libev/ev%2B%2B.h

#ifndef EVPP_H__
#define EVPP_H__

#include "ev.h"

namespace ev {

  template<class watcher>
  class callback
  {
    struct klass; // it is vital that this is never defined

    klass *o;
    void (klass::*m)(watcher &, int);

  public:
    template<class O1, class O2>
    explicit callback (O1 *object, void (O2::*method)(watcher &, int))
    {
      o = reinterpret_cast<klass *>(object);
      m = reinterpret_cast<void (klass::*)(watcher &, int)>(method);
    }

    // this works because a standards-compliant C++ compiler
    // basically can't help it: it doesn't have the knowledge
    // required to miscompile (klass is not defined anywhere
    // and nothing is known about the constructor arguments) :)
    void call (watcher *w, int revents)
    {
      (o->*m) (*w, revents);
    }
  };

  enum {
    UNDEF    = EV_UNDEF,
    NONE     = EV_NONE,
    READ     = EV_READ,
    WRITE    = EV_WRITE,
    TIMEOUT  = EV_TIMEOUT,
    PERIODIC = EV_PERIODIC,
    SIGNAL   = EV_SIGNAL,
    CHILD    = EV_CHILD,
    STAT     = EV_STAT,
    IDLE     = EV_IDLE,
    CHECK    = EV_CHECK,
    PREPARE  = EV_PREPARE,
    FORK     = EV_FORK,
    EMBED    = EV_EMBED,
    ERROR    = EV_ERROR,
  };

  typedef ev_tstamp tstamp;

  inline ev_tstamp now (EV_P)
  {
    return ev_now (EV_A);
  }

  #if EV_MULTIPLICITY

    #define EV_CONSTRUCT(cppstem)                                                       \
      EV_P;                                                                             \
                                                                                        \
      void set (EV_P)                                                                   \
      {                                                                                 \
        this->EV_A = EV_A;                                                              \
      }                                                                                 \
                                                                                        \
      template<class O1, class O2>                                                      \
      explicit cppstem (O1 *object, void (O2::*method)(cppstem &, int), EV_P = ev_default_loop (0)) \
      : callback<cppstem> (object, method), EV_A (EV_A)

  #else

    #define EV_CONSTRUCT(cppstem)                                                       \
      template<class O1, class O2>                                                      \
      explicit cppstem (O1 *object, void (O2::*method)(cppstem &, int))                 \
      : callback<cppstem> (object, method)

  #endif

  /* using a template here would require quite a bit more lines,
   * so a macro solution was chosen */
  #define EV_BEGIN_WATCHER(cppstem,cstem)                                               \
                                                                                        \
  struct cppstem : ev_ ## cstem, callback<cppstem>                                      \
  {                                                                                     \
    EV_CONSTRUCT (cppstem)                                                              \
    {                                                                                   \
      ev_init (static_cast<ev_ ## cstem *>(this), thunk);                               \
    }                                                                                   \
                                                                                        \
    bool is_active () const                                                             \
    {                                                                                   \
      return ev_is_active (static_cast<const ev_ ## cstem *>(this));                    \
    }                                                                                   \
                                                                                        \
    bool is_pending () const                                                            \
    {                                                                                   \
      return ev_is_pending (static_cast<const ev_ ## cstem *>(this));                   \
    }                                                                                   \
                                                                                        \
    void start ()                                                                       \
    {                                                                                   \
      ev_ ## cstem ## _start (EV_A_ static_cast<ev_ ## cstem *>(this));                 \
    }                                                                                   \
                                                                                        \
    void stop ()                                                                        \
    {                                                                                   \
      ev_ ## cstem ## _stop (EV_A_ static_cast<ev_ ## cstem *>(this));                  \
    }                                                                                   \
                                                                                        \
    void operator ()(int events = EV_UNDEF)                                             \
    {                                                                                   \
      return call (this, events);                                                       \
    }                                                                                   \
                                                                                        \
    ~cppstem ()                                                                         \
    {                                                                                   \
      stop ();                                                                          \
    }                                                                                   \
                                                                                        \
  private:                                                                              \
                                                                                        \
    cppstem (const cppstem &o)                                                          \
    : callback<cppstem> (this, (void (cppstem::*)(cppstem &, int))0)                    \
    { /* disabled */ }                                                                  \
                                                                                        \
    void operator =(const cppstem &o) { /* disabled */ }                                \
                                                                                        \
    static void thunk (EV_P_ struct ev_ ## cstem *w, int revents)                       \
    {                                                                                   \
      (*static_cast<cppstem *>(w))(revents);                                            \
    }                                                                                   \
                                                                                        \
  public:

