Fence.cpp revision d83d67b5d5e98b7f0bdf54b68f6ea28fa4905a33 
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        status_t err = -errno;
59        ALOGE("merge: sync_merge(\"%s\", %d, %d) returned an error: %s (%d)",
60                name.string(), f1->mFenceFd, f2->mFenceFd,
61                strerror(-err), err);
62        return NO_FENCE;
63    }
64    return sp<Fence>(new Fence(result));
65}
66
67int Fence::dup() const {
68    if (mFenceFd == -1) {
69        return -1;
70    }
71    return ::dup(mFenceFd);
72}
73
74size_t Fence::getFlattenedSize() const {
75    return 0;
76}
77
78size_t Fence::getFdCount() const {
79    return 1;
80}
81
82status_t Fence::flatten(void* buffer, size_t size, int fds[],
83        size_t count) const {
84    if (size != 0 || count != 1) {
85        return BAD_VALUE;
86    }
87
88    fds[0] = mFenceFd;
89    return NO_ERROR;
90}
91
92status_t Fence::unflatten(void const* buffer, size_t size, int fds[],
93        size_t count) {
94    if (size != 0 || count != 1) {
95        return BAD_VALUE;
96    }
97    if (mFenceFd != -1) {
98        // Don't unflatten if we already have a valid fd.
99        return INVALID_OPERATION;
100    }
101
102    mFenceFd = fds[0];
103    return NO_ERROR;
104}
105
106} // namespace android
107