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Boereckdblock
Boereck
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Pulled varargs test out of the loop to avoid checking on each parameter
The Method#isVarargs method is now referenced statically to avoid costs of looking it up on each native method call with at least one parameter. This also can save a lot of memory, since on every Class#getMethod() call a new Method object is returned. Added null check uses the double-checked locking to speed up subsequent calls to the same function. Made Function$Handler$FunctionInfo immutable class to make double check locking work correctly. Added description of changes to CHANGES.md
1 parent 80d4c13 commit 7f2c689

3 files changed

Lines changed: 69 additions & 34 deletions

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‎CHANGES.md‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -18,6 +18,7 @@ Features
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* [#286](https://github.com/twall/jna/pull/286): Added in com.sun.jna.platform.win32.Kernel32: CreateRemoteThread, WritePocessMemory and ReadProcessMemory - [@sstokic-tgm](https://github.com/sstokic-tgm).
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* [#350](https://github.com/twall/jna/pull/350): Added `jnacontrib.x11.api.X.Window.getSubwindows` - [@rm5248](https://github.com/rm5248).
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* Improved `contrib/msoffice` sample - [@wolftobias](https://github.com/wolftobias).
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* [#352](https://github.com/twall/jna/pull/352): Performance improvements due to reduced locking in `com.sun.jna.Library$Handler` and fewer vararg checks in `com.sun.jna.Function` - [@Boereck](https://github.com/Boereck).
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Bug Fixes
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---------

‎src/com/sun/jna/Function.java‎

Lines changed: 28 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -288,9 +288,10 @@ public Object invoke(Class returnType, Object[] inArgs, Map options) {
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Method invokingMethod = (Method)options.get(OPTION_INVOKING_METHOD);
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Class[] paramTypes = invokingMethod != null ? invokingMethod.getParameterTypes() : null;
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boolean allowObjects = Boolean.TRUE.equals(options.get(Library.OPTION_ALLOW_OBJECTS));
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boolean isVarArgs = args.length > 0 && invokingMethod != null ? isVarArgs(invokingMethod) : false;
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for (int i=0; i < args.length; i++) {
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Class paramType = invokingMethod != null
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? (isVarArgs(invokingMethod) && i >= paramTypes.length-1
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? (isVarArgs && i >= paramTypes.length-1
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? paramTypes[paramTypes.length-1].getComponentType()
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: paramTypes[i])
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: null;
@@ -776,21 +777,34 @@ static Object[] concatenateVarArgs(Object[] inArgs) {
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return inArgs;
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}
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779-
/** Varargs are only supported on 1.5+. */
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static boolean isVarArgs(Method m) {
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/**
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* Reference to Method.isVarArgs
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*/
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private static Method isVarArgsMethod = getIsVarArgsMethod();
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/**
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* If possible returns the Method.isVarArgs method via reflection
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* @return Method.isVarArgs method
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*/
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private static Method getIsVarArgsMethod() {
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try {
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Method v = m.getClass().getMethod("isVarArgs", new Class[0]);
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return Boolean.TRUE.equals(v.invoke(m, new Object[0]));
784-
}
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catch (SecurityException e) {
791+
return Method.class.getMethod("isVarArgs", new Class[0]);
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} catch (SecurityException e) {
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return null;
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} catch (NoSuchMethodException e) {
795+
return null;
786796
}
787-
catch (NoSuchMethodException e) {
788-
}
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catch (IllegalArgumentException e) {
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}
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catch (IllegalAccessException e) {
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}
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catch (InvocationTargetException e) {
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}
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/** Varargs are only supported on 1.5+. */
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static boolean isVarArgs(Method m) {
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if(isVarArgsMethod != null) {
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try {
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return Boolean.TRUE.equals(isVarArgsMethod.invoke(m, new Object[0]));
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} catch (IllegalArgumentException e) {
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} catch (IllegalAccessException e) {
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} catch (InvocationTargetException e) {
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}
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}
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return false;
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}

‎src/com/sun/jna/Library.java‎

Lines changed: 40 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -160,11 +160,25 @@ public Class getInterfaceClass() {
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return interfaceClass;
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}
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163-
private static class FunctionInfo {
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InvocationHandler handler;
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Function function;
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boolean isVarArgs;
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Map options;
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/**
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* FunctionInfo has to be immutable to to make the object visible
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* to other threads fully initialized. This is a prerequisite for
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* using the class in the double checked locking scenario of {@link Handler#invoke(Object, Method, Object[])}
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*/
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private static final class FunctionInfo {
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FunctionInfo(InvocationHandler handler, Function function, boolean isVarArgs, Map options) {
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super();
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this.handler = handler;
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this.function = function;
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this.isVarArgs = isVarArgs;
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this.options = options;
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}
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final InvocationHandler handler;
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final Function function;
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final boolean isVarArgs;
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final Map options;
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}
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public Object invoke(Object proxy, Method method, Object[] inArgs)
@@ -185,22 +199,28 @@ else if (OBJECT_EQUALS.equals(method)) {
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return Boolean.FALSE;
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}
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188-
FunctionInfo f = null;
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synchronized(functions) {
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f = (FunctionInfo)functions.get(method);
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if (f == null) {
192-
f = new FunctionInfo();
193-
f.isVarArgs = Function.isVarArgs(method);
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if (invocationMapper != null) {
195-
f.handler = invocationMapper.getInvocationHandler(nativeLibrary, method);
196-
}
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if (f.handler == null) {
198-
// Find the function to invoke
199-
f.function = nativeLibrary.getFunction(method.getName(), method);
200-
f.options = new HashMap(this.options);
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f.options.put(Function.OPTION_INVOKING_METHOD, method);
202+
// Using the double-checked locking pattern to speed up function calls
203+
FunctionInfo f = (FunctionInfo)functions.get(method);
204+
if(f == null) {
205+
synchronized(functions) {
206+
f = (FunctionInfo)functions.get(method);
207+
if (f == null) {
208+
boolean isVarArgs = Function.isVarArgs(method);
209+
InvocationHandler handler = null;
210+
if (invocationMapper != null) {
211+
handler = invocationMapper.getInvocationHandler(nativeLibrary, method);
212+
}
213+
Function function = null;
214+
Map options = null;
215+
if (handler == null) {
216+
// Find the function to invoke
217+
function = nativeLibrary.getFunction(method.getName(), method);
218+
options = new HashMap(this.options);
219+
options.put(Function.OPTION_INVOKING_METHOD, method);
220+
}
221+
f = new FunctionInfo(handler, function, isVarArgs, options);
222+
functions.put(method, f);
202223
}
203-
functions.put(method, f);
204224
}
205225
}
206226
if (f.isVarArgs) {

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