include/wx/private/fdiodispatcher.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/private/fdiodispatcher.h
   3 // Purpose:     classes for dispatching IO notifications for file descriptors
   4 // Authors:     Lukasz Michalski
   5 // Created:     December 2006
   6 // Copyright:   (c) Lukasz Michalski
   7 // RCS-ID:      $Id$
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_PRIVATE_FDIODISPATCHER_H_
  12 #define _WX_PRIVATE_FDIODISPATCHER_H_
  13
  14 #include "wx/hashmap.h"
  15
  16 // handler used to process events on descriptors
  17 class wxFDIOHandler
  18 {
  19 public:
  20     // called when descriptor is available for non-blocking read
  21     virtual void OnReadWaiting() = 0;
  22
  23     // called when descriptor is available  for non-blocking write
  24     virtual void OnWriteWaiting() = 0;
  25
  26     // called when there is exception on descriptor
  27     virtual void OnExceptionWaiting() = 0;
  28
  29     // called to check if the handler is still valid, only used by
  30     // wxSocketImplUnix currently
  31     virtual bool IsOk() const { return true; }
  32
  33     // virtual dtor for the base class
  34     virtual ~wxFDIOHandler() { }
  35 };
  36
  37 // those flags describes sets where descriptor should be added
  38 enum wxFDIODispatcherEntryFlags
  39 {
  40     wxFDIO_INPUT = 1,
  41     wxFDIO_OUTPUT = 2,
  42     wxFDIO_EXCEPTION = 4,
  43     wxFDIO_ALL = wxFDIO_INPUT | wxFDIO_OUTPUT | wxFDIO_EXCEPTION
  44 };
  45
  46 // base class for wxSelectDispatcher and wxEpollDispatcher
  47 class WXDLLIMPEXP_BASE wxFDIODispatcher
  48 {
  49 public:
  50     enum { TIMEOUT_INFINITE = -1 };
  51
  52     // return the global dispatcher to be used for IO events, can be NULL only
  53     // if wxSelectDispatcher wasn't compiled into the library at all as
  54     // creating it never fails
  55     //
  56     // don't delete the returned pointer
  57     static wxFDIODispatcher *Get();
  58
  59     // if we have any registered handlers, check for any pending events to them
  60     // and dispatch them -- this is used from wxX11 and wxDFB event loops
  61     // implementation
  62     static void DispatchPending();
  63
  64     // register handler for the given descriptor with the dispatcher, return
  65     // true on success or false on error
  66     virtual bool RegisterFD(int fd, wxFDIOHandler *handler, int flags) = 0;
  67
  68     // modify descriptor flags or handler, return true on success
  69     virtual bool ModifyFD(int fd, wxFDIOHandler *handler, int flags) = 0;
  70
  71     // unregister descriptor previously registered with RegisterFD()
  72     virtual bool UnregisterFD(int fd) = 0;
  73
  74     // check if any events are currently available without dispatching them
  75     virtual bool HasPending() const = 0;
  76
  77     // wait for an event for at most timeout milliseconds and process it;
  78     // return the number of events processed (possibly 0 if timeout expired) or
  79     // -1 if an error occurred
  80     virtual int Dispatch(int timeout = TIMEOUT_INFINITE) = 0;
  81
  82     virtual ~wxFDIODispatcher() { }
  83 };
  84
  85 //entry for wxFDIOHandlerMap
  86 struct wxFDIOHandlerEntry
  87 {
  88     wxFDIOHandlerEntry()
  89     {
  90     }
  91
  92     wxFDIOHandlerEntry(wxFDIOHandler *handler_, int flags_)
  93         : handler(handler_),
  94           flags(flags_)
  95     {
  96     }
  97
  98     wxFDIOHandler *handler;
  99     int flags;
 100 };
 101
 102 // this hash is used to map file descriptors to their handlers
 103 WX_DECLARE_HASH_MAP(
 104   int,
 105   wxFDIOHandlerEntry,
 106   wxIntegerHash,
 107   wxIntegerEqual,
 108   wxFDIOHandlerMap
 109 );
 110
 111 // FDIODispatcher that holds map fd <-> FDIOHandler, this should be used if
 112 // this map isn't maintained elsewhere already as it is usually needed anyhow
 113 //
 114 // notice that all functions for FD management have implementation
 115 // in the base class and should be called from the derived classes
 116 class WXDLLIMPEXP_BASE wxMappedFDIODispatcher : public wxFDIODispatcher
 117 {
 118 public:
 119     // find the handler for the given fd, return NULL if none
 120     wxFDIOHandler *FindHandler(int fd) const;
 121
 122     // register handler for the given descriptor with the dispatcher, return
 123     // true on success or false on error
 124     virtual bool RegisterFD(int fd, wxFDIOHandler *handler, int flags);
 125
 126     // modify descriptor flags or handler, return true on success
 127     virtual bool ModifyFD(int fd, wxFDIOHandler *handler, int flags);
 128
 129     // unregister descriptor previously registered with RegisterFD()
 130     virtual bool UnregisterFD(int fd);
 131
 132     virtual ~wxMappedFDIODispatcher() { }
 133
 134 protected:
 135     // the fd -> handler map containing all the registered handlers
 136     wxFDIOHandlerMap m_handlers;
 137 };
 138
 139 #endif // _WX_PRIVATE_FDIODISPATCHER_H_