80 lines
2.5 KiB
C++
80 lines
2.5 KiB
C++
/*
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* Copyright (C) 2017 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <jni.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <android/sharedmem.h>
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#include <android/sharedmem_jni.h>
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#include <cutils/ashmem.h>
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#include <log/log.h>
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#include <utils/Errors.h>
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#include <mutex>
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static struct {
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jclass clazz;
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jmethodID getFd;
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} sSharedMemory;
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static void jniInit(JNIEnv* env) {
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static std::once_flag sJniInitialized;
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std::call_once(sJniInitialized, [](JNIEnv* env) {
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jclass clazz = env->FindClass("android/os/SharedMemory");
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LOG_ALWAYS_FATAL_IF(clazz == nullptr, "Failed to find android.os.SharedMemory");
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sSharedMemory.clazz = (jclass) env->NewGlobalRef(clazz);
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LOG_ALWAYS_FATAL_IF(sSharedMemory.clazz == nullptr,
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"Failed to create global ref of android.os.SharedMemory");
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sSharedMemory.getFd = env->GetMethodID(sSharedMemory.clazz, "getFd", "()I");
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LOG_ALWAYS_FATAL_IF(sSharedMemory.getFd == nullptr,
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"Failed to find method SharedMemory#getFd()");
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}, env);
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}
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int ASharedMemory_create(const char *name, size_t size) {
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if (size == 0) {
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return android::BAD_VALUE;
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}
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return ashmem_create_region(name, size);
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}
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size_t ASharedMemory_getSize(int fd) {
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return ashmem_valid(fd) ? ashmem_get_size_region(fd) : 0;
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}
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int ASharedMemory_setProt(int fd, int prot) {
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return ashmem_set_prot_region(fd, prot);
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}
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int ASharedMemory_dupFromJava(JNIEnv* env, jobject javaSharedMemory) {
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if (env == nullptr || javaSharedMemory == nullptr) {
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return -1;
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}
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jniInit(env);
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if (!env->IsInstanceOf(javaSharedMemory, sSharedMemory.clazz)) {
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ALOGW("ASharedMemory_dupFromJava called with object "
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"that's not an instanceof android.os.SharedMemory");
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return -1;
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}
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int fd = env->CallIntMethod(javaSharedMemory, sSharedMemory.getFd);
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if (fd != -1) {
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fd = fcntl(fd, F_DUPFD_CLOEXEC, 0);
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}
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return fd;
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}
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