native.h

//Copyright (C) 2018 Cornell University

// This file supports dynamically looking up Java native method pointers.
// We cannot link to native methods ahead-of-time, because native methods
// are often registered with the VM dynamically at runtime.
#pragma once

#include "jni.h"

// Links a native method to the given function pointer.
void
RegisterJavaNativeFunc(
    jclass cls,            // e.g., java.lang.Object
    const char* name,      // e.g., wait
    const char* signature, // e.g., (J)V
    void* func
);

// Returns a pointer to a Java native method.
//
// The name and signature are used in the case that the
// native method has been registered dynamically through JNI,
// or in the case that the native method has been cached.
//
// The short symbol and long symbol are used in case the native method
// needs to be searched for in the symbol table.
//
// The signature of this function must precisely match
// the signature used in JLang.
extern "C"
void*
GetJavaNativeFunc(
    jclass cls,               // e.g., java.lang.Object
    const char* name,         // e.g., wait
    const char* signature,    // e.g., (J)V
    const char* short_symbol, // e.g., Java_java_lang_Object_wait
    const char* long_symbol   // e.g., Java_java_lang_Object_wait__J
);