From b843791b61ee3912515ce3f82f296823c17e10c9 Mon Sep 17 00:00:00 2001 From: Chia-I Wu Date: Fri, 23 Sep 2016 11:17:11 +0800 Subject: Add native_handle_init HIDL requires file descriptors to be wrapped in native_handle_t. We want a low overhead way to do that when the number of file descriptors is known at compile time. Instead of // wrap an fd in native_handle_t native_handle_t* fd_handle = native_handle_create(1, 0); if (!fd_handle) { // clean up and return error } fd_handle->data[0] = fd; hidl_cb(..., fd_handle); native_handle_delete(fd_handle); this change adds native_handle_init to allow for // wrap an fd in native_handle_t NATIVE_HANDLE_DECLARE_STORAGE(fd_storage, 1, 0); native_handle_t* fd_handle = native_handle_init(fd_storage, 1, 0); fd_handle->data[0] = fd; hidl_cb(..., fd_handle); Test: make libcutils Bug: 32021609 Change-Id: If1fd07482243d37492fdea57c602a1b13c8953cc --- include/cutils/native_handle.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/cutils') diff --git a/include/cutils/native_handle.h b/include/cutils/native_handle.h index 813dadc7c..7d6a98802 100644 --- a/include/cutils/native_handle.h +++ b/include/cutils/native_handle.h @@ -17,10 +17,17 @@ #ifndef NATIVE_HANDLE_H_ #define NATIVE_HANDLE_H_ +#include + #ifdef __cplusplus extern "C" { #endif +/* Declare a char array for use with native_handle_init */ +#define NATIVE_HANDLE_DECLARE_STORAGE(name, maxFds, maxInts) \ + alignas(native_handle_t) char name[ \ + sizeof(native_handle_t) + sizeof(int) * (maxFds + maxInts)] + typedef struct native_handle { int version; /* sizeof(native_handle_t) */ @@ -46,6 +53,14 @@ typedef struct native_handle */ int native_handle_close(const native_handle_t* h); +/* + * native_handle_init + * + * Initializes a native_handle_t from storage. storage must be declared with + * NATIVE_HANDLE_DECLARE_STORAGE. numFds and numInts must not respectively + * exceed maxFds and maxInts used to declare the storage. + */ +native_handle_t* native_handle_init(char* storage, int numFds, int numInts); /* * native_handle_create -- cgit v1.2.3