1 /* 2 * Copyright (C) 2019 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 #ifndef ANDROID_FENCE_H 18 #define ANDROID_FENCE_H 19 20 #include <utils/String8.h> 21 #include <utils/RefBase.h> 22 23 typedef int64_t nsecs_t; 24 25 namespace android { 26 27 class Fence : public LightRefBase<Fence> { 28 public: Fence()29 Fence() { } Fence(int)30 Fence(int) { } 31 static const sp<Fence> NO_FENCE; 32 static constexpr nsecs_t SIGNAL_TIME_PENDING = INT64_MAX; 33 static constexpr nsecs_t SIGNAL_TIME_INVALID = -1; merge(const char * name,const sp<Fence> & f1,const sp<Fence> & f2)34 static sp<Fence> merge(const char* name, const sp<Fence>& f1, const sp<Fence>& f2) { 35 return NO_FENCE; 36 } 37 merge(const String8 & name,const sp<Fence> & f1,const sp<Fence> & f2)38 static sp<Fence> merge(const String8& name, const sp<Fence>& f1, const sp<Fence>& f2) { 39 return NO_FENCE; 40 } 41 42 enum class Status { 43 Invalid, // Fence is invalid 44 Unsignaled, // Fence is valid but has not yet signaled 45 Signaled, // Fence is valid and has signaled 46 }; 47 wait(int timeout)48 status_t wait(int timeout) { return OK; } 49 waitForever(const char * logname)50 status_t waitForever(const char* logname) { return OK; } 51 dup()52 int dup() const { return 0; } 53 getStatus()54 inline Status getStatus() { 55 // The sync_wait call underlying wait() has been measured to be 56 // significantly faster than the sync_fence_info call underlying 57 // getSignalTime(), which might otherwise appear to be the more obvious 58 // way to check whether a fence has signaled. 59 switch (wait(0)) { 60 case NO_ERROR: 61 return Status::Signaled; 62 case -ETIME: 63 return Status::Unsignaled; 64 default: 65 return Status::Invalid; 66 } 67 } 68 }; 69 70 } // namespace android 71 72 #endif // ANDROID_FENCE_H 73