/* The contents of this file is dual-licensed under 2 * alternative Open Source/Free licenses: LGPL 2.1 or later and * Apache License 2.0. (starting with JNA version 4.0.0). * * You can freely decide which license you want to apply to * the project. * * You may obtain a copy of the LGPL License at: * * http://www.gnu.org/licenses/licenses.html * * A copy is also included in the downloadable source code package * containing JNA, in file "LGPL2.1". * * You may obtain a copy of the Apache License at: * * http://www.apache.org/licenses/ * * A copy is also included in the downloadable source code package * containing JNA, in file "AL2.0". */ package com.sun.jna; import java.lang.reflect.Method; import java.util.Collections; import java.util.Map; /** * <p>An abstraction for a native function pointer. An instance of * <code>Function</code> represents a pointer to some native function. * {@link #invoke(Class,Object[],Map)} is the primary means to call * the function. </p> * <a name=callflags></a> * Function call behavior may be modified by passing one of the following call * flags: * <ul> * <li>{@link Function#C_CONVENTION} Use C calling convention (default) * <li>{@link Function#ALT_CONVENTION} Use alternate calling convention (e.g. stdcall) * <li>{@link Function#THROW_LAST_ERROR} Throw a {@link LastErrorException} if * the native function sets the system error to a non-zero value (errno or * GetLastError). Setting this flag will cause the system error to be cleared * prior to native function invocation. * </ul> * * @author Sheng Liang, originator * @author Todd Fast, suitability modifications * @author Timothy Wall * @see Pointer */ public class Function extends Pointer { /** Any argument which implements this interface will have the * {@link #read} method called immediately after function invocation. */ public interface PostCallRead { /** Perform any necessary post-call synchronization. Normally this * just means reading from native memory any changes made by * the native function call. */ void read(); } /** Maximum number of arguments supported by a JNA function call. */ public static final int MAX_NARGS = 256; /** Standard C calling convention. */ public static final int C_CONVENTION = 0; /** First alternate convention (currently used only for w32 stdcall). */ public static final int ALT_CONVENTION = 0x3F; private static final int MASK_CC = 0x3F; /** Whether to throw an exception if last error is non-zero after call. */ public static final int THROW_LAST_ERROR = 0x40; /** Mask for number of fixed args (1-3) for varargs calls. */ public static final int USE_VARARGS = 0x180; static final Integer INTEGER_TRUE = Integer.valueOf(-1); static final Integer INTEGER_FALSE = Integer.valueOf(0); /** * Obtain a <code>Function</code> representing a native * function that follows the standard "C" calling convention. * * <p>The allocated instance represents a pointer to the named native * function from the named library, called with the standard "C" calling * convention. * * @param libraryName * Library in which to find the native function * @param functionName * Name of the native function to be linked with * @throws UnsatisfiedLinkError if the library is not found or * the given function name is not found within the library. */ public static Function getFunction(String libraryName, String functionName) { return NativeLibrary.getInstance(libraryName).getFunction(functionName); } /** * Obtain a <code>Function</code> representing a native * function. * * <p>The allocated instance represents a pointer to the named native * function from the named library. * * @param libraryName * Library in which to find the function * @param functionName * Name of the native function to be linked with * @param callFlags * Function <a href="#callflags">call flags</a> * * @throws UnsatisfiedLinkError if the library is not found or * the given function name is not found within the library. */ public static Function getFunction(String libraryName, String functionName, int callFlags) { return NativeLibrary.getInstance(libraryName).getFunction(functionName, callFlags, null); } /** * Obtain a <code>Function</code> representing a native * function. * * <p>The allocated instance represents a pointer to the named native * function from the named library. * * @param libraryName * Library in which to find the function * @param functionName * Name of the native function to be linked with * @param callFlags * Function <a href="#callflags">call flags</a> * @param encoding * Encoding to use for conversion between Java and native * strings. * * @throws UnsatisfiedLinkError if the library