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/*
* Copyright (C) 2019 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.
*/
#include "android_os_HidlMemory.h"
#include "core_jni_helpers.h"
#include "android_os_NativeHandle.h"
#define PACKAGE_PATH "android/os"
#define CLASS_NAME "HidlMemory"
#define CLASS_PATH PACKAGE_PATH "/" CLASS_NAME
namespace android {
namespace {
static struct {
jclass clazz;
jfieldID nativeContext; // long
jmethodID constructor; // HidlMemory(String, long, NativeHandle)
jmethodID getName; // String HidlMemory.getName()
jmethodID getSize; // int HidlMemory.getSize()
jmethodID getHandle; // NativeHandle HidlMemory.getHandle()
} gFields;
std::string stringFromJava(JNIEnv* env, jstring jstr) {
ScopedUtfChars s(env, jstr);
return s.c_str();
}
jstring stringToJava(JNIEnv* env, const std::string& cstr) {
return env->NewStringUTF(cstr.c_str());
}
static void nativeFinalize(JNIEnv* env, jobject jobj) {
jlong jNativeContext = env->GetLongField(jobj, gFields.nativeContext);
JHidlMemory* native = reinterpret_cast<JHidlMemory*>(jNativeContext);
delete native;
}
static JNINativeMethod gMethods[] = {
{"nativeFinalize", "()V", (void*) nativeFinalize},
};
} // namespace
JHidlMemory::~JHidlMemory() {
if (mObj) {
// Must manually delete the underlying handle - hidl_memory doesn't own
// it.
native_handle_delete(const_cast<native_handle_t*>(mObj->handle()));
}
}
/* static */ const hardware::hidl_memory* JHidlMemory::fromJava(JNIEnv* env,
jobject jobj) {
// Try to get the result from cache.
env->MonitorEnter(jobj);
JHidlMemory* obj = getNativeContext(env, jobj);
if (!obj->mObj) {
// Create and cache.
obj->mObj = javaToNative(env, jobj);
}
env->MonitorExit(jobj);
return obj->mObj.get();
}
/* static */ jobject JHidlMemory::toJava(JNIEnv* env,
const hardware::hidl_memory& cobj) {
if (cobj.size() > std::numeric_limits<jlong>::max()) {
return nullptr;
}
jstring jname = stringToJava(env, cobj.name());
jlong jsize = static_cast<jlong>(cobj.size());
jobject jhandle =
JNativeHandle::MakeJavaNativeHandleObj(env, cobj.handle());
// We're sharing the handle of cobj, so the Java instance doesn't own it.
return env->NewObject(gFields.clazz,
gFields.constructor,
jname,
jsize,
jhandle,
false);
}
/* static */ std::unique_ptr<hardware::hidl_memory> JHidlMemory::javaToNative(
JNIEnv* env,
jobject jobj) {
jstring jname =
static_cast<jstring>(env->CallObjectMethod(jobj, gFields.getName));
jlong jsize = env->CallLongMethod(jobj, gFields.getSize);
jobject jhandle = env->CallObjectMethod(jobj, gFields.getHandle);
if (jsize > std::numeric_limits<size_t>::max()) {
return nullptr;
}
std::string cname = stringFromJava(env, jname);
size_t csize = jsize;
// We created the handle here, we're responsible to call
// native_handle_delete() on it. However, we don't assume ownership of the
// underlying fd, so we shouldn't call native_handle_close() on it.
native_handle_t* chandle = JNativeHandle::MakeCppNativeHandle(env, jhandle,
nullptr);
// hidl_memory doesn't take ownership of the handle here, so won't delete
// or close it.
return std::make_unique<hardware::hidl_memory>(cname, chandle, csize);
}
/* static */ JHidlMemory* JHidlMemory::getNativeContext(JNIEnv* env,
jobject jobj) {
env->MonitorEnter(jobj);
jlong jNativeContext = env->GetLongField(jobj, gFields.nativeContext);
JHidlMemory* native = reinterpret_cast<JHidlMemory*>(jNativeContext);
if (!native) {
native = new JHidlMemory();
env->SetLongField(jobj,
gFields.nativeContext,
reinterpret_cast<jlong>(native));
}
env->MonitorExit(jobj);
return native;
}
int register_android_os_HidlMemory(JNIEnv* env) {
jclass clazz = FindClassOrDie(env, CLASS_PATH);
gFields.clazz = MakeGlobalRefOrDie(env, clazz);
gFields.nativeContext = GetFieldIDOrDie(env, clazz, "mNativeContext", "J");
gFields.constructor = GetMethodIDOrDie(env,
clazz,
"<init>",
"(Ljava/lang/String;JL" PACKAGE_PATH "/NativeHandle;)V");
gFields.getName =
GetMethodIDOrDie(env, clazz, "getName", "()Ljava/lang/String;");
gFields.getSize = GetMethodIDOrDie(env, clazz, "getSize", "()J");
gFields.getHandle = GetMethodIDOrDie(env,
clazz,
"getHandle",
"()L" PACKAGE_PATH "/NativeHandle;");
RegisterMethodsOrDie(env, CLASS_PATH, gMethods, NELEM(gMethods));
return 0;
}
} // namespace android
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