/*
 * BridJ - Dynamic and blazing-fast native interop for Java.
 * http://bridj.googlecode.com/
 *
 * Copyright (c) 2010-2013, Olivier Chafik (http://ochafik.com/)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of Olivier Chafik nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY OLIVIER CHAFIK AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.bridj;

import org.bridj.util.ProcessUtils;

import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Set;
import java.util.HashSet;
import java.util.regex.Pattern;
import java.io.*;
import java.net.URL;

import java.util.List;
import java.util.Collections;
import java.util.Collection;
import java.util.ArrayList;
import java.net.MalformedURLException;
import java.net.URLClassLoader;
import java.util.Arrays;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import org.bridj.util.StringUtils;

/**
 * Information about the execution platform (OS, architecture, native sizes...)
 * and platform-specific actions.
 * <ul>
 * <li>To know if the JVM platform is 32 bits or 64 bits, use
 * {@link Platform#is64Bits()}
 * </li><li>To know if the OS is an Unix-like system, use
 * {@link Platform#isUnix()}
 * </li><li>To open files and URLs in a platform-specific way, use
 * {@link Platform#open(File)}, {@link Platform#open(URL)}, {@link Platform#show(File)}
 * </li></ul>
 *
 * @author ochafik
 */
public class Platform {

    static final String osName = System.getProperty("os.name", "");
    private static boolean inited;
    static final String BridJLibraryName = "bridj";
    public static final int POINTER_SIZE,
            WCHAR_T_SIZE,
            SIZE_T_SIZE,
            TIME_T_SIZE,
            CLONG_SIZE;
    /*interface FunInt {
     int apply();
     }
     static int tryInt(FunInt f, int defaultValue) {
     try {
     return f.apply();
     } catch (Throwable th) {
     return defaultValue;
     }
     }*/
    static final ClassLoader systemClassLoader;

    public static ClassLoader getClassLoader() {
        return getClassLoader(BridJ.class);
    }

    public static ClassLoader getClassLoader(Class<?> cl) {
        ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
        if (contextClassLoader != null) {
            return contextClassLoader;
        }
        ClassLoader classLoader = cl == null ? null : cl.getClassLoader();
        return classLoader == null ? systemClassLoader : classLoader;
    }

    public static InputStream getResourceAsStream(String path) {
        URL url = getResource(path);
        try {
            return url != null ? url.openStream() : null;
        } catch (IOException ex) {
            if (BridJ.verbose) {
                BridJ.warning("Failed to get resource '" + path + "'", ex);
            }
            return null;
        }
    }

    public static URL getResource(String path) {
        if (!path.startsWith("/")) {
            path = "/" + path;
        }

        URL in = BridJ.class.getResource(path);
        if (in != null) {
            return in;
        }

        ClassLoader[] cls = {
            BridJ.class.getClassLoader(),
            Thread.currentThread().getContextClassLoader(),
            systemClassLoader
        };
        for (ClassLoader cl : cls) {
            if (cl != null && (in = cl.getResource(path)) != null) {
                return in;
            }
        }
        return null;
    }
    /*
     public static class utsname {
     public final String sysname, nodename, release, version, machine;
     public utsname(String sysname, String nodename, String release, String version, String machine) {
     this.sysname = sysname;
     this.nodename = nodename;
     this.release = release;
     this.version = version;
     this.machine = machine;
     }
     public String toString() {
     StringBuilder b = new StringBuilder("{\n");
     b.append("\tsysname: \"").append(sysname).append("\",\n");
     b.append("\tnodename: \"").append(nodename).append("\",\n");
     b.append("\trelease: \"").append(release).append("\",\n");
     b.append("\tversion: \"").append(version).append("\",\n");
     b.append("\tmachine: \"").append(machine).append("\"\n");
     return b.append("}").toString();
     }
     }
     public static native utsname uname();
     */
    static final List<String> embeddedLibraryResourceRoots = new ArrayList<String>();

