816 | } |
| 817 | /* Finished execution - start cleaning up. |
| 818 | Note that we may arrive here from outside the enclosing while() loop. |
| 819 | In that case we won't loop though as we haven't added worker to the |
| 820 | worker list, which means nobody could ask us to re-evaluate polling). */ |
| 821 | done: |
| 822 | if (!locked) { |
| 823 | queued_work |= grpc_exec_ctx_flush(exec_ctx); |
| 824 | gpr_mu_lock(&pollset->mu); |
| 825 | locked = 1; |
| 826 | } |
| 827 | /* If we're forced to re-evaluate polling (via pollset_kick with |
| 828 | GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) then we land here and force |
| 829 | a loop */ |
| 830 | if (worker.reevaluate_polling_on_wakeup) { |
| 831 | worker.reevaluate_polling_on_wakeup = 0; |
| 832 | pollset->kicked_without_pollers = 0; |
| 833 | if (queued_work || worker.kicked_specifically) { |
| 834 | /* If there's queued work on the list, then set the deadline to be |
| 835 | immediate so we get back out of the polling loop quickly */ |
| 836 | deadline = gpr_inf_past(GPR_CLOCK_MONOTONIC); |
| 837 | } |
| 838 | keep_polling = 1; |
| 839 | } |
| 840 | } |
| 841 | if (added_worker) { |
| 842 | remove_worker(pollset, &worker); |
| 843 | gpr_tls_set(&g_current_thread_worker, 0); |
| 844 | } |
| 845 | /* release wakeup fd to the local pool */ |
| 846 | worker.wakeup_fd->next = pollset->local_wakeup_cache; |
| 847 | pollset->local_wakeup_cache = worker.wakeup_fd; |
| 848 | /* check shutdown conditions */ |
| 849 | if (pollset->shutting_down) { |
| 850 | if (pollset_has_workers(pollset)) { |
| 851 | pollset_kick(pollset, NULL); |
| 852 | } else if (!pollset->called_shutdown) { |
| 853 | pollset->called_shutdown = 1; |
| 854 | gpr_mu_unlock(&pollset->mu); |
| 855 | finish_shutdown(exec_ctx, pollset); |
| 856 | grpc_exec_ctx_flush(exec_ctx); |
| 857 | /* Continuing to access pollset here is safe -- it is the caller's |
| 858 | * responsibility to not destroy when it has outstanding calls to |
| 859 | * pollset_work. |
| 860 | * TODO(dklempner): Can we refactor the shutdown logic to avoid this? */ |
| 861 | gpr_mu_lock(&pollset->mu); |
| 862 | } |
| 863 | } |
| 864 | *worker_hdl = NULL; |
| 865 | GPR_TIMER_END("pollset_work", 0); |
| 866 | } |
| 867 | |
| 868 | /* TODO: (sreek) Do something with the pollset island link */ |
| 869 | static void pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 870 | grpc_closure *closure) { |
| 871 | GPR_ASSERT(!pollset->shutting_down); |
| 872 | pollset->shutting_down = 1; |
| 873 | pollset->shutdown_done = closure; |
| 874 | pollset_kick(pollset, GRPC_POLLSET_KICK_BROADCAST); |
| 875 | |
| 876 | if (!pollset->called_shutdown && !pollset_has_workers(pollset)) { |
| 877 | pollset->called_shutdown = 1; |
| 878 | finish_shutdown(exec_ctx, pollset); |
| 879 | } |
| 880 | } |
| 881 | |
| 882 | static int poll_deadline_to_millis_timeout(gpr_timespec deadline, |
| 883 | gpr_timespec now) { |
| 884 | gpr_timespec timeout; |
| 885 | static const int64_t max_spin_polling_us = 10; |