is not found or * the given function name is not found within the library. */ public static Function getFunction(String libraryName, String functionName, int callFlags, String encoding) { return NativeLibrary.getInstance(libraryName).getFunction(functionName, callFlags, encoding); } /** * Obtain a <code>Function</code> representing a native * function pointer. In general, this function should be used by dynamic * languages; Java code should allow JNA to bind to a specific Callback * interface instead by defining a return type or Structure field type. * * <p>The allocated instance represents a pointer to the native * function pointer. * * @param p Native function pointer */ public static Function getFunction(Pointer p) { return getFunction(p, 0, null); } /** * Obtain a <code>Function</code> representing a native * function pointer. In general, this function should be used by dynamic * languages; Java code should allow JNA to bind to a specific Callback * interface instead by defining a return type or Structure field type. * * <p>The allocated instance represents a pointer to the native * function pointer. * * @param p * Native function pointer * @param callFlags * Function <a href="#callflags">call flags</a> */ public static Function getFunction(Pointer p, int callFlags) { return getFunction(p, callFlags, null); } /** * Obtain a <code>Function</code> representing a native * function pointer. In general, this function should be used by dynamic * languages; Java code should allow JNA to bind to a specific Callback * interface instead by defining a return type or Structure field type. * * <p>The allocated instance represents a pointer to the native * function pointer. * * @param p * Native function pointer * @param callFlags * Function <a href="#callflags">call flags</a> * @param encoding * Encoding to use for conversion between Java and native * strings. */ public static Function getFunction(Pointer p, int callFlags, String encoding) { return new Function(p, callFlags, encoding); } // Keep a reference to the NativeLibrary so it does not get garbage // collected until the function is private NativeLibrary library; private final String functionName; final String encoding; final int callFlags; final Map<String, ?> options; /** For internal JNA use. */ static final String OPTION_INVOKING_METHOD = "invoking-method"; /** For checking if methods declare varargs */ private static final VarArgsChecker IS_VARARGS = VarArgsChecker.create(); /** * Create a new <code>Function</code> that is linked with a native * function that follows the given calling convention. * * <p>The allocated instance represents a pointer to the named native * function from the supplied library, called with the given calling * convention. * * @param library * {@link NativeLibrary} in which to find the function * @param functionName * Name of the native function to be linked with * @param callFlags * Function <a href="#callflags">call flags</a> * @param encoding * Encoding for conversion between Java and native strings. * @throws UnsatisfiedLinkError if the given function name is * not found within the library. */ Function(NativeLibrary library, String functionName, int callFlags, String encoding) { checkCallingConvention(callFlags & MASK_CC); if (functionName == null) { throw new NullPointerException("Function name must not be null"); } this.library = library; this.functionName = functionName; this.callFlags = callFlags; this.options = library.options; this.encoding = encoding != null ? encoding : Native.getDefaultStringEncoding(); try { this.peer = library.getSymbolAddress(functionName); } catch(UnsatisfiedLinkError e) { throw new UnsatisfiedLinkError("Error looking up function '" + functionName + "': " + e.getMessage()); } } /** * Create a new <code>Function</code> that is linked with a native * function that follows the given calling convention. * * <p>The allocated instance represents a pointer to the given * function address, called with the given calling * convention. * * @param functionAddress * Address of the native function * @param callFlags * Function <a href="#callflags">call flags</a> * @param encoding * Encoding for conversion between Java and native strings. */ Function(Pointer functionAddress, int callFlags, String encoding) { checkCallingConvention(callFlags & MASK_CC); if (functionAddress == null || functionAddress.peer == 0) { throw new NullPointerException("Function address may not be null"); } this.functionName = functionAddress.toString(); this.callFlags = callFlags; this.peer = functionAddress.peer; this.options = Collections.EMPTY_MAP; this.encoding = encoding != null ? encoding : Native.getDefaultStringEncoding(); } private void checkCallingConvention(int convention) throws IllegalArgumentException { // TODO: perform per-platform calling convention checks if ((convention & MASK_CC) != convention) { throw new IllegalArgumentException("Unrecognized calling convention: " + convention); } } public String getName() { return functionName; } public int getCallingConvention() { return callFlags & MASK_CC; } /** Invoke the native function with the given arguments, returning the * native result as an Object. */ public Object invoke(Class<?