[Java] Add a reachabilityFence on underlying trait impl calls
[ldk-java] / java_strings.py
index 5452829d70275e4e547bcf47dfc50fc2dba4df44..3a8ba6cb613047a728cb77a09abd7b5557664aba 100644 (file)
@@ -16,10 +16,16 @@ class Consts:
             uint32_t = ['int'],
             uint64_t = ['long'],
         )
+        self.java_type_map = dict(
+            String = "String"
+        )
+        self.java_hu_type_map = dict(
+            String = "String"
+        )
 
         self.to_hu_conv_templates = dict(
-            ptr = '{human_type} {var_name}_hu_conv = new {human_type}(null, {var_name});',
-            default = '{human_type} {var_name}_hu_conv = new {human_type}(null, {var_name});'
+            ptr = '{human_type} {var_name}_hu_conv = null; if ({var_name} < 0 || {var_name} > 4096) { {var_name}_hu_conv = new {human_type}(null, {var_name}); }',
+            default = '{human_type} {var_name}_hu_conv = null; if ({var_name} < 0 || {var_name} > 4096) { {var_name}_hu_conv = new {human_type}(null, {var_name}); }'
         )
 
         self.bindings_header = """package org.ldk.impl;
@@ -103,9 +109,11 @@ public class version {
 
         self.util_fn_pfx = """package org.ldk.structs;
 import org.ldk.impl.bindings;
+import org.ldk.enums.*;
+import org.ldk.util.*;
 import java.util.Arrays;
+import java.lang.ref.Reference;
 import javax.annotation.Nullable;
-import org.ldk.enums.*;
 
 public class UtilMethods {
 """
@@ -115,10 +123,34 @@ import java.util.LinkedList;
 class CommonBase {
        long ptr;
        LinkedList<Object> ptrs_to = new LinkedList();
-       protected CommonBase(long ptr) { assert ptr > 1024; this.ptr = ptr; }
+       protected CommonBase(long ptr) { assert ptr < 0 || ptr > 4096; this.ptr = ptr; }
 }
 """
 
+        self.txout_defn = """public class TxOut extends CommonBase {
+       /** The script_pubkey in this output */
+       public final byte[] script_pubkey;
+       /** The value, in satoshis, of this output */
+       public final long value;
+
+       TxOut(java.lang.Object _dummy, long ptr) {
+               super(ptr);
+               this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
+               this.value = bindings.TxOut_get_value(ptr);
+       }
+       public TxOut(long value, byte[] script_pubkey) {
+               super(bindings.TxOut_new(script_pubkey, value));
+               this.script_pubkey = bindings.TxOut_get_script_pubkey(ptr);
+               this.value = bindings.TxOut_get_value(ptr);
+       }
+
+       @Override @SuppressWarnings(\"deprecation\")
+       protected void finalize() throws Throwable {
+               super.finalize();
+               if (ptr != 0) { bindings.TxOut_free(ptr); }
+       }
+}"""
+
         self.c_file_pfx = """#include <jni.h>
 // On OSX jlong (ie long long) is not equivalent to int64_t, so we override here
 #define int64_t jlong
@@ -128,6 +160,9 @@ class CommonBase {
 #include <stdatomic.h>
 #include <stdlib.h>
 
+#define LIKELY(v) __builtin_expect(!!(v), 1)
+#define UNLIKELY(v) __builtin_expect(!!(v), 0)
+
 """
 
         if self.target == Target.ANDROID:
@@ -161,7 +196,9 @@ void __attribute__((constructor)) spawn_stderr_redirection() {
 
