ADHOC
/
replicant-frameworks_native
3
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

x86_64: Align uint64_t/int64_t structure member to 8 bytes 

To make sure the stature which pass between 32/64bit process have
same memory layout for 32/64bit.

Signed-off-by: Fengwei Yin <fengwei.yin@intel.com>
Co-Authored-by: Narayan Kamath <narayan@google.com> (Unit test only.)
Change-Id: I1bc2d12cce41ec0bc484adcaf968f274bec75c12
This commit is contained in:
Fengwei Yin 2014-05-24 05:32:09 +08:00 committed by Narayan Kamath
parent 63645c69e0
commit 83e0e425c6
4 changed files with 94 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/input/Input.h
View File

@ -170,7 +170,7 @@ struct PointerCoords {
enum { MAX_AXES = 14 }; // 14 so that sizeof(PointerCoords) == 64
// Bitfield of axes that are present in this structure.
uint64_t bits;
uint64_t bits __attribute__((aligned(8)));
// Values of axes that are stored in this structure packed in order by axis id
// for each axis that is present in the structure according to 'bits'.

22
include/input/InputTransport.h
View File

@ -39,6 +39,9 @@ namespace android {
/*
* Intermediate representation used to send input events and related signals.
*
* Note that this structure is used for IPCs so its layout must be identical
* on 64 and 32 bit processes. This is tested in StructLayout_test.cpp.
*/
struct InputMessage {
enum {
@ -49,13 +52,17 @@ struct InputMessage {
struct Header {
uint32_t type;
uint32_t padding; // 8 byte alignment for the body that follows
// We don't need this field in order to align the body below but we
// leave it here because InputMessage::size() and other functions
// compute the size of this structure as sizeof(Header) + sizeof(Body).
uint32_t padding;
} header;
// Body *must* be 8 byte aligned.
union Body {
struct Key {
uint32_t seq;
nsecs_t eventTime;
nsecs_t eventTime __attribute__((aligned(8)));
int32_t deviceId;
int32_t source;
int32_t action;
@ -64,7 +71,7 @@ struct InputMessage {
int32_t scanCode;
int32_t metaState;
int32_t repeatCount;
nsecs_t downTime;
nsecs_t downTime __attribute__((aligned(8)));
inline size_t size() const {
return sizeof(Key);
@ -73,7 +80,7 @@ struct InputMessage {
struct Motion {
uint32_t seq;
nsecs_t eventTime;
nsecs_t eventTime __attribute__((aligned(8)));
int32_t deviceId;
int32_t source;
int32_t action;
@ -81,13 +88,14 @@ struct InputMessage {
int32_t metaState;
int32_t buttonState;
int32_t edgeFlags;
nsecs_t downTime;
nsecs_t downTime __attribute__((aligned(8)));
float xOffset;
float yOffset;
float xPrecision;
float yPrecision;
uint32_t pointerCount;
struct Pointer {
// Note that PointerCoords requires 8 byte alignment.
struct Pointer{
PointerProperties properties;
PointerCoords coords;
} pointers[MAX_POINTERS];
@ -112,7 +120,7 @@ struct InputMessage {
return sizeof(Finished);
}
} finished;
} body;
} __attribute__((aligned(8))) body;
bool isValid(size_t actualSize) const;
size_t size() const;

11
libs/input/tests/Android.mk
View File

@ -29,5 +29,16 @@ $(foreach file,$(test_src_files), \
$(eval include $(BUILD_NATIVE_TEST)) \
)
# NOTE: This is a compile time test, and does not need to be
# run. All assertions are static_asserts and will fail during
# buildtime if something's wrong.
include $(CLEAR_VARS)
LOCAL_SRC_FILES := StructLayout_test.cpp
LOCAL_MODULE := StructLayout_test
LOCAL_CFLAGS := -std=c++11 -O0
LOCAL_MULTILIB := both
include $(BUILD_STATIC_LIBRARY)
# Build the manual test programs.
include $(call all-makefiles-under, $(LOCAL_PATH))

67
libs/input/tests/StructLayout_test.cpp Normal file
View File

@ -0,0 +1,67 @@
/*
* Copyright (C) 2014 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 <input/InputTransport.h>
#include <input/Input.h>
namespace android {
#define CHECK_OFFSET(type, member, expected_offset) \
static_assert((offsetof(type, member) == expected_offset), "")
struct Foo {
uint32_t dummy;
PointerCoords coords;
};
void TestPointerCoordsAlignment() {
CHECK_OFFSET(Foo, coords, 8);
}
void TestInputMessageAlignment() {
CHECK_OFFSET(InputMessage, body, 8);
CHECK_OFFSET(InputMessage::Body::Key, seq, 0);
CHECK_OFFSET(InputMessage::Body::Key, eventTime, 8);
CHECK_OFFSET(InputMessage::Body::Key, deviceId, 16);
CHECK_OFFSET(InputMessage::Body::Key, source, 20);
CHECK_OFFSET(InputMessage::Body::Key, action, 24);
CHECK_OFFSET(InputMessage::Body::Key, flags, 28);
CHECK_OFFSET(InputMessage::Body::Key, keyCode, 32);
CHECK_OFFSET(InputMessage::Body::Key, scanCode, 36);
CHECK_OFFSET(InputMessage::Body::Key, metaState, 40);
CHECK_OFFSET(InputMessage::Body::Key, repeatCount, 44);
CHECK_OFFSET(InputMessage::Body::Key, downTime, 48);
CHECK_OFFSET(InputMessage::Body::Motion, seq, 0);
CHECK_OFFSET(InputMessage::Body::Motion, eventTime, 8);
CHECK_OFFSET(InputMessage::Body::Motion, deviceId, 16);
CHECK_OFFSET(InputMessage::Body::Motion, source, 20);
CHECK_OFFSET(InputMessage::Body::Motion, action, 24);
CHECK_OFFSET(InputMessage::Body::Motion, flags, 28);
CHECK_OFFSET(InputMessage::Body::Motion, metaState, 32);
CHECK_OFFSET(InputMessage::Body::Motion, buttonState, 36);
CHECK_OFFSET(InputMessage::Body::Motion, edgeFlags, 40);
CHECK_OFFSET(InputMessage::Body::Motion, downTime, 48);
CHECK_OFFSET(InputMessage::Body::Motion, xOffset, 56);
CHECK_OFFSET(InputMessage::Body::Motion, yOffset, 60);
CHECK_OFFSET(InputMessage::Body::Motion, xPrecision, 64);
CHECK_OFFSET(InputMessage::Body::Motion, yPrecision, 68);
CHECK_OFFSET(InputMessage::Body::Motion, pointerCount, 72);
CHECK_OFFSET(InputMessage::Body::Motion, pointers, 80);
}
} // namespace android