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_POLLSET_H 20 #define GRPC_SRC_CORE_LIB_IOMGR_POLLSET_H 21 22 #include <grpc/support/port_platform.h> 23 #include <grpc/support/sync.h> 24 #include <grpc/support/time.h> 25 26 #include "src/core/lib/iomgr/exec_ctx.h" 27 #include "src/core/lib/iomgr/iomgr_fwd.h" 28 29 // A grpc_pollset is a set of file descriptors that a higher level item is 30 // interested in. For example: 31 // - a server will typically keep a pollset containing all connected channels, 32 // so that it can find new calls to service 33 // - a completion queue might keep a pollset with an entry for each transport 34 // that is servicing a call that it's tracking 35 36 typedef struct grpc_pollset_worker grpc_pollset_worker; 37 38 typedef struct grpc_pollset_vtable { 39 void (*global_init)(void); 40 void (*global_shutdown)(void); 41 void (*init)(grpc_pollset* pollset, gpr_mu** mu); 42 void (*shutdown)(grpc_pollset* pollset, grpc_closure* closure); 43 void (*destroy)(grpc_pollset* pollset); 44 grpc_error_handle (*work)(grpc_pollset* pollset, grpc_pollset_worker** worker, 45 grpc_core::Timestamp deadline); 46 grpc_error_handle (*kick)(grpc_pollset* pollset, 47 grpc_pollset_worker* specific_worker); 48 size_t (*pollset_size)(void); 49 } grpc_pollset_vtable; 50 51 void grpc_set_pollset_vtable(grpc_pollset_vtable* vtable); 52 53 void grpc_pollset_global_init(void); 54 void grpc_pollset_global_shutdown(void); 55 56 size_t grpc_pollset_size(void); 57 // Initialize a pollset: assumes *pollset contains all zeros 58 void grpc_pollset_init(grpc_pollset* pollset, gpr_mu** mu); 59 // Begin shutting down the pollset, and call closure when done. 60 // pollset's mutex must be held 61 void grpc_pollset_shutdown(grpc_pollset* pollset, grpc_closure* closure); 62 void grpc_pollset_destroy(grpc_pollset* pollset); 63 64 // Do some work on a pollset. 65 // May involve invoking asynchronous callbacks, or actually polling file 66 // descriptors. 67 // Requires pollset's mutex locked. 68 // May unlock its mutex during its execution. 69 70 // worker is a (platform-specific) handle that can be used to wake up 71 // from grpc_pollset_work before any events are received and before the timeout 72 // has expired. It is both initialized and destroyed by grpc_pollset_work. 73 // Initialization of worker is guaranteed to occur BEFORE the 74 // pollset's mutex is released for the first time by grpc_pollset_work 75 // and it is guaranteed that it will not be released by grpc_pollset_work 76 // AFTER worker has been destroyed. 77 78 // It's legal for worker to be NULL: in that case, this specific thread can not 79 // be directly woken with a kick, but maybe be indirectly (with a kick against 80 // the pollset as a whole). 81 82 // Tries not to block past deadline. 83 // May call grpc_closure_list_run on grpc_closure_list, without holding the 84 // pollset 85 // lock 86 grpc_error_handle grpc_pollset_work(grpc_pollset* pollset, 87 grpc_pollset_worker** worker, 88 grpc_core::Timestamp deadline); 89 90 // Break one polling thread out of polling work for this pollset. 91 // If specific_worker is non-NULL, then kick that worker. 92 grpc_error_handle grpc_pollset_kick(grpc_pollset* pollset, 93 grpc_pollset_worker* specific_worker); 94 95 #endif // GRPC_SRC_CORE_LIB_IOMGR_POLLSET_H 96