callback*
create_callback(JNIEnv* env, jobject obj, jobject method,
jobjectArray param_types, jclass return_type,
callconv_t calling_convention, jboolean direct) {
callback* cb;
ffi_abi abi = FFI_DEFAULT_ABI;
ffi_abi java_abi = FFI_DEFAULT_ABI;
ffi_type* ffi_rtype;
ffi_status status;
jsize argc;
JavaVM* vm;
int rtype;
char msg[64];
int i;
int cvt = 0;
const char* throw_type = NULL;
const char* throw_msg = NULL;
if ((*env)->GetJavaVM(env, &vm) != JNI_OK) {
throwByName(env, EUnsatisfiedLink, "Can't get Java VM");
return NULL;
}
argc = (*env)->GetArrayLength(env, param_types);
cb = (callback *)malloc(sizeof(callback));
cb->closure = ffi_closure_alloc(sizeof(ffi_closure), &cb->x_closure);
cb->object = (*env)->NewWeakGlobalRef(env, obj);
cb->methodID = (*env)->FromReflectedMethod(env, method);
cb->vm = vm;
cb->arg_types = (ffi_type**)malloc(sizeof(ffi_type*) * argc);
cb->java_arg_types = (ffi_type**)malloc(sizeof(ffi_type*) * (argc + 3));
cb->arg_jtypes = (char*)malloc(sizeof(char) * argc);
cb->flags = (int *)malloc(sizeof(int) * argc);
cb->rflag = CVT_DEFAULT;
cb->arg_classes = (jobject*)malloc(sizeof(jobject) * argc);
cb->direct = direct;
cb->java_arg_types[0] = cb->java_arg_types[1] = cb->java_arg_types[2] = &ffi_type_pointer;
for (i=0;i < argc;i++) {
int jtype;
jclass cls = (*env)->GetObjectArrayElement(env, param_types, i);
if ((cb->flags[i] = get_conversion_flag(env, cls)) != CVT_DEFAULT) {
cb->arg_classes[i] = (*env)->NewWeakGlobalRef(env, cls);
cvt = 1;
}
jtype = get_jtype(env, cls);
if (jtype == -1) {
snprintf(msg, sizeof(msg), "Unsupported argument at index %d", i);
throw_type = EIllegalArgument;
throw_msg = msg;
goto failure_cleanup;
}
cb->arg_jtypes[i] = (char)jtype;
cb->java_arg_types[i+3] = cb->arg_types[i] = get_ffi_type(env, cls, cb->arg_jtypes[i]);
if (cb->flags[i] == CVT_NATIVE_MAPPED
|| cb->flags[i] == CVT_POINTER_TYPE
|| cb->flags[i] == CVT_INTEGER_TYPE) {
jclass ncls;
ncls = getNativeType(env, cls);
jtype = get_jtype(env, ncls);
if (jtype == -1) {
snprintf(msg, sizeof(msg), "Unsupported NativeMapped argument native type at argument %d", i);
throw_type = EIllegalArgument;
throw_msg = msg;
goto failure_cleanup;
}
cb->arg_jtypes[i] = (char)jtype;
cb->java_arg_types[i+3] = &ffi_type_pointer;
cb->arg_types[i] = get_ffi_type(env, ncls, cb->arg_jtypes[i]);
}
if (cb->arg_types[i]->type == FFI_TYPE_FLOAT) {
// Java method is varargs, so promote floats to double
cb->java_arg_types[i+3] = &ffi_type_double;
cb->flags[i] = CVT_FLOAT;
cvt = 1;
}
else if (cb->java_arg_types[i+3]->type == FFI_TYPE_STRUCT) {
// All callback structure arguments are passed as a jobject
cb->java_arg_types[i+3] = &ffi_type_pointer;
}
}
if (!direct || !cvt) {
free(cb->flags);
cb->flags = NULL;
free(cb->arg_classes);
cb->arg_classes = NULL;
}
if (direct) {
cb->rflag = get_conversion_flag(env, return_type);
if (cb->rflag == CVT_NATIVE_MAPPED
|| cb->rflag == CVT_INTEGER_TYPE
|| cb->rflag == CVT_POINTER_TYPE) {
return_type = getNativeType(env, return_type);
}
}
#if defined(_WIN32) && !defined(_WIN64)
if (calling_convention == CALLCONV_STDCALL) {
abi = FFI_STDCALL;
}
java_abi = FFI_STDCALL;
#endif // _WIN32
rtype = get_jtype(env, return_type);
if (rtype == -1) {
throw_type = EIllegalArgument;
throw_msg = "Unsupported return type";
goto failure_cleanup;
}
ffi_rtype = get_ffi_rtype(env, return_type, (char)rtype);
if (!ffi_rtype) {
throw_type = EIllegalArgument;
throw_msg = "Error in return type";
goto failure_cleanup;
}
status = ffi_prep_cif(&cb->cif, abi, argc, ffi_rtype, cb->arg_types);
if (!ffi_error(env, "callback setup", status)) {
