WDL/shm_msgreply.h

   1 #ifndef _WDL_SHM_MSGREPLY_
   2 #define _WDL_SHM_MSGREPLY_
   3
   4 #include <time.h>
   5 #include "shm_connection.h"
   6 #include "mutex.h"
   7
   8
   9 /*
  10   4 byte message type
  11
  12   4 byte unique message ID (0 for no reply needed/wanted)
  13
  14   4 byte message length (following)
  15
  16
  17   type: 0 reply
  18     call specific return data
  19   type: all others user defined
  20
  21 */
  22 // type is user defined, however type=0 is reserved for reply
  23 class SHM_MsgReplyConnection
  24 {
  25
  26 public:
  27
  28   class WaitingMessage
  29   {
  30   public:
  31     WaitingMessage() { }
  32     ~WaitingMessage() { }
  33
  34     WaitingMessage *_next;
  35
  36     int m_msgid;
  37     int m_msgtype;
  38
  39     WDL_HeapBuf m_msgdata;
  40   };
  41
  42
  43   SHM_MsgReplyConnection(int bufsize, int maxqueuesize, bool dir, const char *uniquestr=NULL, int timeout_sec=0, int extra_flags=0);
  44   ~SHM_MsgReplyConnection();
  45
  46   // be sure to set these, and have OnRecv() Reply() to any nonzero msgID !
  47   void *userData;
  48   WaitingMessage *(*OnRecv)(SHM_MsgReplyConnection *con, WaitingMessage *msg);
  49   bool (*IdleProc)(SHM_MsgReplyConnection *con); // return TRUE to abort (this will set the m_has_had_error to true / kill the connection)
  50   // can return NULL To temporarily buffer msg, can return a chain of msgs too to return them to the spare list
  51
  52   // run as you wish, Send() will also run internally when waiting for reply
  53   // note: the checkForReplyID etc are for INTERNAL USE ONLY :)
  54
  55   bool Run(bool runFull=true);
  56
  57   // returns <0 if no reply, otherwise lenght of replybuf used
  58   // no retbuf = no wait for reply
  59   int Send(int type, const void *msg, int msglen,
  60            void *replybuf, int maxretbuflen, const int *forceMsgID=NULL,
  61            const void *secondchunk=NULL, int secondchunklen=0, // allow sending two blocks as one message (for speed in certain instances)
  62            WDL_HeapBuf *hbreplyout=NULL);  // if hbreplyout is set it will get the full message (replybuf can be NULL then)
  63   void Reply(int msgID, const void *msg, int msglen);
  64   void Wait(HANDLE extraEvt=NULL);
  65
  66   const char *GetUniqueString() { return m_uniq; }
  67
  68   void ReturnSpares(WaitingMessage *msglist);
  69
  70 private:
  71   bool RunInternal(int checkForReplyID=0, WaitingMessage **replyPtr=0); // nonzero on error
  72
  73   char m_uniq[256];
  74   WDL_Mutex m_shmmutex;
  75   WDL_SHM_Connection *m_shm;
  76
  77
  78   WaitingMessage *m_waiting_replies;
  79   WaitingMessage *m_spares;
  80
  81   int m_lastmsgid;
  82   int m_maxqueuesize;
  83   bool m_has_had_error;
  84 };
  85
  86 #endif