| 886 | if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) { |
| 887 | return -1; |
| 888 | } |
| 889 | if (gpr_time_cmp(deadline, gpr_time_add(now, gpr_time_from_micros( |
| 890 | max_spin_polling_us, |
| 891 | GPR_TIMESPAN))) <= 0) { |
| 892 | return 0; |
| 893 | } |
| 894 | timeout = gpr_time_sub(deadline, now); |
| 895 | return gpr_time_to_millis(gpr_time_add( |
| 896 | timeout, gpr_time_from_nanos(GPR_NS_PER_MS - 1, GPR_TIMESPAN))); |
| 897 | } |
| 898 | |
| 899 | /******************************************************************************* |
| 900 | * pollset_multipoller_with_epoll_posix.c |
| 901 | */ |
| 902 | |
| 903 | static void set_ready(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure **st) { |
| 904 | /* only one set_ready can be active at once (but there may be a racing |
| 905 | notify_on) */ |
| 906 | gpr_mu_lock(&fd->mu); |
| 907 | set_ready_locked(exec_ctx, fd, st); |
| 908 | gpr_mu_unlock(&fd->mu); |
| 909 | } |
| 910 | |
| 911 | static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) { |
| 912 | set_ready(exec_ctx, fd, &fd->read_closure); |
| 913 | } |
| 914 | |
| 915 | static void fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) { |
| 916 | set_ready(exec_ctx, fd, &fd->write_closure); |
| 917 | } |
| 918 | |
| 919 | /* TODO (sreek): Maybe this global list is not required. Double check*/ |
| 920 | struct epoll_fd_list { |
| 921 | int *epoll_fds; |
| 922 | size_t count; |
| 923 | size_t capacity; |
| 924 | }; |
| 925 | |
| 926 | static struct epoll_fd_list epoll_fd_global_list; |
| 927 | static gpr_once init_epoll_fd_list_mu = GPR_ONCE_INIT; |
| 928 | static gpr_mu epoll_fd_list_mu; |
| 929 | |
| 930 | static void init_mu(void) { gpr_mu_init(&epoll_fd_list_mu); } |
| 931 | |
| 932 | static void add_epoll_fd_to_global_list(int epoll_fd) { |
| 933 | gpr_once_init(&init_epoll_fd_list_mu, init_mu); |
| 934 | |
| 935 | gpr_mu_lock(&epoll_fd_list_mu); |
| 936 | if (epoll_fd_global_list.count == epoll_fd_global_list.capacity) { |
| 937 | epoll_fd_global_list.capacity = |
| 938 | GPR_MAX((size_t)8, epoll_fd_global_list.capacity * 2); |
| 939 | epoll_fd_global_list.epoll_fds = |
| 940 | gpr_realloc(epoll_fd_global_list.epoll_fds, |
| 941 | epoll_fd_global_list.capacity * sizeof(int)); |
| 942 | } |
| 943 | epoll_fd_global_list.epoll_fds[epoll_fd_global_list.count++] = epoll_fd; |
| 944 | gpr_mu_unlock(&epoll_fd_list_mu); |
| 945 | } |
| 946 | |
| 947 | static void remove_epoll_fd_from_global_list(int epoll_fd) { |
| 948 | gpr_mu_lock(&epoll_fd_list_mu); |
| 949 | GPR_ASSERT(epoll_fd_global_list.count > 0); |
| 950 | for (size_t i = 0; i < epoll_fd_global_list.count; i++) { |
| 951 | if (epoll_fd == epoll_fd_global_list.epoll_fds[i]) { |
| 952 | epoll_fd_global_list.epoll_fds[i] = |
| 953 | epoll_fd_global_list.epoll_fds[--(epoll_fd_global_list.count)]; |
| 954 | break; |
| 955 | } |
| 956 | } |
| 957 | gpr_mu_unlock(&epoll_fd_list_mu); |
| 958 | } |
| 959 | |
| 960 | static void remove_fd_from_all_epoll_sets(int fd) { |