ffi_type* java_ffi_rtype = ffi_rtype;
if (cb->rflag == CVT_STRUCTURE_BYVAL
|| cb->rflag == CVT_NATIVE_MAPPED
|| cb->rflag == CVT_POINTER_TYPE
|| cb->rflag == CVT_INTEGER_TYPE) {
// Java method returns a jobject, not a struct
java_ffi_rtype = &ffi_type_pointer;
rtype = '*';
}
switch(rtype) {
case 'V': cb->fptr = (*env)->CallVoidMethod; break;
case 'Z': cb->fptr = (*env)->CallBooleanMethod; break;
case 'B': cb->fptr = (*env)->CallByteMethod; break;
case 'S': cb->fptr = (*env)->CallShortMethod; break;
case 'C': cb->fptr = (*env)->CallCharMethod; break;
case 'I': cb->fptr = (*env)->CallIntMethod; break;
case 'J': cb->fptr = (*env)->CallLongMethod; break;
case 'F': cb->fptr = (*env)->CallFloatMethod; break;
case 'D': cb->fptr = (*env)->CallDoubleMethod; break;
default: cb->fptr = (*env)->CallObjectMethod; break;
}
status = ffi_prep_cif(&cb->java_cif, java_abi, argc+3, java_ffi_rtype, cb->java_arg_types);
if (!ffi_error(env, "callback setup (2)", status)) {
ffi_prep_closure_loc(cb->closure, &cb->cif, callback_dispatch, cb,
cb->x_closure);
return cb;
}
}
failure_cleanup:
free_callback(env, cb);
if (throw_type) {
throwByName(env, throw_type, msg);
}
return NULL;
}
callback*
create_callback(JNIEnv* env, jobject obj, jobject method,
jobjectArray param_types, jclass return_type,
callconv_t calling_convention, jint options,
jstring encoding) {
jboolean direct = options & CB_OPTION_DIRECT;
jboolean in_dll = options & CB_OPTION_IN_DLL;
callback* cb;
ffi_abi abi = FFI_DEFAULT_ABI;
ffi_abi java_abi = FFI_DEFAULT_ABI;
ffi_type* ffi_rtype;
ffi_status status;
jsize argc;
JavaVM* vm;
int rtype;
char msg[MSG_SIZE];
int i;
int cvt = 0;
const char* throw_type = NULL;
const char* throw_msg = NULL;
if ((*env)->GetJavaVM(env, &vm) != JNI_OK) {
throwByName(env, EUnsatisfiedLink, "Can't get Java VM to create native callback");
return NULL;
}
argc = (*env)->GetArrayLength(env, param_types);
cb = (callback *)malloc(sizeof(callback));
cb->closure = ffi_closure_alloc(sizeof(ffi_closure), &cb->x_closure);
cb->saved_x_closure = cb->x_closure;
cb->object = (*env)->NewWeakGlobalRef(env, obj);
cb->methodID = (*env)->FromReflectedMethod(env, method);
cb->vm = vm;
cb->arg_types = (ffi_type**)malloc(sizeof(ffi_type*) * argc);
cb->java_arg_types = (ffi_type**)malloc(sizeof(ffi_type*) * (argc + 3));
cb->arg_jtypes = (char*)malloc(sizeof(char) * argc);
cb->conversion_flags = (int *)malloc(sizeof(int) * argc);
cb->rflag = CVT_DEFAULT;
cb->arg_classes = (jobject*)malloc(sizeof(jobject) * argc);
cb->direct = direct;
cb->java_arg_types[0] = cb->java_arg_types[1] = cb->java_arg_types[2] = &ffi_type_pointer;
cb->encoding = newCStringUTF8(env, encoding);
for (i=0;i < argc;i++) {
int jtype;
jclass cls = (*env)->GetObjectArrayElement(env, param_types, i);
if ((cb->conversion_flags[i] = get_conversion_flag(env, cls)) != CVT_DEFAULT) {
cb->arg_classes[i] = (*env)->NewWeakGlobalRef(env, cls);
cvt = 1;
}
else {
cb->arg_classes[i] = NULL;
}
jtype = get_jtype(env, cls);
if (jtype == -1) {
snprintf(msg, sizeof(msg), "Unsupported callback argument at index %d", i);
throw_type = EIllegalArgument;
throw_msg = msg;
goto failure_cleanup;
}
cb->arg_jtypes[i] = (char)jtype;
cb->java_arg_types[i+3] = cb->arg_types[i] = get_ffi_type(env, cls, cb->arg_jtypes[i]);
if (!cb->java_arg_types[i+3]) {
goto failure_cleanup;
}
if (cb->conversion_flags[i] == CVT_NATIVE_MAPPED
|| cb->conversion_flags[i] == CVT_POINTER_TYPE
|| cb->conversion_flags[i] == CVT_INTEGER_TYPE) {
jclass ncls;
ncls = getNativeType(env, cls);
jtype = get_jtype(env, ncls);
if (jtype == -1) {