    /**
     * BridJ is able to automatically extract native binaries bundled in the
     * application's JARs, using a customizable root path and a predefined
     * architecture-dependent subpath. This method adds an alternative root path
     * to the search list.<br>
     * For instance, if you want to load library "mylib" and call
     * <code>addEmbeddedLibraryResourceRoot("my/company/lib/")</code>, BridJ
     * will look for library in the following locations :
     * <ul>
     * <li>"my/company/lib/darwin_universal/libmylib.dylib" on MacOS X (or
     * darwin_x86, darwin_x64, darwin_ppc if the binary is not universal)</li>
     * <li>"my/company/lib/win32/mylib.dll" on Windows (use win64 on 64 bits
     * architectures)</li>
     * <li>"my/company/lib/linux_x86/libmylib.so" on Linux (use linux_x64 on 64
     * bits architectures)</li>
     * <li>"my/company/lib/sunos_x86/libmylib.so" on Solaris (use sunos_x64 /
     * sunos_sparc on other architectures)</li>
     * <li>"lib/armeabi/libmylib.so" on Android (for Android-specific reasons,
     * only the "lib" sub-path can effectively contain loadable binaries)</li>
     * </ul>
     * For other platforms or for an updated list of supported platforms, please
     * have a look at BridJ's JAR contents (under "org/bridj/lib") and/or to its
     * source tree, browsable online.
     */
    public static synchronized void addEmbeddedLibraryResourceRoot(String root) {
        embeddedLibraryResourceRoots.add(0, root);
    }
    static Set<File> temporaryExtractedLibraryCanonicalFiles = Collections.synchronizedSet(new LinkedHashSet<File>());

    static void addTemporaryExtractedLibraryFileToDeleteOnExit(File file) throws IOException {
        File canonicalFile = file.getCanonicalFile();

        // Give a chance to NativeLibrary.release() to delete the file :
        temporaryExtractedLibraryCanonicalFiles.add(canonicalFile);

        // Ask Java to delete the file upon exit if it still exists
        canonicalFile.deleteOnExit();
    }
    private static final String arch;
    private static boolean is64Bits;
    private static File extractedLibrariesTempDir;

    static {
        arch = System.getProperty("os.arch");
        {
            String dataModel = System.getProperty("sun.arch.data.model", System.getProperty("com.ibm.vm.bitmode"));
            if ("32".equals(dataModel)) {
                is64Bits = false;
            } else if ("64".equals(dataModel)) {
                is64Bits = true;
            } else {
                is64Bits =
                        arch.contains("64")
                        || arch.equalsIgnoreCase("sparcv9");
            }
        }
        systemClassLoader = createClassLoader();

        addEmbeddedLibraryResourceRoot("libs/");
        if (!isAndroid()) {
            addEmbeddedLibraryResourceRoot("lib/");
            addEmbeddedLibraryResourceRoot("org/bridj/lib/");
            if (!Version.VERSION_SPECIFIC_SUB_PACKAGE.equals("")) {
                addEmbeddedLibraryResourceRoot("org/bridj/" + Version.VERSION_SPECIFIC_SUB_PACKAGE + "/lib/");
            }
        }

        try {
            extractedLibrariesTempDir = createTempDir("BridJExtractedLibraries");
            initLibrary();
        } catch (Throwable th) {
            th.printStackTrace();
        }
        POINTER_SIZE = sizeOf_ptrdiff_t();
        WCHAR_T_SIZE = sizeOf_wchar_t();
        SIZE_T_SIZE = sizeOf_size_t();
        TIME_T_SIZE = sizeOf_time_t();
        CLONG_SIZE = sizeOf_long();

        is64Bits = POINTER_SIZE == 8;

        Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                shutdown();
            }
        });
    }
    private static List<NativeLibrary> nativeLibraries = new ArrayList<NativeLibrary>();

    static void addNativeLibrary(NativeLibrary library) {
        synchronized (nativeLibraries) {
            nativeLibraries.add(library);
        }
    }

    private static void shutdown() {
        //releaseNativeLibraries();
        deleteTemporaryExtractedLibraryFiles();
    }

    private static void releaseNativeLibraries() {
        synchronized (nativeLibraries) {
            // Release libraries in reverse order :
            for (int iLibrary = nativeLibraries.size(); iLibrary-- != 0;) {
                NativeLibrary lib = nativeLibraries.get(iLibrary);
                try {
                    lib.release();
                } catch (Throwable th) {
                    BridJ.error("Failed to release library '" + lib.path + "' : " + th, th);
                }
            }
        }
    }

    private static void deleteTemporaryExtractedLibraryFiles() {
        synchronized (temporaryExtractedLibraryCanonicalFiles) {
            temporaryExtractedLibraryCanonicalFiles.add(extractedLibrariesTempDir);

            // Release libraries in reverse order :
            List<File> filesToDeleteAfterExit = new ArrayList<File>();
            for (File tempFile : Platform.temporaryExtractedLibraryCanonicalFiles) {
                if (tempFile.delete()) {
                    if (BridJ.verbose) {
                        BridJ.info("Deleted temporary library file '" + tempFile + "'");
                    }
                } else {
                    filesToDeleteAfterExit.add(tempFile);
                }
            }
            if (!filesToDeleteAfterExit.isEmpty()) {
                if (BridJ.verbose) {
                    BridJ.info("Attempting to delete " + filesToDeleteAfterExit.size() + " files after JVM exit : " + StringUtils.implode(filesToDeleteAfterExit, ", "));
                }

                try {
                    ProcessUtils.startJavaProcess(DeleteFiles.class, filesToDeleteAfterExit);
                } catch (Throwable ex) {
                    BridJ.error("Failed to launch process to delete files after JVM exit : " + ex, ex);
                }
            }
        }
    }

    public static class DeleteFiles {

        static boolean delete(List<File> files) {
            for (Iterator<File> it = files.iterator(); it.hasNext();) {
                File file = it.next();
                if (file.delete()) {
                    it.remove();
                }
            }
            return files.isEmpty();
        }
        final static long TRY_DELETE_EVERY_MILLIS = 50,
                FAIL_AFTER_MILLIS = 10000;

        public static void main(String[] args) {
            try {
                List<File> files = new LinkedList<File>();
                for (String arg : args) {
                    files.add(new File(arg));
                }

                long start = System.currentTimeMillis();
                while (!delete(files)) {
                    long elapsed = System.currentTimeMillis() - start;
                    if (elapsed > FAIL_AFTER_MILLIS) {
                        BridJ.error("Failed to delete the following files : " + StringUtils.implode(files));
                        System.exit(1);
                    }

                    Thread.sleep(TRY_DELETE_EVERY_MILLIS);
                }
            } catch (Throwable th) {
                th.printStackTrace();
            } finally {
                System.exit(0);
            }
        }
    }

    static ClassLoader createClassLoader() {
        List<URL> urls = new ArrayList<URL>();
        for (String propName : new String[]{"java.class.path", "sun.boot.class.path"}) {
            String prop = System.getProperty(propName);
            if (prop == null) {
                continue;
            }

            for (String path : prop.split(File.pathSeparator)) {
                path = path.trim();
                if (path.length() == 0) {
                    continue;
                }

                URL url;
                try {
                    url = new URL(path);
                } catch (MalformedURLException ex) {
                    try {
                        url = new File(path).toURI().toURL();
                    } catch (MalformedURLException ex2) {
                        url = null;
                    }
                }
                if (url != null) {
                    urls.add(url);
                }
            }
        }
        //System.out.println("URLs for synthetic class loader :");
        //for (URL url : urls)
        //      System.out.println("\t" + url);
        return new URLClassLoader(urls.toArray(new URL[urls.size()]));
    }

    static String getenvOrProperty(String envName, String javaName, String defaultValue) {
        String value = System.getenv(envName);
        if (value == null) {
            value = System.getProperty(javaName);
        }
        if (value == null) {
            value = defaultValue;
        }
        return value;
    }

    public static synchronized void initLibrary() {
        if (inited) {
            return;
        }
        inited = true;

        try {
            boolean loaded = false;

