1 //
2 //
3 // Copyright 2015 gRPC authors.
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 // http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 //
17 //
18
19 #include <grpc/support/port_platform.h>
20
21 #include <grpc/grpc.h>
22
23 #include "src/core/lib/iomgr/port.h"
24
25 #ifdef GRPC_POSIX_SOCKET_EV
26
27 #include <string.h>
28
29 #include "absl/strings/str_format.h"
30 #include "absl/strings/str_split.h"
31
32 #include <grpc/support/alloc.h>
33 #include <grpc/support/log.h>
34 #include <grpc/support/string_util.h>
35
36 #include "src/core/lib/config/config_vars.h"
37 #include "src/core/lib/debug/trace.h"
38 #include "src/core/lib/gpr/useful.h"
39 #include "src/core/lib/gprpp/crash.h"
40 #include "src/core/lib/iomgr/ev_epoll1_linux.h"
41 #include "src/core/lib/iomgr/ev_poll_posix.h"
42 #include "src/core/lib/iomgr/ev_posix.h"
43 #include "src/core/lib/iomgr/internal_errqueue.h"
44
45 grpc_core::DebugOnlyTraceFlag grpc_polling_trace(
46 false, "polling"); // Disabled by default
47
48 // Traces fd create/close operations
49 grpc_core::DebugOnlyTraceFlag grpc_fd_trace(false, "fd_trace");
50 grpc_core::DebugOnlyTraceFlag grpc_trace_fd_refcount(false, "fd_refcount");
51 grpc_core::DebugOnlyTraceFlag grpc_polling_api_trace(false, "polling_api");
52
53 // Polling API trace only enabled in debug builds
54 #ifndef NDEBUG
55 #define GRPC_POLLING_API_TRACE(format, ...) \
56 if (GRPC_TRACE_FLAG_ENABLED(grpc_polling_api_trace)) { \
57 gpr_log(GPR_INFO, "(polling-api) " format, __VA_ARGS__); \
58 }
59 #else
60 #define GRPC_POLLING_API_TRACE(...)
61 #endif // NDEBUG
62
63 /// Default poll() function - a pointer so that it can be overridden by some
64 /// tests
65 #ifndef GPR_AIX
66 grpc_poll_function_type grpc_poll_function = poll;
67 #else
aix_poll(struct pollfd fds[],nfds_t nfds,int timeout)68 int aix_poll(struct pollfd fds[], nfds_t nfds, int timeout) {
69 return poll(fds, nfds, timeout);
70 }
71 grpc_poll_function_type grpc_poll_function = aix_poll;
72 #endif // GPR_AIX
73
74 grpc_wakeup_fd grpc_global_wakeup_fd;
75
76 static const grpc_event_engine_vtable* g_event_engine = nullptr;
77 static gpr_once g_choose_engine = GPR_ONCE_INIT;
78
79 // The global array of event-engine factories. Each entry is a pair with a name
80 // and an event-engine generator function (nullptr if there is no generator
81 // registered for this name). The middle entries are the engines predefined by
82 // open-source gRPC. The head entries represent an opportunity for specific
83 // high-priority custom pollers to be added by the initializer plugins of
84 // custom-built gRPC libraries. The tail entries represent the same, but for
85 // low-priority custom pollers. The actual poller selected is either the first
86 // available one in the list if no specific poller is requested, or the first
87 // specific poller that is requested by name in the GRPC_POLL_STRATEGY
88 // environment variable if that variable is set (which should be a
89 // comma-separated list of one or more event engine names)
90 static const grpc_event_engine_vtable* g_vtables[] = {
91 nullptr,
92 nullptr,
93 nullptr,
94 nullptr,
95 &grpc_ev_epoll1_posix,
96 &grpc_ev_poll_posix,
97 &grpc_ev_none_posix,
98 nullptr,
99 nullptr,
100 nullptr,
101 nullptr,
102 };
103
is(absl::string_view want,absl::string_view have)104 static bool is(absl::string_view want, absl::string_view have) {
105 return want == "all" || want == have;
106 }
107
try_engine(absl::string_view engine)108 static void try_engine(absl::string_view engine) {
109 for (size_t i = 0; i < GPR_ARRAY_SIZE(g_vtables); i++) {
110 if (g_vtables[i] != nullptr && is(engine, g_vtables[i]->name) &&
111 g_vtables[i]->check_engine_available(engine == g_vtables[i]->name)) {
112 g_event_engine = g_vtables[i];
113 gpr_log(GPR_DEBUG, "Using polling engine: %s", g_event_engine->name);
114 return;
115 }
116 }
117 }
118
119 // Call this before calling grpc_event_engine_init()
grpc_register_event_engine_factory(const grpc_event_engine_vtable * vtable,bool add_at_head)120 void grpc_register_event_engine_factory(const grpc_event_engine_vtable* vtable,
121 bool add_at_head) {
122 const grpc_event_engine_vtable** first_null = nullptr;
123 const grpc_event_engine_vtable** last_null = nullptr;
124
125 // Overwrite an existing registration if already registered
126 for (size_t i = 0; i < GPR_ARRAY_SIZE(g_vtables); i++) {
127 if (g_vtables[i] == nullptr) {
128 if (first_null == nullptr) first_null = &g_vtables[i];
129 last_null = &g_vtables[i];
130 } else if (0 == strcmp(g_vtables[i]->name, vtable->name)) {
131 g_vtables[i] = vtable;
132 return;
133 }
134 }
135
136 *(add_at_head ? first_null : last_null) = vtable;
137 }
138
139 // If grpc_event_engine_init() has been called, returns the poll_strategy_name.