| 961 | int err; |
| 962 | gpr_once_init(&init_epoll_fd_list_mu, init_mu); |
| 963 | gpr_mu_lock(&epoll_fd_list_mu); |
| 964 | if (epoll_fd_global_list.count == 0) { |
| 965 | gpr_mu_unlock(&epoll_fd_list_mu); |
| 966 | return; |
| 967 | } |
| 968 | for (size_t i = 0; i < epoll_fd_global_list.count; i++) { |
| 969 | err = epoll_ctl(epoll_fd_global_list.epoll_fds[i], EPOLL_CTL_DEL, fd, NULL); |
| 970 | if (err < 0 && errno != ENOENT) { |
| 971 | gpr_log(GPR_ERROR, "epoll_ctl del for %d failed: %s", fd, |
| 972 | strerror(errno)); |
| 973 | } |
| 974 | } |
| 975 | gpr_mu_unlock(&epoll_fd_list_mu); |
| 976 | } |
| 977 | |
| 978 | /* TODO: sreek - This function multipoll_with_epoll_pollset_add_fd() and |
| 979 | * finally_add_fd() in ev_poll_and_epoll_posix.c */ |
| 980 | static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, |
| 981 | grpc_fd *fd) { |
| 982 | |
| 983 | /* TODO sreek - Check if we need to get a pollset->mu lock here */ |
| 984 | |
| 985 | struct epoll_event ev; |
| 986 | int err; |
| 987 | |
| 988 | /* Hold a ref to the fd to keep it from being closed during the add. This may |
| 989 | result in a spurious wakeup being assigned to this pollset whilst adding, |
| 990 | but that should be benign. */ |
| 991 | /* TODO: (sreek): Understand how a spurious wake up migh be assinged to this |
| 992 | * pollset..and how holding a reference will prevent the fd from being closed |
| 993 | * (and perhaps more importantly, see how can an fd be closed while being |
| 994 | * added to the epollset */ |
| 995 | GRPC_FD_REF(fd, "add fd"); |
| 996 | |
| 997 | gpr_mu_lock(&fd->mu); |
| 998 | if (fd->shutdown) { |
| 999 | gpr_mu_unlock(&fd->mu); |
| 1000 | GRPC_FD_UNREF(fd, "add fd"); |
| 1001 | return; |
| 1002 | } |
| 1003 | gpr_mu_unlock(&fd->mu); |
| 1004 | |
| 1005 | ev.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET); |
| 1006 | ev.data.ptr = fd; |
| 1007 | err = epoll_ctl(pollset->epoll_fd, EPOLL_CTL_ADD, fd->fd, &ev); |
| 1008 | if (err < 0) { |
| 1009 | /* FDs may be added to a pollset multiple times, so EEXIST is normal. */ |
| 1010 | if (errno != EEXIST) { |
| 1011 | gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s", fd->fd, |
| 1012 | strerror(errno)); |
| 1013 | } |
| 1014 | } |
| 1015 | |
| 1016 | /* The fd might have been orphaned while we were adding it to the epoll set. |
| 1017 | Close the fd in such a case (which will also take care of removing it from |
| 1018 | the epoll set */ |
| 1019 | gpr_mu_lock(&fd->mu); |
| 1020 | if (fd_is_orphaned(fd) && !fd->closed) { |
| 1021 | close_fd_locked(exec_ctx, fd); |
| 1022 | } |
| 1023 | gpr_mu_unlock(&fd->mu); |
| 1024 | |
| 1025 | GRPC_FD_UNREF(fd, "add fd"); |
| 1026 | } |
| 1027 | |
| 1028 | /* Creates an epoll fd and initializes the pollset */ |
| 1029 | /* TODO: This has to be called ONLY from pollset_init function. and hence it |
| 1030 | * does not acquire any lock */ |
| 1031 | static void multipoll_with_epoll_pollset_create_efd(grpc_pollset *pollset) { |