            String forceLibFile = getenvOrProperty("BRIDJ_LIBRARY", "bridj.library", null);

            String lib = null;

            if (forceLibFile != null) {
                try {
                    System.load(lib = forceLibFile);
                    loaded = true;
                } catch (Throwable ex) {
                    BridJ.error("Failed to load forced library " + forceLibFile, ex);
                }
            }

            if (!loaded) {
                if (!Platform.isAndroid()) {
                    try {
                        File libFile = extractEmbeddedLibraryResource(BridJLibraryName);
                        if (libFile == null) {
                            throw new FileNotFoundException("Failed to extract embedded library '" + BridJLibraryName + "' (could be a classloader issue, or missing binary in resource path " + StringUtils.implode(embeddedLibraryResourceRoots, ", ") + ")");
                        }

                        if (BridJ.veryVerbose) {
                            BridJ.info("Loading library " + libFile);
                        }
                        System.load(lib = libFile.toString());
                        BridJ.setNativeLibraryFile(BridJLibraryName, libFile);
                        loaded = true;
                    } catch (IOException ex) {
                        BridJ.error("Failed to load '" + BridJLibraryName + "'", ex);
                    }
                }
                if (!loaded) {
                    System.loadLibrary("bridj");
                }
            }
            if (BridJ.veryVerbose) {
                BridJ.info("Loaded library " + lib);
            }

            init();

            //if (BridJ.protectedMode)
            //          BridJ.info("Protected mode enabled");
            if (BridJ.logCalls) {
                BridJ.info("Calls logs enabled");
            }

        } catch (Throwable ex) {
            throw new RuntimeException("Failed to initialize " + BridJ.class.getSimpleName() + " (" + ex + ")", ex);
        }
    }

    private static native void init();

    public static boolean isLinux() {
        return isUnix() && osName.toLowerCase().contains("linux");
    }

    public static boolean isMacOSX() {
        return isUnix() && (osName.startsWith("Mac") || osName.startsWith("Darwin"));
    }

    public static boolean isSolaris() {
        return isUnix() && (osName.startsWith("SunOS") || osName.startsWith("Solaris"));
    }

    public static boolean isBSD() {
        return isUnix() && (osName.contains("BSD") || isMacOSX());
    }

    public static boolean isUnix() {
        return File.separatorChar == '/';
    }

    public static boolean isWindows() {
        return File.separatorChar == '\\';
    }

    public static boolean isWindows7() {
        return osName.equals("Windows 7");
    }
    /**
     * Whether to use Unicode versions of Windows APIs rather than ANSI versions
     * (for functions that haven't been bound yet : has no effect on functions
     * that have already been bound).<br>
     * Some Windows APIs such as SendMessage have two versions :
     * <ul>
     * <li>one that uses single-byte character strings (SendMessageA, with 'A'
     * for ANSI strings)</li>
     * <li>one that uses unicode character strings (SendMessageW, with 'W' for
     * Wide strings).</li>
     * </ul>
     * <br>
     * In a C/C++ program, this behaviour is controlled by the UNICODE macro
     * definition.<br>
     * By default, BridJ will use the Unicode versions. Set this field to false,
     * set the bridj.useUnicodeVersionOfWindowsAPIs property to "false" or the
     * BRIDJ_USE_UNICODE_VERSION_OF_WINDOWS_APIS environment variable to "0" to
     * use the ANSI string version instead.
     */
    public static boolean useUnicodeVersionOfWindowsAPIs = !("false".equals(System.getProperty("bridj.useUnicodeVersionOfWindowsAPIs"))
            || "0".equals(System.getenv("BRIDJ_USE_UNICODE_VERSION_OF_WINDOWS_APIS")));

