1/* 2 * Copyright (C) 2009 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#ifndef NATIVE_HANDLE_H_ 18#define NATIVE_HANDLE_H_ 19 20#include <stdalign.h> 21 22#ifdef __cplusplus 23extern "C" { 24#endif 25 26/* Declare a char array for use with native_handle_init */ 27#define NATIVE_HANDLE_DECLARE_STORAGE(name, maxFds, maxInts) \ 28 alignas(native_handle_t) char name[ \ 29 sizeof(native_handle_t) + sizeof(int) * (maxFds + maxInts)] 30 31typedef struct native_handle 32{ 33 int version; /* sizeof(native_handle_t) */ 34 int numFds; /* number of file-descriptors at &data[0] */ 35 int numInts; /* number of ints at &data[numFds] */ 36#if defined(__clang__) 37#pragma clang diagnostic push 38#pragma clang diagnostic ignored "-Wzero-length-array" 39#endif 40 int data[0]; /* numFds + numInts ints */ 41#if defined(__clang__) 42#pragma clang diagnostic pop 43#endif 44} native_handle_t; 45 46/* 47 * native_handle_close 48 * 49 * closes the file descriptors contained in this native_handle_t 50 * 51 * return 0 on success, or a negative error code on failure 52 * 53 */ 54int native_handle_close(const native_handle_t* h); 55 56/* 57 * native_handle_init 58 * 59 * Initializes a native_handle_t from storage. storage must be declared with 60 * NATIVE_HANDLE_DECLARE_STORAGE. numFds and numInts must not respectively 61 * exceed maxFds and maxInts used to declare the storage. 62 */ 63native_handle_t* native_handle_init(char* storage, int numFds, int numInts); 64 65/* 66 * native_handle_create 67 * 68 * creates a native_handle_t and initializes it. must be destroyed with 69 * native_handle_delete(). 70 * 71 */ 72native_handle_t* native_handle_create(int numFds, int numInts); 73 74/* 75 * native_handle_clone 76 * 77 * creates a native_handle_t and initializes it from another native_handle_t. 78 * Must be destroyed with native_handle_delete(). 79 * 80 */ 81native_handle_t* native_handle_clone(const native_handle_t* handle); 82 83/* 84 * native_handle_delete 85 * 86 * frees a native_handle_t allocated with native_handle_create(). 87 * This ONLY frees the memory allocated for the native_handle_t, but doesn't 88 * close the file descriptors; which can be achieved with native_handle_close(). 89 * 90 * return 0 on success, or a negative error code on failure 91 * 92 */ 93int native_handle_delete(native_handle_t* h); 94 95 96#ifdef __cplusplus 97} 98#endif 99 100#endif /* NATIVE_HANDLE_H_ */ 101