| /* |
| * |
| * Copyright 2016 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #include "src/core/lib/iomgr/port.h" |
| |
| #ifdef GRPC_POSIX_SOCKET |
| |
| #include "src/core/lib/iomgr/ev_poll_posix.h" |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <limits.h> |
| #include <poll.h> |
| #include <string.h> |
| #include <sys/socket.h> |
| #include <unistd.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/string_util.h> |
| #include <grpc/support/thd.h> |
| #include <grpc/support/tls.h> |
| #include <grpc/support/useful.h> |
| |
| #include "src/core/lib/debug/stats.h" |
| #include "src/core/lib/iomgr/block_annotate.h" |
| #include "src/core/lib/iomgr/iomgr_internal.h" |
| #include "src/core/lib/iomgr/wakeup_fd_cv.h" |
| #include "src/core/lib/iomgr/wakeup_fd_posix.h" |
| #include "src/core/lib/profiling/timers.h" |
| #include "src/core/lib/support/murmur_hash.h" |
| |
| #define GRPC_POLLSET_KICK_BROADCAST ((grpc_pollset_worker*)1) |
| |
| /******************************************************************************* |
| * FD declarations |
| */ |
| typedef struct grpc_fd_watcher { |
| struct grpc_fd_watcher* next; |
| struct grpc_fd_watcher* prev; |
| grpc_pollset* pollset; |
| grpc_pollset_worker* worker; |
| grpc_fd* fd; |
| } grpc_fd_watcher; |
| |
| struct grpc_fd { |
| int fd; |
| /* refst format: |
| bit0: 1=active/0=orphaned |
| bit1-n: refcount |
| meaning that mostly we ref by two to avoid altering the orphaned bit, |
| and just unref by 1 when we're ready to flag the object as orphaned */ |
| gpr_atm refst; |
| |
| gpr_mu mu; |
| int shutdown; |
| int closed; |
| int released; |
| gpr_atm pollhup; |
| grpc_error* shutdown_error; |
| |
| /* The watcher list. |
| |
| The following watcher related fields are protected by watcher_mu. |
| |
| An fd_watcher is an ephemeral object created when an fd wants to |
| begin polling, and destroyed after the poll. |
| |
| It denotes the fd's interest in whether to read poll or write poll |
| or both or neither on this fd. |
| |
| If a watcher is asked to poll for reads or writes, the read_watcher |
| or write_watcher fields are set respectively. A watcher may be asked |
| to poll for both, in which case both fields will be set. |
| |
| read_watcher and write_watcher may be NULL if no watcher has been |
| asked to poll for reads or writes. |
| |
| If an fd_watcher is not asked to poll for reads or writes, it's added |
| to a linked list of inactive watchers, rooted at inactive_watcher_root. |
| If at a later time there becomes need of a poller to poll, one of |
| the inactive pollers may be kicked out of their poll loops to take |
| that responsibility. */ |
| grpc_fd_watcher inactive_watcher_root; |
| grpc_fd_watcher* read_watcher; |
| grpc_fd_watcher* write_watcher; |
| |
| grpc_closure* read_closure; |
| grpc_closure* write_closure; |
| |
| grpc_closure* on_done_closure; |
| |
| grpc_iomgr_object iomgr_object; |
| |
| /* The pollset that last noticed and notified that the fd is readable */ |
| grpc_pollset* read_notifier_pollset; |
| }; |
| |
| /* Begin polling on an fd. |
| Registers that the given pollset is interested in this fd - so that if read |
| or writability interest changes, the pollset can be kicked to pick up that |
| new interest. |
| Return value is: |
| (fd_needs_read? read_mask : 0) | (fd_needs_write? write_mask : 0) |
| i.e. a combination of read_mask and write_mask determined by the fd's current |
| interest in said events. |
| Polling strategies that do not need to alter their behavior depending on the |
| fd's current interest (such as epoll) do not need to call this function. |
| MUST NOT be called with a pollset lock taken */ |
| static uint32_t fd_begin_poll(grpc_fd* fd, grpc_pollset* pollset, |
| grpc_pollset_worker* worker, uint32_t read_mask, |
| uint32_t write_mask, grpc_fd_watcher* rec); |
| /* Complete polling previously started with fd_begin_poll |
| MUST NOT be called with a pollset lock taken |
| if got_read or got_write are 1, also does the become_{readable,writable} as |
| appropriate. */ |
| static void fd_end_poll(grpc_exec_ctx* exec_ctx, grpc_fd_watcher* rec, |
| int got_read, int got_write, |
| grpc_pollset* read_notifier_pollset); |
| |
| /* Return 1 if this fd is orphaned, 0 otherwise */ |
| static bool fd_is_orphaned(grpc_fd* fd); |
| |
| #ifndef NDEBUG |
| static void fd_ref(grpc_fd* fd, const char* reason, const char* file, int line); |
| static void fd_unref(grpc_fd* fd, const char* reason, const char* file, |
| int line); |
| #define GRPC_FD_REF(fd, reason) fd_ref(fd, reason, __FILE__, __LINE__) |
| #define GRPC_FD_UNREF(fd, reason) fd_unref(fd, reason, __FILE__, __LINE__) |
| #else |
| static void fd_ref(grpc_fd* fd); |
| static void fd_unref(grpc_fd* fd); |
| #define GRPC_FD_REF(fd, reason) fd_ref(fd) |
| #define GRPC_FD_UNREF(fd, reason) fd_unref(fd) |
| #endif |
| |
| #define CLOSURE_NOT_READY ((grpc_closure*)0) |
| #define CLOSURE_READY ((grpc_closure*)1) |
| |
| /******************************************************************************* |
| * pollset declarations |
| */ |
| |
| typedef struct grpc_cached_wakeup_fd { |
| grpc_wakeup_fd fd; |
| struct grpc_cached_wakeup_fd* next; |
| } grpc_cached_wakeup_fd; |
| |
| struct grpc_pollset_worker { |
| grpc_cached_wakeup_fd* wakeup_fd; |
| int reevaluate_polling_on_wakeup; |
| int kicked_specifically; |
| struct grpc_pollset_worker* next; |
| struct grpc_pollset_worker* prev; |
| }; |
| |
| struct grpc_pollset { |
| gpr_mu mu; |
| grpc_pollset_worker root_worker; |
| int shutting_down; |
| int called_shutdown; |
| int kicked_without_pollers; |
| grpc_closure* shutdown_done; |
| grpc_closure_list idle_jobs; |
| int pollset_set_count; |
| /* all polled fds */ |
| size_t fd_count; |
| size_t fd_capacity; |
| grpc_fd** fds; |
| /* Local cache of eventfds for workers */ |
| grpc_cached_wakeup_fd* local_wakeup_cache; |
| }; |
| |
| /* Add an fd to a pollset */ |
| static void pollset_add_fd(grpc_exec_ctx* exec_ctx, grpc_pollset* pollset, |
| struct grpc_fd* fd); |
| |
| static void pollset_set_add_fd(grpc_exec_ctx* exec_ctx, |
| grpc_pollset_set* pollset_set, grpc_fd* fd); |
| |
| /* Convert a timespec to milliseconds: |
| - very small or negative poll times are clamped to zero to do a |
| non-blocking poll (which becomes spin polling) |
| - other small values are rounded up to one millisecond |
| - longer than a millisecond polls are rounded up to the next nearest |
| millisecond to avoid spinning |
| - infinite timeouts are converted to -1 */ |
| static int poll_deadline_to_millis_timeout(grpc_exec_ctx* exec_ctx, |
| grpc_millis deadline); |
| |
| /* Allow kick to wakeup the currently polling worker */ |
| #define GRPC_POLLSET_CAN_KICK_SELF 1 |
| /* Force the wakee to repoll when awoken */ |
| #define GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP 2 |
| /* As per pollset_kick, with an extended set of flags (defined above) |
| -- mostly for fd_posix's use. */ |
| static grpc_error* pollset_kick_ext(grpc_exec_ctx* exec_ctx, grpc_pollset* p, |
