JNI: native method that spawns threads that need to interact with Java
I have a C method that is called from a Java process:
extern "C" {
JNIEXPORT jstring JNICALL Java_bla_bla_bla(JNIEnv *env, jclass java_class, jint param) {
/* Spawn C threads that are going to call Java methods */
}
}
The problem is that all what my native method gets from Java is a JNIEnv instance. In order to call AttachCurrentThread(), I need a JavaVM object.
How can I get the JavaVM pointer from my native method?
java jni jnienv
asked Nov 13 '18 at 15:08
SomethingSomethingSomethingSomething
4,23873565
add a comment |
I have a C method that is called from a Java process:
extern "C" {
JNIEXPORT jstring JNICALL Java_bla_bla_bla(JNIEnv *env, jclass java_class, jint param) {
/* Spawn C threads that are going to call Java methods */
}
}
The problem is that all what my native method gets from Java is a JNIEnv instance. In order to call AttachCurrentThread(), I need a JavaVM object.
How can I get the JavaVM pointer from my native method?
java jni jnienv
asked Nov 13 '18 at 15:08
SomethingSomethingSomethingSomething
4,23873565
add a comment |
I have a C method that is called from a Java process:
extern "C" {
JNIEXPORT jstring JNICALL Java_bla_bla_bla(JNIEnv *env, jclass java_class, jint param) {
/* Spawn C threads that are going to call Java methods */
}
}
The problem is that all what my native method gets from Java is a JNIEnv instance. In order to call AttachCurrentThread(), I need a JavaVM object.
How can I get the JavaVM pointer from my native method?
java jni jnienv
asked Nov 13 '18 at 15:08
SomethingSomethingSomethingSomething
4,23873565
I have a C method that is called from a Java process:
extern "C" {
JNIEXPORT jstring JNICALL Java_bla_bla_bla(JNIEnv *env, jclass java_class, jint param) {
/* Spawn C threads that are going to call Java methods */
}
}
The problem is that all what my native method gets from Java is a JNIEnv instance. In order to call AttachCurrentThread(), I need a JavaVM object.
How can I get the JavaVM pointer from my native method?
java jni jnienv
java jni jnienv
asked Nov 13 '18 at 15:08
SomethingSomethingSomethingSomething
4,23873565
asked Nov 13 '18 at 15:08
SomethingSomethingSomethingSomething
4,23873565
asked Nov 13 '18 at 15:08
SomethingSomethingSomethingSomething
4,23873565
asked Nov 13 '18 at 15:08
SomethingSomethingSomethingSomething
4,23873565
asked Nov 13 '18 at 15:08
SomethingSomethingSomethingSomething
4,23873565
4,23873565
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
One alternative is to cache the JavaVM* you receive in JNI_OnLoad.
Another alternative is to call the GetJavaVM function that is part of the JNIEnv:
JNIEXPORT jstring JNICALL Java_bla_bla_bla(JNIEnv *env, jclass java_class, jint param) {
JavaVM *jvm;
if (env->GetJavaVM(&jvm)) {
// Something went wrong
}
// Pass jvm to the new thread
answered Nov 13 '18 at 15:40
MichaelMichael
42.7k84293
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
One alternative is to cache the JavaVM* you receive in JNI_OnLoad.
Another alternative is to call the GetJavaVM function that is part of the JNIEnv:
JNIEXPORT jstring JNICALL Java_bla_bla_bla(JNIEnv *env, jclass java_class, jint param) {
JavaVM *jvm;
if (env->GetJavaVM(&jvm)) {
// Something went wrong
}
// Pass jvm to the new thread
answered Nov 13 '18 at 15:40
MichaelMichael
42.7k84293
add a comment |
One alternative is to cache the JavaVM* you receive in JNI_OnLoad.
Another alternative is to call the GetJavaVM function that is part of the JNIEnv:
JNIEXPORT jstring JNICALL Java_bla_bla_bla(JNIEnv *env, jclass java_class, jint param) {
JavaVM *jvm;
if (env->GetJavaVM(&jvm)) {
// Something went wrong
}
// Pass jvm to the new thread
answered Nov 13 '18 at 15:40
MichaelMichael
42.7k84293
add a comment |
One alternative is to cache the JavaVM* you receive in JNI_OnLoad.
Another alternative is to call the GetJavaVM function that is part of the JNIEnv:
JNIEXPORT jstring JNICALL Java_bla_bla_bla(JNIEnv *env, jclass java_class, jint param) {
JavaVM *jvm;
if (env->GetJavaVM(&jvm)) {
// Something went wrong
}
// Pass jvm to the new thread
answered Nov 13 '18 at 15:40
MichaelMichael
42.7k84293
One alternative is to cache the JavaVM* you receive in JNI_OnLoad.
Another alternative is to call the GetJavaVM function that is part of the JNIEnv:
JNIEXPORT jstring JNICALL Java_bla_bla_bla(JNIEnv *env, jclass java_class, jint param) {
JavaVM *jvm;
if (env->GetJavaVM(&jvm)) {
// Something went wrong
}
// Pass jvm to the new thread
answered Nov 13 '18 at 15:40
MichaelMichael
42.7k84293
answered Nov 13 '18 at 15:40
MichaelMichael
42.7k84293
answered Nov 13 '18 at 15:40
MichaelMichael
42.7k84293
answered Nov 13 '18 at 15:40
MichaelMichael
42.7k84293
42.7k84293
add a comment |
add a comment |
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