  #define EV_END_WATCHER(cppstem,cstem)                                                 \
  };

  EV_BEGIN_WATCHER (io, io)
    void set (int fd, int events)
    {
      int active = is_active ();
      if (active) stop ();
      ev_io_set (static_cast<ev_io *>(this), fd, events);
      if (active) start ();
    }

    void set (int events)
    {
      int active = is_active ();
      if (active) stop ();
      ev_io_set (static_cast<ev_io *>(this), fd, events);
      if (active) start ();
    }

    void start (int fd, int events)
    {
      set (fd, events);
      start ();
    }
  EV_END_WATCHER (io, io)

  EV_BEGIN_WATCHER (timer, timer)
    void set (ev_tstamp after, ev_tstamp repeat = 0.)
    {
      int active = is_active ();
      if (active) stop ();
      ev_timer_set (static_cast<ev_timer *>(this), after, repeat);
      if (active) start ();
    }

    void start (ev_tstamp after, ev_tstamp repeat = 0.)
    {
      set (after, repeat);
      start ();
    }

    void again ()
    {
      ev_timer_again (EV_A_ static_cast<ev_timer *>(this));
    }
  EV_END_WATCHER (timer, timer)

  #if EV_PERIODIC_ENABLE
  EV_BEGIN_WATCHER (periodic, periodic)
    void set (ev_tstamp at, ev_tstamp interval = 0.)
    {
      int active = is_active ();
      if (active) stop ();
      ev_periodic_set (static_cast<ev_periodic *>(this), at, interval, 0);
      if (active) start ();
    }

    void start (ev_tstamp at, ev_tstamp interval = 0.)
    {
      set (at, interval);
      start ();
    }

    void again ()
    {
      ev_periodic_again (EV_A_ static_cast<ev_periodic *>(this));
    }
  EV_END_WATCHER (periodic, periodic)
  #endif

  EV_BEGIN_WATCHER (sig, signal)
    void set (int signum)
    {
      int active = is_active ();
      if (active) stop ();
      ev_signal_set (static_cast<ev_signal *>(this), signum);
      if (active) start ();
    }

    void start (int signum)
    {
      set (signum);
      start ();
    }
  EV_END_WATCHER (sig, signal)

  EV_BEGIN_WATCHER (child, child)
    void set (int pid)
    {
      int active = is_active ();
      if (active) stop ();
      ev_child_set (static_cast<ev_child *>(this), pid);
      if (active) start ();
    }

    void start (int pid)
    {
      set (pid);
      start ();
    }
  EV_END_WATCHER (child, child)

  #if EV_STAT_ENABLE
  EV_BEGIN_WATCHER (stat, stat)
    void set (const char *path, ev_tstamp interval = 0.)
    {
      int active = is_active ();
      if (active) stop ();
      ev_stat_set (static_cast<ev_stat *>(this), path, interval);
      if (active) start ();
    }

    void start (const char *path, ev_tstamp interval = 0.)
    {
      set (path, interval);
      start ();
    }

    void update ()
    {
      ev_stat_stat (EV_A_ static_cast<ev_stat *>(this));
    }
  EV_END_WATCHER (stat, stat)
  #endif

