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/*
*
* Copyright 2015 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 <grpc/support/port_platform.h>
#include "src/core/lib/iomgr/port.h"
#ifdef GRPC_POSIX_SOCKET_EV
#include "src/core/lib/iomgr/ev_posix.h"
#include <string.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include "src/core/lib/debug/trace.h"
#include "src/core/lib/gpr/env.h"
#include "src/core/lib/gpr/useful.h"
#include "src/core/lib/iomgr/ev_epoll1_linux.h"
#include "src/core/lib/iomgr/ev_epollex_linux.h"
#include "src/core/lib/iomgr/ev_epollsig_linux.h"
#include "src/core/lib/iomgr/ev_poll_posix.h"
grpc_core::TraceFlag grpc_polling_trace(false,
"polling"); /* Disabled by default */
/* Traces fd create/close operations */
grpc_core::TraceFlag grpc_fd_trace(false, "fd_trace");
grpc_core::DebugOnlyTraceFlag grpc_trace_fd_refcount(false, "fd_refcount");
grpc_core::DebugOnlyTraceFlag grpc_polling_api_trace(false, "polling_api");
#ifndef NDEBUG
// Polling API trace only enabled in debug builds
#define GRPC_POLLING_API_TRACE(format, ...) \
if (grpc_polling_api_trace.enabled()) { \
gpr_log(GPR_INFO, "(polling-api) " format, __VA_ARGS__); \
}
#else
#define GRPC_POLLING_API_TRACE(...)
#endif
/** Default poll() function - a pointer so that it can be overridden by some
* tests */
grpc_poll_function_type grpc_poll_function = poll;
grpc_wakeup_fd grpc_global_wakeup_fd;
static const grpc_event_engine_vtable* g_event_engine = nullptr;
static const char* g_poll_strategy_name = nullptr;
typedef const grpc_event_engine_vtable* (*event_engine_factory_fn)(
bool explicit_request);
typedef struct {
const char* name;
event_engine_factory_fn factory;
} event_engine_factory;
namespace {
grpc_poll_function_type real_poll_function;
int dummy_poll(struct pollfd fds[], nfds_t nfds, int timeout) {
if (timeout == 0) {
return real_poll_function(fds, nfds, 0);
} else {
gpr_log(GPR_ERROR, "Attempted a blocking poll when declared non-polling.");
GPR_ASSERT(false);
return -1;
}
}
const grpc_event_engine_vtable* init_non_polling(bool explicit_request) {
if (!explicit_request) {
return nullptr;
}
// return the simplest engine as a dummy but also override the poller
auto ret = grpc_init_poll_posix(explicit_request);
real_poll_function = grpc_poll_function;
grpc_poll_function = dummy_poll;
return ret;
}
} // namespace
#define ENGINE_HEAD_CUSTOM "head_custom"
#define ENGINE_TAIL_CUSTOM "tail_custom"
// The global array of event-engine factories. Each entry is a pair with a name
// and an event-engine generator function (nullptr if there is no generator
// registered for this name). The middle entries are the engines predefined by
// open-source gRPC. The head entries represent an opportunity for specific
// high-priority custom pollers to be added by the initializer plugins of
// custom-built gRPC libraries. The tail entries represent the same, but for
// low-priority custom pollers. The actual poller selected is either the first
// available one in the list if no specific poller is requested, or the first
// specific poller that is requested by name in the GRPC_POLL_STRATEGY
// environment variable if that variable is set (which should be a
// comma-separated list of one or more event engine names)
static event_engine_factory g_factories[] = {
{ENGINE_HEAD_CUSTOM, nullptr}, {ENGINE_HEAD_CUSTOM, nullptr},
{ENGINE_HEAD_CUSTOM, nullptr}, {ENGINE_HEAD_CUSTOM, nullptr},
{"epollex", grpc_init_epollex_linux}, {"epoll1", grpc_init_epoll1_linux},
{"epollsig", grpc_init_epollsig_linux}, {"poll", grpc_init_poll_posix},
{"poll-cv", grpc_init_poll_cv_posix}, {"none", init_non_polling},
{ENGINE_TAIL_CUSTOM, nullptr}, {ENGINE_TAIL_CUSTOM, nullptr},
{ENGINE_TAIL_CUSTOM, nullptr}, {ENGINE_TAIL_CUSTOM, nullptr},
};
static void add(const char* beg, const char* end, char*** ss, size_t* ns) {
size_t n = *ns;
size_t np = n + 1;
char* s;
size_t len;