> returnType, Object[] inArgs) { return invoke(returnType, inArgs, this.options); } /** Invoke the native function with the given arguments, returning the * native result as an Object. */ public Object invoke(Class<?> returnType, Object[] inArgs, Map<String, ?> options) { Method invokingMethod = (Method)options.get(OPTION_INVOKING_METHOD); Class<?>[] paramTypes = invokingMethod != null ? invokingMethod.getParameterTypes() : null; return invoke(invokingMethod, paramTypes, returnType, inArgs, options); } /** Invoke the native function with the given arguments, returning the * native result as an Object. This method can be called if invoking method and parameter * types are already at hand. When calling {@link Function#invoke(Class, Object[], Map)}, * the method has to be in the options under key {@link Function#OPTION_INVOKING_METHOD}. */ Object invoke(Method invokingMethod, Class<?>[] paramTypes, Class<?> returnType, Object[] inArgs, Map<String, ?> options) { // Clone the argument array to obtain a scratch space for modified // types/values Object[] args = { }; if (inArgs != null) { if (inArgs.length > MAX_NARGS) { throw new UnsupportedOperationException("Maximum argument count is " + MAX_NARGS); } args = new Object[inArgs.length]; System.arraycopy(inArgs, 0, args, 0, args.length); } TypeMapper mapper = (TypeMapper)options.get(Library.OPTION_TYPE_MAPPER); boolean allowObjects = Boolean.TRUE.equals(options.get(Library.OPTION_ALLOW_OBJECTS)); boolean isVarArgs = args.length > 0 && invokingMethod != null ? isVarArgs(invokingMethod) : false; int fixedArgs = args.length > 0 && invokingMethod != null ? fixedArgs(invokingMethod) : 0; for (int i=0; i < args.length; i++) { Class<?> paramType = invokingMethod != null ? (isVarArgs && i >= paramTypes.length-1 ? paramTypes[paramTypes.length-1].getComponentType() : paramTypes[i]) : null; args[i] = convertArgument(args, i, invokingMethod, mapper, allowObjects, paramType); } Class<?> nativeReturnType = returnType; FromNativeConverter resultConverter = null; if (NativeMapped.class.isAssignableFrom(returnType)) { NativeMappedConverter tc = NativeMappedConverter.getInstance(returnType); resultConverter = tc; nativeReturnType = tc.nativeType(); } else if (mapper != null) { resultConverter = mapper.getFromNativeConverter(returnType); if (resultConverter != null) { nativeReturnType = resultConverter.nativeType(); } } Object result = invoke(args, nativeReturnType, allowObjects, fixedArgs); // Convert the result to a custom value/type if appropriate if (resultConverter != null) { FromNativeContext context; if (invokingMethod != null) { context = new MethodResultContext(returnType, this, inArgs, invokingMethod); } else { context = new FunctionResultContext(returnType, this, inArgs); } result = resultConverter.fromNative(result, context); } // Sync all memory which might have been modified by the native call if (inArgs != null) { for (int i=0; i < inArgs.length; i++) { Object inArg = inArgs[i]; if (inArg == null) continue; if (inArg instanceof Structure) { if (!(inArg instanceof Structure.ByValue)) { ((Structure)inArg).autoRead(); } } else if (args[i] instanceof PostCallRead) { ((PostCallRead)args[i]).read(); if (args[i] instanceof PointerArray) { PointerArray array = (PointerArray)args[i]; if (Structure.ByReference[].class.isAssignableFrom(inArg.getClass())) { Class<?> type = inArg.getClass().getComponentType(); Structure[] ss = (Structure[])inArg; for (int si=0;si < ss.length;si++) { Pointer p = array.getPointer(Pointer.SIZE * si); ss[si] = Structure.updateStructureByReference(type, ss[si], p); } } } } else if (Structure[].class.isAssignableFrom(inArg.getClass())) { Structure.autoRead((Structure[])inArg); } } } return result; } /* @see NativeLibrary#NativeLibrary(String,String,long,Map) implementation */ Object invoke(Object[] args, Class<?> returnType, boolean allowObjects) { return invoke(args, returnType, allowObjects, 0); } /* @see NativeLibrary#NativeLibrary(String,String,long,Map) implementation */ Object invoke(Object[] args, Class<?