Ytai Ben-Tsvi | 4659e18 | 2019-11-06 09:53:34 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2019 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include "android_os_HidlMemory.h" |
| 18 | #include "core_jni_helpers.h" |
| 19 | #include "android_os_NativeHandle.h" |
| 20 | |
| 21 | #define PACKAGE_PATH "android/os" |
| 22 | #define CLASS_NAME "HidlMemory" |
| 23 | #define CLASS_PATH PACKAGE_PATH "/" CLASS_NAME |
| 24 | |
| 25 | namespace android { |
| 26 | |
| 27 | namespace { |
| 28 | |
| 29 | static struct { |
| 30 | jclass clazz; |
| 31 | jfieldID nativeContext; // long |
| 32 | jmethodID constructor; // HidlMemory(String, long, NativeHandle) |
| 33 | jmethodID getName; // String HidlMemory.getName() |
| 34 | jmethodID getSize; // int HidlMemory.getSize() |
| 35 | jmethodID getHandle; // NativeHandle HidlMemory.getHandle() |
| 36 | } gFields; |
| 37 | |
| 38 | std::string stringFromJava(JNIEnv* env, jstring jstr) { |
| 39 | ScopedUtfChars s(env, jstr); |
| 40 | return s.c_str(); |
| 41 | } |
| 42 | |
| 43 | jstring stringToJava(JNIEnv* env, const std::string& cstr) { |
| 44 | return env->NewStringUTF(cstr.c_str()); |
| 45 | } |
| 46 | |
| 47 | static void nativeFinalize(JNIEnv* env, jobject jobj) { |
| 48 | jlong jNativeContext = env->GetLongField(jobj, gFields.nativeContext); |
| 49 | JHidlMemory* native = reinterpret_cast<JHidlMemory*>(jNativeContext); |
| 50 | delete native; |
| 51 | } |
| 52 | |
| 53 | static JNINativeMethod gMethods[] = { |
| 54 | {"nativeFinalize", "()V", (void*) nativeFinalize}, |
| 55 | }; |
| 56 | |
| 57 | } // namespace |
| 58 | |
| 59 | JHidlMemory::~JHidlMemory() { |
| 60 | if (mObj) { |
| 61 | // Must manually delete the underlying handle - hidl_memory doesn't own |
| 62 | // it. |
| 63 | native_handle_delete(const_cast<native_handle_t*>(mObj->handle())); |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | /* static */ const hardware::hidl_memory* JHidlMemory::fromJava(JNIEnv* env, |
| 68 | jobject jobj) { |
| 69 | // Try to get the result from cache. |
| 70 | env->MonitorEnter(jobj); |
| 71 | JHidlMemory* obj = getNativeContext(env, jobj); |
| 72 | if (!obj->mObj) { |
| 73 | // Create and cache. |
| 74 | obj->mObj = javaToNative(env, jobj); |
| 75 | } |
| 76 | env->MonitorExit(jobj); |
| 77 | return obj->mObj.get(); |
| 78 | } |
| 79 | |
| 80 | /* static */ jobject JHidlMemory::toJava(JNIEnv* env, |
| 81 | const hardware::hidl_memory& cobj) { |
| 82 | if (cobj.size() > std::numeric_limits<jlong>::max()) { |
| 83 | return nullptr; |
| 84 | } |
| 85 | jstring jname = stringToJava(env, cobj.name()); |
| 86 | jlong jsize = static_cast<jlong>(cobj.size()); |
| 87 | jobject jhandle = |
| 88 | JNativeHandle::MakeJavaNativeHandleObj(env, cobj.handle()); |
| 89 | |
| 90 | // We're sharing the handle of cobj, so the Java instance doesn't own it. |
| 91 | return env->NewObject(gFields.clazz, |
| 92 | gFields.constructor, |
| 93 | jname, |
| 94 | jsize, |
| 95 | jhandle, |
| 96 | false); |
| 97 | } |
| 98 | |
| 99 | /* static */ std::unique_ptr<hardware::hidl_memory> JHidlMemory::javaToNative( |
| 100 | JNIEnv* env, |
| 101 | jobject jobj) { |
| 102 | jstring jname = |
| 103 | static_cast<jstring>(env->CallObjectMethod(jobj, gFields.getName)); |
| 104 | jlong jsize = env->CallLongMethod(jobj, gFields.getSize); |
| 105 | jobject jhandle = env->CallObjectMethod(jobj, gFields.getHandle); |
| 106 | |
| 107 | if (jsize > std::numeric_limits<size_t>::max()) { |
| 108 | return nullptr; |
| 109 | } |
| 110 | |
| 111 | std::string cname = stringFromJava(env, jname); |
| 112 | size_t csize = jsize; |
| 113 | // We created the handle here, we're responsible to call |
| 114 | // native_handle_delete() on it. However, we don't assume ownership of the |
| 115 | // underlying fd, so we shouldn't call native_handle_close() on it. |
| 116 | native_handle_t* chandle = JNativeHandle::MakeCppNativeHandle(env, jhandle, |
| 117 | nullptr); |
| 118 | // hidl_memory doesn't take ownership of the handle here, so won't delete |
| 119 | // or close it. |
| 120 | return std::make_unique<hardware::hidl_memory>(cname, chandle, csize); |
| 121 | } |
| 122 | |
| 123 | /* static */ JHidlMemory* JHidlMemory::getNativeContext(JNIEnv* env, |
| 124 | jobject jobj) { |
| 125 | env->MonitorEnter(jobj); |
| 126 | jlong jNativeContext = env->GetLongField(jobj, gFields.nativeContext); |
| 127 | JHidlMemory* native = reinterpret_cast<JHidlMemory*>(jNativeContext); |
| 128 | if (!native) { |
| 129 | native = new JHidlMemory(); |
| 130 | env->SetLongField(jobj, |
| 131 | gFields.nativeContext, |
| 132 | reinterpret_cast<jlong>(native)); |
| 133 | } |
| 134 | env->MonitorExit(jobj); |
| 135 | return native; |
| 136 | } |
| 137 | |
| 138 | int register_android_os_HidlMemory(JNIEnv* env) { |
| 139 | jclass clazz = FindClassOrDie(env, CLASS_PATH); |
| 140 | gFields.clazz = MakeGlobalRefOrDie(env, clazz); |
| 141 | |
| 142 | gFields.nativeContext = GetFieldIDOrDie(env, clazz, "mNativeContext", "J"); |
| 143 | |
| 144 | gFields.constructor = GetMethodIDOrDie(env, |
| 145 | clazz, |
| 146 | "<init>", |
| 147 | "(Ljava/lang/String;JL" PACKAGE_PATH "/NativeHandle;)V"); |
| 148 | gFields.getName = |
| 149 | GetMethodIDOrDie(env, clazz, "getName", "()Ljava/lang/String;"); |
| 150 | gFields.getSize = GetMethodIDOrDie(env, clazz, "getSize", "()J"); |
| 151 | gFields.getHandle = GetMethodIDOrDie(env, |
| 152 | clazz, |
| 153 | "getHandle", |
| 154 | "()L" PACKAGE_PATH "/NativeHandle;"); |
| 155 | |
| 156 | RegisterMethodsOrDie(env, CLASS_PATH, gMethods, NELEM(gMethods)); |
| 157 | |
| 158 | return 0; |
| 159 | } |
| 160 | |
| 161 | } // namespace android |
| 162 | |