    private static String getArch() {
        return arch;
    }

    /**
     * Machine (as returned by `uname -m`, except for i686 which is actually
     * i386), adjusted to the JVM platform (32 or 64 bits)
     */
    public static String getMachine() {
        String arch = getArch();
        if (arch.equals("amd64") || arch.equals("x86_64")) {
            if (is64Bits()) {
                return "x86_64";
            } else {
                return "i386"; // we are running a 32 bits JVM on a 64 bits platform
            }
        }
        return arch;
    }

    public static boolean isAndroid() {
        return "dalvik".equalsIgnoreCase(System.getProperty("java.vm.name")) && isLinux();
    }

    public static boolean isArm() {
        String arch = getArch();
        return "arm".equals(arch);
    }

    public static boolean isSparc() {
        String arch = getArch();
        return "sparc".equals(arch)
                || "sparcv9".equals(arch);
    }

    public static boolean is64Bits() {
        return is64Bits;
    }

    public static boolean isAmd64Arch() {
        String arch = getArch();
        return arch.equals("x86_64");
    }

    static List<String> getPossibleFileNames(String name) {
        List<String> fileNames = new ArrayList<String>(1);
        if (isWindows()) {
            fileNames.add(name + ".dll");
            fileNames.add(name + ".drv");
        } else {
            String jniName = "lib" + name + ".jnilib";
            if (isMacOSX()) {
                fileNames.add("lib" + name + ".dylib");
                fileNames.add(jniName);
            } else {
                fileNames.add("lib" + name + ".so");
                fileNames.add(name + ".so");
                fileNames.add(jniName);
            }
        }

        assert !fileNames.isEmpty();
        if (name.contains(".")) {
            fileNames.add(name);
        }
        return fileNames;
    }

    static synchronized List<String> getEmbeddedLibraryPaths(String name) {
        List<String> paths = new ArrayList<String>(embeddedLibraryResourceRoots.size());
        for (String root : embeddedLibraryResourceRoots) {
            if (root == null) {
                continue;
            }

            if (isWindows()) {
                paths.add(root + (is64Bits() ? "win64/" : "win32/"));
            } else if (isMacOSX()) {
                if (isArm()) {
                    paths.add(root + "iphoneos_arm32_arm/");
                } else {
                    paths.add(root + "darwin_universal/");
                    if (isAmd64Arch()) {
                        paths.add(root + "darwin_x64/");
                    }
                }
            } else {
                if (isAndroid()) {
                    assert root.equals("libs/");
                    paths.add(root + "armeabi/"); // Android SDK + NDK-style .so embedding = lib/armeabi/libTest.so
                } else if (isLinux()) {
                    if (isArm()) {
                        //TODO: ARM support is still broken!
                        //There are 2 ABIs: ARMEL and ARMHF
                        //ARMEL should work ok
                        //ARMHF has two (largely) incompatible calling conventions: softfp and hard/vfp.
                        //The differences are largely down to which registers are used for passing double/float arguments; 
                        //in hard/vfp mode, the vfp registers are used, whereas in softfp the normal cpu registers
                        //are used. Calling a function with the wrong convention can lead to stack corruption (although I think
                        //you are probably safe if you stay away from floats and doubles)...
                        //At the time of writing, dyncall only supports softfp, but the common
                        //linux distributions are using hard/vfp.
                        //In the future we need to make bridj support both conventions.

