# See the License for the specific language governing permissions and
# limitations under the License.
-# Java Virtual Machine services
+# Java Virtual Machine invocation API and others services from the JNI C API
+#
+# Users of this module and the Java FFI, on desktop computers, must define three environment variables:
+# * `JAVA_HOME` points to the installation folder of the target Java VM.
+# This folder should contain the JNI header file `include/jni.h`.
+# e.g. `/usr/lib/jvm/default-java` on Debian Jessie.
+# * `JNI_LIB_PATH` points to the folder with `libjvm.so`.
+# e.g. `/usr/lib/jvm/default-java/jre/lib/amd64/server/` on Debian Jessie.
+# * `LD_LIBRARY_PATH` has the path to the folder with `libjvm.so`.
+# It's the same value as `JNI_LIB_PATH` but `LD_LIBRARY_PATH` is a colon separated list
+# which may contain other paths.
#
# See: http://docs.oracle.com/javase/1.5.0/docs/guide/jni/spec/jniTOC.html
module jvm is
# var env = builder.jni_env
# ~~~~
class JavaVMBuilder
- super JniEnvRef
# Version code of the JVM requested by `create_jvm`
#
- # Default at 0x00010002
+ # Default at 0x00010002 for `JNI_VERSION_1_2`.
var version = 0x00010002 is writable
# Additional option strings
var options = new Array[String]
- # Create the JVM and return it on success
+ # Create a JVM instance, or return `null` on error
fun create_jvm: nullable JavaVM
do
var args = new JavaVMInitArgs
args.options = c_options
- var jvm = new JavaVM(args, self)
+ var jvm = new JavaVM(args)
args.free
c_options.free
end
private extern class JavaVMOption `{ JavaVMOption* `}
- fun string: String import NativeString.to_s `{
- return NativeString_to_s((char*)self->optionString);
+ fun string: String import CString.to_s `{
+ return CString_to_s((char*)self->optionString);
`}
fun string=(v: String) import String.to_cstring `{
self->optionString = String_to_cstring(v);
`}
- fun extra_info: String import NativeString.to_s `{
- return NativeString_to_s((char*)self->extraInfo);
+ fun extra_info: String import CString.to_s `{
+ return CString_to_s((char*)self->extraInfo);
`}
fun extra_info=(v: String) import String.to_cstring `{
self->extraInfo = String_to_cstring(v);
# Represents a jni JavaVM
extern class JavaVM `{JavaVM *`}
- # Create the JVM, returns its handle and store the a pointer to JniEnv in `env_ref`
+ # Create the JVM
#
- # Unavailable on Android, where you cannot instanciate a new JVM.
- private new(args: JavaVMInitArgs, env_ref: JniEnvRef)
- import jni_error, JniEnvRef.jni_env=, JniEnv.as nullable `{
+ # The corresponding `JniEnv` can be obtained by calling `env`.
+ #
+ # Unavailable on some platforms, including Android where you cannot instanciate a new JVM.
+ private new(args: JavaVMInitArgs) import jni_error `{
#ifdef ANDROID
JavaVM_jni_error(NULL, "JVM creation not supported on Android", 0);
res = JNI_CreateJavaVM(&jvm, (void**)&env, args);
- if (res != 0) {
+ if (res != JNI_OK) {
JavaVM_jni_error(NULL, "Could not create Java VM", res);
return NULL;
}
- else {
- JniEnvRef_jni_env__assign(env_ref, JniEnv_as_nullable_JniEnv(env));
- return jvm;
- }
+
+ return jvm;
`}
- private fun jni_error(msg: NativeString, v: Int)
+ private fun jni_error(msg: CString, v: Int)
do
print "JNI Error: {msg} ({v})"
abort
end
+ # Unload the Java VM when the calling thread is the only remaining non-daemon attached user thread
fun destroy `{
(*self)->DestroyJavaVM(self);
`}
+ # `JniEnv` attached to the calling thread
+ #
+ # A null pointer is returned if the calling thread is not attached to the JVM.
fun env: JniEnv import jni_error `{
JNIEnv *env;
int res = (*self)->GetEnv(self, (void **)&env, JNI_VERSION_1_6);
- if (res != JNI_OK) {
+ if (res == JNI_EDETACHED) {
+ JavaVM_jni_error(NULL, "Requesting JNIEnv from an unattached thread", res);
+ return NULL;
+ }
+ else if (res != JNI_OK) {
JavaVM_jni_error(NULL, "Could not get JNIEnv from Java VM", res);
return NULL;
}
return env;
`}
+ # Attach the calling thread to the JVM and return its `JniEnv`
fun attach_current_thread: JniEnv import jni_error `{
JNIEnv *env;
#ifdef ANDROID
}
return env;
`}
+
+ # Detach the calling thread from this JVM
+ fun detach_current_thread import jni_error `{
+ int res = (*self)->DetachCurrentThread(self);
+ if (res != JNI_OK) {
+ JavaVM_jni_error(NULL, "Could not detach current thread to Java VM", res);
+ }
+ `}
end
# Represents a jni JNIEnv, which is a thread in a JavaVM
return res;
`}
- # Call a method on `obj` designed by `method_id` with an array `args` of arguments returning a NativeString
- fun call_string_method(obj: JavaObject, method_id: JMethodID, args: nullable Array[nullable Object]): NativeString import convert_args_to_jni `{
+ # Call a method on `obj` designed by `method_id` with an array `args` of arguments returning a CString
+ fun call_string_method(obj: JavaObject, method_id: JMethodID, args: nullable Array[nullable Object]): CString import convert_args_to_jni `{
jvalue * args_tab = JniEnv_convert_args_to_jni(self, args);
jobject jobj = (*self)->CallObjectMethod(self, obj, method_id, args_tab);
free(args_tab);
`}
end
-# used to initialize a JavaVM
-class JniEnvRef
- var jni_env: nullable JniEnv = null
-end
-
# Represents a jni jclass
extern class JClass `{jclass`}
end
# Represents a jni JNINNativeMethod
extern class JNINativeMethod `{ JNINativeMethod* `}
- fun name: String import NativeString.to_s `{
- return NativeString_to_s((void*)self->name);
+ fun name: String import CString.to_s `{
+ return CString_to_s((void*)self->name);
`}
fun name=(name: String) import String.to_cstring `{
self->name = String_to_cstring(name);
`}
- fun signature: String import NativeString.to_s `{
- return NativeString_to_s((void*)self->signature);
+ fun signature: String import CString.to_s `{
+ return CString_to_s((void*)self->signature);
`}
fun signature=(signature: String) import String.to_cstring `{
`}
end
-redef class NativeString
+redef class CString
redef fun to_jvalue(env)`{
jvalue value;
value.l = (*env)->NewStringUTF(env, self);
nitlanguage / nit.git / blobdiff