         if not DEBUG or sys.platform == "darwin":
             self.c_file_pfx = self.c_file_pfx + """#define MALLOC(a, _) malloc(a)
-#define FREE(p) if ((uint64_t)(p) > 1024) { free(p); }
+#define FREE(p) if ((uint64_t)(p) > 4096) { free(p); }
+#define CHECK_ACCESS(p)
+#define CHECK_INNER_FIELD_ACCESS_OR_NULL(v)
 """
         if not DEBUG:
             self.c_file_pfx += """#define DO_ASSERT(a) (void)(a)
@@ -282,7 +319,7 @@ static void alloc_freed(void* ptr) {
        while (it->ptr != ptr) {
                p = it; it = it->next;
                if (it == NULL) {
-                       DEBUG_PRINT("Tried to free unknown pointer %p at:\\n", ptr);
+                       DEBUG_PRINT("ERROR: Tried to free unknown pointer %p at:\\n", ptr);
                        void* bt[BT_MAX];
                        int bt_len = backtrace(bt, BT_MAX);
                        backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
@@ -297,7 +334,7 @@ static void alloc_freed(void* ptr) {
        __real_free(it);
 }
 static void FREE(void* ptr) {
-       if ((uint64_t)ptr < 1024) return; // Rust loves to create pointers to the NULL page for dummys
+       if ((uint64_t)ptr <= 4096) return; // Rust loves to create pointers to the NULL page for dummys
        alloc_freed(ptr);
        __real_free(ptr);
 }
@@ -318,6 +355,31 @@ void __wrap_free(void* ptr) {
        __real_free(ptr);
 }
 
+static void CHECK_ACCESS(const void* ptr) {
+       DO_ASSERT(!pthread_mutex_lock(&allocation_mtx));
+       allocation* it = allocation_ll;
+       while (it->ptr != ptr) {
+               it = it->next;
+               if (it == NULL) {
+                       DEBUG_PRINT("ERROR: Tried to access unknown pointer %p at:\\n", ptr);
+                       void* bt[BT_MAX];
+                       int bt_len = backtrace(bt, BT_MAX);
+                       backtrace_symbols_fd(bt, bt_len, STDERR_FILENO);
+                       DEBUG_PRINT("\\n\\n");
+                       DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
+                       return; // addrsan should catch and print more info than we have
+               }
+       }
+       DO_ASSERT(!pthread_mutex_unlock(&allocation_mtx));
+}
+#define CHECK_INNER_FIELD_ACCESS_OR_NULL(v) \\
+       if (v.is_owned && v.inner != NULL) { \\
+               const void *p = __unmangle_inner_ptr(v.inner); \\
+               if (p != NULL) { \\
+                       CHECK_ACCESS(p); \\
+               } \\
+       }
+
 void* __real_realloc(void* ptr, size_t newlen);
 void* __wrap_realloc(void* ptr, size_t len) {
        if (ptr != NULL) alloc_freed(ptr);
@@ -484,6 +546,7 @@ import org.ldk.impl.bindings;
 import org.ldk.enums.*;
 import org.ldk.util.*;
 import java.util.Arrays;
+import java.lang.ref.Reference;
 import javax.annotation.Nullable;
 
 """
@@ -562,10 +625,24 @@ import javax.annotation.Nullable;
         else:
             return "(*env)->Release" + ty_info.java_ty.strip("[]").title() + "ArrayElements(env, " + arr_name + ", " + dest_name + ", 0)"
 
+    def map_hu_array_elems(self, arr_name, conv_name, arr_ty, elem_ty):
+        if elem_ty.java_ty == "long" and elem_ty.java_hu_ty != "long":
+            return arr_name + " != null ? Arrays.stream(" + arr_name + ").mapToLong(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
+        elif elem_ty.java_ty == "long":
+            return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray() : null"
+        elif elem_ty.java_hu_ty == "UInt5":
+            return arr_name + " != null ? InternalUtils.convUInt5Array(" + arr_name + ") : null"
+        else:
+            return arr_name + " != null ? Arrays.stream(" + arr_name + ").map(" + conv_name + " -> " + elem_ty.from_hu_conv[0] + ").toArray(" + arr_ty.java_ty + "::new) : null"
+
     def str_ref_to_native_call(self, var_name, str_len):
         return "str_ref_to_java(env, " + var_name + ", " + str_len + ")"
     def str_ref_to_c_call(self, var_name):
         return "java_to_owned_str(env, " + var_name + ")"
+    def str_to_hu_conv(self, var_name):
+        return None
+    def str_from_hu_conv(self, var_name):
+        return None
 
     def c_fn_name_define_pfx(self, fn_name, has_args):
         if has_args:
@@ -584,43 +661,91 @@ import javax.annotation.Nullable;
         res = res + "}\n"
         return res
 
