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 #include <ui/Fence.h>
18
19 #define LOG_TAG "Fence"
20 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
21 //#define LOG_NDEBUG 0
22
23 // We would eliminate the non-conforming zero-length array, but we can't since
24 // this is effectively included from the Linux kernel
25 #pragma clang diagnostic push
26 #pragma clang diagnostic ignored "-Wzero-length-array"
27 #include <sync/sync.h>
28 #pragma clang diagnostic pop
29
30 #include <sys/types.h>
31 #include <unistd.h>
32 #include <utils/Log.h>
33 #include <utils/String8.h>
34 #include <utils/Trace.h>
35
36 namespace android {
37
38 const sp<Fence> Fence::NO_FENCE = sp<Fence>(new Fence);
39
Fence(int fenceFd)40 Fence::Fence(int fenceFd) :
41 mFenceFd(fenceFd) {
42 }
43
Fence(base::unique_fd fenceFd)44 Fence::Fence(base::unique_fd fenceFd) :
45 mFenceFd(std::move(fenceFd)) {
46 }
47
wait(int timeout)48 status_t Fence::wait(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
waitForever(const char * logname)57 status_t Fence::waitForever(const char* logname) {
58 ATRACE_CALL();
59 if (mFenceFd == -1) {
60 return NO_ERROR;
61 }
62 int warningTimeout = 3000;
63 int err = sync_wait(mFenceFd, warningTimeout);
64 if (err < 0 && errno == ETIME) {
65 ALOGE("%s: fence %d didn't signal in %u ms", logname, mFenceFd.get(),
66 warningTimeout);
67 err = sync_wait(mFenceFd, TIMEOUT_NEVER);
68 }
69 return err < 0 ? -errno : status_t(NO_ERROR);
70 }
71
merge(const char * name,const sp<Fence> & f1,const sp<Fence> & f2)72 sp<Fence> Fence::merge(const char* name, const sp<Fence>& f1,
73 const sp<Fence>& f2) {
74 ATRACE_CALL();
75 int result;
76 // Merge the two fences. In the case where one of the fences is not a
77 // valid fence (e.g. NO_FENCE) we merge the one valid fence with itself so
78 // that a new fence with the given name is created.
79 if (f1->isValid() && f2->isValid()) {
80 result = sync_merge(name, f1->mFenceFd, f2->mFenceFd);
81 } else if (f1->isValid()) {
82 result = sync_merge(name, f1->mFenceFd, f1->mFenceFd);
83 } else if (f2->isValid()) {
84 result = sync_merge(name, f2->mFenceFd, f2->mFenceFd);
85 } else {
86 return NO_FENCE;
87 }
88 if (result == -1) {
89 status_t err = -errno;
90 ALOGE("merge: sync_merge(\"%s\", %d, %d) returned an error: %s (%d)",
91 name, f1->mFenceFd.get(), f2->mFenceFd.get(),
92 strerror(-err), err);
93 return NO_FENCE;
94 }
95 return sp<Fence>(new Fence(result));
96 }
97
merge(const String8 & name,const sp<Fence> & f1,const sp<Fence> & f2)98 sp<Fence> Fence::merge(const String8& name, const sp<Fence>& f1,
99 const sp<Fence>& f2) {
100 return merge(name.string(), f1, f2);
101 }
102
dup() const103 int Fence::dup() const {
104 return ::dup(mFenceFd);
105 }
106
getSignalTime() const107 nsecs_t Fence::getSignalTime() const {
108 if (mFenceFd == -1) {
109 return SIGNAL_TIME_INVALID;
110 }
111
112 struct sync_file_info* finfo = sync_file_info(mFenceFd);
113 if (finfo == nullptr) {
114 ALOGE("sync_file_info returned NULL for fd %d", mFenceFd.get());
115 return SIGNAL_TIME_INVALID;
116 }
117 if (finfo->status != 1) {
118 sync_file_info_free(finfo);
119 return SIGNAL_TIME_PENDING;
120 }
121
122 uint64_t timestamp = 0;
123 struct sync_fence_info* pinfo = sync_get_fence_info(finfo);
124 for (size_t i = 0; i < finfo->num_fences; i++) {
125 if (pinfo[i].timestamp_ns > timestamp) {
126 timestamp = pinfo[i].timestamp_ns;
127 }
128 }
129
130 sync_file_info_free(finfo);
131 return nsecs_t(timestamp);
132 }
133
getFlattenedSize() const134 size_t Fence::getFlattenedSize() const {
135 return 4;
136 }
137
getFdCount() const138 size_t Fence::getFdCount() const {
139 return isValid() ? 1 : 0;
140 }
141
flatten(void * & buffer,size_t & size,int * & fds,size_t & count) const142 status_t Fence::flatten(void*& buffer, size_t& size, int*& fds, size_t& count) const {
143 if (size < getFlattenedSize() || count < getFdCount()) {
144 return NO_MEMORY;
145 }
146 // Cast to uint32_t since the size of a size_t can vary between 32- and
147 // 64-bit processes
148 FlattenableUtils::write(buffer, size, static_cast<uint32_t>(getFdCount()));
149 if (isValid()) {
150 *fds++ = mFenceFd;
151 count--;
152 }
153 return NO_ERROR;
154 }
155
unflatten(void const * & buffer,size_t & size,int const * & fds,size_t & count)156 status_t Fence::unflatten(void const*& buffer, size_t& size, int const*& fds, size_t& count) {
157 if (mFenceFd != -1) {
158 // Don't unflatten if we already have a valid fd.
159 return INVALID_OPERATION;
160 }
161
162 if (size < getFlattenedSize()) {
163 return NO_MEMORY;
164 }
165
166 uint32_t numFds;
167 FlattenableUtils::read(buffer, size, numFds);
168
169 if (numFds > 1) {
170 return BAD_VALUE;
171 }
172
173 if (count < numFds) {
174 return NO_MEMORY;
175 }
176
177 if (numFds) {
178 mFenceFd.reset(*fds++);
179 count--;
180 }
181
182 return NO_ERROR;
183 }
184
185 } // namespace android
186