activator.java

OSGI这是一个中间件,与UPNP齐名,是用于移植到嵌入式平台之上

        if (dla != null) {
            for (int i = 0; i < dla.length; i++) {
                try {
                    DriverLocator dl = dla[i];
                    String[] dria = dl.findDrivers(props);
                    for (int j = 0; j < dria.length; j++) {
                        String dri = dria[j];
                        MatchImpl m = null;
                        for (int k = 0; k < matches.size(); k++) {
                            m = (MatchImpl) matches.elementAt(k);
                            if (m.equals(dri))
                                break;
                            m = null;
                        }
                        if (m == null) {
                            m = new MatchImpl(this, dev, dri);
                            matches.addElement(m);
                        }
                        m.addDriverLocator(dl);
                    }
                } catch (Exception e) {
                }
            }
        }

        for (;;) {
            // Add current drivers to matches
            for (int i = 0; i < drivers.size(); i++) {
                DriverRef dr = (DriverRef) drivers.elementAt(i);
                MatchImpl m = null;
                for (int k = 0; k < matches.size(); k++) {
                    m = (MatchImpl) matches.elementAt(k);
                    if (m.connect(dr))
                        break;
                    m = null;
                }
                if (m == null) {
                    m = new MatchImpl(this, dev, dr);
                    matches.addElement(m);
                }
            }

            int n = 0;
            boolean loading = false;

            // Count good matches and trigger loading
            for (int i = 0; i < matches.size(); i++) {
                MatchImpl m = (MatchImpl) matches.elementAt(i);
                int match = m.getMatchValue();
                if (match == MatchImpl.UNKNOWN)
                    loading = true;
                else if (match > Device.MATCH_NONE)
                    n++;
            }

            // If not finished loading continue
            if (loading)
                continue;

            // If nothing matches we're done
            if (n == 0) {
                tellNotFound(dev);
                return;
            }

            // Filter out good matches and select default best match
            MatchImpl best = null;
            Match[] sel = new Match[n];
            n = 0;
            for (int i = 0; i < matches.size(); i++) {
                MatchImpl m = (MatchImpl) matches.elementAt(i);
                if (m.getMatchValue() > Device.MATCH_NONE) {
                    sel[n++] = m;
                    if (best == null || best.compare(m) < 0)
                        best = m;
                }
            }

            // Maybe use driver selector instead
            DriverSelector ds = selector;
            if (ds != null) {
                int ix = ds.select(dev, sel);
                if (ix == DriverSelector.SELECT_NONE) {
                    tellNotFound(dev);
                    return;
                }
                try {
                    best = (MatchImpl) sel[ix];
                } catch (Exception e) {
                }
            }

            // If attach succeeds we're done
            String ref = null;
            try {
                ref = best.attach();
            } catch (Exception e) {
                error("failed attach " + showDriver(best.getDriver()) + " -> "
                        + showDevice(dev));
                continue;
            }

            if (best.getMatchValue() > Device.MATCH_NONE) {
                // Just loaded, go around and pick up the driver ref
                continue;
            }

            if (ref == null) {
                info("attached " + showDriver(best.getDriver()) + " -> "
                        + showDevice(dev));
                Bundle b = best.getBundle();
                if (b != null)
                    updateLife(b, LONG_LIFE);
                return;
            }

            info(showDriver(best.getDriver()) + " refers to " + ref);

            // Append the referred match
            MatchImpl m = null;
            for (int i = 0; i < matches.size(); i++) {
                m = (MatchImpl) matches.elementAt(i);
                if (m.equals(ref))
                    break;
                m = null;
            }
            if (m == null) {
                m = new MatchImpl(this, dev, ref);
                matches.addElement(m);
            }
        }
    }

    private void updateLife(Bundle b, long t) {
        tempDrivers.put(b, new Long(System.currentTimeMillis() + t));
    }

    private boolean isUsed(ServiceReference sr) {
        Bundle[] ba = sr.getUsingBundles();
        if (ba != null) {
            for (int i = 0; i < ba.length; i++) {
                Bundle b = ba[i];
                try {
                    for (int j = 0; j < drivers.size(); j++) {
                        DriverRef dr = (DriverRef) drivers.elementAt(j);
                        if (dr.sr.getBundle() == b)
                            return true;
                    }
                } catch (Exception e) {
                    return true;
                }
            }
        }
        return false;
    }

    private void reapDrivers() {
        long now = System.currentTimeMillis();
        Bundle[] ba = bc.getBundles();
        if (ba != null) {
            for (int i = 0; i < ba.length; i++) {
                try {
                    Bundle b = ba[i];
                    if (b.getLocation().startsWith(DYNAMIC_DRIVER_TAG)) {
                        Long expire = (Long) tempDrivers.get(b);
                        boolean inUse = false;

                        ServiceReference[] sra = b.getServicesInUse();
                        if (sra != null) {
                            for (int j = 0; j < sra.length; j++) {
                                if (isDevice.match(sra[j])) {
                                    inUse = true;
                                    break;
                                }
                            }
                        }