                        paths.add(root + getARMLinuxLibDir());
                        //for compatibility with the older OpenIMAJ forks supporting ARM
                        paths.add(root + getARMLinuxLibDir().replace("_arm", "_arm32_arm"));
                    } else {
                        paths.add(root + (is64Bits() ? "linux_x64/" : "linux_x86/"));
                    }
                } else if (isSolaris()) {
                    if (isSparc()) {
                        paths.add(root + (is64Bits() ? "sunos_sparc64/" : "sunos_sparc/"));
                    } else {
                        paths.add(root + (is64Bits() ? "sunos_x64/" : "sunos_x86/"));
                    }
                }
            }
        }

        if (paths.isEmpty()) {
            throw new RuntimeException("Platform not supported ! (os.name='" + osName + "', os.arch='" + System.getProperty("os.arch") + "')");
        }
        return paths;
    }

    static synchronized List<String> getEmbeddedLibraryResource(String name) {
        List<String> paths = getEmbeddedLibraryPaths(name);
        List<String> fileNames = getPossibleFileNames(name);
        List<String> ret = new ArrayList<String>(paths.size() * fileNames.size());
        for (String path : paths) {
            for (String fileName : fileNames) {
                ret.add(path + fileName);
            }
        }

        if (BridJ.veryVerbose) {
            BridJ.info("Embedded resource paths for library '" + name + "': " + ret);
        }
        return ret;
    }

    static void tryDeleteFilesInSameDirectory(final File legitFile, final Pattern fileNamePattern, long atLeastOlderThanMillis) {
        final long maxModifiedDateForDeletion = System.currentTimeMillis() - atLeastOlderThanMillis;
        new Thread(new Runnable() {
            public void run() {
                File dir = legitFile.getParentFile();
                String legitFileName = legitFile.getName();
                try {
                    for (String name : dir.list()) {
                        if (name.equals(legitFileName)) {
                            continue;
                        }

                        if (!fileNamePattern.matcher(name).matches()) {
                            continue;
                        }

                        File file = new File(dir, name);
                        if (file.lastModified() > maxModifiedDateForDeletion) {
                            continue;
                        }

                        if (file.delete() && BridJ.verbose) {
                            BridJ.info("Deleted old binary file '" + file + "'");
                        }
                    }
                } catch (SecurityException ex) {
                    // no right to delete files in that directory
                    BridJ.warning("Failed to delete files matching '" + fileNamePattern + "' in directory '" + dir + "'", ex);
                } catch (Throwable ex) {
                    BridJ.error("Unexpected error : " + ex, ex);
                }
            }
        }).start();
    }
    static final long DELETE_OLD_BINARIES_AFTER_MILLIS = 24 * 60 * 60 * 1000; // 24 hours

    static File extractEmbeddedLibraryResource(String name) throws IOException {
        String firstLibraryResource = null;

        List<String> libraryResources = getEmbeddedLibraryResource(name);
        if (BridJ.veryVerbose) {
            BridJ.info("Library resources for " + name + ": " + libraryResources);
        }               
        for (String libraryResource : libraryResources) {
            if (firstLibraryResource == null) {
                firstLibraryResource = libraryResource;
            }
            int i = libraryResource.lastIndexOf('.');
            int len;
            byte[] b = new byte[8196];
            InputStream in = getResourceAsStream(libraryResource);
            if (in == null) {
                File f = new File(libraryResource);
                if (!f.exists()) {
                    f = new File(f.getName());
                }
                if (f.exists()) {
                    return f.getCanonicalFile();
                }
                continue;
            }
            String fileName = new File(libraryResource).getName();
            File libFile = new File(extractedLibrariesTempDir, fileName);
            OutputStream out = new BufferedOutputStream(new FileOutputStream(libFile));
            while ((len = in.read(b)) > 0) {
                out.write(b, 0, len);
            }
            out.close();
            in.close();

            addTemporaryExtractedLibraryFileToDeleteOnExit(libFile);
            addTemporaryExtractedLibraryFileToDeleteOnExit(libFile.getParentFile());

            return libFile;
        }
        return null;
    }
    static final int maxTempFileAttempts = 20;

    static File createTempDir(String prefix) throws IOException {
        File dir;
        for (int i = 0; i < maxTempFileAttempts; i++) {
            dir = File.createTempFile(prefix, "");
            if (dir.delete() && dir.mkdirs()) {
                return dir;
            }
        }
        throw new RuntimeException("Failed to create temp dir with prefix '" + prefix + "' despite " + maxTempFileAttempts + " attempts!");
    }