+    def var_decl_statement(self, ty_string, var_name, statement):
+        return ty_string + " " + var_name + " = " + statement
+
+    def get_java_arr_len(self, arr_name):
+        return arr_name + ".length"
+    def get_java_arr_elem(self, elem_ty, arr_name, idx):
+        return arr_name + "[" + idx + "]"
+    def constr_hu_array(self, ty_info, arr_len):
+        base_ty = ty_info.subty.java_hu_ty.split("[")[0].split("<")[0]
+        conv = "new " + base_ty + "[" + arr_len + "]"
+        if "[" in ty_info.subty.java_hu_ty.split("<")[0]:
+            # Do a bit of a dance to move any excess [] to the end
+            conv += "[" + ty_info.subty.java_hu_ty.split("<")[0].split("[")[1]
+        return conv
+    def cleanup_converted_native_array(self, ty_info, arr_name):
+        return None
+
+    def primitive_arr_from_hu(self, mapped_ty, fixed_len, arr_name):
+        if fixed_len is not None:
+            return ("InternalUtils.check_arr_len(" + arr_name + ", " + fixed_len + ")", "")
+        return None
+    def primitive_arr_to_hu(self, primitive_ty, fixed_len, arr_name, conv_name):
+        return None
+
+    def java_arr_ty_str(self, elem_ty_str):
+        return elem_ty_str + "[]"
+
+    def for_n_in_range(self, n, minimum, maximum):
+        return "for (int " + n + " = " + minimum + "; " + n + " < " + maximum + "; " + n + "++) {"
+    def for_n_in_arr(self, n, arr_name, arr_elem_ty):
+        return ("for (" + arr_elem_ty.java_hu_ty + " " + n + ": " + arr_name + ") { ", " }")
+
+    def get_ptr(self, var):
+        return var + ".ptr"
+    def set_null_skip_free(self, var):
+        return var + ".ptr" + " = 0;"
+
+    def add_ref(self, holder, referent):
+        return holder + ".ptrs_to.add(" + referent + ")"
+
     def native_c_unitary_enum_map(self, struct_name, variants, enum_doc_comment):
         out_java_enum = "package org.ldk.enums;\n\n"
         out_java = ""
         out_c = ""
-        out_c = out_c + "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
-        out_c = out_c + "\tswitch ((*env)->CallIntMethod(env, clz, ordinal_meth)) {\n"
+        out_c += "static inline LDK" + struct_name + " LDK" + struct_name + "_from_java(" + self.c_fn_args_pfx + ") {\n"
+        out_c += "\tjint ord = (*env)->CallIntMethod(env, clz, ordinal_meth);\n"
+        out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
+        out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
+        out_c += "\t\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust threw an exception.\");\n"
+        out_c += "\t}\n"
+        out_c += "\tswitch (ord) {\n"
 
         if enum_doc_comment is not None:
             out_java_enum += "/**\n * " + enum_doc_comment.replace("\n", "\n * ") + "\n */\n"
         out_java_enum += "public enum " + struct_name + " {\n"
         ord_v = 0
-        for var in variants:
-            out_java_enum = out_java_enum + "\t" + var + ",\n"
+        for var, var_docs in variants:
+            if var_docs is not None:
+                out_java_enum += "\t/**\n\t * " + var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
+            out_java_enum += "\t" + var + ",\n"
             out_c = out_c + "\t\tcase %d: return %s;\n" % (ord_v, var)
             ord_v = ord_v + 1
         out_java_enum = out_java_enum + "\t; static native void init();\n"
         out_java_enum = out_java_enum + "\tstatic { init(); }\n"
         out_java_enum = out_java_enum + "}"
         out_java = out_java + "\tstatic { " + struct_name + ".values(); /* Force enum statics to run */ }\n"
-        out_c = out_c + "\t}\n"
-        out_c = out_c + "\tabort();\n"
-        out_c = out_c + "}\n"
+        out_c += "\t}\n"
+        out_c += "\t(*env)->FatalError(env, \"A call to " + struct_name + ".ordinal() from rust returned an invalid value.\");\n"
+        out_c += "\tabort(); // Unreachable, but will let the compiler know we don't return here\n"
+        out_c += "}\n"
 
