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 #ifndef ANDROID_FENCE_H 18 #define ANDROID_FENCE_H 19 20 #include <stdint.h> 21 #include <sys/types.h> 22 23 #include <ui/ANativeObjectBase.h> 24 #include <ui/PixelFormat.h> 25 #include <ui/Rect.h> 26 #include <utils/Flattenable.h> 27 #include <utils/String8.h> 28 #include <utils/Timers.h> 29 30 struct ANativeWindowBuffer; 31 32 namespace android { 33 34 // =========================================================================== 35 // Fence 36 // =========================================================================== 37 38 class Fence 39 : public LightRefBase<Fence>, public Flattenable<Fence> 40 { 41 public: 42 static const sp<Fence> NO_FENCE; 43 44 // TIMEOUT_NEVER may be passed to the wait method to indicate that it 45 // should wait indefinitely for the fence to signal. 46 enum { TIMEOUT_NEVER = -1 }; 47 48 // Construct a new Fence object with an invalid file descriptor. This 49 // should be done when the Fence object will be set up by unflattening 50 // serialized data. 51 Fence(); 52 53 // Construct a new Fence object to manage a given fence file descriptor. 54 // When the new Fence object is destructed the file descriptor will be 55 // closed. 56 Fence(int fenceFd); 57 58 // Check whether the Fence has an open fence file descriptor. Most Fence 59 // methods treat an invalid file descriptor just like a valid fence that 60 // is already signalled, so using this is usually not necessary. 61 bool isValid() const { return mFenceFd != -1; } 62 63 // wait waits for up to timeout milliseconds for the fence to signal. If 64 // the fence signals then NO_ERROR is returned. If the timeout expires 65 // before the fence signals then -ETIME is returned. A timeout of 66 // TIMEOUT_NEVER may be used to indicate that the call should wait 67 // indefinitely for the fence to signal. 68 status_t wait(unsigned int timeout); 69 70 // waitForever is a convenience function for waiting forever for a fence to 71 // signal (just like wait(TIMEOUT_NEVER)), but issuing an error to the 72 // system log and fence state to the kernel log if the wait lasts longer 73 // than a warning timeout. 74 // The logname argument should be a string identifying 75 // the caller and will be included in the log message. 76 status_t waitForever(const char* logname); 77 78 // merge combines two Fence objects, creating a new Fence object that 79 // becomes signaled when both f1 and f2 are signaled (even if f1 or f2 is 80 // destroyed before it becomes signaled). The name argument specifies the 81 // human-readable name to associated with the new Fence object. 82 static sp<Fence> merge(const String8& name, const sp<Fence>& f1, 83 const sp<Fence>& f2); 84 85 // Return a duplicate of the fence file descriptor. The caller is 86 // responsible for closing the returned file descriptor. On error, -1 will 87 // be returned and errno will indicate the problem. 88 int dup() const; 89 90 // getSignalTime returns the system monotonic clock time at which the 91 // fence transitioned to the signaled state. If the fence is not signaled 92 // then INT64_MAX is returned. If the fence is invalid or if an error 93 // occurs then -1 is returned. 94 nsecs_t getSignalTime() const; 95 96 // Flattenable interface 97 size_t getFlattenedSize() const; 98 size_t getFdCount() const; 99 status_t flatten(void*& buffer, size_t& size, int*& fds, size_t& count) const; 100 status_t unflatten(void const*& buffer, size_t& size, int const*& fds, size_t& count); 101 102 private: 103 // Only allow instantiation using ref counting. 104 friend class LightRefBase<Fence>; 105 ~Fence(); 106 107 // Disallow copying 108 Fence(const Fence& rhs); 109 Fence& operator = (const Fence& rhs); 110 const Fence& operator = (const Fence& rhs) const; 111 112 int mFenceFd; 113 }; 114 115 }; // namespace android 116 117 #endif // ANDROID_FENCE_H 118
