Fence.cpp revision ef19414bd8b77a26f5751f3845be79025a8263fe 
1/*
2 * Copyright (C) 2012 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#define LOG_TAG "Fence"
18#define ATRACE_TAG ATRACE_TAG_GRAPHICS
19//#define LOG_NDEBUG 0
20
21#include <sync/sync.h>
22#include <ui/Fence.h>
23#include <unistd.h>
24#include <utils/Log.h>
25#include <utils/Trace.h>
26
27namespace android {
28
29const sp<Fence> Fence::NO_FENCE = sp<Fence>();
30
31Fence::Fence() :
32    mFenceFd(-1) {
33}
34
35Fence::Fence(int fenceFd) :
36    mFenceFd(fenceFd) {
37}
38
39Fence::~Fence() {
40    if (mFenceFd != -1) {
41        close(mFenceFd);
42    }
43}
44
45int Fence::wait(unsigned int timeout) {
46    ATRACE_CALL();
47    if (mFenceFd == -1) {
48        return NO_ERROR;
49    }
50    return sync_wait(mFenceFd, timeout);
51}
52
53sp<Fence> Fence::merge(const String8& name, const sp<Fence>& f1,
54        const sp<Fence>& f2) {
55    ATRACE_CALL();
56    int result = sync_merge(name.string(), f1->mFenceFd, f2->mFenceFd);
57    if (result == -1) {
58        ALOGE("merge: sync_merge returned an error: %s (%d)", strerror(-errno),
59                errno);
60        return NO_FENCE;
61    }
62    return sp<Fence>(new Fence(result));
63}
64
65size_t Fence::getFlattenedSize() const {
66    return 0;
67}
68
69size_t Fence::getFdCount() const {
70    return 1;
71}
72
73status_t Fence::flatten(void* buffer, size_t size, int fds[],
74        size_t count) const {
75    if (size != 0 || count != 1) {
76        return BAD_VALUE;
77    }
78
79    fds[0] = mFenceFd;
80    return NO_ERROR;
81}
82
83status_t Fence::unflatten(void const* buffer, size_t size, int fds[],
84        size_t count) {
85    if (size != 0 || count != 1) {
86        return BAD_VALUE;
87    }
88    if (mFenceFd != -1) {
89        // Don't unflatten if we already have a valid fd.
90        return INVALID_OPERATION;
91    }
92
93    mFenceFd = fds[0];
94    return NO_ERROR;
95}
96
97} // namespace android
98