| grpc_pollset_worker* specific_worker, |
| uint32_t flags) GRPC_MUST_USE_RESULT; |
| |
| /* Return 1 if the pollset has active threads in pollset_work (pollset must |
| * be locked) */ |
| static bool pollset_has_workers(grpc_pollset* pollset); |
| |
| /******************************************************************************* |
| * pollset_set definitions |
| */ |
| |
| struct grpc_pollset_set { |
| gpr_mu mu; |
| |
| size_t pollset_count; |
| size_t pollset_capacity; |
| grpc_pollset** pollsets; |
| |
| size_t pollset_set_count; |
| size_t pollset_set_capacity; |
| struct grpc_pollset_set** pollset_sets; |
| |
| size_t fd_count; |
| size_t fd_capacity; |
| grpc_fd** fds; |
| }; |
| |
| /******************************************************************************* |
| * condition variable polling definitions |
| */ |
| |
| #define POLLCV_THREAD_GRACE_MS 1000 |
| #define CV_POLL_PERIOD_MS 1000 |
| #define CV_DEFAULT_TABLE_SIZE 16 |
| |
| typedef struct poll_result { |
| gpr_refcount refcount; |
| cv_node* watchers; |
| int watchcount; |
| struct pollfd* fds; |
| nfds_t nfds; |
| int retval; |
| int err; |
| int completed; |
| } poll_result; |
| |
| typedef struct poll_args { |
| gpr_cv trigger; |
| int trigger_set; |
| struct pollfd* fds; |
| nfds_t nfds; |
| poll_result* result; |
| struct poll_args* next; |
| struct poll_args* prev; |
| } poll_args; |
| |
| // This is a 2-tiered cache, we mantain a hash table |
| // of active poll calls, so we can wait on the result |
| // of that call. We also maintain a freelist of inactive |
| // poll threads. |
| typedef struct poll_hash_table { |
| poll_args* free_pollers; |
| poll_args** active_pollers; |
| unsigned int size; |
| unsigned int count; |
| } poll_hash_table; |
| |
| poll_hash_table poll_cache; |
| cv_fd_table g_cvfds; |
| |
| /******************************************************************************* |
| * fd_posix.c |
| */ |
| |
| #ifndef NDEBUG |
| #define REF_BY(fd, n, reason) ref_by(fd, n, reason, __FILE__, __LINE__) |
| #define UNREF_BY(fd, n, reason) unref_by(fd, n, reason, __FILE__, __LINE__) |
| static void ref_by(grpc_fd* fd, int n, const char* reason, const char* file, |
| int line) { |
| if (grpc_trace_fd_refcount.enabled()) { |
| gpr_log(GPR_DEBUG, |
| "FD %d %p ref %d %" PRIdPTR " -> %" PRIdPTR " [%s; %s:%d]", |
| fd->fd, fd, n, gpr_atm_no_barrier_load(&fd->refst), |
| gpr_atm_no_barrier_load(&fd->refst) + n, reason, file, line); |
| } |
| #else |
| #define REF_BY(fd, n, reason) ref_by(fd, n) |
| #define UNREF_BY(fd, n, reason) unref_by(fd, n) |
| static void ref_by(grpc_fd* fd, int n) { |
| #endif |
| GPR_ASSERT(gpr_atm_no_barrier_fetch_add(&fd->refst, n) > 0); |
| } |
| |
| #ifndef NDEBUG |
| static void unref_by(grpc_fd* fd, int n, const char* reason, const char* file, |
| int line) { |
| if (grpc_trace_fd_refcount.enabled()) { |
| gpr_log(GPR_DEBUG, |
| "FD %d %p unref %d %" PRIdPTR " -> %" PRIdPTR " [%s; %s:%d]", |
| fd->fd, fd, n, gpr_atm_no_barrier_load(&fd->refst), |
| gpr_atm_no_barrier_load(&fd->refst) - n, reason, file, line); |
| } |
| #else |
| static void unref_by(grpc_fd* fd, int n) { |
| #endif |
| gpr_atm old = gpr_atm_full_fetch_add(&fd->refst, -n); |
| if (old == n) { |
| gpr_mu_destroy(&fd->mu); |
| grpc_iomgr_unregister_object(&fd->iomgr_object); |
| if (fd->shutdown) GRPC_ERROR_UNREF(fd->shutdown_error); |
| gpr_free(fd); |
| } else { |
| GPR_ASSERT(old > n); |
| } |
| } |
| |
| static grpc_fd* fd_create(int fd, const char* name) { |
| grpc_fd* r = (grpc_fd*)gpr_malloc(sizeof(*r)); |
| gpr_mu_init(&r->mu); |
| gpr_atm_rel_store(&r->refst, 1); |
| r->shutdown = 0; |
| r->read_closure = CLOSURE_NOT_READY; |
| r->write_closure = CLOSURE_NOT_READY; |
| r->fd = fd; |
| r->inactive_watcher_root.next = r->inactive_watcher_root.prev = |
| &r->inactive_watcher_root; |
| r->read_watcher = r->write_watcher = nullptr; |
| r->on_done_closure = nullptr; |
| r->closed = 0; |
| r->released = 0; |
| gpr_atm_no_barrier_store(&r->pollhup, 0); |
| r->read_notifier_pollset = nullptr; |
| |
| char* name2; |
| gpr_asprintf(&name2, "%s fd=%d", name, fd); |
| grpc_iomgr_register_object(&r->iomgr_object, name2); |
| gpr_free(name2); |
| return r; |
| } |
| |
| static bool fd_is_orphaned(grpc_fd* fd) { |
| return (gpr_atm_acq_load(&fd->refst) & 1) == 0; |
| } |
| |
| /* Return the read-notifier pollset */ |
| static grpc_pollset* fd_get_read_notifier_pollset(grpc_exec_ctx* exec_ctx, |
| grpc_fd* fd) { |
| grpc_pollset* notifier = nullptr; |
| |
| gpr_mu_lock(&fd->mu); |
| notifier = fd->read_notifier_pollset; |
| gpr_mu_unlock(&fd->mu); |
| |
| return notifier; |
| } |
| |
| static grpc_error* pollset_kick_locked(grpc_exec_ctx* exec_ctx, |
| grpc_fd_watcher* watcher) { |
| gpr_mu_lock(&watcher->pollset->mu); |
| GPR_ASSERT(watcher->worker); |
| grpc_error* err = |
| pollset_kick_ext(exec_ctx, watcher->pollset, watcher->worker, |
| GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP); |
| gpr_mu_unlock(&watcher->pollset->mu); |
| return err; |
| } |
| |
| static void maybe_wake_one_watcher_locked(grpc_exec_ctx* exec_ctx, |
| grpc_fd* fd) { |
| if (fd->inactive_watcher_root.next != &fd->inactive_watcher_root) { |
| pollset_kick_locked(exec_ctx, fd->inactive_watcher_root.next); |
| } else if (fd->read_watcher) { |
| pollset_kick_locked(exec_ctx, fd->read_watcher); |
| } else if (fd->write_watcher) { |
| pollset_kick_locked(exec_ctx, fd->write_watcher); |
| } |
| } |
| |
| static void wake_all_watchers_locked(grpc_exec_ctx* exec_ctx, grpc_fd* fd) { |
| grpc_fd_watcher* watcher; |
| for (watcher = fd->inactive_watcher_root.next; |
| watcher != &fd->inactive_watcher_root; watcher = watcher->next) { |
| pollset_kick_locked(exec_ctx, watcher); |
| } |
| if (fd->read_watcher) { |
| pollset_kick_locked(exec_ctx, fd->read_watcher); |
| } |
| if (fd->write_watcher && fd->write_watcher != fd->read_watcher) { |
| pollset_kick_locked(exec_ctx, fd->write_watcher); |
| } |
| } |
| |
| static int has_watchers(grpc_fd* fd) { |
| return fd->read_watcher != nullptr || fd->write_watcher != nullptr || |
| fd->inactive_watcher_root.next != &fd->inactive_watcher_root; |
| } |
| |
| static void close_fd_locked(grpc_exec_ctx* exec_ctx, grpc_fd* fd) { |
| fd->closed = 1; |
| if (!fd->released) { |
| close(fd->fd); |
| } |
| GRPC_CLOSURE_SCHED(exec_ctx, fd->on_done_closure, GRPC_ERROR_NONE); |
| } |
| |
| static int fd_wrapped_fd(grpc_fd* fd) { |
| if (fd->released || fd->closed) { |
| return -1; |
| } else { |
| return fd->fd; |
| } |
| } |
| |
| static void fd_orphan(grpc_exec_ctx* exec_ctx, grpc_fd* fd, |
| grpc_closure* on_done, int* release_fd, |
| bool already_closed, const char* reason) { |
| fd->on_done_closure = on_done; |
| fd->released = release_fd != nullptr; |
| if (release_fd != nullptr) { |
| *release_fd = fd->fd; |
| fd->released = true; |
| } else if (already_closed) { |
| fd->released = true; |
| } |
| gpr_mu_lock(&fd->mu); |
| REF_BY(fd, 1, reason); /* remove active status, but keep referenced */ |
| if (!has_watchers(fd)) { |
| close_fd_locked(exec_ctx, fd); |
| } else { |