140 // Otherwise, returns nullptr.
grpc_get_poll_strategy_name()141 const char* grpc_get_poll_strategy_name() { return g_event_engine->name; }
142
grpc_event_engine_init(void)143 void grpc_event_engine_init(void) {
144 gpr_once_init(&g_choose_engine, []() {
145 auto value = grpc_core::ConfigVars::Get().PollStrategy();
146 for (auto trial : absl::StrSplit(value, ',')) {
147 try_engine(trial);
148 if (g_event_engine != nullptr) return;
149 }
150
151 if (g_event_engine == nullptr) {
152 grpc_core::Crash(
153 absl::StrFormat("No event engine could be initialized from %s",
154 std::string(value).c_str()));
155 }
156 });
157 g_event_engine->init_engine();
158 }
159
grpc_event_engine_shutdown(void)160 void grpc_event_engine_shutdown(void) { g_event_engine->shutdown_engine(); }
161
grpc_event_engine_can_track_errors(void)162 bool grpc_event_engine_can_track_errors(void) {
163 // Only track errors if platform supports errqueue.
164 return grpc_core::KernelSupportsErrqueue() && g_event_engine->can_track_err;
165 }
166
grpc_event_engine_run_in_background(void)167 bool grpc_event_engine_run_in_background(void) {
168 // g_event_engine is nullptr when using a custom iomgr.
169 return g_event_engine != nullptr && g_event_engine->run_in_background;
170 }
171
grpc_fd_create(int fd,const char * name,bool track_err)172 grpc_fd* grpc_fd_create(int fd, const char* name, bool track_err) {
173 GRPC_POLLING_API_TRACE("fd_create(%d, %s, %d)", fd, name, track_err);
174 GRPC_FD_TRACE("fd_create(%d, %s, %d)", fd, name, track_err);
175 return g_event_engine->fd_create(
176 fd, name, track_err && grpc_event_engine_can_track_errors());
177 }
178
grpc_fd_wrapped_fd(grpc_fd * fd)179 int grpc_fd_wrapped_fd(grpc_fd* fd) {
180 return g_event_engine->fd_wrapped_fd(fd);
181 }
182
grpc_fd_orphan(grpc_fd * fd,grpc_closure * on_done,int * release_fd,const char * reason)183 void grpc_fd_orphan(grpc_fd* fd, grpc_closure* on_done, int* release_fd,
184 const char* reason) {
185 GRPC_POLLING_API_TRACE("fd_orphan(%d, %p, %p, %s)", grpc_fd_wrapped_fd(fd),
186 on_done, release_fd, reason);
187 GRPC_FD_TRACE("grpc_fd_orphan, fd:%d closed", grpc_fd_wrapped_fd(fd));
188
189 g_event_engine->fd_orphan(fd, on_done, release_fd, reason);
190 }
191
grpc_fd_set_pre_allocated(grpc_fd * fd)192 void grpc_fd_set_pre_allocated(grpc_fd* fd) {
193 GRPC_POLLING_API_TRACE("fd_set_pre_allocated(%d)", grpc_fd_wrapped_fd(fd));
194 GRPC_FD_TRACE("fd_set_pre_allocated(%d)", grpc_fd_wrapped_fd(fd));
195 g_event_engine->fd_set_pre_allocated(fd);
196 }
197
grpc_fd_shutdown(grpc_fd * fd,grpc_error_handle why)198 void grpc_fd_shutdown(grpc_fd* fd, grpc_error_handle why) {
199 GRPC_POLLING_API_TRACE("fd_shutdown(%d)", grpc_fd_wrapped_fd(fd));
200 GRPC_FD_TRACE("fd_shutdown(%d)", grpc_fd_wrapped_fd(fd));
201 g_event_engine->fd_shutdown(fd, why);
202 }
203
grpc_fd_is_shutdown(grpc_fd * fd)204 bool grpc_fd_is_shutdown(grpc_fd* fd) {
205 return g_event_engine->fd_is_shutdown(fd);
206 }
207
grpc_fd_notify_on_read(grpc_fd * fd,grpc_closure * closure)208 void grpc_fd_notify_on_read(grpc_fd* fd, grpc_closure* closure) {
209 g_event_engine->fd_notify_on_read(fd, closure);
210 }
211