                        if (inUse) {
                            updateLife(b, LONG_LIFE);
                        } else if (expire == null) {
                            updateLife(b, SHORT_LIFE);
                        } else if (expire.longValue() < now) {
                            info("uninstalling " + b.getLocation());
                            b.uninstall();
                        }
                    }
                } catch (Exception e) {
                }
            }
        }
    }

    private void touchDevice(ServiceReference dev) {
        if (newDevices.put(dev, dev) == null) {
            synchronized (this) {
                notifyAll();
            }
        }
    }

    private void touchAllDevices() {
        boolean added = false;
        try {
            ServiceReference[] sra = bc.getServiceReferences(null,
                    DEVICE_FILTER);
            if (sra != null) {
                for (int i = 0; i < sra.length; i++) {
                    ServiceReference dev = sra[i];
                    if (newDevices.put(dev, dev) == null)
                        added = true;
                }
            }
        } catch (Exception e) {
        }
        if (added) {
            synchronized (this) {
                notifyAll();
            }
        }
    }

    private void tellNotFound(ServiceReference dev) {
        // NB: Should we avoid repeating the call to the same device?

        info("no driver for " + showDevice(dev));
        Object d = null;
        try {
            d = bc.getService(dev);
            ((Device) d).noDriverFound();
        } catch (Exception e) {
        } finally {
            try {
                bc.ungetService(dev);
            } catch (Exception e1) {
            }
        }
    }

    private Dictionary /* String->Object */collectProperties(
            ServiceReference sr) {
        Dictionary props = new Hashtable();
        String[] keys = sr.getPropertyKeys();
        if (keys != null) {
            for (int i = 0; i < keys.length; i++) {
                String key = keys[i];
                props.put(key, sr.getProperty(key));
            }
        }
        return props;
    }

    Bundle installBundle(String name, InputStream is) {
        Bundle b = null;
        try {
            info("installing " + name);
            b = bc.installBundle(name, is);
            b.start();
            updateLife(b, SHORT_LIFE);
            return b;
        } catch (Exception e) {
            error("failed to install " + name);
            try {
                b.uninstall();
            } catch (Exception e1) {
            }
            return null;
        } finally {
            try {
                is.close();
            } catch (Exception e1) {
            }
        }
    }

    void removeSRCachedMatch(ServiceReference sr) {

        // NB: Index to speed up this process?

        String pid = null;
        try {
            pid = (String) sr
                    .getProperty(org.osgi.framework.Constants.SERVICE_PID);
        } catch (Exception e) {
        }
        if (pid != null)
            return;
        for (Enumeration e = cache.keys(); e.hasMoreElements();) {
            Integer k = (Integer) e.nextElement();
            MatchValue mv0 = (MatchValue) cache.get(k);
            MatchValue mv = mv0;
            while (mv != null) {
                if (mv.dev != sr) {
                    // Keep it
                    mv0 = mv;
                    mv = mv.next;
                } else if (mv == mv0) {
                    // Update hash table entry
                    mv0 = mv = mv.next;
                    if (mv != null)
                        cache.put(k, mv);
                    else
                        cache.remove(k);
                } else {
                    // Link past this one
                    mv = mv.next;
                    mv0.next = mv;
                }
            }
        }
    }

    int getCachedMatch(String drvid, ServiceReference dev) {
        MatchValue mv = findMatch(drvid, dev, false);
        return mv != null ? mv.match : MatchImpl.UNKNOWN;
    }

    void putCachedMatch(String drvid, ServiceReference dev, int match) {
        MatchValue mv = findMatch(drvid, dev, true);
        mv.match = match;
    }

    private MatchValue findMatch(String drvid, ServiceReference dev,
            boolean create) {
        String pid = null;
        try {
            pid = (String) dev
                    .getProperty(org.osgi.framework.Constants.SERVICE_PID);
        } catch (Exception e) {
        }
        int k1 = pid != null ? pid.hashCode() : dev.hashCode();
        int k2 = drvid.hashCode();
        Integer key = new Integer(k1 + k2);
        MatchValue mv0 = (MatchValue) cache.get(key);
        MatchValue mv = mv0;
        while (mv != null) {
            if (drvid.equals(mv.drvid) && pid != null ? pid.equals(mv.pid)
                    : dev == mv.dev)
                return mv;
            mv = mv.next;
        }

        if (!create)
            return null;

        mv = new MatchValue();
        mv.next = mv0;
        mv.key = key;
        mv.drvid = drvid;
        mv.pid = pid;
        if (pid == null)
            mv.dev = dev;
        cache.put(key, mv);
        return mv;
    }

    private String showDevice(ServiceReference sr) {
        StringBuffer sb = new StringBuffer();
        Object o = sr
                .getProperty(org.osgi.service.device.Constants.DEVICE_CATEGORY);
        if (o instanceof String) {
            sb.append(o);
        } else if (o instanceof String[]) {
            String[] dca = (String[]) o;
            for (int i = 0; i < dca.length; i++) {
                if (i > 0)
                    sb.append('_');
                sb.append(dca[i]);
            }
        }
        o = sr.getProperty(org.osgi.framework.Constants.SERVICE_ID);
        if (o != null)
            sb.append(o);
        Bundle b = sr.getBundle();
        if (b != null) {
            sb.append('/');
            sb.append(b.getBundleId());
        }
        return sb.toString();
    }

    private String showDriver(ServiceReference sr) {
        StringBuffer sb = new StringBuffer();
        String s = (String) sr
                .getProperty(org.osgi.service.device.Constants.DRIVER_ID);
        sb.append(s != null ? s : "driver");
        Bundle b = sr.getBundle();
        if (b != null) {
            sb.append('/');
            sb.append(b.getBundleId());
        }
        return sb.toString();
    }
}