GPR_ASSERT(end >= beg);
len = static_cast<size_t>(end - beg);
s = static_cast<char*>(gpr_malloc(len + 1));
memcpy(s, beg, len);
s[len] = 0;
*ss = static_cast<char**>(gpr_realloc(*ss, sizeof(char**) * np));
(*ss)[n] = s;
*ns = np;
}
static void split(const char* s, char*** ss, size_t* ns) {
const char* c = strchr(s, ',');
if (c == nullptr) {
add(s, s + strlen(s), ss, ns);
} else {
add(s, c, ss, ns);
split(c + 1, ss, ns);
}
}
static bool is(const char* want, const char* have) {
return 0 == strcmp(want, "all") || 0 == strcmp(want, have);
}
static void try_engine(const char* engine) {
for (size_t i = 0; i < GPR_ARRAY_SIZE(g_factories); i++) {
if (g_factories[i].factory != nullptr && is(engine, g_factories[i].name)) {
if ((g_event_engine = g_factories[i].factory(
0 == strcmp(engine, g_factories[i].name)))) {
g_poll_strategy_name = g_factories[i].name;
gpr_log(GPR_DEBUG, "Using polling engine: %s", g_factories[i].name);
return;
}
}
}
}
/* Call this before calling grpc_event_engine_init() */
void grpc_register_event_engine_factory(const char* name,
event_engine_factory_fn factory,
bool add_at_head) {
const char* custom_match =
add_at_head ? ENGINE_HEAD_CUSTOM : ENGINE_TAIL_CUSTOM;
// Overwrite an existing registration if already registered
for (size_t i = 0; i < GPR_ARRAY_SIZE(g_factories); i++) {
if (0 == strcmp(name, g_factories[i].name)) {
g_factories[i].factory = factory;
return;
}
}
// Otherwise fill in an available custom slot
for (size_t i = 0; i < GPR_ARRAY_SIZE(g_factories); i++) {
if (0 == strcmp(g_factories[i].name, custom_match)) {
g_factories[i].name = name;
g_factories[i].factory = factory;
return;
}
}
// Otherwise fail
GPR_ASSERT(false);
}
/* Call this only after calling grpc_event_engine_init() */
const char* grpc_get_poll_strategy_name() { return g_poll_strategy_name; }
void grpc_event_engine_init(void) {
char* s = gpr_getenv("GRPC_POLL_STRATEGY");
if (s == nullptr) {
s = gpr_strdup("all");
}
char** strings = nullptr;
size_t nstrings = 0;
split(s, &strings, &nstrings);
for (size_t i = 0; g_event_engine == nullptr && i < nstrings; i++) {
try_engine(strings[i]);
}
for (size_t i = 0; i < nstrings; i++) {
gpr_free(strings[i]);
}
gpr_free(strings);
if (g_event_engine == nullptr) {
gpr_log(GPR_ERROR, "No event engine could be initialized from %s", s);
abort();
}
gpr_free(s);
}
void grpc_event_engine_shutdown(void) {
g_event_engine->shutdown_engine();
g_event_engine = nullptr;
}
bool grpc_event_engine_can_track_errors(void) {
return g_event_engine->can_track_err;
}
grpc_fd* grpc_fd_create(int fd, const char* name, bool track_err) {
GRPC_POLLING_API_TRACE("fd_create(%d, %s, %d)", fd, name, track_err);
GRPC_FD_TRACE("fd_create(%d, %s, %d)", fd, name, track_err);
GPR_DEBUG_ASSERT(!track_err || g_event_engine->can_track_err);
return g_event_engine->fd_create(fd, name, track_err);
}
int grpc_fd_wrapped_fd(grpc_fd* fd) {
return g_event_engine->fd_wrapped_fd(fd);
}
void grpc_fd_orphan(grpc_fd* fd, grpc_closure* on_done, int* release_fd,
const char* reason) {
GRPC_POLLING_API_TRACE("fd_orphan(%d, %p, %p, %s)", grpc_fd_wrapped_fd(fd),
on_done, release_fd, reason);
GRPC_FD_TRACE("grpc_fd_orphan, fd:%d closed", grpc_fd_wrapped_fd(fd));
g_event_engine->fd_orphan(fd, on_done, release_fd, reason);
}
void grpc_fd_shutdown(grpc_fd* fd, grpc_error* why) {
GRPC_POLLING_API_TRACE("fd_shutdown(%d)", grpc_fd_wrapped_fd(fd));
GRPC_FD_TRACE("fd_shutdown(%d)", grpc_fd_wrapped_fd(fd));
g_event_engine->fd_shutdown(fd, why);
}
bool grpc_fd_is_shutdown(grpc_fd* fd) {
return g_event_engine->fd_is_shutdown(fd);
}
void grpc_fd_notify_on_read(grpc_fd* fd, grpc_closure* closure) {
g_event_engine->fd_notify_on_read(fd, closure);
}
void grpc_fd_notify_on_write(grpc_fd* fd, grpc_closure* closure) {
g_event_engine->fd_notify_on_write(fd, closure);
}
void grpc_fd_notify_on_error(grpc_fd* fd, grpc_closure* closure) {
g_event_engine->fd_notify_on_error(fd, closure);