  EV_BEGIN_WATCHER (idle, idle)
    void set () { }
  EV_END_WATCHER (idle, idle)

  EV_BEGIN_WATCHER (prepare, prepare)
    void set () { }
  EV_END_WATCHER (prepare, prepare)

  EV_BEGIN_WATCHER (check, check)
    void set () { }
  EV_END_WATCHER (check, check)

  #if EV_EMBED_ENABLE
  EV_BEGIN_WATCHER (embed, embed)
    void set (struct ev_loop *loop)
    {
      int active = is_active ();
      if (active) stop ();
      ev_embed_set (static_cast<ev_embed *>(this), loop);
      if (active) start ();
    }

    void start (struct ev_loop *embedded_loop)
    {
      set (embedded_loop);
      start ();
    }

    void sweep ()
    {
      ev_embed_sweep (EV_A_ static_cast<ev_embed *>(this));
    }
  EV_END_WATCHER (embed, embed)
  #endif

  #if EV_FORK_ENABLE
  EV_BEGIN_WATCHER (fork, fork)
    void set () { }
  EV_END_WATCHER (fork, fork)
  #endif

  #undef EV_CONSTRUCT
  #undef EV_BEGIN_WATCHER
  #undef EV_END_WATCHER
}

#endif

Revision:	1.11
Committed:	Tue Nov 27 22:31:52 2007 UTC (16 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-1_5
Changes since 1.10:	+11 -24 lines
Log Message:	great idea. radically simplify the method callbacks
#	User	Rev	Content
1	root	1.1	#ifndef EVPP_H__
2			#define EVPP_H__
3
4	root	1.7	#include "ev.h"
5	root	1.1
6			namespace ev {
7
8			template<class watcher>
9			class callback
10			{
11	root	1.11	struct klass; // it is vital that this is never defined
12	root	1.1
13	root	1.11	klass *o;
14			void (klass::*m)(watcher &, int);
15	root	1.1
16			public:
17			template<class O1, class O2>
18			explicit callback (O1 object, void (O2::method)(watcher &, int))
19			{
20	root	1.11	o = reinterpret_cast<klass *>(object);
21			m = reinterpret_cast<void (klass::*)(watcher &, int)>(method);
22	root	1.1	}
23
24	root	1.11	// this works because a standards-compliant C++ compiler
25			// basically can't help it: it doesn't have the knowledge
26			// required to miscompile (klass is not defined anywhere
27			// and nothing is known about the constructor arguments) :)
28			void call (watcher *w, int revents)
29	root	1.1	{
30	root	1.11	(o->m) (w, revents);
31	root	1.1	}
32			};
33
34	root	1.2	enum {
35			UNDEF = EV_UNDEF,
36			NONE = EV_NONE,
37			READ = EV_READ,
38			WRITE = EV_WRITE,
39			TIMEOUT = EV_TIMEOUT,
40			PERIODIC = EV_PERIODIC,
41			SIGNAL = EV_SIGNAL,
42	root	1.9	CHILD = EV_CHILD,
43			STAT = EV_STAT,
44	root	1.2	IDLE = EV_IDLE,
45			CHECK = EV_CHECK,
46			PREPARE = EV_PREPARE,
47	root	1.9	FORK = EV_FORK,
48			EMBED = EV_EMBED,
49	root	1.2	ERROR = EV_ERROR,
50			};
51
52	root	1.1	typedef ev_tstamp tstamp;
53
54			inline ev_tstamp now (EV_P)
55			{
56			return ev_now (EV_A);
57			}
58
59			#if EV_MULTIPLICITY
60
61			#define EV_CONSTRUCT(cppstem) \
62			EV_P; \
63			\
64			void set (EV_P) \
65			{ \
66			this->EV_A = EV_A; \
67			} \
68			\
69			template<class O1, class O2> \
70			explicit cppstem (O1 object, void (O2::method)(cppstem &, int), EV_P = ev_default_loop (0)) \
71			: callback<cppstem> (object, method), EV_A (EV_A)
72