| wake_all_watchers_locked(exec_ctx, fd); |
| } |
| gpr_mu_unlock(&fd->mu); |
| UNREF_BY(fd, 2, reason); /* drop the reference */ |
| } |
| |
| /* increment refcount by two to avoid changing the orphan bit */ |
| #ifndef NDEBUG |
| static void fd_ref(grpc_fd* fd, const char* reason, const char* file, |
| int line) { |
| ref_by(fd, 2, reason, file, line); |
| } |
| |
| static void fd_unref(grpc_fd* fd, const char* reason, const char* file, |
| int line) { |
| unref_by(fd, 2, reason, file, line); |
| } |
| #else |
| static void fd_ref(grpc_fd* fd) { ref_by(fd, 2); } |
| |
| static void fd_unref(grpc_fd* fd) { unref_by(fd, 2); } |
| #endif |
| |
| static grpc_error* fd_shutdown_error(grpc_fd* fd) { |
| if (!fd->shutdown) { |
| return GRPC_ERROR_NONE; |
| } else { |
| return GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING( |
| "FD shutdown", &fd->shutdown_error, 1); |
| } |
| } |
| |
| static void notify_on_locked(grpc_exec_ctx* exec_ctx, grpc_fd* fd, |
| grpc_closure** st, grpc_closure* closure) { |
| if (fd->shutdown) { |
| GRPC_CLOSURE_SCHED(exec_ctx, closure, |
| GRPC_ERROR_CREATE_FROM_STATIC_STRING("FD shutdown")); |
| } else if (*st == CLOSURE_NOT_READY) { |
| /* not ready ==> switch to a waiting state by setting the closure */ |
| *st = closure; |
| } else if (*st == CLOSURE_READY) { |
| /* already ready ==> queue the closure to run immediately */ |
| *st = CLOSURE_NOT_READY; |
| GRPC_CLOSURE_SCHED(exec_ctx, closure, fd_shutdown_error(fd)); |
| maybe_wake_one_watcher_locked(exec_ctx, fd); |
| } else { |
| /* upcallptr was set to a different closure. This is an error! */ |
| gpr_log(GPR_ERROR, |
| "User called a notify_on function with a previous callback still " |
| "pending"); |
| abort(); |
| } |
| } |
| |
| /* returns 1 if state becomes not ready */ |
| static int set_ready_locked(grpc_exec_ctx* exec_ctx, grpc_fd* fd, |
| grpc_closure** st) { |
| if (*st == CLOSURE_READY) { |
| /* duplicate ready ==> ignore */ |
| return 0; |
| } else if (*st == CLOSURE_NOT_READY) { |
| /* not ready, and not waiting ==> flag ready */ |
| *st = CLOSURE_READY; |
| return 0; |
| } else { |
| /* waiting ==> queue closure */ |
| GRPC_CLOSURE_SCHED(exec_ctx, *st, fd_shutdown_error(fd)); |
| *st = CLOSURE_NOT_READY; |
| return 1; |
| } |
| } |
| |
| static void set_read_notifier_pollset_locked( |
| grpc_exec_ctx* exec_ctx, grpc_fd* fd, grpc_pollset* read_notifier_pollset) { |
| fd->read_notifier_pollset = read_notifier_pollset; |
| } |
| |
| static void fd_shutdown(grpc_exec_ctx* exec_ctx, grpc_fd* fd, grpc_error* why) { |
| gpr_mu_lock(&fd->mu); |
| /* only shutdown once */ |
| if (!fd->shutdown) { |
| fd->shutdown = 1; |
| fd->shutdown_error = why; |
| /* signal read/write closed to OS so that future operations fail */ |
| shutdown(fd->fd, SHUT_RDWR); |
| set_ready_locked(exec_ctx, fd, &fd->read_closure); |
| set_ready_locked(exec_ctx, fd, &fd->write_closure); |
| } else { |
| GRPC_ERROR_UNREF(why); |
| } |
| gpr_mu_unlock(&fd->mu); |
| } |
| |
| static bool fd_is_shutdown(grpc_fd* fd) { |
| gpr_mu_lock(&fd->mu); |
| bool r = fd->shutdown; |
| gpr_mu_unlock(&fd->mu); |
| return r; |
| } |
| |
| static void fd_notify_on_read(grpc_exec_ctx* exec_ctx, grpc_fd* fd, |
| grpc_closure* closure) { |
| gpr_mu_lock(&fd->mu); |
| notify_on_locked(exec_ctx, fd, &fd->read_closure, closure); |
| gpr_mu_unlock(&fd->mu); |
| } |
| |
| static void fd_notify_on_write(grpc_exec_ctx* exec_ctx, grpc_fd* fd, |
| grpc_closure* closure) { |
| gpr_mu_lock(&fd->mu); |
| notify_on_locked(exec_ctx, fd, &fd->write_closure, closure); |
| gpr_mu_unlock(&fd->mu); |
| } |
| |
| static uint32_t fd_begin_poll(grpc_fd* fd, grpc_pollset* pollset, |
| grpc_pollset_worker* worker, uint32_t read_mask, |
| uint32_t write_mask, grpc_fd_watcher* watcher) { |
| uint32_t mask = 0; |
| grpc_closure* cur; |
| int requested; |
| /* keep track of pollers that have requested our events, in case they change |
| */ |
| GRPC_FD_REF(fd, "poll"); |
| |
| gpr_mu_lock(&fd->mu); |
| |
| /* if we are shutdown, then don't add to the watcher set */ |
| if (fd->shutdown) { |
| watcher->fd = nullptr; |
| watcher->pollset = nullptr; |
| watcher->worker = nullptr; |
| gpr_mu_unlock(&fd->mu); |
| GRPC_FD_UNREF(fd, "poll"); |
| return 0; |
| } |
| |
| /* if there is nobody polling for read, but we need to, then start doing so */ |
| cur = fd->read_closure; |
| requested = cur != CLOSURE_READY; |
| if (read_mask && fd->read_watcher == nullptr && requested) { |
| fd->read_watcher = watcher; |
| mask |= read_mask; |
| } |
| /* if there is nobody polling for write, but we need to, then start doing so |
| */ |
| cur = fd->write_closure; |
| requested = cur != CLOSURE_READY; |
| if (write_mask && fd->write_watcher == nullptr && requested) { |
| fd->write_watcher = watcher; |
| mask |= write_mask; |
| } |
| /* if not polling, remember this watcher in case we need someone to later */ |
| if (mask == 0 && worker != nullptr) { |
| watcher->next = &fd->inactive_watcher_root; |
| watcher->prev = watcher->next->prev; |
| watcher->next->prev = watcher->prev->next = watcher; |
| } |
| watcher->pollset = pollset; |
| watcher->worker = worker; |
| watcher->fd = fd; |
| gpr_mu_unlock(&fd->mu); |
| |
| return mask; |
| } |
| |
| static void fd_end_poll(grpc_exec_ctx* exec_ctx, grpc_fd_watcher* watcher, |
| int got_read, int got_write, |
| grpc_pollset* read_notifier_pollset) { |
| int was_polling = 0; |
| int kick = 0; |
| grpc_fd* fd = watcher->fd; |
| |
| if (fd == nullptr) { |
| return; |
| } |
| |
| gpr_mu_lock(&fd->mu); |
| |
| if (watcher == fd->read_watcher) { |
| /* remove read watcher, kick if we still need a read */ |
| was_polling = 1; |
| if (!got_read) { |
| kick = 1; |
| } |
| fd->read_watcher = nullptr; |
| } |
| if (watcher == fd->write_watcher) { |
| /* remove write watcher, kick if we still need a write */ |
| was_polling = 1; |
| if (!got_write) { |
| kick = 1; |
| } |
| fd->write_watcher = nullptr; |
| } |
| if (!was_polling && watcher->worker != nullptr) { |
| /* remove from inactive list */ |
| watcher->next->prev = watcher->prev; |
| watcher->prev->next = watcher->next; |
| } |
| if (got_read) { |
| if (set_ready_locked(exec_ctx, fd, &fd->read_closure)) { |
| kick = 1; |
| } |
| if (read_notifier_pollset != nullptr) { |
| set_read_notifier_pollset_locked(exec_ctx, fd, read_notifier_pollset); |
| } |
| } |
| if (got_write) { |
| if (set_ready_locked(exec_ctx, fd, &fd->write_closure)) { |
| kick = 1; |
| } |
| } |
| if (kick) { |
| maybe_wake_one_watcher_locked(exec_ctx, fd); |
| } |
| if (fd_is_orphaned(fd) && !has_watchers(fd) && !fd->closed) { |
| close_fd_locked(exec_ctx, fd); |
| } |
| gpr_mu_unlock(&fd->mu); |
| |
| GRPC_FD_UNREF(fd, "poll"); |
| } |
| |
| /******************************************************************************* |
| * pollset_posix.c |
| */ |
| |
| GPR_TLS_DECL(g_current_thread_poller); |
| GPR_TLS_DECL(g_current_thread_worker); |
| |
| static void remove_worker(grpc_pollset* p, grpc_pollset_worker* worker) { |
| worker->prev->next = worker->next; |
