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/*
* Copyright (C) 2017 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 <jni.h>
#include <fcntl.h>
#include <unistd.h>
#include <android/sharedmem.h>
#include <android/sharedmem_jni.h>
#include <cutils/ashmem.h>
#include <log/log.h>
#include <utils/Errors.h>
#include <mutex>
static struct {
jclass clazz;
jmethodID getFd;
} sSharedMemory;
static void jniInit(JNIEnv* env) {
static std::once_flag sJniInitialized;
std::call_once(sJniInitialized, [](JNIEnv* env) {
jclass clazz = env->FindClass("android/os/SharedMemory");
LOG_ALWAYS_FATAL_IF(clazz == nullptr, "Failed to find android.os.SharedMemory");
sSharedMemory.clazz = (jclass) env->NewGlobalRef(clazz);
LOG_ALWAYS_FATAL_IF(sSharedMemory.clazz == nullptr,
"Failed to create global ref of android.os.SharedMemory");
sSharedMemory.getFd = env->GetMethodID(sSharedMemory.clazz, "getFd", "()I");
LOG_ALWAYS_FATAL_IF(sSharedMemory.getFd == nullptr,
"Failed to find method SharedMemory#getFd()");
}, env);
}
int ASharedMemory_create(const char *name, size_t size) {
if (size == 0) {
return android::BAD_VALUE;
}
return ashmem_create_region(name, size);
}
size_t ASharedMemory_getSize(int fd) {
return ashmem_valid(fd) ? ashmem_get_size_region(fd) : 0;
}
int ASharedMemory_setProt(int fd, int prot) {
return ashmem_set_prot_region(fd, prot);
}
int ASharedMemory_dupFromJava(JNIEnv* env, jobject javaSharedMemory) {
if (env == nullptr || javaSharedMemory == nullptr) {
return -1;
}
jniInit(env);
if (!env->IsInstanceOf(javaSharedMemory, sSharedMemory.clazz)) {
ALOGW("ASharedMemory_dupFromJava called with object "
"that's not an instanceof android.os.SharedMemory");
return -1;
}
int fd = env->CallIntMethod(javaSharedMemory, sSharedMemory.getFd);
if (fd != -1) {
fd = fcntl(fd, F_DUPFD_CLOEXEC, 0);
}
return fd;
}