src/ipc/SharedListen.h

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