| worker->next->prev = worker->prev; |
| } |
| |
| static bool pollset_has_workers(grpc_pollset* p) { |
| return p->root_worker.next != &p->root_worker; |
| } |
| |
| static bool pollset_in_pollset_sets(grpc_pollset* p) { |
| return p->pollset_set_count; |
| } |
| |
| static bool pollset_has_observers(grpc_pollset* p) { |
| return pollset_has_workers(p) || pollset_in_pollset_sets(p); |
| } |
| |
| static grpc_pollset_worker* pop_front_worker(grpc_pollset* p) { |
| if (pollset_has_workers(p)) { |
| grpc_pollset_worker* w = p->root_worker.next; |
| remove_worker(p, w); |
| return w; |
| } else { |
| return nullptr; |
| } |
| } |
| |
| static void push_back_worker(grpc_pollset* p, grpc_pollset_worker* worker) { |
| worker->next = &p->root_worker; |
| worker->prev = worker->next->prev; |
| worker->prev->next = worker->next->prev = worker; |
| } |
| |
| static void push_front_worker(grpc_pollset* p, grpc_pollset_worker* worker) { |
| worker->prev = &p->root_worker; |
| worker->next = worker->prev->next; |
| worker->prev->next = worker->next->prev = worker; |
| } |
| |
| static void kick_append_error(grpc_error** composite, grpc_error* error) { |
| if (error == GRPC_ERROR_NONE) return; |
| if (*composite == GRPC_ERROR_NONE) { |
| *composite = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Kick Failure"); |
| } |
| *composite = grpc_error_add_child(*composite, error); |
| } |
| |
| static grpc_error* pollset_kick_ext(grpc_exec_ctx* exec_ctx, grpc_pollset* p, |
| grpc_pollset_worker* specific_worker, |
| uint32_t flags) { |
| GPR_TIMER_BEGIN("pollset_kick_ext", 0); |
| grpc_error* error = GRPC_ERROR_NONE; |
| GRPC_STATS_INC_POLLSET_KICK(exec_ctx); |
| |
| /* pollset->mu already held */ |
| if (specific_worker != nullptr) { |
| if (specific_worker == GRPC_POLLSET_KICK_BROADCAST) { |
| GPR_TIMER_BEGIN("pollset_kick_ext.broadcast", 0); |
| GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0); |
| for (specific_worker = p->root_worker.next; |
| specific_worker != &p->root_worker; |
| specific_worker = specific_worker->next) { |
| kick_append_error( |
| &error, grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd)); |
| } |
| p->kicked_without_pollers = true; |
| GPR_TIMER_END("pollset_kick_ext.broadcast", 0); |
| } else if (gpr_tls_get(&g_current_thread_worker) != |
| (intptr_t)specific_worker) { |
| GPR_TIMER_MARK("different_thread_worker", 0); |
| if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) { |
| specific_worker->reevaluate_polling_on_wakeup = true; |
| } |
| specific_worker->kicked_specifically = true; |
| kick_append_error(&error, |
| grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd)); |
| } else if ((flags & GRPC_POLLSET_CAN_KICK_SELF) != 0) { |
| GPR_TIMER_MARK("kick_yoself", 0); |
| if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) { |
| specific_worker->reevaluate_polling_on_wakeup = true; |
| } |
| specific_worker->kicked_specifically = true; |
| kick_append_error(&error, |
| grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd)); |
| } |
| } else if (gpr_tls_get(&g_current_thread_poller) != (intptr_t)p) { |
| GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0); |
| GPR_TIMER_MARK("kick_anonymous", 0); |
| specific_worker = pop_front_worker(p); |
| if (specific_worker != nullptr) { |
| if (gpr_tls_get(&g_current_thread_worker) == (intptr_t)specific_worker) { |
| GPR_TIMER_MARK("kick_anonymous_not_self", 0); |
| push_back_worker(p, specific_worker); |
| specific_worker = pop_front_worker(p); |
| if ((flags & GRPC_POLLSET_CAN_KICK_SELF) == 0 && |
| gpr_tls_get(&g_current_thread_worker) == |
| (intptr_t)specific_worker) { |
| push_back_worker(p, specific_worker); |
| specific_worker = nullptr; |
| } |
| } |
| if (specific_worker != nullptr) { |
| GPR_TIMER_MARK("finally_kick", 0); |
| push_back_worker(p, specific_worker); |
| kick_append_error( |
| &error, grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd)); |
| } |
| } else { |
| GPR_TIMER_MARK("kicked_no_pollers", 0); |
| p->kicked_without_pollers = true; |
| } |
| } |
| |
| GPR_TIMER_END("pollset_kick_ext", 0); |
| GRPC_LOG_IF_ERROR("pollset_kick_ext", GRPC_ERROR_REF(error)); |
| return error; |
| } |
| |
| static grpc_error* pollset_kick(grpc_exec_ctx* exec_ctx, grpc_pollset* p, |
| grpc_pollset_worker* specific_worker) { |
| return pollset_kick_ext(exec_ctx, p, specific_worker, 0); |
| } |
| |
| /* global state management */ |
| |
| static grpc_error* pollset_global_init(void) { |
| gpr_tls_init(&g_current_thread_poller); |
| gpr_tls_init(&g_current_thread_worker); |
| return GRPC_ERROR_NONE; |
| } |
| |
| static void pollset_global_shutdown(void) { |
| gpr_tls_destroy(&g_current_thread_poller); |
| gpr_tls_destroy(&g_current_thread_worker); |
| } |
| |
| /* main interface */ |
| |
| static void pollset_init(grpc_pollset* pollset, gpr_mu** mu) { |
| gpr_mu_init(&pollset->mu); |
| *mu = &pollset->mu; |
| pollset->root_worker.next = pollset->root_worker.prev = &pollset->root_worker; |
| pollset->shutting_down = 0; |
| pollset->called_shutdown = 0; |
| pollset->kicked_without_pollers = 0; |
| pollset->idle_jobs.head = pollset->idle_jobs.tail = nullptr; |
| pollset->local_wakeup_cache = nullptr; |
| pollset->kicked_without_pollers = 0; |
| pollset->fd_count = 0; |
| pollset->fd_capacity = 0; |
| pollset->fds = nullptr; |
| pollset->pollset_set_count = 0; |
| } |
| |
| static void pollset_destroy(grpc_exec_ctx* exec_ctx, grpc_pollset* pollset) { |
| GPR_ASSERT(!pollset_has_workers(pollset)); |
| GPR_ASSERT(pollset->idle_jobs.head == pollset->idle_jobs.tail); |
| while (pollset->local_wakeup_cache) { |
| grpc_cached_wakeup_fd* next = pollset->local_wakeup_cache->next; |
| grpc_wakeup_fd_destroy(&pollset->local_wakeup_cache->fd); |
| gpr_free(pollset->local_wakeup_cache); |
| pollset->local_wakeup_cache = next; |
| } |
| gpr_free(pollset->fds); |
| gpr_mu_destroy(&pollset->mu); |
| } |
| |
| static void pollset_add_fd(grpc_exec_ctx* exec_ctx, grpc_pollset* pollset, |
| grpc_fd* fd) { |
| gpr_mu_lock(&pollset->mu); |
| size_t i; |
| /* TODO(ctiller): this is O(num_fds^2); maybe switch to a hash set here */ |
| for (i = 0; i < pollset->fd_count; i++) { |
| if (pollset->fds[i] == fd) goto exit; |
| } |
| if (pollset->fd_count == pollset->fd_capacity) { |
| pollset->fd_capacity = |
| GPR_MAX(pollset->fd_capacity + 8, pollset->fd_count * 3 / 2); |
| pollset->fds = (grpc_fd**)gpr_realloc( |
| pollset->fds, sizeof(grpc_fd*) * pollset->fd_capacity); |
| } |
| pollset->fds[pollset->fd_count++] = fd; |
| GRPC_FD_REF(fd, "multipoller"); |
| pollset_kick(exec_ctx, pollset, nullptr); |
| exit: |
| gpr_mu_unlock(&pollset->mu); |
| } |
| |
| static void finish_shutdown(grpc_exec_ctx* exec_ctx, grpc_pollset* pollset) { |
| GPR_ASSERT(grpc_closure_list_empty(pollset->idle_jobs)); |
| size_t i; |
| for (i = 0; i < pollset->fd_count; i++) { |
| GRPC_FD_UNREF(pollset->fds[i], "multipoller"); |
| } |
| pollset->fd_count = 0; |
| GRPC_CLOSURE_SCHED(exec_ctx, pollset->shutdown_done, GRPC_ERROR_NONE); |
| } |
| |
| static void work_combine_error(grpc_error** composite, grpc_error* error) { |