> returnType, boolean allowObjects, int fixedArgs) { Object result = null; int callFlags = this.callFlags | ((fixedArgs & 0x3) << 7); if (returnType == null || returnType==void.class || returnType==Void.class) { Native.invokeVoid(this, this.peer, callFlags, args); result = null; } else if (returnType==boolean.class || returnType==Boolean.class) { result = valueOf(Native.invokeInt(this, this.peer, callFlags, args) != 0); } else if (returnType==byte.class || returnType==Byte.class) { result = Byte.valueOf((byte)Native.invokeInt(this, this.peer, callFlags, args)); } else if (returnType==short.class || returnType==Short.class) { result = Short.valueOf((short)Native.invokeInt(this, this.peer, callFlags, args)); } else if (returnType==char.class || returnType==Character.class) { result = Character.valueOf((char)Native.invokeInt(this, this.peer, callFlags, args)); } else if (returnType==int.class || returnType==Integer.class) { result = Integer.valueOf(Native.invokeInt(this, this.peer, callFlags, args)); } else if (returnType==long.class || returnType==Long.class) { result = Long.valueOf(Native.invokeLong(this, this.peer, callFlags, args)); } else if (returnType==float.class || returnType==Float.class) { result = Float.valueOf(Native.invokeFloat(this, this.peer, callFlags, args)); } else if (returnType==double.class || returnType==Double.class) { result = Double.valueOf(Native.invokeDouble(this, this.peer, callFlags, args)); } else if (returnType==String.class) { result = invokeString(callFlags, args, false); } else if (returnType==WString.class) { String s = invokeString(callFlags, args, true); if (s != null) { result = new WString(s); } } else if (Pointer.class.isAssignableFrom(returnType)) { return invokePointer(callFlags, args); } else if (Structure.class.isAssignableFrom(returnType)) { if (Structure.ByValue.class.isAssignableFrom(returnType)) { Structure s = Native.invokeStructure(this, this.peer, callFlags, args, Structure.newInstance(returnType)); s.autoRead(); result = s; } else { result = invokePointer(callFlags, args); if (result != null) { Structure s = Structure.newInstance(returnType, (Pointer)result); s.conditionalAutoRead(); result = s; } } } else if (Callback.class.isAssignableFrom(returnType)) { result = invokePointer(callFlags, args); if (result != null) { result = CallbackReference.getCallback(returnType, (Pointer)result); } } else if (returnType==String[].class) { Pointer p = invokePointer(callFlags, args); if (p != null) { result = p.getStringArray(0, encoding); } } else if (returnType==WString[].class) { Pointer p = invokePointer(callFlags, args); if (p != null) { String[] arr = p.getWideStringArray(0); WString[] warr = new WString[arr.length]; for (int i=0;i < arr.length;i++) { warr[i] = new WString(arr[i]); } result = warr; } } else if (returnType==Pointer[].class) { Pointer p = invokePointer(callFlags, args); if (p != null) { result = p.getPointerArray(0); } } else if (allowObjects) { result = Native.invokeObject(this, this.peer, callFlags, args); if (result != null && !returnType.isAssignableFrom(result.getClass())) { throw new ClassCastException("Return type " + returnType + " does not match result " + result.getClass()); } } else { throw new IllegalArgumentException("Unsupported return type " + returnType + " in function " + getName()); } return result; } private Pointer invokePointer(int callFlags, Object[] args) { long ptr = Native.invokePointer(this, this.peer, callFlags, args); return ptr == 0 ? null : new Pointer(ptr); } private Object convertArgument(Object[] args, int index, Method invokingMethod, TypeMapper mapper, boolean allowObjects, Class<?> expectedType) { Object arg = args[index]; if (arg != null) { Class<?> type = arg.getClass(); ToNativeConverter converter = null; if (NativeMapped.class.isAssignableFrom(type)) { converter = NativeMappedConverter.getInstance(type); } else if (mapper != null) { converter = mapper.getToNativeConverter(type); } if (converter != null) { ToNativeContext context; if (invokingMethod != null) { context = new MethodParameterContext(this, args, index, invokingMethod) ; } else { context = new FunctionParameterContext(this, args, index); } arg = converter.toNative(arg, context); } } if (arg == null || isPrimitiveArray(arg.getClass())) { return arg; } Class<?> argClass = arg.getClass(); // Convert Structures to native pointers if (arg instanceof Structure) { Structure struct = (Structure)arg; struct.autoWrite(); if (struct instanceof Structure.ByValue) { // Double-check against the method signature, if available Class<?> ptype = struct.getClass(); if (invokingMethod != null) { Class<?