Security-57031.1.35.tar.gz

[apple/security.git] / Security / libsecurity_utilities / lib / selector.h

diff --git a/Security/libsecurity_utilities/lib/selector.h b/Security/libsecurity_utilities/lib/selector.h
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+/*
+ * Copyright (c) 2000-2004,2011,2014 Apple Inc. All Rights Reserved.
+ * 
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+
+//
+// selector - I/O stream multiplexing
+//
+#ifndef _H_SELECTOR
+#define _H_SELECTOR
+
+#include <security_utilities/utilities.h>
+#include <security_utilities/fdsel.h>
+#include "timeflow.h"
+#include <sys/types.h>
+#include <cstdio>
+#include <cstdarg>
+#include <map>
+#include <security_utilities/debugging.h>
+
+
+namespace Security {
+namespace UnixPlusPlus {
+
+
+//
+// A Selector is an I/O dispatch facility that can supervise any number of "file descriptors",
+// each of which can perform I/O. Obviously this is geared towards the UNIX facility.
+//
+class Selector {
+public:
+    class Client; friend class Client;
+
+    Selector();
+    virtual ~Selector();
+    
+    //@@@ preliminary interface
+    void operator () ();               // run just once (now)
+    void operator () (Time::Absolute stopTime);
+    void operator () (Time::Interval duration)
+    { (*this)(Time::now() + duration); }
+    
+    typedef unsigned int Type;
+    static const Type none = 0x00;
+    static const Type input = 0x01;
+    static const Type output = 0x02;
+    static const Type critical = 0x04;
+    static const Type all = input | output | critical;
+    
+public:
+    class Client {
+    public:
+        typedef Selector::Type Type;
+        friend class Selector;
+
+        Client() : mSelector(NULL) { }
+        virtual void notify(int fd, Type type) = 0;
+        virtual ~Client() { }
+        
+        bool isActive() const          { return mSelector != NULL; }
+
+        static const Type input = Selector::input;
+        static const Type output = Selector::output;
+        static const Type critical = Selector::critical;
+        
+    protected:
+        void events(Type type) { mSelector->set(mFd, type); mEvents = type; }
+        Type events() const            { return mEvents; }
+
+        void enable(Type type) { events(events() | type); }
+        void disable(Type type)        { events(events() & ~type); }
+
+        template <class Sel> Sel &selectorAs()
+        { assert(mSelector); return safer_cast<Sel &>(*mSelector); }
+        
+    private:
+        int mFd;
+        Selector *mSelector;
+        Type mEvents;
+    };
+    
+    void add(int fd, Client &client, Type type = all);
+    void remove(int fd);
+    bool isEmpty() const                               { return clientMap.empty(); }
+    
+private:
+    void set(int fd, Type type);               // (re)set mask for one client
+    
+    void singleStep(Time::Interval maxWait);
+    
+private:
+    unsigned int fdSetSize;                            // number of fd_masks allocated in FDSets
+    int fdMin, fdMax;                                  // highest/lowest fds in use
+    FDSet inSet, outSet, errSet;               // current in/out/error select masks
+    
+private:
+    typedef map<int, Client *> ClientMap;
+    ClientMap clientMap;
+};
+
+
+}      // end namespace UnixPlusPlus
+}      // end namespace Security
+
+
+#endif //_H_SELECTOR