| if (error == GRPC_ERROR_NONE) return; |
| if (*composite == GRPC_ERROR_NONE) { |
| *composite = GRPC_ERROR_CREATE_FROM_STATIC_STRING("pollset_work"); |
| } |
| *composite = grpc_error_add_child(*composite, error); |
| } |
| |
| static grpc_error* pollset_work(grpc_exec_ctx* exec_ctx, grpc_pollset* pollset, |
| grpc_pollset_worker** worker_hdl, |
| grpc_millis deadline) { |
| grpc_pollset_worker worker; |
| if (worker_hdl) *worker_hdl = &worker; |
| grpc_error* error = GRPC_ERROR_NONE; |
| |
| /* Avoid malloc for small number of elements. */ |
| enum { inline_elements = 96 }; |
| struct pollfd pollfd_space[inline_elements]; |
| struct grpc_fd_watcher watcher_space[inline_elements]; |
| |
| /* pollset->mu already held */ |
| int added_worker = 0; |
| int locked = 1; |
| int queued_work = 0; |
| int keep_polling = 0; |
| GPR_TIMER_BEGIN("pollset_work", 0); |
| /* this must happen before we (potentially) drop pollset->mu */ |
| worker.next = worker.prev = nullptr; |
| worker.reevaluate_polling_on_wakeup = 0; |
| if (pollset->local_wakeup_cache != nullptr) { |
| worker.wakeup_fd = pollset->local_wakeup_cache; |
| pollset->local_wakeup_cache = worker.wakeup_fd->next; |
| } else { |
| worker.wakeup_fd = |
| (grpc_cached_wakeup_fd*)gpr_malloc(sizeof(*worker.wakeup_fd)); |
| error = grpc_wakeup_fd_init(&worker.wakeup_fd->fd); |
| if (error != GRPC_ERROR_NONE) { |
| GRPC_LOG_IF_ERROR("pollset_work", GRPC_ERROR_REF(error)); |
| return error; |
| } |
| } |
| worker.kicked_specifically = 0; |
| /* If there's work waiting for the pollset to be idle, and the |
| pollset is idle, then do that work */ |
| if (!pollset_has_workers(pollset) && |
| !grpc_closure_list_empty(pollset->idle_jobs)) { |
| GPR_TIMER_MARK("pollset_work.idle_jobs", 0); |
| GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pollset->idle_jobs); |
| goto done; |
| } |
| /* If we're shutting down then we don't execute any extended work */ |
| if (pollset->shutting_down) { |
| GPR_TIMER_MARK("pollset_work.shutting_down", 0); |
| goto done; |
| } |
| /* Start polling, and keep doing so while we're being asked to |
| re-evaluate our pollers (this allows poll() based pollers to |
| ensure they don't miss wakeups) */ |
| keep_polling = 1; |
| gpr_tls_set(&g_current_thread_poller, (intptr_t)pollset); |
| while (keep_polling) { |
| keep_polling = 0; |
| if (!pollset->kicked_without_pollers) { |
| if (!added_worker) { |
| push_front_worker(pollset, &worker); |
| added_worker = 1; |
| gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker); |
| } |
| GPR_TIMER_BEGIN("maybe_work_and_unlock", 0); |
| #define POLLOUT_CHECK (POLLOUT | POLLHUP | POLLERR) |
| #define POLLIN_CHECK (POLLIN | POLLHUP | POLLERR) |
| |
| int timeout; |
| int r; |
| size_t i, fd_count; |
| nfds_t pfd_count; |
| grpc_fd_watcher* watchers; |
| struct pollfd* pfds; |
| |
| timeout = poll_deadline_to_millis_timeout(exec_ctx, deadline); |
| |
| if (pollset->fd_count + 2 <= inline_elements) { |
| pfds = pollfd_space; |
| watchers = watcher_space; |
| } else { |
| /* Allocate one buffer to hold both pfds and watchers arrays */ |
| const size_t pfd_size = sizeof(*pfds) * (pollset->fd_count + 2); |
| const size_t watch_size = sizeof(*watchers) * (pollset->fd_count + 2); |
| void* buf = gpr_malloc(pfd_size + watch_size); |
| pfds = (struct pollfd*)buf; |
| watchers = (grpc_fd_watcher*)(void*)((char*)buf + pfd_size); |
| } |
| |
| fd_count = 0; |
| pfd_count = 1; |
| pfds[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker.wakeup_fd->fd); |
| pfds[0].events = POLLIN; |
| pfds[0].revents = 0; |
| for (i = 0; i < pollset->fd_count; i++) { |
| if (fd_is_orphaned(pollset->fds[i]) || |
| gpr_atm_no_barrier_load(&pollset->fds[i]->pollhup) == 1) { |
| GRPC_FD_UNREF(pollset->fds[i], "multipoller"); |
| } else { |
| pollset->fds[fd_count++] = pollset->fds[i]; |
| watchers[pfd_count].fd = pollset->fds[i]; |
| GRPC_FD_REF(watchers[pfd_count].fd, "multipoller_start"); |
| pfds[pfd_count].fd = pollset->fds[i]->fd; |
| pfds[pfd_count].revents = 0; |
| pfd_count++; |
| } |
| } |
| pollset->fd_count = fd_count; |
| gpr_mu_unlock(&pollset->mu); |
| |
| for (i = 1; i < pfd_count; i++) { |
| grpc_fd* fd = watchers[i].fd; |
| pfds[i].events = (short)fd_begin_poll(fd, pollset, &worker, POLLIN, |
| POLLOUT, &watchers[i]); |
| GRPC_FD_UNREF(fd, "multipoller_start"); |
| } |
| |
| /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid |
| even going into the blocking annotation if possible */ |
| GRPC_SCHEDULING_START_BLOCKING_REGION; |
| GRPC_STATS_INC_SYSCALL_POLL(exec_ctx); |
| r = grpc_poll_function(pfds, pfd_count, timeout); |
| GRPC_SCHEDULING_END_BLOCKING_REGION_WITH_EXEC_CTX(exec_ctx); |
| |
| if (grpc_polling_trace.enabled()) { |
| gpr_log(GPR_DEBUG, "%p poll=%d", pollset, r); |
| } |
| |
| if (r < 0) { |
| if (errno != EINTR) { |
| work_combine_error(&error, GRPC_OS_ERROR(errno, "poll")); |
| } |
| |
| for (i = 1; i < pfd_count; i++) { |
| if (watchers[i].fd == nullptr) { |
| fd_end_poll(exec_ctx, &watchers[i], 0, 0, nullptr); |
| } else { |
| // Wake up all the file descriptors, if we have an invalid one |
| // we can identify it on the next pollset_work() |
| fd_end_poll(exec_ctx, &watchers[i], 1, 1, pollset); |
| } |
| } |
| } else if (r == 0) { |
| for (i = 1; i < pfd_count; i++) { |
| fd_end_poll(exec_ctx, &watchers[i], 0, 0, nullptr); |
| } |
| } else { |
| if (pfds[0].revents & POLLIN_CHECK) { |
| if (grpc_polling_trace.enabled()) { |
| gpr_log(GPR_DEBUG, "%p: got_wakeup", pollset); |
| } |
| work_combine_error( |
| &error, grpc_wakeup_fd_consume_wakeup(&worker.wakeup_fd->fd)); |
| } |
| for (i = 1; i < pfd_count; i++) { |
| if (watchers[i].fd == nullptr) { |
| fd_end_poll(exec_ctx, &watchers[i], 0, 0, nullptr); |
| } else { |
| if (grpc_polling_trace.enabled()) { |
| gpr_log(GPR_DEBUG, "%p got_event: %d r:%d w:%d [%d]", pollset, |
| pfds[i].fd, (pfds[i].revents & POLLIN_CHECK) != 0, |
| (pfds[i].revents & POLLOUT_CHECK) != 0, pfds[i].revents); |
| } |
| /* This is a mitigation to prevent poll() from spinning on a |
| ** POLLHUP https://github.com/grpc/grpc/pull/13665 |
| */ |
| if (pfds[i].revents & POLLHUP) { |
| gpr_atm_no_barrier_store(&watchers[i].fd->pollhup, 1); |
| } |
| fd_end_poll(exec_ctx, &watchers[i], pfds[i].revents & POLLIN_CHECK, |
| pfds[i].revents & POLLOUT_CHECK, pollset); |
| } |
| } |
| } |
| |
| if (pfds != pollfd_space) { |
| /* pfds and watchers are in the same memory block pointed to by pfds */ |
| gpr_free(pfds); |
| } |
| |
| GPR_TIMER_END("maybe_work_and_unlock", 0); |
| locked = 0; |
| } else { |
| GPR_TIMER_MARK("pollset_work.kicked_without_pollers", 0); |
| pollset->kicked_without_pollers = 0; |
| } |
| /* Finished execution - start cleaning up. |
| Note that we may arrive here from outside the enclosing while() loop. |
| In that case we won't loop though as we haven't added worker to the |
| worker list, which means nobody could ask us to re-evaluate polling). */ |
| done: |
| if (!locked) { |
| queued_work |= grpc_exec_ctx_flush(exec_ctx); |
| gpr_mu_lock(&pollset->mu); |