| 1032 | struct epoll_event ev; |
| 1033 | int err; |
| 1034 | |
| 1035 | pollset->epoll_fd = epoll_create1(EPOLL_CLOEXEC); |
| 1036 | if (pollset->epoll_fd < 0) { |
| 1037 | gpr_log(GPR_ERROR, "epoll_create1 failed: %s", strerror(errno)); |
| 1038 | abort(); |
| 1039 | } |
| 1040 | add_epoll_fd_to_global_list(pollset->epoll_fd); |
| 1041 | |
| 1042 | ev.events = (uint32_t)(EPOLLIN | EPOLLET); |
| 1043 | ev.data.ptr = NULL; |
| 1044 | |
| 1045 | err = epoll_ctl(pollset->epoll_fd, EPOLL_CTL_ADD, |
| 1046 | GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd), &ev); |
| 1047 | if (err < 0) { |
| 1048 | gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s", |
| 1049 | GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd), |
| 1050 | strerror(errno)); |
| 1051 | } |
| 1052 | } |
| 1053 | |
| 1054 | /* TODO(klempner): We probably want to turn this down a bit */ |
| 1055 | #define GRPC_EPOLL_MAX_EVENTS 1000 |
| 1056 | |
| 1057 | static void multipoll_with_epoll_pollset_maybe_work_and_unlock( |
| 1058 | grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker, |
| 1059 | gpr_timespec deadline, gpr_timespec now) { |
| 1060 | struct epoll_event ep_ev[GRPC_EPOLL_MAX_EVENTS]; |
| 1061 | int epoll_fd = pollset->epoll_fd; |
| 1062 | int ep_rv; |
| 1063 | int poll_rv; |
| 1064 | int timeout_ms; |
| 1065 | struct pollfd pfds[2]; |
| 1066 | |
| 1067 | /* If you want to ignore epoll's ability to sanely handle parallel pollers, |
| 1068 | * for a more apples-to-apples performance comparison with poll, add a |
| 1069 | * if (pollset->counter != 0) { return 0; } |
| 1070 | * here. |
| 1071 | */ |
| 1072 | |
| 1073 | gpr_mu_unlock(&pollset->mu); |
| 1074 | |
| 1075 | timeout_ms = poll_deadline_to_millis_timeout(deadline, now); |
| 1076 | |
| 1077 | pfds[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd); |
| 1078 | pfds[0].events = POLLIN; |
| 1079 | pfds[0].revents = 0; |
| 1080 | pfds[1].fd = epoll_fd; |
| 1081 | pfds[1].events = POLLIN; |
| 1082 | pfds[1].revents = 0; |
| 1083 | |
| 1084 | /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid |
| 1085 | even going into the blocking annotation if possible */ |
| 1086 | GPR_TIMER_BEGIN("poll", 0); |
| 1087 | GRPC_SCHEDULING_START_BLOCKING_REGION; |
| 1088 | poll_rv = grpc_poll_function(pfds, 2, timeout_ms); |
| 1089 | GRPC_SCHEDULING_END_BLOCKING_REGION; |
| 1090 | GPR_TIMER_END("poll", 0); |
| 1091 | |
| 1092 | if (poll_rv < 0) { |
| 1093 | if (errno != EINTR) { |
| 1094 | gpr_log(GPR_ERROR, "poll() failed: %s", strerror(errno)); |
| 1095 | } |
| 1096 | } else if (poll_rv == 0) { |
| 1097 | /* do nothing */ |
| 1098 | } else { |
| 1099 | if (pfds[0].revents) { |
| 1100 | grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd); |
| 1101 | } |
| 1102 | if (pfds[1].revents) { |
| 1103 | do { |
| 1104 | /* The following epoll_wait never blocks; it has a timeout of 0 */ |
| 1105 | ep_rv = epoll_wait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, 0); |
| 1106 | if (ep_rv < 0) { |