>[] ptypes = invokingMethod.getParameterTypes(); if (IS_VARARGS.isVarArgs(invokingMethod)) { if (index < ptypes.length-1) { ptype = ptypes[index]; } else { Class<?> etype = ptypes[ptypes.length-1].getComponentType(); if (etype != Object.class) { ptype = etype; } } } else { ptype = ptypes[index]; } } if (Structure.ByValue.class.isAssignableFrom(ptype)) { return struct; } } return struct.getPointer(); } else if (arg instanceof Callback) { // Convert Callback to Pointer return CallbackReference.getFunctionPointer((Callback)arg); } else if (arg instanceof String) { // String arguments are converted to native pointers here rather // than in native code so that the values will be valid until // this method returns. // Convert String to native pointer (const) return new NativeString((String)arg, false).getPointer(); } else if (arg instanceof WString) { // Convert WString to native pointer (const) return new NativeString(arg.toString(), true).getPointer(); } else if (arg instanceof Boolean) { // Default conversion of boolean to int; if you want something // different, use a ToNativeConverter return Boolean.TRUE.equals(arg) ? INTEGER_TRUE : INTEGER_FALSE; } else if (String[].class == argClass) { return new StringArray((String[])arg, encoding); } else if (WString[].class == argClass) { return new StringArray((WString[])arg); } else if (Pointer[].class == argClass) { return new PointerArray((Pointer[])arg); } else if (NativeMapped[].class.isAssignableFrom(argClass)) { return new NativeMappedArray((NativeMapped[])arg); } else if (Structure[].class.isAssignableFrom(argClass)) { // If the signature is Structure[], disallow // Structure.ByReference[] and Structure.ByReference elements Structure[] ss = (Structure[])arg; Class<?> type = argClass.getComponentType(); boolean byRef = Structure.ByReference.class.isAssignableFrom(type); if (expectedType != null) { if (!Structure.ByReference[].class.isAssignableFrom(expectedType)) { if (byRef) { throw new IllegalArgumentException("Function " + getName() + " declared Structure[] at parameter " + index + " but array of " + type + " was passed"); } for (int i=0;i < ss.length;i++) { if (ss[i] instanceof Structure.ByReference) { throw new IllegalArgumentException("Function " + getName() + " declared Structure[] at parameter " + index + " but element " + i + " is of Structure.ByReference type"); } } } } if (byRef) { Structure.autoWrite(ss); Pointer[] pointers = new Pointer[ss.length + 1]; for (int i=0;i < ss.length;i++) { pointers[i] = ss[i] != null ? ss[i].getPointer() : null; } return new PointerArray(pointers); } else if (ss.length == 0) { throw new IllegalArgumentException("Structure array must have non-zero length"); } else if (ss[0] == null) { Structure.newInstance(type).toArray(ss); return ss[0].getPointer(); } else { Structure.autoWrite(ss); return ss[0].getPointer(); } } else if (argClass.isArray()){ throw new IllegalArgumentException("Unsupported array argument type: " + argClass.getComponentType()); } else if (allowObjects) { return arg; } else if (!Native.isSupportedNativeType(arg.getClass())) { throw new IllegalArgumentException("Unsupported argument type " + arg.getClass().getName() + " at parameter " + index + " of function " + getName()); } return arg; } private boolean isPrimitiveArray(Class<?> argClass) { return argClass.isArray() && argClass.getComponentType().isPrimitive(); } /** * Call the native function being represented by this object * * @param args * Arguments to pass to the native function */ public void invoke(Object[] args) { invoke(Void.class, args); } /** * Call the native function being represented by this object * * @param callFlags calling convention to be used * @param args * Arguments to pass to the native function * @param wide whether the native string uses <code>wchar_t</code>; * if false, <code>char</code> is assumed * @return The value returned by the target native function, as a String */ private String invokeString(int callFlags, Object[] args, boolean wide) { Pointer ptr = invokePointer(callFlags, args); String s = null; if (ptr != null) { if (wide) { s = ptr.getWideString(0); } else { s = ptr.getString(0, encoding); } } return s; } /** Provide a human-readable representation of this object. */ @Override public String toString() { if (library != null) { return "native function " + functionName + "(" + library.getName() + ")@0x" + Long.toHexString(peer); } return "native function@0x" + Long.toHexString(peer); } /** Convenience method for * {@link #invoke(Class,Object[]) invokeObject(Object.class, args)}. */ public Object invokeObject(Object[] args) { return