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     // virtual dtor for the base class
  30     virtual ~wxFDIOHandler() { }
  31 };
  32
  33 // those flags describes sets where descriptor should be added
  34 enum wxFDIODispatcherEntryFlags
  35 {
  36     wxFDIO_INPUT = 1,
  37     wxFDIO_OUTPUT = 2,
  38     wxFDIO_EXCEPTION = 4,
  39     wxFDIO_ALL = wxFDIO_INPUT | wxFDIO_OUTPUT | wxFDIO_EXCEPTION
  40 };
  41
  42 // base class for wxSelectDispatcher and wxEpollDispatcher
  43 class WXDLLIMPEXP_BASE wxFDIODispatcher
  44 {
  45 public:
  46     enum { TIMEOUT_INFINITE = -1 };
  47
  48     // return the global dispatcher to be used for IO events, can be NULL only
  49     // if wxSelectDispatcher wasn't compiled into the library at all as
  50     // creating it never fails
  51     //
  52     // don't delete the returned pointer
  53     static wxFDIODispatcher *Get();
  54
  55     // if we have any registered handlers, check for any pending events to them
  56     // and dispatch them -- this is used from wxX11 and wxDFB event loops
  57     // implementation
  58     static void DispatchPending();
  59
  60     // register handler for the given descriptor with the dispatcher, return
  61     // true on success or false on error
  62     virtual bool RegisterFD(int fd, wxFDIOHandler *handler, int flags) = 0;
  63
  64     // modify descriptor flags or handler, return true on success
  65     virtual bool ModifyFD(int fd, wxFDIOHandler *handler, int flags) = 0;
  66
  67     // unregister descriptor previously registered with RegisterFD()
  68     virtual bool UnregisterFD(int fd) = 0;
  69
  70     // check if any events are currently available without dispatching them
  71     virtual bool HasPending() const = 0;
  72
  73     // wait for an event for at most timeout milliseconds and process it;
  74     // return the number of events processed (possibly 0 if timeout expired) or
  75     // -1 if an error occurred
  76     virtual int Dispatch(int timeout = TIMEOUT_INFINITE) = 0;
  77
  78     virtual ~wxFDIODispatcher() { }
  79 };
  80
  81 //entry for wxFDIOHandlerMap
  82 struct wxFDIOHandlerEntry
  83 {
  84     wxFDIOHandlerEntry()
  85     {
  86     }
  87
  88     wxFDIOHandlerEntry(wxFDIOHandler *handler_, int flags_)
  89         : handler(handler_),
  90           flags(flags_)
  91     {
  92     }
  93
  94     wxFDIOHandler *handler;
  95     int flags;
  96 };
  97
  98 // this hash is used to map file descriptors to their handlers
  99 WX_DECLARE_HASH_MAP(
 100   int,
 101   wxFDIOHandlerEntry,
 102   wxIntegerHash,
 103   wxIntegerEqual,
 104   wxFDIOHandlerMap
 105 );
 106
 107 // FDIODispatcher that holds map fd <-> FDIOHandler, this should be used if
 108 // this map isn't maintained elsewhere already as it is usually needed anyhow
 109 //
 110 // notice that all functions for FD management have implementation
 111 // in the base class and should be called from the derived classes
 112 class WXDLLIMPEXP_BASE wxMappedFDIODispatcher : public wxFDIODispatcher
 113 {
 114 public:
 115     // find the handler for the given fd, return NULL if none
 116     wxFDIOHandler *FindHandler(int fd) const;
 117
 118     // register handler for the given descriptor with the dispatcher, return
 119     // true on success or false on error
 120     virtual bool RegisterFD(int fd, wxFDIOHandler *handler, int flags);
 121
 122     // modify descriptor flags or handler, return true on success
 123     virtual bool ModifyFD(int fd, wxFDIOHandler *handler, int flags);
 124
 125     // unregister descriptor previously registered with RegisterFD()
 126     virtual bool UnregisterFD(int fd);
 127
 128     virtual ~wxMappedFDIODispatcher() { }
 129
 130 protected:
 131     // the fd -> handler map containing all the registered handlers
 132     wxFDIOHandlerMap m_handlers;
 133 };
 134
 135 #endif // _WX_PRIVATE_FDIODISPATCHER_H_