1 /*
2 * Copyright (C) 2017 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 <jni.h>
18
19 #include <android/sharedmem_jni.h>
20
21 #include <sys/mman.h>
22 #include <unistd.h>
23
nWriteByte(JNIEnv * env,jobject,jobject jSharedMemory,jint index,jbyte value)24 jboolean nWriteByte(JNIEnv* env, jobject, jobject jSharedMemory, jint index, jbyte value) {
25 int fd = ASharedMemory_dupFromJava(env, jSharedMemory);
26 if (fd == -1) return false;
27 void* addr = mmap(nullptr, 1, PROT_READ | PROT_WRITE, MAP_SHARED, fd, index);
28 if (addr == nullptr) {
29 close(fd);
30 return false;
31 }
32 reinterpret_cast<int8_t*>(addr)[0] = value;
33 munmap(addr, 1);
34 close(fd);
35 return true;
36 }
37
38 static JNINativeMethod gMethods[] = {
39 { "nWriteByte", "(Landroid/os/SharedMemory;IB)Z", (void *) nWriteByte },
40 };
41
register_android_os_cts_SharedMemoryTest(JNIEnv * env)42 int register_android_os_cts_SharedMemoryTest(JNIEnv* env)
43 {
44 jclass clazz = env->FindClass("android/os/cts/SharedMemoryTest");
45
46 return env->RegisterNatives(clazz, gMethods,
47 sizeof(gMethods) / sizeof(JNINativeMethod));
48 }
49