}
void grpc_fd_set_readable(grpc_fd* fd) { g_event_engine->fd_set_readable(fd); }
void grpc_fd_set_writable(grpc_fd* fd) { g_event_engine->fd_set_writable(fd); }
void grpc_fd_set_error(grpc_fd* fd) { g_event_engine->fd_set_error(fd); }
static size_t pollset_size(void) { return g_event_engine->pollset_size; }
static void pollset_init(grpc_pollset* pollset, gpr_mu** mu) {
GRPC_POLLING_API_TRACE("pollset_init(%p)", pollset);
g_event_engine->pollset_init(pollset, mu);
}
static void pollset_shutdown(grpc_pollset* pollset, grpc_closure* closure) {
GRPC_POLLING_API_TRACE("pollset_shutdown(%p)", pollset);
g_event_engine->pollset_shutdown(pollset, closure);
}
static void pollset_destroy(grpc_pollset* pollset) {
GRPC_POLLING_API_TRACE("pollset_destroy(%p)", pollset);
g_event_engine->pollset_destroy(pollset);
}
static grpc_error* pollset_work(grpc_pollset* pollset,
grpc_pollset_worker** worker,
grpc_millis deadline) {
GRPC_POLLING_API_TRACE("pollset_work(%p, %" PRId64 ") begin", pollset,
deadline);
grpc_error* err = g_event_engine->pollset_work(pollset, worker, deadline);
GRPC_POLLING_API_TRACE("pollset_work(%p, %" PRId64 ") end", pollset,
deadline);
return err;
}
static grpc_error* pollset_kick(grpc_pollset* pollset,
grpc_pollset_worker* specific_worker) {
GRPC_POLLING_API_TRACE("pollset_kick(%p, %p)", pollset, specific_worker);
return g_event_engine->pollset_kick(pollset, specific_worker);
}
void grpc_pollset_add_fd(grpc_pollset* pollset, struct grpc_fd* fd) {
GRPC_POLLING_API_TRACE("pollset_add_fd(%p, %d)", pollset,
grpc_fd_wrapped_fd(fd));
g_event_engine->pollset_add_fd(pollset, fd);
}
void pollset_global_init() {}
void pollset_global_shutdown() {}
grpc_pollset_vtable grpc_posix_pollset_vtable = {
pollset_global_init, pollset_global_shutdown,
pollset_init, pollset_shutdown,
pollset_destroy, pollset_work,
pollset_kick, pollset_size};
static grpc_pollset_set* pollset_set_create(void) {
grpc_pollset_set* pss = g_event_engine->pollset_set_create();
GRPC_POLLING_API_TRACE("pollset_set_create(%p)", pss);
return pss;
}
static void pollset_set_destroy(grpc_pollset_set* pollset_set) {
GRPC_POLLING_API_TRACE("pollset_set_destroy(%p)", pollset_set);
g_event_engine->pollset_set_destroy(pollset_set);
}
static void pollset_set_add_pollset(grpc_pollset_set* pollset_set,
grpc_pollset* pollset) {
GRPC_POLLING_API_TRACE("pollset_set_add_pollset(%p, %p)", pollset_set,
pollset);
g_event_engine->pollset_set_add_pollset(pollset_set, pollset);
}
static void pollset_set_del_pollset(grpc_pollset_set* pollset_set,
grpc_pollset* pollset) {
GRPC_POLLING_API_TRACE("pollset_set_del_pollset(%p, %p)", pollset_set,
pollset);
g_event_engine->pollset_set_del_pollset(pollset_set, pollset);
}
static void pollset_set_add_pollset_set(grpc_pollset_set* bag,
grpc_pollset_set* item) {
GRPC_POLLING_API_TRACE("pollset_set_add_pollset_set(%p, %p)", bag, item);
g_event_engine->pollset_set_add_pollset_set(bag, item);
}
static void pollset_set_del_pollset_set(grpc_pollset_set* bag,
grpc_pollset_set* item) {
GRPC_POLLING_API_TRACE("pollset_set_del_pollset_set(%p, %p)", bag, item);
g_event_engine->pollset_set_del_pollset_set(bag, item);
}
grpc_pollset_set_vtable grpc_posix_pollset_set_vtable = {
pollset_set_create, pollset_set_destroy,
pollset_set_add_pollset, pollset_set_del_pollset,
pollset_set_add_pollset_set, pollset_set_del_pollset_set};
void grpc_pollset_set_add_fd(grpc_pollset_set* pollset_set, grpc_fd* fd) {
GRPC_POLLING_API_TRACE("pollset_set_add_fd(%p, %d)", pollset_set,
grpc_fd_wrapped_fd(fd));
g_event_engine->pollset_set_add_fd(pollset_set, fd);
}
void grpc_pollset_set_del_fd(grpc_pollset_set* pollset_set, grpc_fd* fd) {
GRPC_POLLING_API_TRACE("pollset_set_del_fd(%p, %d)", pollset_set,
grpc_fd_wrapped_fd(fd));
g_event_engine->pollset_set_del_fd(pollset_set, fd);
}
#endif // GRPC_POSIX_SOCKET_EV
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