| 1107 | if (errno != EINTR) { |
| 1108 | gpr_log(GPR_ERROR, "epoll_wait() failed: %s", strerror(errno)); |
| 1109 | } |
| 1110 | } else { |
| 1111 | int i; |
| 1112 | for (i = 0; i < ep_rv; ++i) { |
| 1113 | grpc_fd *fd = ep_ev[i].data.ptr; |
| 1114 | /* TODO(klempner): We might want to consider making err and pri |
| 1115 | * separate events */ |
| 1116 | int cancel = ep_ev[i].events & (EPOLLERR | EPOLLHUP); |
| 1117 | int read_ev = ep_ev[i].events & (EPOLLIN | EPOLLPRI); |
| 1118 | int write_ev = ep_ev[i].events & EPOLLOUT; |
| 1119 | if (fd == NULL) { |
| 1120 | grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd); |
| 1121 | } else { |
| 1122 | if (read_ev || cancel) { |
| 1123 | fd_become_readable(exec_ctx, fd); |
| 1124 | } |
| 1125 | if (write_ev || cancel) { |
| 1126 | fd_become_writable(exec_ctx, fd); |
| 1127 | } |
| 1128 | } |
| 1129 | } |
| 1130 | } |
| 1131 | } while (ep_rv == GRPC_EPOLL_MAX_EVENTS); |
| 1132 | } |
| 1133 | } |
| 1134 | } |
| 1135 | |
| 1136 | static void multipoll_with_epoll_pollset_finish_shutdown( |
| 1137 | grpc_pollset *pollset) {} |
| 1138 | |
| 1139 | static void multipoll_with_epoll_pollset_destroy(grpc_pollset *pollset) { |
| 1140 | close(pollset->epoll_fd); |
| 1141 | remove_epoll_fd_from_global_list(pollset->epoll_fd); |
| 1142 | } |
| 1143 | |
| 1144 | /******************************************************************************* |
| 1145 | * pollset_set_posix.c |
| 1146 | */ |
| 1147 | |
| 1148 | static grpc_pollset_set *pollset_set_create(void) { |
| 1149 | grpc_pollset_set *pollset_set = gpr_malloc(sizeof(*pollset_set)); |
| 1150 | memset(pollset_set, 0, sizeof(*pollset_set)); |
| 1151 | gpr_mu_init(&pollset_set->mu); |
| 1152 | return pollset_set; |
| 1153 | } |
| 1154 | |
| 1155 | static void pollset_set_destroy(grpc_pollset_set *pollset_set) { |
| 1156 | size_t i; |
| 1157 | gpr_mu_destroy(&pollset_set->mu); |
| 1158 | for (i = 0; i < pollset_set->fd_count; i++) { |
| 1159 | GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set"); |
| 1160 | } |
| 1161 | gpr_free(pollset_set->pollsets); |
| 1162 | gpr_free(pollset_set->pollset_sets); |
| 1163 | gpr_free(pollset_set->fds); |
| 1164 | gpr_free(pollset_set); |
| 1165 | } |
| 1166 | |
| 1167 | static void pollset_set_add_pollset(grpc_exec_ctx *exec_ctx, |
| 1168 | grpc_pollset_set *pollset_set, |
| 1169 | grpc_pollset *pollset) { |
| 1170 | size_t i, j; |
| 1171 | gpr_mu_lock(&pollset_set->mu); |
| 1172 | if (pollset_set->pollset_count == pollset_set->pollset_capacity) { |
| 1173 | pollset_set->pollset_capacity = |
| 1174 | GPR_MAX(8, 2 * pollset_set->pollset_capacity); |
| 1175 | pollset_set->pollsets = |
| 1176 | gpr_realloc(pollset_set->pollsets, pollset_set->pollset_capacity * |
| 1177 | sizeof(*pollset_set->pollsets)); |
| 1178 | } |
| 1179 | pollset_set->pollsets[pollset_set->pollset_count++] = pollset; |
| 1180 | for (i = 0, j = 0; i < pollset_set->fd_count; i++) { |
| 1181 | if (fd_is_orphaned(pollset_set->fds[i])) { |