| locked = 1; |
| } |
| /* If we're forced to re-evaluate polling (via pollset_kick with |
| GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) then we land here and force |
| a loop */ |
| if (worker.reevaluate_polling_on_wakeup && error == GRPC_ERROR_NONE) { |
| worker.reevaluate_polling_on_wakeup = 0; |
| pollset->kicked_without_pollers = 0; |
| if (queued_work || worker.kicked_specifically) { |
| /* If there's queued work on the list, then set the deadline to be |
| immediate so we get back out of the polling loop quickly */ |
| deadline = 0; |
| } |
| keep_polling = 1; |
| } |
| } |
| gpr_tls_set(&g_current_thread_poller, 0); |
| if (added_worker) { |
| remove_worker(pollset, &worker); |
| gpr_tls_set(&g_current_thread_worker, 0); |
| } |
| /* release wakeup fd to the local pool */ |
| worker.wakeup_fd->next = pollset->local_wakeup_cache; |
| pollset->local_wakeup_cache = worker.wakeup_fd; |
| /* check shutdown conditions */ |
| if (pollset->shutting_down) { |
| if (pollset_has_workers(pollset)) { |
| pollset_kick(exec_ctx, pollset, nullptr); |
| } else if (!pollset->called_shutdown && !pollset_has_observers(pollset)) { |
| pollset->called_shutdown = 1; |
| gpr_mu_unlock(&pollset->mu); |
| finish_shutdown(exec_ctx, pollset); |
| grpc_exec_ctx_flush(exec_ctx); |
| /* Continuing to access pollset here is safe -- it is the caller's |
| * responsibility to not destroy when it has outstanding calls to |
| * pollset_work. |
| * TODO(dklempner): Can we refactor the shutdown logic to avoid this? */ |
| gpr_mu_lock(&pollset->mu); |
| } else if (!grpc_closure_list_empty(pollset->idle_jobs)) { |
| GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pollset->idle_jobs); |
| gpr_mu_unlock(&pollset->mu); |
| grpc_exec_ctx_flush(exec_ctx); |
| gpr_mu_lock(&pollset->mu); |
| } |
| } |
| if (worker_hdl) *worker_hdl = nullptr; |
| GPR_TIMER_END("pollset_work", 0); |
| GRPC_LOG_IF_ERROR("pollset_work", GRPC_ERROR_REF(error)); |
| return error; |
| } |
| |
| static void pollset_shutdown(grpc_exec_ctx* exec_ctx, grpc_pollset* pollset, |
| grpc_closure* closure) { |
| GPR_ASSERT(!pollset->shutting_down); |
| pollset->shutting_down = 1; |
| pollset->shutdown_done = closure; |
| pollset_kick(exec_ctx, pollset, GRPC_POLLSET_KICK_BROADCAST); |
| if (!pollset_has_workers(pollset)) { |
| GRPC_CLOSURE_LIST_SCHED(exec_ctx, &pollset->idle_jobs); |
| } |
| if (!pollset->called_shutdown && !pollset_has_observers(pollset)) { |
| pollset->called_shutdown = 1; |
| finish_shutdown(exec_ctx, pollset); |
| } |
| } |
| |
| static int poll_deadline_to_millis_timeout(grpc_exec_ctx* exec_ctx, |
| grpc_millis deadline) { |
| if (deadline == GRPC_MILLIS_INF_FUTURE) return -1; |
| if (deadline == 0) return 0; |
| grpc_millis n = deadline - grpc_exec_ctx_now(exec_ctx); |
| if (n < 0) return 0; |
| if (n > INT_MAX) return -1; |
| return (int)n; |
| } |
| |
| /******************************************************************************* |
| * pollset_set_posix.c |
| */ |
| |
| static grpc_pollset_set* pollset_set_create(void) { |
| grpc_pollset_set* pollset_set = |
| (grpc_pollset_set*)gpr_zalloc(sizeof(*pollset_set)); |
| gpr_mu_init(&pollset_set->mu); |
| return pollset_set; |
| } |
| |
| static void pollset_set_destroy(grpc_exec_ctx* exec_ctx, |
| grpc_pollset_set* pollset_set) { |
| size_t i; |
| gpr_mu_destroy(&pollset_set->mu); |
| for (i = 0; i < pollset_set->fd_count; i++) { |
| GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set"); |
| } |
| for (i = 0; i < pollset_set->pollset_count; i++) { |
| grpc_pollset* pollset = pollset_set->pollsets[i]; |
| gpr_mu_lock(&pollset->mu); |
| pollset->pollset_set_count--; |
| /* check shutdown */ |
| if (pollset->shutting_down && !pollset->called_shutdown && |
| !pollset_has_observers(pollset)) { |
| pollset->called_shutdown = 1; |
| gpr_mu_unlock(&pollset->mu); |
| finish_shutdown(exec_ctx, pollset); |
| } else { |
| gpr_mu_unlock(&pollset->mu); |
| } |
| } |
| gpr_free(pollset_set->pollsets); |
| gpr_free(pollset_set->pollset_sets); |
| gpr_free(pollset_set->fds); |
| gpr_free(pollset_set); |
| } |
| |
| static void pollset_set_add_pollset(grpc_exec_ctx* exec_ctx, |
| grpc_pollset_set* pollset_set, |
| grpc_pollset* pollset) { |
| size_t i, j; |
| gpr_mu_lock(&pollset->mu); |
| pollset->pollset_set_count++; |
| gpr_mu_unlock(&pollset->mu); |
| gpr_mu_lock(&pollset_set->mu); |
| if (pollset_set->pollset_count == pollset_set->pollset_capacity) { |
| pollset_set->pollset_capacity = |
| GPR_MAX(8, 2 * pollset_set->pollset_capacity); |
| pollset_set->pollsets = (grpc_pollset**)gpr_realloc( |
| pollset_set->pollsets, |
| pollset_set->pollset_capacity * sizeof(*pollset_set->pollsets)); |
| } |
| pollset_set->pollsets[pollset_set->pollset_count++] = pollset; |
| for (i = 0, j = 0; i < pollset_set->fd_count; i++) { |
| if (fd_is_orphaned(pollset_set->fds[i])) { |
| GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set"); |
| } else { |
| pollset_add_fd(exec_ctx, pollset, pollset_set->fds[i]); |
| pollset_set->fds[j++] = pollset_set->fds[i]; |
| } |
| } |
| pollset_set->fd_count = j; |
| gpr_mu_unlock(&pollset_set->mu); |
| } |
| |
| static void pollset_set_del_pollset(grpc_exec_ctx* exec_ctx, |
| grpc_pollset_set* pollset_set, |
| grpc_pollset* pollset) { |
| size_t i; |
| gpr_mu_lock(&pollset_set->mu); |
| for (i = 0; i < pollset_set->pollset_count; i++) { |
| if (pollset_set->pollsets[i] == pollset) { |
| pollset_set->pollset_count--; |
| GPR_SWAP(grpc_pollset*, pollset_set->pollsets[i], |
| pollset_set->pollsets[pollset_set->pollset_count]); |
| break; |
| } |
| } |
| gpr_mu_unlock(&pollset_set->mu); |
| gpr_mu_lock(&pollset->mu); |
| pollset->pollset_set_count--; |
| /* check shutdown */ |
| if (pollset->shutting_down && !pollset->called_shutdown && |
| !pollset_has_observers(pollset)) { |
| pollset->called_shutdown = 1; |
| gpr_mu_unlock(&pollset->mu); |
| finish_shutdown(exec_ctx, pollset); |
| } else { |
| gpr_mu_unlock(&pollset->mu); |
| } |
| } |
| |
| static void pollset_set_add_pollset_set(grpc_exec_ctx* exec_ctx, |
| grpc_pollset_set* bag, |
| grpc_pollset_set* item) { |
| size_t i, j; |
| gpr_mu_lock(&bag->mu); |
| if (bag->pollset_set_count == bag->pollset_set_capacity) { |
| bag->pollset_set_capacity = GPR_MAX(8, 2 * bag->pollset_set_capacity); |
| bag->pollset_sets = (grpc_pollset_set**)gpr_realloc( |
| bag->pollset_sets, |
| bag->pollset_set_capacity * sizeof(*bag->pollset_sets)); |
| } |
| bag->pollset_sets[bag->pollset_set_count++] = item; |
| for (i = 0, j = 0; i < bag->fd_count; i++) { |
| if (fd_is_orphaned(bag->fds[i])) { |
| GRPC_FD_UNREF(bag->fds[i], "pollset_set"); |
| } else { |
| pollset_set_add_fd(exec_ctx, item, bag->fds[i]); |
| bag->fds[j++] = bag->fds[i]; |
| } |
| } |
| bag->fd_count = j; |
| gpr_mu_unlock(&bag->mu); |
| } |
| |
| static void pollset_set_del_pollset_set(grpc_exec_ctx* exec_ctx, |
| grpc_pollset_set* bag, |
| grpc_pollset_set* item) { |
| size_t i; |
| gpr_mu_lock(&bag->mu); |
| for (i = 0; i < bag->pollset_set_count; i++) { |
| if (bag->pollset_sets[i] == item) { |
