Fence.cpp revision 82dbc7429f5f9f2b303b31dc5b9f2bfd1bbe6add 
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 // This is needed for stdint.h to define INT64_MAX in C++
22 #define __STDC_LIMIT_MACROS
23
24#include <sync/sync.h>
25#include <ui/Fence.h>
26#include <unistd.h>
27#include <utils/Log.h>
28#include <utils/Trace.h>
29
30namespace android {
31
32const sp<Fence> Fence::NO_FENCE = sp<Fence>();
33
34Fence::Fence() :
35    mFenceFd(-1) {
36}
37
38Fence::Fence(int fenceFd) :
39    mFenceFd(fenceFd) {
40}
41
42Fence::~Fence() {
43    if (mFenceFd != -1) {
44        close(mFenceFd);
45    }
46}
47
48status_t Fence::wait(unsigned int timeout) {
49    ATRACE_CALL();
50    if (mFenceFd == -1) {
51        return NO_ERROR;
52    }
53    int err = sync_wait(mFenceFd, timeout);
54    return err < 0 ? -errno : status_t(NO_ERROR);
55}
56
57status_t Fence::waitForever(unsigned int warningTimeout, const char* logname) {
58    ATRACE_CALL();
59    if (mFenceFd == -1) {
60        return NO_ERROR;
61    }
62    int err = sync_wait(mFenceFd, warningTimeout);
63    if (err < 0 && errno == ETIME) {
64        ALOGE("%s: fence %d didn't signal in %u ms", logname, mFenceFd,
65                warningTimeout);
66        err = sync_wait(mFenceFd, TIMEOUT_NEVER);
67    }
68    return err < 0 ? -errno : status_t(NO_ERROR);
69}
70
71sp<Fence> Fence::merge(const String8& name, const sp<Fence>& f1,
72        const sp<Fence>& f2) {
73    ATRACE_CALL();
74    int result = sync_merge(name.string(), f1->mFenceFd, f2->mFenceFd);
75    if (result == -1) {
76        status_t err = -errno;
77        ALOGE("merge: sync_merge(\"%s\", %d, %d) returned an error: %s (%d)",
78                name.string(), f1->mFenceFd, f2->mFenceFd,
79                strerror(-err), err);
80        return NO_FENCE;
81    }
82    return sp<Fence>(new Fence(result));
83}
84
85int Fence::dup() const {
86    if (mFenceFd == -1) {
87        return -1;
88    }
89    return ::dup(mFenceFd);
90}
91
92nsecs_t Fence::getSignalTime() const {
93    if (mFenceFd == -1) {
94        return -1;
95    }
96
97    struct sync_fence_info_data* finfo = sync_fence_info(mFenceFd);
98    if (finfo == NULL) {
99        ALOGE("sync_fence_info returned NULL for fd %d", mFenceFd);
100        return -1;
101    }
102    if (finfo->status != 1) {
103        return INT64_MAX;
104    }
105
106    struct sync_pt_info* pinfo = NULL;
107    uint64_t timestamp = 0;
108    while ((pinfo = sync_pt_info(finfo, pinfo)) != NULL) {
109        if (pinfo->timestamp_ns > timestamp) {
110            timestamp = pinfo->timestamp_ns;
111        }
112    }
113    sync_fence_info_free(finfo);
114
115    return nsecs_t(timestamp);
116}
117
118size_t Fence::getFlattenedSize() const {
119    return 0;
120}
121
122size_t Fence::getFdCount() const {
123    return 1;
124}
125
126status_t Fence::flatten(void* buffer, size_t size, int fds[],
127        size_t count) const {
128    if (size != 0 || count != 1) {
129        return BAD_VALUE;
130    }
131
132    fds[0] = mFenceFd;
133    return NO_ERROR;
134}
135
136status_t Fence::unflatten(void const* buffer, size_t size, int fds[],
137        size_t count) {
138    if (size != 0 || count != 1) {
139        return BAD_VALUE;
140    }
141    if (mFenceFd != -1) {
142        // Don't unflatten if we already have a valid fd.
143        return INVALID_OPERATION;
144    }
145
146    mFenceFd = fds[0];
147    return NO_ERROR;
148}
149
150} // namespace android
151