1/*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All Rights Reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23
24
25//
26// selector - I/O stream multiplexing
27//
28#ifndef _H_SELECTOR
29#define _H_SELECTOR
30
31#include <security_utilities/utilities.h>
32#include <security_utilities/fdsel.h>
33#include "timeflow.h"
34#include <sys/types.h>
35#include <cstdio>
36#include <cstdarg>
37#include <map>
38#include <security_utilities/debugging.h>
39
40
41namespace Security {
42namespace UnixPlusPlus {
43
44
45//
46// A Selector is an I/O dispatch facility that can supervise any number of "file descriptors",
47// each of which can perform I/O. Obviously this is geared towards the UNIX facility.
48//
49class Selector {
50public:
51    class Client; friend class Client;
52
53    Selector();
54    virtual ~Selector();
55
56    //@@@ preliminary interface
57    void operator () ();		// run just once (now)
58    void operator () (Time::Absolute stopTime);
59    void operator () (Time::Interval duration)
60    { (*this)(Time::now() + duration); }
61
62    typedef unsigned int Type;
63    static const Type none = 0x00;
64    static const Type input = 0x01;
65    static const Type output = 0x02;
66    static const Type critical = 0x04;
67    static const Type all = input | output | critical;
68
69public:
70    class Client {
71    public:
72        typedef Selector::Type Type;
73        friend class Selector;
74
75        Client() : mSelector(NULL) { }
76        virtual void notify(int fd, Type type) = 0;
77        virtual ~Client() { }
78
79        bool isActive() const		{ return mSelector != NULL; }
80
81        static const Type input = Selector::input;
82        static const Type output = Selector::output;
83        static const Type critical = Selector::critical;
84
85    protected:
86        void events(Type type)	{ mSelector->set(mFd, type); mEvents = type; }
87        Type events() const		{ return mEvents; }
88
89        void enable(Type type)	{ events(events() | type); }
90        void disable(Type type)	{ events(events() & ~type); }
91
92        template <class Sel> Sel &selectorAs()
93        { assert(mSelector); return safer_cast<Sel &>(*mSelector); }
94
95    private:
96        int mFd;
97        Selector *mSelector;
98        Type mEvents;
99    };
100
101    void add(int fd, Client &client, Type type = all);
102    void remove(int fd);
103    bool isEmpty() const				{ return clientMap.empty(); }
104
105private:
106    void set(int fd, Type type);		// (re)set mask for one client
107
108    void singleStep(Time::Interval maxWait);
109
110private:
111    unsigned int fdSetSize;				// number of fd_masks allocated in FDSets
112    int fdMin, fdMax;					// highest/lowest fds in use
113    FDSet inSet, outSet, errSet;		// current in/out/error select masks
114
115private:
116    typedef map<int, Client *> ClientMap;
117    ClientMap clientMap;
118};
119
120
121}	// end namespace UnixPlusPlus
122}	// end namespace Security
123
124
125#endif //_H_SELECTOR
126