         out_c = out_c + "static jclass " + struct_name + "_class = NULL;\n"
-        for var in variants:
+        for var, _ in variants:
             out_c = out_c + "static jfieldID " + struct_name + "_" + var + " = NULL;\n"
         out_c = out_c + self.c_fn_ty_pfx + "void JNICALL Java_org_ldk_enums_" + struct_name.replace("_", "_1") + "_init (" + self.c_fn_args_pfx + ") {\n"
         out_c = out_c + "\t" + struct_name + "_class = (*env)->NewGlobalRef(env, clz);\n"
         out_c = out_c + "\tCHECK(" + struct_name + "_class != NULL);\n"
-        for var in variants:
+        for var, _ in variants:
             out_c = out_c + "\t" + struct_name + "_" + var + " = (*env)->GetStaticFieldID(env, " + struct_name + "_class, \"" + var + "\", \"Lorg/ldk/enums/" + struct_name + ";\");\n"
             out_c = out_c + "\tCHECK(" + struct_name + "_" + var + " != NULL);\n"
         out_c = out_c + "}\n"
         out_c = out_c + "static inline jclass LDK" + struct_name + "_to_java(JNIEnv *env, LDK" + struct_name + " val) {\n"
         out_c = out_c + "\tswitch (val) {\n"
         ord_v = 0
-        for var in variants:
+        for var, _ in variants:
             out_c = out_c + "\t\tcase " + var + ":\n"
             out_c = out_c + "\t\t\treturn (*env)->GetStaticObjectField(env, " + struct_name + "_class, " + struct_name + "_" + var + ");\n"
             ord_v = ord_v + 1
@@ -642,14 +767,11 @@ import javax.annotation.Nullable;
             out_c = out_c + "static jmethodID " + struct_name + "_" + var + "_meth = NULL;\n"
         out_c = out_c + self.c_fn_ty_pfx + "void JNICALL Java_org_ldk_impl_bindings_00024" + struct_name.replace("_", "_1") + "_init (" + self.c_fn_args_pfx + ") {\n"
         for var_name in variants:
-            out_c = out_c + "\t" + struct_name + "_" + var_name + "_class =\n"
-            if self.target == Target.ANDROID:
-                out_c = out_c + "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
-            else:
-                out_c = out_c + "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"Lorg/ldk/impl/bindings$" + struct_name + "$" + var_name + ";\"));\n"
-            out_c = out_c + "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
-            out_c = out_c + "\t" + struct_name + "_" + var_name + "_meth = (*env)->GetMethodID(env, " + struct_name + "_" + var_name + "_class, \"<init>\", \"(" + init_meth_jty_strs[var_name] + ")V\");\n"
-            out_c = out_c + "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
+            out_c += "\t" + struct_name + "_" + var_name + "_class =\n"
+            out_c += "\t\t(*env)->NewGlobalRef(env, (*env)->FindClass(env, \"org/ldk/impl/bindings$" + struct_name + "$" + var_name + "\"));\n"
+            out_c += "\tCHECK(" + struct_name + "_" + var_name + "_class != NULL);\n"
+            out_c += "\t" + struct_name + "_" + var_name + "_meth = (*env)->GetMethodID(env, " + struct_name + "_" + var_name + "_class, \"<init>\", \"(" + init_meth_jty_strs[var_name] + ")V\");\n"
+            out_c += "\tCHECK(" + struct_name + "_" + var_name + "_meth != NULL);\n"
         out_c = out_c + "}\n"
         return out_c
 
@@ -760,7 +882,8 @@ import javax.annotation.Nullable;
                     else:
                         java_trait_constr = java_trait_constr + arg_info.arg_name
 
-                java_trait_constr = java_trait_constr + ");\n"
+                java_trait_constr += ");\n"
+                java_trait_constr += "\t\t\t\tReference.reachabilityFence(arg);\n"
                 if fn_line.ret_ty_info.java_ty != "void":
                     if fn_line.ret_ty_info.from_hu_conv is not None:
                         java_trait_constr = java_trait_constr + "\t\t\t\t" + fn_line.ret_ty_info.java_ty + " result = " + fn_line.ret_ty_info.from_hu_conv[0] + ";\n"
@@ -856,7 +979,7 @@ import javax.annotation.Nullable;
                     out_c = out_c + "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
                 elif fn_line.ret_ty_info.c_ty == "void":
                     out_c += "\t(*env)->Call" + fn_line.ret_ty_info.java_ty.title() + "Method(env, obj, j_calls->" + fn_line.fn_name + "_meth"
-                elif fn_line.ret_ty_info.java_ty == "String":
+                elif fn_line.ret_ty_info.java_hu_ty == "String":
                     # Manually write out String methods as they're just an Object
                     out_c += "\t" + fn_line.ret_ty_info.c_ty + " ret = (*env)->CallObjectMethod(env, obj, j_calls->" + fn_line.fn_name + "_meth"
                 elif not fn_line.ret_ty_info.passed_as_ptr:
@@ -871,7 +994,7 @@ import javax.annotation.Nullable;
                         out_c = out_c + ", " + arg_info.arg_name
                 out_c = out_c + ");\n"
 