| 1182 | GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set"); |
| 1183 | } else { |
| 1184 | pollset_add_fd(exec_ctx, pollset, pollset_set->fds[i]); |
| 1185 | pollset_set->fds[j++] = pollset_set->fds[i]; |
| 1186 | } |
| 1187 | } |
| 1188 | pollset_set->fd_count = j; |
| 1189 | gpr_mu_unlock(&pollset_set->mu); |
| 1190 | } |
| 1191 | |
| 1192 | static void pollset_set_del_pollset(grpc_exec_ctx *exec_ctx, |
| 1193 | grpc_pollset_set *pollset_set, |
| 1194 | grpc_pollset *pollset) { |
| 1195 | size_t i; |
| 1196 | gpr_mu_lock(&pollset_set->mu); |
| 1197 | for (i = 0; i < pollset_set->pollset_count; i++) { |
| 1198 | if (pollset_set->pollsets[i] == pollset) { |
| 1199 | pollset_set->pollset_count--; |
| 1200 | GPR_SWAP(grpc_pollset *, pollset_set->pollsets[i], |
| 1201 | pollset_set->pollsets[pollset_set->pollset_count]); |
| 1202 | break; |
| 1203 | } |
| 1204 | } |
| 1205 | gpr_mu_unlock(&pollset_set->mu); |
| 1206 | } |
| 1207 | |
| 1208 | static void pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx, |
| 1209 | grpc_pollset_set *bag, |
| 1210 | grpc_pollset_set *item) { |
| 1211 | size_t i, j; |
| 1212 | gpr_mu_lock(&bag->mu); |
| 1213 | if (bag->pollset_set_count == bag->pollset_set_capacity) { |
| 1214 | bag->pollset_set_capacity = GPR_MAX(8, 2 * bag->pollset_set_capacity); |
| 1215 | bag->pollset_sets = |
| 1216 | gpr_realloc(bag->pollset_sets, |
| 1217 | bag->pollset_set_capacity * sizeof(*bag->pollset_sets)); |
| 1218 | } |
| 1219 | bag->pollset_sets[bag->pollset_set_count++] = item; |
| 1220 | for (i = 0, j = 0; i < bag->fd_count; i++) { |
| 1221 | if (fd_is_orphaned(bag->fds[i])) { |
| 1222 | GRPC_FD_UNREF(bag->fds[i], "pollset_set"); |
| 1223 | } else { |
| 1224 | pollset_set_add_fd(exec_ctx, item, bag->fds[i]); |
| 1225 | bag->fds[j++] = bag->fds[i]; |
| 1226 | } |
| 1227 | } |
| 1228 | bag->fd_count = j; |
| 1229 | gpr_mu_unlock(&bag->mu); |
| 1230 | } |
| 1231 | |
| 1232 | static void pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx, |
| 1233 | grpc_pollset_set *bag, |
| 1234 | grpc_pollset_set *item) { |
| 1235 | size_t i; |
| 1236 | gpr_mu_lock(&bag->mu); |
| 1237 | for (i = 0; i < bag->pollset_set_count; i++) { |
| 1238 | if (bag->pollset_sets[i] == item) { |
| 1239 | bag->pollset_set_count--; |
| 1240 | GPR_SWAP(grpc_pollset_set *, bag->pollset_sets[i], |
| 1241 | bag->pollset_sets[bag->pollset_set_count]); |
| 1242 | break; |
| 1243 | } |
| 1244 | } |
| 1245 | gpr_mu_unlock(&bag->mu); |
| 1246 | } |
| 1247 | |
| 1248 | static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx, |
| 1249 | grpc_pollset_set *pollset_set, grpc_fd *fd) { |
| 1250 | size_t i; |
| 1251 | gpr_mu_lock(&pollset_set->mu); |
| 1252 | if (pollset_set->fd_count == pollset_set->fd_capacity) { |
| 1253 | pollset_set->fd_capacity = GPR_MAX(8, 2 * pollset_set->fd_capacity); |
| 1254 | pollset_set->fds = gpr_realloc( |
| 1255 | pollset_set->fds, pollset_set->fd_capacity * sizeof(*pollset_set->fds)); |
| 1256 | } |
| 1257 | GRPC_FD_REF(fd, "pollset_set"); |
