src/ipc/SharedListen.h

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 54    Interprocess Communication */
  10
  11 #ifndef SQUID_IPC_SHARED_LISTEN_H
  12 #define SQUID_IPC_SHARED_LISTEN_H
  13
  14 #include "base/AsyncCall.h"
  15 #include "base/Subscription.h"
  16
  17 namespace Ipc
  18 {
  19
  20 /// "shared listen" is when concurrent processes are listening on the same fd
  21
  22 /// Comm::ConnAcceptor parameters holder
  23 /// all the details necessary to recreate a Comm::Connection and fde entry for the kid listener FD
  24 class OpenListenerParams
  25 {
  26 public:
  27     OpenListenerParams();
  28
  29     bool operator <(const OpenListenerParams &p) const; ///< useful for map<>
  30
  31     // bits to re-create the fde entry
  32     int sock_type;
  33     int proto;
  34     int fdNote; ///< index into fd_note() comment strings
  35
  36     // bits to re-create the listener Comm::Connection descriptor
  37     Ip::Address addr; ///< will be memset and memcopied
  38     int flags;
  39
  40     /// handler to subscribe to Comm::ConnAcceptor when we get the response
  41     Subscription::Pointer handlerSubscription;
  42 };
  43
  44 class TypedMsgHdr;
  45
  46 /// a request for a listen socket with given parameters
  47 class SharedListenRequest
  48 {
  49 public:
  50     SharedListenRequest(); ///< from OpenSharedListen() which then sets public data
  51     explicit SharedListenRequest(const TypedMsgHdr &hdrMsg); ///< from recvmsg()
  52     void pack(TypedMsgHdr &hdrMsg) const; ///< prepare for sendmsg()
  53
  54 public:
  55     int requestorId; ///< kidId of the requestor
  56
  57     OpenListenerParams params; ///< actual comm_open_sharedListen() parameters
  58
  59     int mapId; ///< to map future response to the requestor's callback
  60 };
  61
  62 /// a response to SharedListenRequest
  63 class SharedListenResponse
  64 {
  65 public:
  66     SharedListenResponse(int fd, int errNo, int mapId);
  67     explicit SharedListenResponse(const TypedMsgHdr &hdrMsg); ///< from recvmsg()
  68     void pack(TypedMsgHdr &hdrMsg) const; ///< prepare for sendmsg()
  69
  70 public:
  71     int fd; ///< opened listening socket or -1
  72     int errNo; ///< errno value from comm_open_sharedListen() call
  73     int mapId; ///< to map future response to the requestor's callback
  74 };
  75
  76 /// prepare and send SharedListenRequest to Coordinator
  77 void JoinSharedListen(const OpenListenerParams &, AsyncCall::Pointer &);
  78
  79 /// process Coordinator response to SharedListenRequest
  80 void SharedListenJoined(const SharedListenResponse &response);
  81
  82 } // namespace Ipc;
  83
  84 #endif /* SQUID_IPC_SHARED_LISTEN_H */
  85