legacy-libs/grpc/deps/grpc/src/core/lib/transport/connectivity_state.h

   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_CORE_LIB_TRANSPORT_CONNECTIVITY_STATE_H
  20 #define GRPC_CORE_LIB_TRANSPORT_CONNECTIVITY_STATE_H
  21
  22 #include <grpc/support/port_platform.h>
  23
  24 #include <grpc/grpc.h>
  25 #include "src/core/lib/debug/trace.h"
  26 #include "src/core/lib/iomgr/closure.h"
  27
  28 typedef struct grpc_connectivity_state_watcher {
  29   /** we keep watchers in a linked list */
  30   struct grpc_connectivity_state_watcher* next;
  31   /** closure to notify on change */
  32   grpc_closure* notify;
  33   /** the current state as believed by the watcher */
  34   grpc_connectivity_state* current;
  35 } grpc_connectivity_state_watcher;
  36
  37 typedef struct {
  38   /** current grpc_connectivity_state */
  39   gpr_atm current_state_atm;
  40   /** all our watchers */
  41   grpc_connectivity_state_watcher* watchers;
  42   /** a name to help debugging */
  43   char* name;
  44 } grpc_connectivity_state_tracker;
  45
  46 extern grpc_core::TraceFlag grpc_connectivity_state_trace;
  47
  48 /** enum --> string conversion */
  49 const char* grpc_connectivity_state_name(grpc_connectivity_state state);
  50
  51 void grpc_connectivity_state_init(grpc_connectivity_state_tracker* tracker,
  52                                   grpc_connectivity_state init_state,
  53                                   const char* name);
  54 void grpc_connectivity_state_destroy(grpc_connectivity_state_tracker* tracker);
  55
  56 /** Set connectivity state; not thread safe; access must be serialized with an
  57  *  external lock */
  58 void grpc_connectivity_state_set(grpc_connectivity_state_tracker* tracker,
  59                                  grpc_connectivity_state state,
  60                                  const char* reason);
  61
  62 /** Return true if this connectivity state has watchers.
  63     Access must be serialized with an external lock. */
  64 bool grpc_connectivity_state_has_watchers(
  65     grpc_connectivity_state_tracker* tracker);
  66
  67 /** Return the last seen connectivity state. No need to synchronize access. */
  68 grpc_connectivity_state grpc_connectivity_state_check(
  69     grpc_connectivity_state_tracker* tracker);
  70
  71 /** Return 1 if the channel should start connecting, 0 otherwise.
  72     If current==NULL cancel notify if it is already queued (success==0 in that
  73     case).
  74     Access must be serialized with an external lock. */
  75 bool grpc_connectivity_state_notify_on_state_change(
  76     grpc_connectivity_state_tracker* tracker, grpc_connectivity_state* current,
  77     grpc_closure* notify);
  78
  79 #endif /* GRPC_CORE_LIB_TRANSPORT_CONNECTIVITY_STATE_H */