    /**
     * Opens an URL with the default system action.
     *
     * @param url url to open
     * @throws NoSuchMethodException if opening an URL on the current platform
     * is not supported
     */
    public static final void open(URL url) throws NoSuchMethodException {
        if (url.getProtocol().equals("file")) {
            open(new File(url.getFile()));
        } else {
            if (Platform.isMacOSX()) {
                execArgs("open", url.toString());
            } else if (Platform.isWindows()) {
                execArgs("rundll32", "url.dll,FileProtocolHandler", url.toString());
            } else if (Platform.isUnix() && hasUnixCommand("gnome-open")) {
                execArgs("gnome-open", url.toString());
            } else if (Platform.isUnix() && hasUnixCommand("konqueror")) {
                execArgs("konqueror", url.toString());
            } else if (Platform.isUnix() && hasUnixCommand("mozilla")) {
                execArgs("mozilla", url.toString());
            } else {
                throw new NoSuchMethodException("Cannot open urls on this platform");
            }
        }
    }

    /**
     * Opens a file with the default system action.
     *
     * @param file file to open
     * @throws NoSuchMethodException if opening a file on the current platform
     * is not supported
     */
    public static final void open(File file) throws NoSuchMethodException {
        if (Platform.isMacOSX()) {
            execArgs("open", file.getAbsolutePath());
        } else if (Platform.isWindows()) {
            if (file.isDirectory()) {
                execArgs("explorer", file.getAbsolutePath());
            } else {
                execArgs("start", file.getAbsolutePath());
            }
        } else if (Platform.isUnix() && hasUnixCommand("gnome-open")) {
            execArgs("gnome-open", file.toString());
        } else if (Platform.isUnix() && hasUnixCommand("konqueror")) {
            execArgs("konqueror", file.toString());
        } else if (Platform.isSolaris() && file.isDirectory()) {
            execArgs("/usr/dt/bin/dtfile", "-folder", file.getAbsolutePath());
        } else {
            throw new NoSuchMethodException("Cannot open files on this platform");
        }
    }

    /**
     * Show a file in its parent directory, if possible selecting the file (not
     * possible on all platforms).
     *
     * @param file file to show in the system's default file navigator
     * @throws NoSuchMethodException if showing a file on the current platform
     * is not supported
     */
    public static final void show(File file) throws NoSuchMethodException, IOException {
        if (Platform.isWindows()) {
            exec("explorer /e,/select,\"" + file.getCanonicalPath() + "\"");
        } else {
            open(file.getAbsoluteFile().getParentFile());
        }
    }

    static final void execArgs(String... cmd) throws NoSuchMethodException {
        try {
            Runtime.getRuntime().exec(cmd);
        } catch (Exception ex) {
            ex.printStackTrace();
            throw new NoSuchMethodException(ex.toString());
        }
    }

    static final void exec(String cmd) throws NoSuchMethodException {
        try {
            Runtime.getRuntime().exec(cmd).waitFor();
        } catch (Exception ex) {
            ex.printStackTrace();
            throw new NoSuchMethodException(ex.toString());
        }
    }

    static final boolean hasUnixCommand(String name) {
        try {
            Process p = Runtime.getRuntime().exec(new String[]{"which", name});
            return p.waitFor() == 0;
        } catch (Exception ex) {
            ex.printStackTrace();
            return false;
        }
    }

    static native int sizeOf_size_t();

    static native int sizeOf_time_t();

    static native int sizeOf_wchar_t();

    static native int sizeOf_ptrdiff_t();

        static native int sizeOf_long();
        
        static native int getMaxDirectMappingArgCount();
        
        private static final boolean contains(String data, String[] search) {
                if (null != data && null != search) {
                        for (int i = 0; i < search.length; i++) {
                                if (data.indexOf(search[i]) >= 0) {
                                        return true;
                                }
                        }
                }
                return false;
        }
    