snprintf(msg, sizeof(msg), "Unsupported NativeMapped callback argument native type at argument %d", i);
throw_type = EIllegalArgument;
throw_msg = msg;
goto failure_cleanup;
}
cb->arg_jtypes[i] = (char)jtype;
cb->java_arg_types[i+3] = &ffi_type_pointer;
cb->arg_types[i] = get_ffi_type(env, ncls, cb->arg_jtypes[i]);
if (!cb->arg_types[i]) {
goto failure_cleanup;
}
}
// Java callback method is called using varargs, so promote floats to
// double where appropriate for the platform
if (cb->arg_types[i]->type == FFI_TYPE_FLOAT) {
cb->java_arg_types[i+3] = &ffi_type_double;
cb->conversion_flags[i] = CVT_FLOAT;
cvt = 1;
}
else if (cb->java_arg_types[i+3]->type == FFI_TYPE_STRUCT) {
// All callback structure arguments are passed as a jobject
cb->java_arg_types[i+3] = &ffi_type_pointer;
}
}
if (!direct || !cvt) {
free(cb->conversion_flags);
cb->conversion_flags = NULL;
free(cb->arg_classes);
cb->arg_classes = NULL;
}
if (direct) {
cb->rflag = get_conversion_flag(env, return_type);
if (cb->rflag == CVT_NATIVE_MAPPED
|| cb->rflag == CVT_INTEGER_TYPE
|| cb->rflag == CVT_POINTER_TYPE) {
return_type = getNativeType(env, return_type);
}
}
#if defined(_WIN32) && !defined(_WIN64) && !defined(_WIN32_WCE)
if (calling_convention == CALLCONV_STDCALL) {
abi = FFI_STDCALL;
}
// Calling into Java on win32 *always* uses stdcall
java_abi = FFI_STDCALL;
#endif // _WIN32
rtype = get_jtype(env, return_type);
if (rtype == -1) {
throw_type = EIllegalArgument;
throw_msg = "Unsupported callback return type";
goto failure_cleanup;
}
ffi_rtype = get_ffi_rtype(env, return_type, (char)rtype);
if (!ffi_rtype) {
throw_type = EIllegalArgument;
throw_msg = "Error in callback return type";
goto failure_cleanup;
}
status = ffi_prep_cif(&cb->cif, abi, argc, ffi_rtype, cb->arg_types);
if (!ffi_error(env, "callback setup", status)) {
ffi_type* java_ffi_rtype = ffi_rtype;
if (cb->rflag == CVT_STRUCTURE_BYVAL
|| cb->rflag == CVT_NATIVE_MAPPED
|| cb->rflag == CVT_POINTER_TYPE
|| cb->rflag == CVT_INTEGER_TYPE) {
// Java method returns a jobject, not a struct
java_ffi_rtype = &ffi_type_pointer;
rtype = '*';
}
switch(rtype) {
#define OFFSETOF(ENV,METHOD) ((size_t)((char *)&(*(ENV))->METHOD - (char *)(*(ENV))))
case 'V': cb->fptr_offset = OFFSETOF(env, CallVoidMethod); break;
case 'Z': cb->fptr_offset = OFFSETOF(env, CallBooleanMethod); break;
case 'B': cb->fptr_offset = OFFSETOF(env, CallByteMethod); break;
case 'S': cb->fptr_offset = OFFSETOF(env, CallShortMethod); break;
case 'C': cb->fptr_offset = OFFSETOF(env, CallCharMethod); break;
case 'I': cb->fptr_offset = OFFSETOF(env, CallIntMethod); break;
case 'J': cb->fptr_offset = OFFSETOF(env, CallLongMethod); break;
case 'F': cb->fptr_offset = OFFSETOF(env, CallFloatMethod); break;
case 'D': cb->fptr_offset = OFFSETOF(env, CallDoubleMethod); break;
default: cb->fptr_offset = OFFSETOF(env, CallObjectMethod); break;
}
status = ffi_prep_cif_var(&cb->java_cif, java_abi, 2, argc+3, java_ffi_rtype, cb->java_arg_types);
if (!ffi_error(env, "callback setup (2)", status)) {
ffi_prep_closure_loc(cb->closure, &cb->cif, callback_dispatch, cb,
cb->x_closure);
#ifdef DLL_FPTRS
// Find an available function pointer and assign it
if (in_dll) {
for (i=0;i < DLL_FPTRS;i++) {
if (fn[i] == NULL) {
fn[i] = cb->x_closure;
cb->x_closure = dll_fptrs[i];
break;
}
}
if (i == DLL_FPTRS) {
throw_type = EOutOfMemory;
throw_msg = "No more DLL callback slots available";
goto failure_cleanup;
}
}
#endif
return cb;
}
}
failure_cleanup:
free_callback(env, cb);
if (throw_type) {
throwByName(env, throw_type, throw_msg);
}
return NULL;
}