invoke(Object.class, args); } /** Convenience method for * {@link #invoke(Class,Object[]) invoke(Pointer.class, args)}. */ public Pointer invokePointer(Object[] args) { return (Pointer)invoke(Pointer.class, args); } /** Convenience method for * {@link #invoke(Class,Object[]) invoke(String.class, args)} * or {@link #invoke(Class,Object[]) invoke(WString.class, args)} * @param args Arguments passed to native function * @param wide Whether the return value is of type <code>wchar_t*</code>; * if false, the return value is of type <code>char*</code>. */ public String invokeString(Object[] args, boolean wide) { Object o = invoke(wide ? WString.class : String.class, args); return o != null ? o.toString() : null; } /** Convenience method for * {@link #invoke(Class,Object[]) invoke(Integer.class, args)}. */ public int invokeInt(Object[] args) { return ((Integer)invoke(Integer.class, args)).intValue(); } /** Convenience method for * {@link #invoke(Class,Object[]) invoke(Long.class, args)}. */ public long invokeLong(Object[] args) { return ((Long)invoke(Long.class, args)).longValue(); } /** Convenience method for * {@link #invoke(Class,Object[]) invoke(Float.class, args)}. */ public float invokeFloat(Object[] args) { return ((Float)invoke(Float.class, args)).floatValue(); } /** Convenience method for * {@link #invoke(Class,Object[]) invoke(Double.class, args)}. */ public double invokeDouble(Object[] args) { return ((Double)invoke(Double.class, args)).doubleValue(); } /** Convenience method for * {@link #invoke(Class,Object[]) invoke(Void.class, args)}. */ public void invokeVoid(Object[] args) { invoke(Void.class, args); } /** Two function pointers are equal if they share the same peer address * and calling convention. */ @Override public boolean equals(Object o) { if (o == this) return true; if (o == null) return false; if (o.getClass() == getClass()) { Function other = (Function)o; return other.callFlags == this.callFlags && other.options.equals(this.options) && other.peer == this.peer; } return false; } /** Provide a unique hash code for {@link Function}s which are equivalent. */ @Override public int hashCode() { return callFlags + options.hashCode() + super.hashCode(); } /** Concatenate varargs with normal args to obtain a simple argument * array. */ static Object[] concatenateVarArgs(Object[] inArgs) { // If the final argument is an array of something other than // primitives, Structure, or String, treat it as varargs and // concatenate the previous arguments with the varargs elements. if (inArgs != null && inArgs.length > 0) { Object lastArg = inArgs[inArgs.length-1]; Class<?> argType = lastArg != null ? lastArg.getClass() : null; if (argType != null && argType.isArray()) { Object[] varArgs = (Object[])lastArg; // Promote float varargs to double (https://github.com/java-native-access/jna/issues/463). for (int i=0; i < varArgs.length; i++) { if (varArgs[i] instanceof Float) { varArgs[i] = (double)(Float)varArgs[i]; } } Object[] fullArgs = new Object[inArgs.length+varArgs.length]; System.arraycopy(inArgs, 0, fullArgs, 0, inArgs.length-1); System.arraycopy(varArgs, 0, fullArgs, inArgs.length-1, varArgs.length); // For convenience, always append a NULL argument to the end // of varargs, whether the called API requires it or not. If // it is not needed, it will be ignored, but if it *is* // required, it avoids forcing the Java client to always // explicitly add it. fullArgs[fullArgs.length-1] = null; inArgs = fullArgs; } } return inArgs; } /** Varargs are only supported on 1.5+. */ static boolean isVarArgs(Method m) { return IS_VARARGS.isVarArgs(m); } /** Varargs are only supported on 1.5+. */ static int fixedArgs(Method m) { return IS_VARARGS.fixedArgs(m); } private static class NativeMappedArray extends Memory implements PostCallRead { private final NativeMapped[] original; public NativeMappedArray(NativeMapped[] arg) { super(Native.getNativeSize(arg.getClass(), arg)); this.original = arg; setValue(0, original, original.getClass()); } @Override public void read() { getValue(0, original.getClass(), original); } } private static class PointerArray extends Memory implements PostCallRead { private final Pointer[] original; public PointerArray(Pointer[] arg) { super(Pointer.SIZE * (arg.length+1)); this.original = arg; for (int i=0;i < arg.length;i++) { setPointer(i*Pointer.SIZE, arg[i]); } setPointer(Pointer.SIZE*arg.length, null); } @Override public void read() { read(0, original, 0, original.length); } } /** Implementation of Boolean.valueOf for older VMs. */ static Boolean valueOf(boolean b) { return b ? Boolean.TRUE : Boolean.FALSE; } }