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 #ifndef GRPC_SRC_CORE_LIB_IOMGR_EV_POSIX_H 20 #define GRPC_SRC_CORE_LIB_IOMGR_EV_POSIX_H 21 22 #include <grpc/support/port_platform.h> 23 24 #include <poll.h> 25 26 #include "src/core/lib/debug/trace.h" 27 #include "src/core/lib/iomgr/exec_ctx.h" 28 #include "src/core/lib/iomgr/pollset.h" 29 #include "src/core/lib/iomgr/pollset_set.h" 30 #include "src/core/lib/iomgr/wakeup_fd_posix.h" 31 32 extern grpc_core::DebugOnlyTraceFlag grpc_fd_trace; // Disabled by default 33 extern grpc_core::DebugOnlyTraceFlag grpc_polling_trace; // Disabled by default 34 35 #define GRPC_FD_TRACE(format, ...) \ 36 if (GRPC_TRACE_FLAG_ENABLED(grpc_fd_trace)) { \ 37 gpr_log(GPR_INFO, "(fd-trace) " format, __VA_ARGS__); \ 38 } 39 40 typedef struct grpc_fd grpc_fd; 41 42 typedef struct grpc_event_engine_vtable { 43 size_t pollset_size; 44 bool can_track_err; 45 bool run_in_background; 46 47 grpc_fd* (*fd_create)(int fd, const char* name, bool track_err); 48 int (*fd_wrapped_fd)(grpc_fd* fd); 49 void (*fd_orphan)(grpc_fd* fd, grpc_closure* on_done, int* release_fd, 50 const char* reason); 51 void (*fd_shutdown)(grpc_fd* fd, grpc_error_handle why); 52 void (*fd_notify_on_read)(grpc_fd* fd, grpc_closure* closure); 53 void (*fd_notify_on_write)(grpc_fd* fd, grpc_closure* closure); 54 void (*fd_notify_on_error)(grpc_fd* fd, grpc_closure* closure); 55 void (*fd_set_readable)(grpc_fd* fd); 56 void (*fd_set_writable)(grpc_fd* fd); 57 void (*fd_set_error)(grpc_fd* fd); 58 bool (*fd_is_shutdown)(grpc_fd* fd); 59 60 void (*pollset_init)(grpc_pollset* pollset, gpr_mu** mu); 61 void (*pollset_shutdown)(grpc_pollset* pollset, grpc_closure* closure); 62 void (*pollset_destroy)(grpc_pollset* pollset); 63 grpc_error_handle (*pollset_work)(grpc_pollset* pollset, 64 grpc_pollset_worker** worker, 65 grpc_core::Timestamp deadline); 66 grpc_error_handle (*pollset_kick)(grpc_pollset* pollset, 67 grpc_pollset_worker* specific_worker); 68 void (*pollset_add_fd)(grpc_pollset* pollset, struct grpc_fd* fd); 69 70 grpc_pollset_set* (*pollset_set_create)(void); 71 void (*pollset_set_destroy)(grpc_pollset_set* pollset_set); 72 void (*pollset_set_add_pollset)(grpc_pollset_set* pollset_set, 73 grpc_pollset* pollset); 74 void (*pollset_set_del_pollset)(grpc_pollset_set* pollset_set, 75 grpc_pollset* pollset); 76 void (*pollset_set_add_pollset_set)(grpc_pollset_set* bag, 77 grpc_pollset_set* item); 78 void (*pollset_set_del_pollset_set)(grpc_pollset_set* bag, 79 grpc_pollset_set* item); 80 void (*pollset_set_add_fd)(grpc_pollset_set* pollset_set, grpc_fd* fd); 81 void (*pollset_set_del_fd)(grpc_pollset_set* pollset_set, grpc_fd* fd); 82 83 bool (*is_any_background_poller_thread)(void); 84 const char* name; 85 bool (*check_engine_available)(bool explicit_request); 86 void (*init_engine)(); 87 void (*shutdown_background_closure)(void); 88 void (*shutdown_engine)(void); 89 bool (*add_closure_to_background_poller)(grpc_closure* closure, 90 grpc_error_handle error); 91 92 void (*fd_set_pre_allocated)(grpc_fd* fd); 93 } grpc_event_engine_vtable; 94 95 // register a new event engine factory 96 void grpc_register_event_engine_factory(const grpc_event_engine_vtable* vtable, 97 bool add_at_head); 98 99 void grpc_event_engine_init(void); 100 void grpc_event_engine_shutdown(void); 101 102 // Return the name of the poll strategy 103 const char* grpc_get_poll_strategy_name(); 104 105 // Returns true if polling engine can track errors separately, false otherwise. 106 // If this is true, fd can be created with track_err set. After this, error 107 // events will be reported using fd_notify_on_error. If it is not set, errors 108 // will continue to be reported through fd_notify_on_read and 109 // fd_notify_on_write. 110 // 111 bool grpc_event_engine_can_track_errors(); 112 113 // Returns true if polling engine runs in the background, false otherwise. 114 // Currently only 'epollbg' runs in the background. 115 // 116 bool grpc_event_engine_run_in_background(); 117 118 // Create a wrapped file descriptor. 119 // Requires fd is a non-blocking file descriptor. 