Fixes #2 : Support passing the JNIEnv pointer to native methods.

fusesource · Feb 24, 2012 · f0e3ace · f0e3ace
1 parent 369b4d3
commit f0e3ace
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Showing 6 changed files with 70 additions and 23 deletions.
diff --git a/hawtjni-example/src/main/java/test/Example.java b/hawtjni-example/src/main/java/test/Example.java
@@ -324,5 +324,6 @@ static class Range {
 
     }
 
-
+    public static final native void passingtheenv (String msg, JNIEnv env);
+
 }
diff --git a/hawtjni-example/src/main/native-package/src/foo.c b/hawtjni-example/src/main/native-package/src/foo.c
@@ -36,3 +36,6 @@ char * char_add(char *arg, int count) {
   return arg+count;
 }
 
+void passingtheenv (const char *who, JNIEnv *env) {
+   printf("%s, the JNIEnv is at: %x\n", who, env);
+}
diff --git a/hawtjni-example/src/main/native-package/src/foo.h b/hawtjni-example/src/main/native-package/src/foo.h
@@ -10,6 +10,7 @@
 #define INCLUDED_FOO_H
 
 #include <stdlib.h>
+#include "jni.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -35,6 +36,7 @@ long foowork(struct foo **arg, int count);
 
 void callmeback(void (*thecallback)(int number));
 
+void passingtheenv (const char *who, JNIEnv *env);
 
 #ifdef __cplusplus
 } /* extern "C" */

diff --git a/hawtjni-example/src/test/java/test/ExampleTest.java b/hawtjni-example/src/test/java/test/ExampleTest.java
@@ -4,6 +4,7 @@
 import static test.Example.*;
 
 import org.fusesource.hawtjni.runtime.Callback;
+import org.fusesource.hawtjni.runtime.JNIEnv;
 import org.junit.Test;
 import static org.fusesource.hawtjni.runtime.PointerMath.*;
 
@@ -70,6 +71,8 @@ public void test() {
 
         // Heap memory is not GCed, we must manually free it.
         free(ptr);
+
+        passingtheenv("Hiram", null);
     }
 
