Added implementation of shared memory NDK API

Implemeneted the following APIs:

*  int ASharedMemory_create(const char *name, size_t size);
*  size_t ASharedMemory_getSize(int fd);
*  int ASharedMemory_setProt(int fd, int prot);

Test: cts-tradefed run cts --module CtsSensorTestCases \
      --test android.hardware.cts.SensorNativeTest
Bug: 5995644, 30985702

Change-Id: I645b35e67293673efce9bb90f042ec0d3b83aa42

3 files changed, 38 insertions, 0 deletions

diff --git a/native/android/Android.mk b/native/android/Android.mk
index f8405ef751a4..743732edcf26 100644
--- a/native/android/Android.mk
+++ b/native/android/Android.mk
@@ -21,6 +21,7 @@ LOCAL_SRC_FILES:= \
     net.c \
     obb.cpp \
     sensor.cpp \
+    sharedmem.cpp \
     storage_manager.cpp \
     trace.cpp \
 
diff --git a/native/android/libandroid.map.txt b/native/android/libandroid.map.txt
index f9e8fda81c09..e2623d4fd9ee 100644
--- a/native/android/libandroid.map.txt
+++ b/native/android/libandroid.map.txt
@@ -186,6 +186,9 @@ LIBANDROID {
     ASensor_getType;
     ASensor_getVendor;
     ASensor_isWakeUpSensor; # introduced=21
+    ASharedMemory_create; # introduced=26
+    ASharedMemory_getSize; # introduced=26
+    ASharedMemory_setProt; # introduced=26
     AStorageManager_delete;
     AStorageManager_getMountedObbPath;
     AStorageManager_isObbMounted;
diff --git a/native/android/sharedmem.cpp b/native/android/sharedmem.cpp
new file mode 100644
index 000000000000..9d029dfad41a
--- /dev/null
+++ b/native/android/sharedmem.cpp
@@ -0,0 +1,34 @@
+/*
+ * 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 <android/sharedmem.h>
+#include <cutils/ashmem.h>
+#include <utils/Errors.h>
+
+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);
+}