| 1258 | pollset_set->fds[pollset_set->fd_count++] = fd; |
| 1259 | for (i = 0; i < pollset_set->pollset_count; i++) { |
| 1260 | pollset_add_fd(exec_ctx, pollset_set->pollsets[i], fd); |
| 1261 | } |
| 1262 | for (i = 0; i < pollset_set->pollset_set_count; i++) { |
| 1263 | pollset_set_add_fd(exec_ctx, pollset_set->pollset_sets[i], fd); |
| 1264 | } |
| 1265 | gpr_mu_unlock(&pollset_set->mu); |
| 1266 | } |
| 1267 | |
| 1268 | static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx, |
| 1269 | grpc_pollset_set *pollset_set, grpc_fd *fd) { |
| 1270 | size_t i; |
| 1271 | gpr_mu_lock(&pollset_set->mu); |
| 1272 | for (i = 0; i < pollset_set->fd_count; i++) { |
| 1273 | if (pollset_set->fds[i] == fd) { |
| 1274 | pollset_set->fd_count--; |
| 1275 | GPR_SWAP(grpc_fd *, pollset_set->fds[i], |
| 1276 | pollset_set->fds[pollset_set->fd_count]); |
| 1277 | GRPC_FD_UNREF(fd, "pollset_set"); |
| 1278 | break; |
| 1279 | } |
| 1280 | } |
| 1281 | for (i = 0; i < pollset_set->pollset_set_count; i++) { |
| 1282 | pollset_set_del_fd(exec_ctx, pollset_set->pollset_sets[i], fd); |
| 1283 | } |
| 1284 | gpr_mu_unlock(&pollset_set->mu); |
| 1285 | } |
| 1286 | |
| 1287 | /******************************************************************************* |
| 1288 | * event engine binding |
| 1289 | */ |
| 1290 | |
| 1291 | static void shutdown_engine(void) { |
| 1292 | fd_global_shutdown(); |
| 1293 | pollset_global_shutdown(); |
| 1294 | } |
| 1295 | |
| 1296 | static const grpc_event_engine_vtable vtable = { |
| 1297 | .pollset_size = sizeof(grpc_pollset), |
| 1298 | |
| 1299 | .fd_create = fd_create, |
| 1300 | .fd_wrapped_fd = fd_wrapped_fd, |
| 1301 | .fd_orphan = fd_orphan, |
| 1302 | .fd_shutdown = fd_shutdown, |
| 1303 | .fd_notify_on_read = fd_notify_on_read, |
| 1304 | .fd_notify_on_write = fd_notify_on_write, |
| 1305 | |
| 1306 | .pollset_init = pollset_init, |
| 1307 | .pollset_shutdown = pollset_shutdown, |
| 1308 | .pollset_reset = pollset_reset, |
| 1309 | .pollset_destroy = pollset_destroy, |
| 1310 | .pollset_work = pollset_work, |
| 1311 | .pollset_kick = pollset_kick, |
| 1312 | .pollset_add_fd = pollset_add_fd, |
| 1313 | |
| 1314 | .pollset_set_create = pollset_set_create, |
| 1315 | .pollset_set_destroy = pollset_set_destroy, |
| 1316 | .pollset_set_add_pollset = pollset_set_add_pollset, |
| 1317 | .pollset_set_del_pollset = pollset_set_del_pollset, |
| 1318 | .pollset_set_add_pollset_set = pollset_set_add_pollset_set, |
| 1319 | .pollset_set_del_pollset_set = pollset_set_del_pollset_set, |
| 1320 | .pollset_set_add_fd = pollset_set_add_fd, |
| 1321 | .pollset_set_del_fd = pollset_set_del_fd, |
| 1322 | |
| 1323 | .kick_poller = kick_poller, |
| 1324 | |
| 1325 | .shutdown_engine = shutdown_engine, |
| 1326 | }; |
| 1327 | |
| 1328 | const grpc_event_engine_vtable *grpc_init_epoll_linux(void) { |
| 1329 | fd_global_init(); |
| 1330 | pollset_global_init(); |
| 1331 | polling_island_global_init(); |
| 1332 | return &vtable; |
| 1333 | } |
| 1334 | |
| 1335 | #endif |