     public long instanceCallback(long value) {

diff --git a/hawtjni-generator/src/main/java/org/fusesource/hawtjni/generator/NativesGenerator.java b/hawtjni-generator/src/main/java/org/fusesource/hawtjni/generator/NativesGenerator.java
@@ -596,6 +596,8 @@ boolean generateLocalVars(JNIMethod method, List<JNIParameter> params, JNIType r
                 } else {
                     throw new Error("not done");
                 }
+            } else if (paramType.isType("org.fusesource.hawtjni.runtime.JNIEnv")) {
+                // no need to generate a local for this one..
             } else if (paramType.isType("java.lang.String")) {
                 if (param.getFlag(ArgFlag.UNICODE)) {
                     output("const jchar *lparg" + i);
@@ -631,26 +633,32 @@ boolean generateGetters(JNIMethod method, List<JNIParameter> params) {
         boolean genFailTag = false;
         int criticalCount = 0;
         for (JNIParameter param : params) {
-            if (!isCritical(param)) {
-                genFailTag |= generateGetParameter(method, param, false, 1);
-            } else {
-                criticalCount++;
+            if( !"org.fusesource.hawtjni.runtime.JNIEnv".equals(param.getTypeClass().getName()) ) {
+                if (!isCritical(param)) {
+                    genFailTag |= generateGetParameter(method, param, false, 1);
+                } else {
+                    criticalCount++;
+                }
             }
         }
         if (criticalCount != 0) {
             outputln("#ifdef JNI_VERSION_1_2");
             outputln("\tif (IS_JNI_1_2) {");
             for (JNIParameter param : params) {
-                if (isCritical(param)) {
-                    genFailTag |= generateGetParameter(method, param, true, 2);
+                if( !"org.fusesource.hawtjni.runtime.JNIEnv".equals(param.getTypeClass().getName()) ) {
+                    if (isCritical(param)) {
+                        genFailTag |= generateGetParameter(method, param, true, 2);
+                    }
                 }
             }
             outputln("\t} else");
             outputln("#endif");
             outputln("\t{");
             for (JNIParameter param : params) {
-                if (isCritical(param)) {
-                    genFailTag |= generateGetParameter(method, param, false, 2);
+                if( !"org.fusesource.hawtjni.runtime.JNIEnv".equals(param.getTypeClass().getName()) ) {
+                    if (isCritical(param)) {
+                        genFailTag |= generateGetParameter(method, param, false, 2);
+                    }
                 }
             }
             outputln("\t}");
@@ -662,36 +670,44 @@ void generateSetters(JNIMethod method, List<JNIParameter> params) {
         int criticalCount = 0;
         for (int i = params.size() - 1; i >= 0; i--) {
             JNIParameter param = params.get(i);
-            if (isCritical(param)) {
-                criticalCount++;
+            if( !"org.fusesource.hawtjni.runtime.JNIEnv".equals(param.getTypeClass().getName()) ) {
+                if (isCritical(param)) {
+                    criticalCount++;
+                }
             }
         }
         if (criticalCount != 0) {
             outputln("#ifdef JNI_VERSION_1_2");
             outputln("\tif (IS_JNI_1_2) {");
             for (int i = params.size() - 1; i >= 0; i--) {
                 JNIParameter param = params.get(i);
-                if (isCritical(param)) {
-                    output("\t");
-                    generateSetParameter(param, true);
+                if( !"org.fusesource.hawtjni.runtime.JNIEnv".equals(param.getTypeClass().getName()) ) {
+                    if (isCritical(param)) {
+                        output("\t");
+                        generateSetParameter(param, true);
+                    }
                 }
             }
             outputln("\t} else");
             outputln("#endif");
             outputln("\t{");
             for (int i = params.size() - 1; i >= 0; i--) {
                 JNIParameter param = params.get(i);
-                if (isCritical(param)) {
-                    output("\t");
-                    generateSetParameter(param, false);
+                if( !"org.fusesource.hawtjni.runtime.JNIEnv".equals(param.getTypeClass().getName()) ) {
+                    if (isCritical(param)) {
+                        output("\t");
+                        generateSetParameter(param, false);
+                    }
                 }
             }
             outputln("\t}");
         }
         for (int i = params.size() - 1; i >= 0; i--) {
             JNIParameter param = params.get(i);
-            if (!isCritical(param)) {
-                generateSetParameter(param, false);
+            if( !"org.fusesource.hawtjni.runtime.JNIEnv".equals(param.getTypeClass().getName()) ) {
+                if (!isCritical(param)) {
+                    generateSetParameter(param, false);
+                }
             }
         }
     }
@@ -803,10 +819,14 @@ void generateFunctionCallRightSide(JNIMethod method, List<JNIParameter> params,
                 if (i == params.size() - 1 && param.getFlag(ArgFlag.SENTINEL)) {
                     output("NULL");
                 } else {
-                    JNIType paramType = param.getType32();
-                    if (!paramType.isPrimitive() && !isSystemClass(paramType))
-                        output("lp");
-                    output("arg" + i);
+                    if( "org.fusesource.hawtjni.runtime.JNIEnv".equals(param.getTypeClass().getName()) ) {
+                        output("env");
+                    } else {
+                        JNIType paramType = param.getType32();
+                        if (!paramType.isPrimitive() && !isSystemClass(paramType))
+                            output("lp");
+                        output("arg" + i);
+                    }
                 }
                 if (param.getFlag(ArgFlag.CS_OBJECT))
                     output(")");

diff --git a/hawtjni-runtime/src/main/java/org/fusesource/hawtjni/runtime/JNIEnv.java b/hawtjni-runtime/src/main/java/org/fusesource/hawtjni/runtime/JNIEnv.java
@@ -0,0 +1,18 @@
+/**
+ * Copyright (C) 2010, FuseSource Corp.  All rights reserved.
+ */
+package org.fusesource.hawtjni.runtime;
+
+/**
+ * <p>
+ *  This is a marker class. Methods that take this as an argument
+ *  will receive that actual native 'JNIEnv *' value.  Since this
+ *  class cannot be instantiated, Java callers must pass null
+ *  for the value.
+ * </p>
+ *
+ * @author <a href="http://hiramchirino.com">Hiram Chirino</a>
+ */
+public class JNIEnv {
+    private JNIEnv() {}
+}