135 lines
2.4 KiB
C++
135 lines
2.4 KiB
C++
/*
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* \brief File-system node
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* \author Norman Feske
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* \author Christian Helmuth
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* \date 2013-11-11
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*/
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#ifndef _NODE_H_
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#define _NODE_H_
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/* Genode includes */
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#include <util/list.h>
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#include <base/lock.h>
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#include <base/signal.h>
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namespace File_system {
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class Listener : public List<Listener>::Element
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{
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private:
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Lock _lock;
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Signal_context_capability _sigh;
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bool _marked_as_updated;
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public:
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Listener() : _marked_as_updated(false) { }
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Listener(Signal_context_capability sigh)
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: _sigh(sigh), _marked_as_updated(false) { }
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void notify()
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{
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Lock::Guard guard(_lock);
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if (_marked_as_updated && _sigh.valid())
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Signal_transmitter(_sigh).submit();
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_marked_as_updated = false;
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}
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void mark_as_updated()
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{
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Lock::Guard guard(_lock);
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_marked_as_updated = true;
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}
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bool valid() const { return _sigh.valid(); }
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};
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class Node : public List<Node>::Element
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{
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public:
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typedef char Name[128];
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private:
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Lock _lock;
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Name _name;
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unsigned long const _inode;
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List<Listener> _listeners;
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public:
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Node(unsigned long inode) : _inode(inode) { _name[0] = 0; }
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virtual ~Node()
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{
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/* propagate event to listeners */
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mark_as_updated();
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notify_listeners();
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while (_listeners.first())
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_listeners.remove(_listeners.first());
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}
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unsigned long inode() const { return _inode; }
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char const *name() const { return _name; }
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/**
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* Assign name
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*/
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void name(char const *name) { strncpy(_name, name, sizeof(_name)); }
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void lock() { _lock.lock(); }
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void unlock() { _lock.unlock(); }
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virtual size_t read(char *dst, size_t len, seek_off_t) = 0;
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virtual size_t write(char const *src, size_t len, seek_off_t) = 0;
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void add_listener(Listener *listener)
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{
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_listeners.insert(listener);
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}
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void remove_listener(Listener *listener)
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{
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_listeners.remove(listener);
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}
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void notify_listeners()
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{
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for (Listener *curr = _listeners.first(); curr; curr = curr->next())
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curr->notify();
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}
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void mark_as_updated()
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{
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for (Listener *curr = _listeners.first(); curr; curr = curr->next())
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curr->mark_as_updated();
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}
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};
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/**
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* Guard used for properly releasing node locks
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*/
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struct Node_lock_guard
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{
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Node &node;
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Node_lock_guard(Node &node) : node(node) { }
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~Node_lock_guard() { node.unlock(); }
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};
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}
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#endif /* _NODE_H_ */
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