73			#else
74
75			#define EV_CONSTRUCT(cppstem) \
76			template<class O1, class O2> \
77			explicit cppstem (O1 object, void (O2::method)(cppstem &, int)) \
78			: callback<cppstem> (object, method)
79
80			#endif
81
82			/* using a template here would require quite a bit more lines,
83			* so a macro solution was chosen */
84	root	1.4	#define EV_BEGIN_WATCHER(cppstem,cstem) \
85	root	1.1	\
86			struct cppstem : ev_ ## cstem, callback<cppstem> \
87			{ \
88			EV_CONSTRUCT (cppstem) \
89			{ \
90	root	1.6	ev_init (static_cast<ev_ ## cstem *>(this), thunk); \
91	root	1.1	} \
92			\
93			bool is_active () const \
94			{ \
95			return ev_is_active (static_cast<const ev_ ## cstem *>(this)); \
96			} \
97			\
98			bool is_pending () const \
99			{ \
100			return ev_is_pending (static_cast<const ev_ ## cstem *>(this)); \
101			} \
102			\
103			void start () \
104			{ \
105			ev_ ## cstem ## _start (EV_A_ static_cast<ev_ ## cstem *>(this)); \
106			} \
107			\
108			void stop () \
109			{ \
110			ev_ ## cstem ## _stop (EV_A_ static_cast<ev_ ## cstem *>(this)); \
111			} \
112			\
113			void operator ()(int events = EV_UNDEF) \
114			{ \
115			return call (this, events); \
116			} \
117			\
118	root	1.3	~cppstem () \
119			{ \
120			stop (); \
121			} \
122			\
123	root	1.1	private: \
124			\
125			cppstem (const cppstem &o) \
126			: callback<cppstem> (this, (void (cppstem::*)(cppstem &, int))0) \
127			{ /* disabled */ } \
128	root	1.6	\
129	root	1.1	void operator =(const cppstem &o) { /* disabled */ } \
130			\
131	root	1.6	static void thunk (EV_P_ struct ev_ ## cstem *w, int revents) \
132			{ \
133			(static_cast<cppstem >(w))(revents); \
134			} \
135			\
136	root	1.1	public:
137
138	root	1.4	#define EV_END_WATCHER(cppstem,cstem) \
139	root	1.6	};
140	root	1.4
141			EV_BEGIN_WATCHER (io, io)
142	root	1.1	void set (int fd, int events)
143			{
144			int active = is_active ();
145			if (active) stop ();
146			ev_io_set (static_cast<ev_io *>(this), fd, events);
147			if (active) start ();
148			}
149
150			void set (int events)
151			{
152			int active = is_active ();
153			if (active) stop ();
154			ev_io_set (static_cast<ev_io *>(this), fd, events);
155			if (active) start ();
156			}
157
158			void start (int fd, int events)
159			{
160			set (fd, events);
161			start ();
162			}
163	root	1.4	EV_END_WATCHER (io, io)
164	root	1.1
165	root	1.4	EV_BEGIN_WATCHER (timer, timer)
166	root	1.1	void set (ev_tstamp after, ev_tstamp repeat = 0.)
167			{
168			int active = is_active ();
169			if (active) stop ();
170			ev_timer_set (static_cast<ev_timer *>(this), after, repeat);
171			if (active) start ();
172			}
173
174			void start (ev_tstamp after, ev_tstamp repeat = 0.)
175			{
176			set (after, repeat);
177			start ();
178			}
179
180			void again ()
181			{
182			ev_timer_again (EV_A_ static_cast<ev_timer *>(this));
183			}
184	root	1.4	EV_END_WATCHER (timer, timer)
185	root	1.1
186	root	1.8	#if EV_PERIODIC_ENABLE
187	root	1.4	EV_BEGIN_WATCHER (periodic, periodic)