    /*
     * [From https://github.com/Pi4J/pi4j/blob/develop/pi4j-core/src/main/java/com/pi4j/system/SystemInfo.java]
     * <p>
     * this method will to obtain the version info string from the 'bash' program
     * (this method is used to help determine the HARD-FLOAT / SOFT-FLOAT ABI of the system)
     */
    private static String getBashVersionInfo() {
        String versionInfo = "";
        try {
            
            String cmd = "bash --version";
            Process p = Runtime.getRuntime().exec(cmd); 
            p.waitFor(); 
            BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream())); 
            String line = reader.readLine();
            if(p.exitValue() == 0) {
                while(line != null) {
                    if(!line.isEmpty()) { 
                        versionInfo = line; // return only first output line of version info
                        break;
                    }
                    line = reader.readLine();
                }
            }
        }
        catch (IOException ioe) { ioe.printStackTrace(); }
        catch (InterruptedException ie) { ie.printStackTrace(); }
        return versionInfo;
    }

    /*
     * [From https://github.com/Pi4J/pi4j/blob/develop/pi4j-core/src/main/java/com/pi4j/system/SystemInfo.java]
     * <p>
     * this method will determine if a specified tag exists from the elf info in the '/proc/self/exe' program
     * (this method is used to help determine the HARD-FLOAT / SOFT-FLOAT ABI of the system)
     */    
    private static boolean hasReadElfTag(String tag) {
        String tagValue = getReadElfTag(tag);
        if(tagValue != null && !tagValue.isEmpty())
            return true;
        return false;
    }
    
    /*
     * [From https://github.com/Pi4J/pi4j/blob/develop/pi4j-core/src/main/java/com/pi4j/system/SystemInfo.java]
     * <p>
     * this method will obtain a specified tag value from the elf info in the '/proc/self/exe' program
     * (this method is used to help determine the HARD-FLOAT / SOFT-FLOAT ABI of the system)
     */    
    private static String getReadElfTag(String tag) {
        String tagValue = null;
        try {
            String cmd = "/usr/bin/readelf -A /proc/self/exe";
            Process p = Runtime.getRuntime().exec(cmd); 
            p.waitFor();
            if(p.exitValue() == 0) {
                BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream())); 
                String line = reader.readLine();
                while(line != null) {
                    line = line.trim();
                    if (line.startsWith(tag) && line.contains(":")) {
                        String lineParts[] = line.split(":", 2);
                        if(lineParts.length > 1)
                            tagValue = lineParts[1].trim();
                        break;
                    }
                    line = reader.readLine();
                }
            }
        }
        catch (IOException ioe) { ioe.printStackTrace(); }
        catch (InterruptedException ie) { ie.printStackTrace(); }
        return tagValue;
    }
        
        /**
         * ARM processors have two incompatible ABIs - one for use with the floating
         * point unit (HardFP - armhf), the other without (SoftFP - armel). This
         * generates the correct search path depending on the ABI in use by the JVM.
         * Unfortunately, there isn't currently a standard property that describes
         * the abi, so we have to "guess".
         * <p>
         * The implementation is derived from code in the PI4J project:
         * https://github.com/Pi4J/pi4j/blob/develop/pi4j-core/src/main/java/com/pi4j/system/SystemInfo.java 
         * 
         * @return the library directory
         */
        private static final String getARMLinuxLibDir() {

                final boolean isHF = AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
            private final String[] gnueabihf = new String[] { "gnueabihf", "armhf" };
            public Boolean run() {                    
                if ( contains(System.getProperty("sun.boot.library.path"), gnueabihf) ||
                     contains(System.getProperty("java.library.path"), gnueabihf) ||
                     contains(System.getProperty("java.home"), gnueabihf) || 
                     getBashVersionInfo().contains("gnueabihf") ||
                     hasReadElfTag("Tag_ABI_HardFP_use")) {
                        return true; //
                }
                return false;
            } } );
                
                return "linux_arm" + (isHF ? "hf" : "el") + "/";
        }
}