| bag->pollset_set_count--; |
| GPR_SWAP(grpc_pollset_set*, bag->pollset_sets[i], |
| bag->pollset_sets[bag->pollset_set_count]); |
| break; |
| } |
| } |
| gpr_mu_unlock(&bag->mu); |
| } |
| |
| static void pollset_set_add_fd(grpc_exec_ctx* exec_ctx, |
| grpc_pollset_set* pollset_set, grpc_fd* fd) { |
| size_t i; |
| gpr_mu_lock(&pollset_set->mu); |
| if (pollset_set->fd_count == pollset_set->fd_capacity) { |
| pollset_set->fd_capacity = GPR_MAX(8, 2 * pollset_set->fd_capacity); |
| pollset_set->fds = (grpc_fd**)gpr_realloc( |
| pollset_set->fds, pollset_set->fd_capacity * sizeof(*pollset_set->fds)); |
| } |
| GRPC_FD_REF(fd, "pollset_set"); |
| pollset_set->fds[pollset_set->fd_count++] = fd; |
| for (i = 0; i < pollset_set->pollset_count; i++) { |
| pollset_add_fd(exec_ctx, pollset_set->pollsets[i], fd); |
| } |
| for (i = 0; i < pollset_set->pollset_set_count; i++) { |
| pollset_set_add_fd(exec_ctx, pollset_set->pollset_sets[i], fd); |
| } |
| gpr_mu_unlock(&pollset_set->mu); |
| } |
| |
| static void pollset_set_del_fd(grpc_exec_ctx* exec_ctx, |
| grpc_pollset_set* pollset_set, grpc_fd* fd) { |
| size_t i; |
| gpr_mu_lock(&pollset_set->mu); |
| for (i = 0; i < pollset_set->fd_count; i++) { |
| if (pollset_set->fds[i] == fd) { |
| pollset_set->fd_count--; |
| GPR_SWAP(grpc_fd*, pollset_set->fds[i], |
| pollset_set->fds[pollset_set->fd_count]); |
| GRPC_FD_UNREF(fd, "pollset_set"); |
| break; |
| } |
| } |
| for (i = 0; i < pollset_set->pollset_set_count; i++) { |
| pollset_set_del_fd(exec_ctx, pollset_set->pollset_sets[i], fd); |
| } |
| gpr_mu_unlock(&pollset_set->mu); |
| } |
| |
| /******************************************************************************* |
| * Condition Variable polling extensions |
| */ |
| |
| static void run_poll(void* args); |
| static void cache_poller_locked(poll_args* args); |
| |
| static void cache_insert_locked(poll_args* args) { |
| uint32_t key = gpr_murmur_hash3(args->fds, args->nfds * sizeof(struct pollfd), |
| 0xDEADBEEF); |
| key = key % poll_cache.size; |
| if (poll_cache.active_pollers[key]) { |
| poll_cache.active_pollers[key]->prev = args; |
| } |
| args->next = poll_cache.active_pollers[key]; |
| args->prev = nullptr; |
| poll_cache.active_pollers[key] = args; |
| poll_cache.count++; |
| } |
| |
| static void init_result(poll_args* pargs) { |
| pargs->result = (poll_result*)gpr_malloc(sizeof(poll_result)); |
| gpr_ref_init(&pargs->result->refcount, 1); |
| pargs->result->watchers = nullptr; |
| pargs->result->watchcount = 0; |
| pargs->result->fds = |
| (struct pollfd*)gpr_malloc(sizeof(struct pollfd) * pargs->nfds); |
| memcpy(pargs->result->fds, pargs->fds, sizeof(struct pollfd) * pargs->nfds); |
| pargs->result->nfds = pargs->nfds; |
| pargs->result->retval = 0; |
| pargs->result->err = 0; |
| pargs->result->completed = 0; |
| } |
| |
| // Creates a poll_args object for a given arguments to poll(). |
| // This object may return a poll_args in the cache. |
| static poll_args* get_poller_locked(struct pollfd* fds, nfds_t count) { |
| uint32_t key = |
| gpr_murmur_hash3(fds, count * sizeof(struct pollfd), 0xDEADBEEF); |
| key = key % poll_cache.size; |
| poll_args* curr = poll_cache.active_pollers[key]; |
| while (curr) { |
| if (curr->nfds == count && |
| memcmp(curr->fds, fds, count * sizeof(struct pollfd)) == 0) { |
| gpr_free(fds); |
| return curr; |
| } |
| curr = curr->next; |
| } |
| |
| if (poll_cache.free_pollers) { |
| poll_args* pargs = poll_cache.free_pollers; |
| poll_cache.free_pollers = pargs->next; |
| if (poll_cache.free_pollers) { |
| poll_cache.free_pollers->prev = nullptr; |
| } |
| pargs->fds = fds; |
| pargs->nfds = count; |
| pargs->next = nullptr; |
| pargs->prev = nullptr; |
| init_result(pargs); |
| cache_poller_locked(pargs); |
| return pargs; |
| } |
| |
| poll_args* pargs = (poll_args*)gpr_malloc(sizeof(struct poll_args)); |
| gpr_cv_init(&pargs->trigger); |
| pargs->fds = fds; |
| pargs->nfds = count; |
| pargs->next = nullptr; |
| pargs->prev = nullptr; |
| pargs->trigger_set = 0; |
| init_result(pargs); |
| cache_poller_locked(pargs); |
| gpr_thd_id t_id; |
| gpr_thd_options opt = gpr_thd_options_default(); |
| gpr_ref(&g_cvfds.pollcount); |
| gpr_thd_options_set_detached(&opt); |
| GPR_ASSERT(gpr_thd_new(&t_id, &run_poll, pargs, &opt)); |
| return pargs; |
| } |
| |
| static void cache_delete_locked(poll_args* args) { |
| if (!args->prev) { |
| uint32_t key = gpr_murmur_hash3( |
| args->fds, args->nfds * sizeof(struct pollfd), 0xDEADBEEF); |
| key = key % poll_cache.size; |
| GPR_ASSERT(poll_cache.active_pollers[key] == args); |
| poll_cache.active_pollers[key] = args->next; |
| } else { |
| args->prev->next = args->next; |
| } |
| |
| if (args->next) { |
| args->next->prev = args->prev; |
| } |
| |
| poll_cache.count--; |
| if (poll_cache.free_pollers) { |
| poll_cache.free_pollers->prev = args; |
| } |
| args->prev = nullptr; |
| args->next = poll_cache.free_pollers; |
| gpr_free(args->fds); |
| poll_cache.free_pollers = args; |
| } |
| |
| static void cache_poller_locked(poll_args* args) { |
| if (poll_cache.count + 1 > poll_cache.size / 2) { |
| poll_args** old_active_pollers = poll_cache.active_pollers; |
| poll_cache.size = poll_cache.size * 2; |
| poll_cache.count = 0; |
| poll_cache.active_pollers = |
| (poll_args**)gpr_malloc(sizeof(void*) * poll_cache.size); |
| for (unsigned int i = 0; i < poll_cache.size; i++) { |
| poll_cache.active_pollers[i] = nullptr; |
| } |
| for (unsigned int i = 0; i < poll_cache.size / 2; i++) { |
| poll_args* curr = old_active_pollers[i]; |
| poll_args* next = nullptr; |
| while (curr) { |
| next = curr->next; |
| cache_insert_locked(curr); |
| curr = next; |
| } |
| } |
| gpr_free(old_active_pollers); |
| } |
| |
| cache_insert_locked(args); |
| } |
| |
| static void cache_destroy_locked(poll_args* args) { |
| if (args->next) { |
| args->next->prev = args->prev; |
| } |
| |
| if (args->prev) { |
| args->prev->next = args->next; |
| } else { |
| poll_cache.free_pollers = args->next; |
| } |
| |
| gpr_free(args); |
| } |
| |
| static void decref_poll_result(poll_result* res) { |
| if (gpr_unref(&res->refcount)) { |
| GPR_ASSERT(!res->watchers); |
| gpr_free(res->fds); |
| gpr_free(res); |
| } |
| } |
| |
| void remove_cvn(cv_node** head, cv_node* target) { |
| if (target->next) { |
| target->next->prev = target->prev; |
| } |
| |
| if (target->prev) { |
| target->prev->next = target->next; |
| } else { |
| *head = target->next; |
| } |
| } |
| |
| gpr_timespec thread_grace; |
| |
| // Poll in a background thread |
| static void run_poll(void* args) { |
| poll_args* pargs = (poll_args*)args; |
| while (1) { |
| poll_result* result = pargs->result; |
| int retval = g_cvfds.poll(result->fds, result->nfds, CV_POLL_PERIOD_MS); |
| gpr_mu_lock(&g_cvfds.mu); |
| if (retval != 0) { |
| result->completed = 1; |
| result->retval = retval; |
| result->err = errno; |
| cv_node* watcher = result->watchers; |
| while (watcher) { |
| gpr_cv_signal(watcher->cv); |
| watcher = watcher->next; |
| } |
| } |