-                out_c += "\tif ((*env)->ExceptionCheck(env)) {\n"
+                out_c += "\tif (UNLIKELY((*env)->ExceptionCheck(env))) {\n"
                 out_c += "\t\t(*env)->ExceptionDescribe(env);\n"
                 out_c += "\t\t(*env)->FatalError(env, \"A call to " + fn_line.fn_name + " in " + struct_name + " from rust threw an exception.\");\n"
                 out_c += "\t}\n"
@@ -1030,7 +1153,9 @@ import javax.annotation.Nullable;
         out_java +=  ("\t\tprivate " + struct_name + "() {}\n")
         for var in variant_list:
             out_java +=  ("\t\tpublic final static class " + var.var_name + " extends " + struct_name + " {\n")
-            java_hu_subclasses = java_hu_subclasses + "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
+            if var.var_docs is not None:
+                java_hu_subclasses += "\t/**\n\t * " + var.var_docs.replace("\n", "\n\t * ") + "\n\t */\n"
+            java_hu_subclasses += "\tpublic final static class " + var.var_name + " extends " + java_hu_type + " {\n"
             out_java_enum += ("\t\tif (raw_val.getClass() == bindings." + struct_name + "." + var.var_name + ".class) {\n")
             out_java_enum += ("\t\t\treturn new " + var.var_name + "(ptr, (bindings." + struct_name + "." + var.var_name + ")raw_val);\n")
             init_meth_jty_str = ""
@@ -1112,11 +1237,12 @@ import javax.annotation.Nullable;
         out_opaque_struct_human += self.hu_struct_file_prefix
         out_opaque_struct_human += "\n/**\n * " + struct_doc_comment.replace("\n", "\n * ") + "\n */\n"
         out_opaque_struct_human += "@SuppressWarnings(\"unchecked\") // We correctly assign various generic arrays\n"
-        out_opaque_struct_human += ("public class " + struct_name.replace("LDK","") + " extends CommonBase")
+        hu_name = struct_name.replace("LDKC2Tuple", "TwoTuple").replace("LDKC3Tuple", "ThreeTuple").replace("LDK", "")
+        out_opaque_struct_human += ("public class " + hu_name + " extends CommonBase")
         if struct_name.startswith("LDKLocked"):
             out_opaque_struct_human += (" implements AutoCloseable")
         out_opaque_struct_human += (" {\n")
-        out_opaque_struct_human += ("\t" + struct_name.replace("LDK", "") + "(Object _dummy, long ptr) { super(ptr); }\n")
+        out_opaque_struct_human += ("\t" + hu_name + "(Object _dummy, long ptr) { super(ptr); }\n")
         if struct_name.startswith("LDKLocked"):
             out_opaque_struct_human += ("\t@Override public void close() {\n")
         else:
@@ -1127,8 +1253,62 @@ import javax.annotation.Nullable;
         out_opaque_struct_human += ("\t}\n\n")
         return out_opaque_struct_human
 