188	root	1.1	void set (ev_tstamp at, ev_tstamp interval = 0.)
189			{
190			int active = is_active ();
191			if (active) stop ();
192			ev_periodic_set (static_cast<ev_periodic *>(this), at, interval, 0);
193			if (active) start ();
194			}
195
196			void start (ev_tstamp at, ev_tstamp interval = 0.)
197			{
198			set (at, interval);
199			start ();
200			}
201
202			void again ()
203			{
204			ev_periodic_again (EV_A_ static_cast<ev_periodic *>(this));
205			}
206	root	1.4	EV_END_WATCHER (periodic, periodic)
207	root	1.3	#endif
208	root	1.1
209	root	1.4	EV_BEGIN_WATCHER (sig, signal)
210	root	1.1	void set (int signum)
211			{
212			int active = is_active ();
213			if (active) stop ();
214			ev_signal_set (static_cast<ev_signal *>(this), signum);
215			if (active) start ();
216			}
217
218			void start (int signum)
219			{
220			set (signum);
221			start ();
222			}
223	root	1.4	EV_END_WATCHER (sig, signal)
224	root	1.1
225	root	1.4	EV_BEGIN_WATCHER (child, child)
226	root	1.1	void set (int pid)
227			{
228			int active = is_active ();
229			if (active) stop ();
230			ev_child_set (static_cast<ev_child *>(this), pid);
231			if (active) start ();
232			}
233
234			void start (int pid)
235			{
236			set (pid);
237			start ();
238			}
239	root	1.4	EV_END_WATCHER (child, child)
240	root	1.1
241	root	1.8	#if EV_STAT_ENABLE
242			EV_BEGIN_WATCHER (stat, stat)
243			void set (const char *path, ev_tstamp interval = 0.)
244			{
245			int active = is_active ();
246			if (active) stop ();
247			ev_stat_set (static_cast<ev_stat *>(this), path, interval);
248			if (active) start ();
249			}
250
251			void start (const char *path, ev_tstamp interval = 0.)
252			{
253			set (path, interval);
254			start ();
255			}
256
257			void update ()
258			{
259			ev_stat_stat (EV_A_ static_cast<ev_stat *>(this));
260			}
261			EV_END_WATCHER (stat, stat)
262			#endif
263
264			EV_BEGIN_WATCHER (idle, idle)
265			void set () { }
266			EV_END_WATCHER (idle, idle)
267	root	1.7
268	root	1.8	EV_BEGIN_WATCHER (prepare, prepare)
269			void set () { }
270			EV_END_WATCHER (prepare, prepare)
271
272			EV_BEGIN_WATCHER (check, check)
273			void set () { }
274			EV_END_WATCHER (check, check)
275
276			#if EV_EMBED_ENABLE
277	root	1.7	EV_BEGIN_WATCHER (embed, embed)
278			void set (struct ev_loop *loop)
279			{
280			int active = is_active ();
281			if (active) stop ();
282			ev_embed_set (static_cast<ev_embed *>(this), loop);
283			if (active) start ();
284			}
285
286			void start (struct ev_loop *embedded_loop)
287			{
288			set (embedded_loop);
289			start ();
290			}
291
292			void sweep ()
293			{
294			ev_embed_sweep (EV_A_ static_cast<ev_embed *>(this));
295			}
296			EV_END_WATCHER (embed, embed)
297			#endif
298
299	root	1.10	#if EV_FORK_ENABLE
300			EV_BEGIN_WATCHER (fork, fork)
301			void set () { }
302			EV_END_WATCHER (fork, fork)
303			#endif
304
305	root	1.1	#undef EV_CONSTRUCT
306	root	1.4	#undef EV_BEGIN_WATCHER
307	root	1.7	#undef EV_END_WATCHER
308	root	1.1	}
309
310			#endif
311