| if (result->watchcount == 0 || result->completed) { |
| cache_delete_locked(pargs); |
| decref_poll_result(result); |
| // Leave this polling thread alive for a grace period to do another poll() |
| // op |
| gpr_timespec deadline = gpr_now(GPR_CLOCK_REALTIME); |
| deadline = gpr_time_add(deadline, thread_grace); |
| pargs->trigger_set = 0; |
| gpr_cv_wait(&pargs->trigger, &g_cvfds.mu, deadline); |
| if (!pargs->trigger_set) { |
| cache_destroy_locked(pargs); |
| break; |
| } |
| } |
| gpr_mu_unlock(&g_cvfds.mu); |
| } |
| |
| // We still have the lock here |
| if (gpr_unref(&g_cvfds.pollcount)) { |
| gpr_cv_signal(&g_cvfds.shutdown_cv); |
| } |
| gpr_mu_unlock(&g_cvfds.mu); |
| } |
| |
| // This function overrides poll() to handle condition variable wakeup fds |
| static int cvfd_poll(struct pollfd* fds, nfds_t nfds, int timeout) { |
| unsigned int i; |
| int res, idx; |
| cv_node* pollcv; |
| int skip_poll = 0; |
| nfds_t nsockfds = 0; |
| poll_result* result = nullptr; |
| gpr_mu_lock(&g_cvfds.mu); |
| pollcv = (cv_node*)gpr_malloc(sizeof(cv_node)); |
| pollcv->next = nullptr; |
| gpr_cv pollcv_cv; |
| gpr_cv_init(&pollcv_cv); |
| pollcv->cv = &pollcv_cv; |
| cv_node* fd_cvs = (cv_node*)gpr_malloc(nfds * sizeof(cv_node)); |
| |
| for (i = 0; i < nfds; i++) { |
| fds[i].revents = 0; |
| if (fds[i].fd < 0 && (fds[i].events & POLLIN)) { |
| idx = GRPC_FD_TO_IDX(fds[i].fd); |
| fd_cvs[i].cv = &pollcv_cv; |
| fd_cvs[i].prev = nullptr; |
| fd_cvs[i].next = g_cvfds.cvfds[idx].cvs; |
| if (g_cvfds.cvfds[idx].cvs) { |
| g_cvfds.cvfds[idx].cvs->prev = &(fd_cvs[i]); |
| } |
| g_cvfds.cvfds[idx].cvs = &(fd_cvs[i]); |
| // Don't bother polling if a wakeup fd is ready |
| if (g_cvfds.cvfds[idx].is_set) { |
| skip_poll = 1; |
| } |
| } else if (fds[i].fd >= 0) { |
| nsockfds++; |
| } |
| } |
| |
| gpr_timespec deadline = gpr_now(GPR_CLOCK_REALTIME); |
| if (timeout < 0) { |
| deadline = gpr_inf_future(GPR_CLOCK_REALTIME); |
| } else { |
| deadline = |
| gpr_time_add(deadline, gpr_time_from_millis(timeout, GPR_TIMESPAN)); |
| } |
| |
| res = 0; |
| if (!skip_poll && nsockfds > 0) { |
| struct pollfd* pollfds = |
| (struct pollfd*)gpr_malloc(sizeof(struct pollfd) * nsockfds); |
| idx = 0; |
| for (i = 0; i < nfds; i++) { |
| if (fds[i].fd >= 0) { |
| pollfds[idx].fd = fds[i].fd; |
| pollfds[idx].events = fds[i].events; |
| pollfds[idx].revents = 0; |
| idx++; |
| } |
| } |
| poll_args* pargs = get_poller_locked(pollfds, nsockfds); |
| result = pargs->result; |
| pollcv->next = result->watchers; |
| pollcv->prev = nullptr; |
| if (result->watchers) { |
| result->watchers->prev = pollcv; |
| } |
| result->watchers = pollcv; |
| result->watchcount++; |
| gpr_ref(&result->refcount); |
| |
| pargs->trigger_set = 1; |
| gpr_cv_signal(&pargs->trigger); |
| gpr_cv_wait(&pollcv_cv, &g_cvfds.mu, deadline); |
| res = result->retval; |
| errno = result->err; |
| result->watchcount--; |
| remove_cvn(&result->watchers, pollcv); |
| } else if (!skip_poll) { |
| gpr_cv_wait(&pollcv_cv, &g_cvfds.mu, deadline); |
| } |
| |
| idx = 0; |
| for (i = 0; i < nfds; i++) { |
| if (fds[i].fd < 0 && (fds[i].events & POLLIN)) { |
| remove_cvn(&g_cvfds.cvfds[GRPC_FD_TO_IDX(fds[i].fd)].cvs, &(fd_cvs[i])); |
| if (g_cvfds.cvfds[GRPC_FD_TO_IDX(fds[i].fd)].is_set) { |
| fds[i].revents = POLLIN; |
| if (res >= 0) res++; |
| } |
| } else if (!skip_poll && fds[i].fd >= 0 && result->completed) { |
| fds[i].revents = result->fds[idx].revents; |
| idx++; |
| } |
| } |
| |
| gpr_free(fd_cvs); |
| gpr_free(pollcv); |
| if (result) { |
| decref_poll_result(result); |
| } |
| |
| gpr_mu_unlock(&g_cvfds.mu); |
| |
| return res; |
| } |
| |
| static void global_cv_fd_table_init() { |
| gpr_mu_init(&g_cvfds.mu); |
| gpr_mu_lock(&g_cvfds.mu); |
| gpr_cv_init(&g_cvfds.shutdown_cv); |
| gpr_ref_init(&g_cvfds.pollcount, 1); |
| g_cvfds.size = CV_DEFAULT_TABLE_SIZE; |
| g_cvfds.cvfds = (fd_node*)gpr_malloc(sizeof(fd_node) * CV_DEFAULT_TABLE_SIZE); |
| g_cvfds.free_fds = nullptr; |
| thread_grace = gpr_time_from_millis(POLLCV_THREAD_GRACE_MS, GPR_TIMESPAN); |
| for (int i = 0; i < CV_DEFAULT_TABLE_SIZE; i++) { |
| g_cvfds.cvfds[i].is_set = 0; |
| g_cvfds.cvfds[i].cvs = nullptr; |
| g_cvfds.cvfds[i].next_free = g_cvfds.free_fds; |
| g_cvfds.free_fds = &g_cvfds.cvfds[i]; |
| } |
| // Override the poll function with one that supports cvfds |
| g_cvfds.poll = grpc_poll_function; |
| grpc_poll_function = &cvfd_poll; |
| |
| // Initialize the cache |
| poll_cache.size = 32; |
| poll_cache.count = 0; |
| poll_cache.free_pollers = nullptr; |
| poll_cache.active_pollers = (poll_args**)gpr_malloc(sizeof(void*) * 32); |
| for (unsigned int i = 0; i < poll_cache.size; i++) { |
| poll_cache.active_pollers[i] = nullptr; |
| } |
| |
| gpr_mu_unlock(&g_cvfds.mu); |
| } |
| |
| static void global_cv_fd_table_shutdown() { |
| gpr_mu_lock(&g_cvfds.mu); |
| // Attempt to wait for all abandoned poll() threads to terminate |
| // Not doing so will result in reported memory leaks |
| if (!gpr_unref(&g_cvfds.pollcount)) { |
| int res = gpr_cv_wait(&g_cvfds.shutdown_cv, &g_cvfds.mu, |
| gpr_time_add(gpr_now(GPR_CLOCK_REALTIME), |
| gpr_time_from_seconds(3, GPR_TIMESPAN))); |
| GPR_ASSERT(res == 0); |
| } |
| gpr_cv_destroy(&g_cvfds.shutdown_cv); |
| grpc_poll_function = g_cvfds.poll; |
| gpr_free(g_cvfds.cvfds); |
| |
| gpr_free(poll_cache.active_pollers); |
| |
| gpr_mu_unlock(&g_cvfds.mu); |
| gpr_mu_destroy(&g_cvfds.mu); |
| } |
| |
| /******************************************************************************* |
| * event engine binding |
| */ |
| |
| static void shutdown_engine(void) { |
| pollset_global_shutdown(); |
| if (grpc_cv_wakeup_fds_enabled()) { |
| global_cv_fd_table_shutdown(); |
| } |
| } |
| |
| static const grpc_event_engine_vtable vtable = { |
| sizeof(grpc_pollset), |
| |
| fd_create, |
| fd_wrapped_fd, |
| fd_orphan, |
| fd_shutdown, |
| fd_notify_on_read, |
| fd_notify_on_write, |
| fd_is_shutdown, |
| fd_get_read_notifier_pollset, |
| |
| pollset_init, |
| pollset_shutdown, |
| pollset_destroy, |
| pollset_work, |
| pollset_kick, |
| pollset_add_fd, |
| |
| pollset_set_create, |
| pollset_set_destroy, |
| pollset_set_add_pollset, |
| pollset_set_del_pollset, |
| pollset_set_add_pollset_set, |
| pollset_set_del_pollset_set, |
| pollset_set_add_fd, |
| pollset_set_del_fd, |
| |
| shutdown_engine, |
| }; |
| |
| const grpc_event_engine_vtable* grpc_init_poll_posix(bool explicit_request) { |
| if (!grpc_has_wakeup_fd()) { |
| gpr_log(GPR_ERROR, "Skipping poll because of no wakeup fd."); |
| return nullptr; |
| } |
| if (!GRPC_LOG_IF_ERROR("pollset_global_init", pollset_global_init())) { |
| return nullptr; |
| } |
| return &vtable; |
| } |
| |
| const grpc_event_engine_vtable* grpc_init_poll_cv_posix(bool explicit_request) { |
| global_cv_fd_table_init(); |
| grpc_enable_cv_wakeup_fds(1); |
| if (!GRPC_LOG_IF_ERROR("pollset_global_init", pollset_global_init())) { |
| global_cv_fd_table_shutdown(); |
| grpc_enable_cv_wakeup_fds(0); |
| return nullptr; |
| } |
| return &vtable; |
| } |
| |
| #endif |