| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| /* |
| * This uses the FFI (Foreign Function Interface) library to abstract away |
| * the system-dependent stuff. The FFI code is slower than a custom |
| * assembly version, but has the distinct advantage of having been |
| * written already for several platforms. |
| */ |
| #include "Dalvik.h" |
| #include "ffi.h" |
| |
| #include <assert.h> |
| |
| /* |
| * Convert a signature type character to an FFI type. |
| */ |
| static ffi_type* getFfiType(char sigType) |
| { |
| switch (sigType) { |
| case 'V': return &ffi_type_void; |
| case 'F': return &ffi_type_float; |
| case 'D': return &ffi_type_double; |
| case 'J': return &ffi_type_sint64; |
| case '[': |
| case 'L': return &ffi_type_pointer; |
| default: return &ffi_type_uint32; |
| } |
| } |
| |
| /* |
| * Call "func" with the specified arguments. |
| * |
| * The second argument to JNI native functions is either the object (the |
| * "this" pointer) or, for static functions, a pointer to the class object. |
| * The Dalvik instructions will push "this" into argv[0], but it's up to |
| * us to insert the class object. |
| * |
| * Because there is no such thing in as a null "this" pointer, we use |
| * the non-NULL state of "clazz" to determine whether or not it's static. |
| * |
| * For maximum efficiency we should compute the CIF once and save it with |
| * the method. However, this requires storing the data with every native |
| * method. Since the goal is to have custom assembly versions of this |
| * on the platforms where performance matters, I'm recomputing the CIF on |
| * every call. |
| */ |
| void dvmPlatformInvoke(void* pEnv, ClassObject* clazz, int argInfo, int argc, |
| const u4* argv, const char* shorty, void* func, JValue* pReturn) |
| { |
| const int kMaxArgs = argc+2; /* +1 for env, maybe +1 for clazz */ |
| ffi_cif cif; |
| ffi_type* types[kMaxArgs]; |
| void* values[kMaxArgs]; |
| ffi_type* retType; |
| const char* sig; |
| char sigByte; |
| int srcArg, dstArg; |
| |
| types[0] = &ffi_type_pointer; |
| values[0] = &pEnv; |
| |
| types[1] = &ffi_type_pointer; |
| if (clazz != NULL) { |
| values[1] = &clazz; |
| srcArg = 0; |
| } else { |
| values[1] = (void*) argv++; |
| srcArg = 1; |
| } |
| dstArg = 2; |
| |
| /* |
| * Scan the types out of the short signature. Use them to fill out the |
| * "types" array. Store the start address of the argument in "values". |
| */ |
| retType = getFfiType(*shorty); |
| while ((sigByte = *++shorty) != '\0') { |
| types[dstArg] = getFfiType(sigByte); |
| values[dstArg++] = (void*) argv++; |
| if (sigByte == 'D' || sigByte == 'J') |
| argv++; |
| } |
| |
| /* |
| * Prep the CIF (Call InterFace object). |
| */ |
| if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, dstArg, retType, types) != FFI_OK) { |
| LOGE("ffi_prep_cif failed\n"); |
| dvmAbort(); |
| } |
| |
| ffi_call(&cif, FFI_FN(func), pReturn, values); |
| } |
| |