Fence.cpp revision ba607d53c6a94ea8c4c12571980c4ad159af308b 
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
53int Fence::waitForever(unsigned int warningTimeout, const char* logname) {
54    ATRACE_CALL();
55    if (mFenceFd == -1) {
56        return NO_ERROR;
57    }
58    int err = sync_wait(mFenceFd, warningTimeout);
59    if (err == -ETIME) {
60        ALOGE("%s: fence %d didn't signal in %u ms", logname, mFenceFd,
61                warningTimeout);
62        err = sync_wait(mFenceFd, TIMEOUT_NEVER);
63    }
64    return err;
65}
66
67sp<Fence> Fence::merge(const String8& name, const sp<Fence>& f1,
68        const sp<Fence>& f2) {
69    ATRACE_CALL();
70    int result = sync_merge(name.string(), f1->mFenceFd, f2->mFenceFd);
71    if (result == -1) {
72        status_t err = -errno;
73        ALOGE("merge: sync_merge(\"%s\", %d, %d) returned an error: %s (%d)",
74                name.string(), f1->mFenceFd, f2->mFenceFd,
75                strerror(-err), err);
76        return NO_FENCE;
77    }
78    return sp<Fence>(new Fence(result));
79}
80
81int Fence::dup() const {
82    if (mFenceFd == -1) {
83        return -1;
84    }
85    return ::dup(mFenceFd);
86}
87
88size_t Fence::getFlattenedSize() const {
89    return 0;
90}
91
92size_t Fence::getFdCount() const {
93    return 1;
94}
95
96status_t Fence::flatten(void* buffer, size_t size, int fds[],
97        size_t count) const {
98    if (size != 0 || count != 1) {
99        return BAD_VALUE;
100    }
101
102    fds[0] = mFenceFd;
103    return NO_ERROR;
104}
105
106status_t Fence::unflatten(void const* buffer, size_t size, int fds[],
107        size_t count) {
108    if (size != 0 || count != 1) {
109        return BAD_VALUE;
110    }
111    if (mFenceFd != -1) {
112        // Don't unflatten if we already have a valid fd.
113        return INVALID_OPERATION;
114    }
115
116    mFenceFd = fds[0];
117    return NO_ERROR;
118}
119
120} // namespace android
121