+    def map_tuple(self, struct_name):
+        return self.map_opaque_struct(struct_name, "A Tuple")
+
+    def map_result(self, struct_name, res_map, err_map):
+        human_ty = struct_name.replace("LDKCResult", "Result")
+        java_hu_struct = ""
+        java_hu_struct += self.hu_struct_file_prefix
+        java_hu_struct += "public class " + human_ty + " extends CommonBase {\n"
+        java_hu_struct += "\tprivate " + human_ty + "(Object _dummy, long ptr) { super(ptr); }\n"
+        java_hu_struct += "\tprotected void finalize() throws Throwable {\n"
+        java_hu_struct += "\t\tif (ptr != 0) { bindings." + struct_name.replace("LDK","") + "_free(ptr); } super.finalize();\n"
+        java_hu_struct += "\t}\n\n"
+        java_hu_struct += "\tstatic " + human_ty + " constr_from_ptr(long ptr) {\n"
+        java_hu_struct += "\t\tif (bindings." + struct_name.replace("LDK", "") + "_is_ok(ptr)) {\n"
+        java_hu_struct += "\t\t\treturn new " + human_ty + "_OK(null, ptr);\n"
+        java_hu_struct += "\t\t} else {\n"
+        java_hu_struct += "\t\t\treturn new " + human_ty + "_Err(null, ptr);\n"
+        java_hu_struct += "\t\t}\n"
+        java_hu_struct += "\t}\n"
+
+        java_hu_struct += "\tpublic static final class " + human_ty + "_OK extends " + human_ty + " {\n"
+
+        if res_map.java_hu_ty != "void":
+            java_hu_struct += "\t\tpublic final " + res_map.java_hu_ty + " res;\n"
+        java_hu_struct += "\t\tprivate " + human_ty + "_OK(Object _dummy, long ptr) {\n"
+        java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
+        if res_map.java_hu_ty == "void":
+            pass
+        elif res_map.to_hu_conv is not None:
+            java_hu_struct += "\t\t\t" + res_map.java_ty + " res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
+            java_hu_struct += "\t\t\t" + res_map.to_hu_conv.replace("\n", "\n\t\t\t")
+            java_hu_struct += "\n\t\t\tthis.res = " + res_map.to_hu_conv_name + ";\n"
+        else:
+            java_hu_struct += "\t\t\tthis.res = bindings." + struct_name.replace("LDK", "") + "_get_ok(ptr);\n"
+        java_hu_struct += "\t\t}\n"
+        java_hu_struct += "\t}\n\n"
+
+        java_hu_struct += "\tpublic static final class " + human_ty + "_Err extends " + human_ty + " {\n"
+        if err_map.java_hu_ty != "void":
+            java_hu_struct += "\t\tpublic final " + err_map.java_hu_ty + " err;\n"
+        java_hu_struct += "\t\tprivate " + human_ty + "_Err(Object _dummy, long ptr) {\n"
+        java_hu_struct += "\t\t\tsuper(_dummy, ptr);\n"
+        if err_map.java_hu_ty == "void":
+            pass
+        elif err_map.to_hu_conv is not None:
+            java_hu_struct += "\t\t\t" + err_map.java_ty + " err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
+            java_hu_struct += "\t\t\t" + err_map.to_hu_conv.replace("\n", "\n\t\t\t")
+            java_hu_struct += "\n\t\t\tthis.err = " + err_map.to_hu_conv_name + ";\n"
+        else:
+            java_hu_struct += "\t\t\tthis.err = bindings." + struct_name.replace("LDK", "") + "_get_err(ptr);\n"
+        java_hu_struct += "\t\t}\n"
+
+        java_hu_struct += "\t}\n\n"
+        return java_hu_struct
 
-    def map_function(self, argument_types, c_call_string, method_name, return_type_info, struct_meth, default_constructor_args, takes_self, takes_self_as_ref, args_known, type_mapping_generator, doc_comment):
+    def map_function(self, argument_types, c_call_string, method_name, meth_n, return_type_info, struct_meth, default_constructor_args, takes_self, takes_self_as_ref, args_known, type_mapping_generator, doc_comment):
         out_java = ""
         out_c = ""
         out_java_struct = None
@@ -1152,10 +1332,10 @@ import javax.annotation.Nullable;
                 out_java += (arg_conv_info.java_ty + " " + arg_conv_info.arg_name)
 