grpc_fd_notify_on_write(grpc_fd * fd,grpc_closure * closure)212 void grpc_fd_notify_on_write(grpc_fd* fd, grpc_closure* closure) {
213 g_event_engine->fd_notify_on_write(fd, closure);
214 }
215
grpc_fd_notify_on_error(grpc_fd * fd,grpc_closure * closure)216 void grpc_fd_notify_on_error(grpc_fd* fd, grpc_closure* closure) {
217 g_event_engine->fd_notify_on_error(fd, closure);
218 }
219
grpc_fd_set_readable(grpc_fd * fd)220 void grpc_fd_set_readable(grpc_fd* fd) { g_event_engine->fd_set_readable(fd); }
221
grpc_fd_set_writable(grpc_fd * fd)222 void grpc_fd_set_writable(grpc_fd* fd) { g_event_engine->fd_set_writable(fd); }
223
grpc_fd_set_error(grpc_fd * fd)224 void grpc_fd_set_error(grpc_fd* fd) { g_event_engine->fd_set_error(fd); }
225
pollset_size(void)226 static size_t pollset_size(void) { return g_event_engine->pollset_size; }
227
pollset_init(grpc_pollset * pollset,gpr_mu ** mu)228 static void pollset_init(grpc_pollset* pollset, gpr_mu** mu) {
229 GRPC_POLLING_API_TRACE("pollset_init(%p)", pollset);
230 g_event_engine->pollset_init(pollset, mu);
231 }
232
pollset_shutdown(grpc_pollset * pollset,grpc_closure * closure)233 static void pollset_shutdown(grpc_pollset* pollset, grpc_closure* closure) {
234 GRPC_POLLING_API_TRACE("pollset_shutdown(%p)", pollset);
235 g_event_engine->pollset_shutdown(pollset, closure);
236 }
237
pollset_destroy(grpc_pollset * pollset)238 static void pollset_destroy(grpc_pollset* pollset) {
239 GRPC_POLLING_API_TRACE("pollset_destroy(%p)", pollset);
240 g_event_engine->pollset_destroy(pollset);
241 }
242
pollset_work(grpc_pollset * pollset,grpc_pollset_worker ** worker,grpc_core::Timestamp deadline)243 static grpc_error_handle pollset_work(grpc_pollset* pollset,
244 grpc_pollset_worker** worker,
245 grpc_core::Timestamp deadline) {
246 GRPC_POLLING_API_TRACE("pollset_work(%p, %" PRId64 ") begin", pollset,
247 deadline.milliseconds_after_process_epoch());
248 grpc_error_handle err =
249 g_event_engine->pollset_work(pollset, worker, deadline);
250 GRPC_POLLING_API_TRACE("pollset_work(%p, %" PRId64 ") end", pollset,
251 deadline.milliseconds_after_process_epoch());
252 return err;
253 }
254
pollset_kick(grpc_pollset * pollset,grpc_pollset_worker * specific_worker)255 static grpc_error_handle pollset_kick(grpc_pollset* pollset,
256 grpc_pollset_worker* specific_worker) {
257 GRPC_POLLING_API_TRACE("pollset_kick(%p, %p)", pollset, specific_worker);
258 return g_event_engine->pollset_kick(pollset, specific_worker);
259 }
260
grpc_pollset_add_fd(grpc_pollset * pollset,struct grpc_fd * fd)261 void grpc_pollset_add_fd(grpc_pollset* pollset, struct grpc_fd* fd) {
262 GRPC_POLLING_API_TRACE("pollset_add_fd(%p, %d)", pollset,
263 grpc_fd_wrapped_fd(fd));
264 g_event_engine->pollset_add_fd(pollset, fd);
265 }
266
pollset_global_init()267 void pollset_global_init() {}
pollset_global_shutdown()268 void pollset_global_shutdown() {}
269
270 grpc_pollset_vtable grpc_posix_pollset_vtable = {
271 pollset_global_init, pollset_global_shutdown,
272 pollset_init, pollset_shutdown,
273 pollset_destroy, pollset_work,
274 pollset_kick, pollset_size};
275
pollset_set_create(void)276 static grpc_pollset_set* pollset_set_create(void) {
