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
#	Content
1	#ifndef EVPP_H__
2	#define EVPP_H__
3
4	#include "ev.h"
5
6	namespace ev {
7
8	template<class watcher>
9	class callback
10	{
11	struct klass; // it is vital that this is never defined
12
13	klass *o;
14	void (klass::*m)(watcher &, int);
15
16	public:
17	template<class O1, class O2>
18	explicit callback (O1 object, void (O2::method)(watcher &, int))
19	{
20	o = reinterpret_cast<klass *>(object);
21	m = reinterpret_cast<void (klass::*)(watcher &, int)>(method);
22	}
23
24	// 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	{
30	(o->m) (w, revents);
31	}
32	};
33
34	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	CHILD = EV_CHILD,
43	STAT = EV_STAT,
44	IDLE = EV_IDLE,
45	CHECK = EV_CHECK,
46	PREPARE = EV_PREPARE,
47	FORK = EV_FORK,
48	EMBED = EV_EMBED,
49	ERROR = EV_ERROR,
50	};
51
52	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	#define EV_BEGIN_WATCHER(cppstem,cstem) \
85	\
86	struct cppstem : ev_ ## cstem, callback<cppstem> \
87	{ \
88	EV_CONSTRUCT (cppstem) \
89	{ \
90	ev_init (static_cast<ev_ ## cstem *>(this), thunk); \
91	} \
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	~cppstem () \
119	{ \
120	stop (); \
121	} \
122	\
123	private: \
124	\
125	cppstem (const cppstem &o) \
126	: callback<cppstem> (this, (void (cppstem::*)(cppstem &, int))0) \
127	{ /* disabled */ } \
128	\
129	void operator =(const cppstem &o) { /* disabled */ } \
130	\
131	static void thunk (EV_P_ struct ev_ ## cstem *w, int revents) \
132	{ \
133	(static_cast<cppstem >(w))(revents); \
134	} \
135	\
136	public:
137
138	#define EV_END_WATCHER(cppstem,cstem) \
139	};
140
141	EV_BEGIN_WATCHER (io, io)
142	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	EV_END_WATCHER (io, io)
164
165	EV_BEGIN_WATCHER (timer, timer)
166	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	EV_END_WATCHER (timer, timer)
185
186	#if EV_PERIODIC_ENABLE
187	EV_BEGIN_WATCHER (periodic, periodic)
188	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	EV_END_WATCHER (periodic, periodic)
207	#endif
208
209	EV_BEGIN_WATCHER (sig, signal)
210	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	EV_END_WATCHER (sig, signal)
224
225	EV_BEGIN_WATCHER (child, child)
226	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	EV_END_WATCHER (child, child)
240
241	#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
268	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	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	#if EV_FORK_ENABLE
300	EV_BEGIN_WATCHER (fork, fork)
301	void set () { }
302	EV_END_WATCHER (fork, fork)
303	#endif
304
305	#undef EV_CONSTRUCT
306	#undef EV_BEGIN_WATCHER
307	#undef EV_END_WATCHER
308	}
309
310	#endif
311