         out_java_struct = ""
+        extra_java_struct_out = ""
         if not args_known:
             out_java_struct += ("\t// Skipped " + method_name + "\n")
         else:
-            meth_n = method_name[len(struct_meth) + 1 if len(struct_meth) != 0 else 0:].strip("_")
             if doc_comment is not None:
                 out_java_struct += "\t/**\n\t * " + doc_comment.replace("\n", "\n\t * ") + "\n\t */\n"
             if return_type_info.nullable:
@@ -1167,7 +1347,18 @@ import javax.annotation.Nullable;
                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " with_default("
                 else:
                     out_java_struct += "\tpublic static " + return_type_info.java_hu_ty + " " + meth_n + "("
+            elif meth_n == "clone_ptr" or (struct_meth.startswith("LDKCResult") and (meth_n == "get_ok" or meth_n == "get_err")):
+                out_java_struct += ("\t" + return_type_info.java_hu_ty + " " + meth_n + "(")
             else:
+                if meth_n == "hash" and return_type_info.java_hu_ty == "long":
+                    extra_java_struct_out = "\t@Override public int hashCode() {\n"
+                    extra_java_struct_out += "\t\treturn (int)this.hash();\n"
+                    extra_java_struct_out += "\t}\n"
+                elif meth_n == "eq" and return_type_info.java_hu_ty == "boolean":
+                    extra_java_struct_out = "\t@Override public boolean equals(Object o) {\n"
+                    extra_java_struct_out += "\t\tif (!(o instanceof " + struct_meth + ")) return false;\n"
+                    extra_java_struct_out += "\t\treturn this.eq((" + struct_meth + ")o);\n"
+                    extra_java_struct_out += "\t}\n"
                 out_java_struct += ("\tpublic " + return_type_info.java_hu_ty + " " + meth_n + "(")
             for idx, arg in enumerate(argument_types):
                 if idx != 0:
@@ -1255,8 +1446,47 @@ import javax.annotation.Nullable;
                 else:
                     out_java_struct += (info.arg_name)
             out_java_struct += (");\n")
+
+            # This is completely nuts. The OpenJDK JRE JIT will optimize out a object which is on
+            # the stack, calling its finalizer immediately even if member methods are *actively
+            # executing* on the same object, as long as said object is on the stack. There is no
+            # concrete specification for when the optimizer is allowed to do this, and when it is
+            # not, so there is absolutely no way to be certain that this fix suffices.
+            #
+            # Instead, the "Java Language Specification" says only that an object is reachable
+            # (i.e. will not yet be finalized) if it "can be accessed in any potential continuing
+            # computation from any live thread". To any sensible reader this would mean actively
+            # executing a member function on an object would make it not eligible for finalization.
+            # But, no, dear reader, this statement does not say that. Well, okay, it says that,
+            # very explicitly in fact, but those are just, like, words, man.
+            #
+            # In the seemingly non-normative text further down, a few examples of things the
+            # optimizer can do are given, including "if the values in an object's fields are
+            # stored in registers[, t]he may then access the registers instead of the object, and
+            # never access the object again[, implying] that the object is garbage". This appears
+            # to fully contradict both the above statement, the API documentation in java.lang.ref
+            # regarding when a reference is "strongly reachable", and basic common sense. There is
+            # no concrete set of limitations stated, however, seemingly implying the JIT could
+            # decide your code would run faster by simply garbage collecting everything
+            # immediately, ensuring your code finishes soon, just by SEGFAULT. Thus, we're really
+            # entirely flying blind here. We add some fences and hope that its sufficient, but
+            # with no specification to rely on, we cannot be certain of anything.
+            #
+            # TL;DR: The Java Language "Specification" provides no real guarantees on when an
+            # object will be considered available for garbage collection once the JIT kicks in, so
+            # we put in some fences and hope to god the JIT doesn't get smarter/more broken.
+            for idx, info in enumerate(argument_types):
+                if idx == 0 and takes_self:
+                    out_java_struct += ("\t\tReference.reachabilityFence(this);\n")
+                elif info.arg_name in default_constructor_args:
+                    for explode_idx, explode_arg in enumerate(default_constructor_args[info.arg_name]):
+                        expl_arg_name = info.arg_name + "_" + explode_arg.arg_name
+                        out_java_struct += ("\t\tReference.reachabilityFence(" + expl_arg_name + ");\n")
+                elif info.c_ty != "void":
+                    out_java_struct += ("\t\tReference.reachabilityFence(" + info.arg_name + ");\n")
+
             if return_type_info.java_ty == "long" and return_type_info.java_hu_ty != "long":
-                out_java_struct += "\t\tif (ret < 1024) { return null; }\n"
+                out_java_struct += "\t\tif (ret >= 0 && ret <= 4096) { return null; }\n"
 
             if return_type_info.to_hu_conv is not None:
                 if not takes_self:
@@ -1290,4 +1520,7 @@ import javax.annotation.Nullable;
                 out_java_struct += ("\t\treturn ret;\n")
             out_java_struct += ("\t}\n\n")
 
-        return (out_java, out_c, out_java_struct)
+        return (out_java, out_c, out_java_struct + extra_java_struct_out)
+
+    def cleanup(self):
+        pass