277 grpc_pollset_set* pss = g_event_engine->pollset_set_create();
278 GRPC_POLLING_API_TRACE("pollset_set_create(%p)", pss);
279 return pss;
280 }
281
pollset_set_destroy(grpc_pollset_set * pollset_set)282 static void pollset_set_destroy(grpc_pollset_set* pollset_set) {
283 GRPC_POLLING_API_TRACE("pollset_set_destroy(%p)", pollset_set);
284 g_event_engine->pollset_set_destroy(pollset_set);
285 }
286
pollset_set_add_pollset(grpc_pollset_set * pollset_set,grpc_pollset * pollset)287 static void pollset_set_add_pollset(grpc_pollset_set* pollset_set,
288 grpc_pollset* pollset) {
289 GRPC_POLLING_API_TRACE("pollset_set_add_pollset(%p, %p)", pollset_set,
290 pollset);
291 g_event_engine->pollset_set_add_pollset(pollset_set, pollset);
292 }
293
pollset_set_del_pollset(grpc_pollset_set * pollset_set,grpc_pollset * pollset)294 static void pollset_set_del_pollset(grpc_pollset_set* pollset_set,
295 grpc_pollset* pollset) {
296 GRPC_POLLING_API_TRACE("pollset_set_del_pollset(%p, %p)", pollset_set,
297 pollset);
298 g_event_engine->pollset_set_del_pollset(pollset_set, pollset);
299 }
300
pollset_set_add_pollset_set(grpc_pollset_set * bag,grpc_pollset_set * item)301 static void pollset_set_add_pollset_set(grpc_pollset_set* bag,
302 grpc_pollset_set* item) {
303 GRPC_POLLING_API_TRACE("pollset_set_add_pollset_set(%p, %p)", bag, item);
304 g_event_engine->pollset_set_add_pollset_set(bag, item);
305 }
306
pollset_set_del_pollset_set(grpc_pollset_set * bag,grpc_pollset_set * item)307 static void pollset_set_del_pollset_set(grpc_pollset_set* bag,
308 grpc_pollset_set* item) {
309 GRPC_POLLING_API_TRACE("pollset_set_del_pollset_set(%p, %p)", bag, item);
310 g_event_engine->pollset_set_del_pollset_set(bag, item);
311 }
312
313 grpc_pollset_set_vtable grpc_posix_pollset_set_vtable = {
314 pollset_set_create, pollset_set_destroy,
315 pollset_set_add_pollset, pollset_set_del_pollset,
316 pollset_set_add_pollset_set, pollset_set_del_pollset_set};
317
grpc_pollset_set_add_fd(grpc_pollset_set * pollset_set,grpc_fd * fd)318 void grpc_pollset_set_add_fd(grpc_pollset_set* pollset_set, grpc_fd* fd) {
319 GRPC_POLLING_API_TRACE("pollset_set_add_fd(%p, %d)", pollset_set,
320 grpc_fd_wrapped_fd(fd));
321 g_event_engine->pollset_set_add_fd(pollset_set, fd);
322 }
323
grpc_pollset_set_del_fd(grpc_pollset_set * pollset_set,grpc_fd * fd)324 void grpc_pollset_set_del_fd(grpc_pollset_set* pollset_set, grpc_fd* fd) {
325 GRPC_POLLING_API_TRACE("pollset_set_del_fd(%p, %d)", pollset_set,
326 grpc_fd_wrapped_fd(fd));
327 g_event_engine->pollset_set_del_fd(pollset_set, fd);
328 }
329
grpc_is_any_background_poller_thread(void)330 bool grpc_is_any_background_poller_thread(void) {
331 return g_event_engine->is_any_background_poller_thread();
332 }
333
grpc_add_closure_to_background_poller(grpc_closure * closure,grpc_error_handle error)334 bool grpc_add_closure_to_background_poller(grpc_closure* closure,
335 grpc_error_handle error) {
336 return g_event_engine->add_closure_to_background_poller(closure, error);
337 }
338
grpc_shutdown_background_closure(void)339 void grpc_shutdown_background_closure(void) {
340 g_event_engine->shutdown_background_closure();
341 }
342
343 #endif // GRPC_POSIX_SOCKET_EV
344