120 // \a track_err if true means that error events would be tracked separately 121 // using grpc_fd_notify_on_error. Currently, valid only for linux systems. 122 // This takes ownership of closing fd. 123 grpc_fd* grpc_fd_create(int fd, const char* name, bool track_err); 124 125 // Return the wrapped fd, or -1 if it has been released or closed. 126 int grpc_fd_wrapped_fd(grpc_fd* fd); 127 128 // Releases fd to be asynchronously destroyed. 129 // on_done is called when the underlying file descriptor is definitely close()d. 130 // If on_done is NULL, no callback will be made. 131 // If release_fd is not NULL, it's set to fd and fd will not be closed. 132 // Requires: *fd initialized; no outstanding notify_on_read or 133 // notify_on_write. 134 // MUST NOT be called with a pollset lock taken 135 void grpc_fd_orphan(grpc_fd* fd, grpc_closure* on_done, int* release_fd, 136 const char* reason); 137 138 // Has grpc_fd_shutdown been called on an fd? 139 bool grpc_fd_is_shutdown(grpc_fd* fd); 140 141 // Cause any current and future callbacks to fail. 142 void grpc_fd_shutdown(grpc_fd* fd, grpc_error_handle why); 143 144 // Register read interest, causing read_cb to be called once when fd becomes 145 // readable, on deadline specified by deadline, or on shutdown triggered by 146 // grpc_fd_shutdown. 147 // read_cb will be called with read_cb_arg when *fd becomes readable. 148 // read_cb is Called with status of GRPC_CALLBACK_SUCCESS if readable, 149 // GRPC_CALLBACK_TIMED_OUT if the call timed out, 150 // and CANCELLED if the call was cancelled. 151 152 // Requires:This method must not be called before the read_cb for any previous 153 // call runs. Edge triggered events are used whenever they are supported by the 154 // underlying platform. This means that users must drain fd in read_cb before 155 // calling notify_on_read again. Users are also expected to handle spurious 156 // events, i.e read_cb is called while nothing can be readable from fd 157 void grpc_fd_notify_on_read(grpc_fd* fd, grpc_closure* closure); 158 159 // Exactly the same semantics as above, except based on writable events. 160 void grpc_fd_notify_on_write(grpc_fd* fd, grpc_closure* closure); 161 162 // Exactly the same semantics as above, except based on error events. track_err 163 // needs to have been set on grpc_fd_create 164 void grpc_fd_notify_on_error(grpc_fd* fd, grpc_closure* closure); 165 166 // Forcibly set the fd to be readable, resulting in the closure registered with 167 // grpc_fd_notify_on_read being invoked. 168 // 169 void grpc_fd_set_readable(grpc_fd* fd); 170 171 // Forcibly set the fd to be writable, resulting in the closure registered with 172 // grpc_fd_notify_on_write being invoked. 173 // 174 void grpc_fd_set_writable(grpc_fd* fd); 175 176 // Forcibly set the fd to have errored, resulting in the closure registered with 177 // grpc_fd_notify_on_error being invoked. 178 // 179 void grpc_fd_set_error(grpc_fd* fd); 180 181 // Set the fd to be preallocated 182 void grpc_fd_set_pre_allocated(grpc_fd* fd); 183 184 // pollset_posix functions 185 186 // Add an fd to a pollset 187 void grpc_pollset_add_fd(grpc_pollset* pollset, struct grpc_fd* fd); 188 189 // pollset_set_posix functions 190 191 void grpc_pollset_set_add_fd(grpc_pollset_set* pollset_set, grpc_fd* fd); 192 void grpc_pollset_set_del_fd(grpc_pollset_set* pollset_set, grpc_fd* fd); 193 194 // Returns true if the caller is a worker thread for any background poller. 195 bool grpc_is_any_background_poller_thread(); 196 197 // Returns true if the closure is registered into the background poller. Note 198 // that the closure may or may not run yet when this function returns, and the 199 // closure should not be blocking or long-running. 200 bool grpc_add_closure_to_background_poller(grpc_closure* closure, 201 grpc_error_handle error); 202 203 // Shut down all the closures registered in the background poller. 204 void grpc_shutdown_background_closure(); 205 206 // override to allow tests to hook poll() usage 207 typedef int (*grpc_poll_function_type)(struct pollfd*, nfds_t, int); 208 extern grpc_poll_function_type grpc_poll_function; 209 210 #endif // GRPC_SRC_CORE_LIB_IOMGR_EV_POSIX_H 211