Fence.h revision 9f54ac38860761ef62d9bb8282d54ff51a1a68a3
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 29struct ANativeWindowBuffer; 30 31namespace android { 32 33// =========================================================================== 34// Fence 35// =========================================================================== 36 37class Fence 38 : public LightRefBase<Fence>, public Flattenable 39{ 40public: 41 static const sp<Fence> NO_FENCE; 42 43 // Construct a new Fence object with an invalid file descriptor. This 44 // should be done when the Fence object will be set up by unflattening 45 // serialized data. 46 Fence(); 47 48 // Construct a new Fence object to manage a given fence file descriptor. 49 // When the new Fence object is destructed the file descriptor will be 50 // closed. 51 Fence(int fenceFd); 52 53 // Check whether the Fence has an open fence file descriptor. Most Fence 54 // methods treat an invalid file descriptor just like a valid fence that 55 // is already signalled, so using this is usually not necessary. 56 bool isValid() const { return mFenceFd != -1; } 57 58 // wait waits for up to timeout milliseconds for the fence to signal. If 59 // the fence signals then NO_ERROR is returned. If the timeout expires 60 // before the fence signals then -ETIME is returned. A timeout of 61 // TIMEOUT_NEVER may be used to indicate that the call should wait 62 // indefinitely for the fence to signal. 63 int wait(unsigned int timeout); 64 65 // TIMEOUT_NEVER may be passed to the wait method to indicate that it 66 // should wait indefinitely for the fence to signal. 67 enum { TIMEOUT_NEVER = -1 }; 68 69 // merge combines two Fence objects, creating a new Fence object that 70 // becomes signaled when both f1 and f2 are signaled (even if f1 or f2 is 71 // destroyed before it becomes signaled). The name argument specifies the 72 // human-readable name to associated with the new Fence object. 73 static sp<Fence> merge(const String8& name, const sp<Fence>& f1, 74 const sp<Fence>& f2); 75 76 // Return a duplicate of the fence file descriptor. The caller is 77 // responsible for closing the returned file descriptor. On error, -1 will 78 // be returned and errno will indicate the problem. 79 int dup() const; 80 81 // Flattenable interface 82 size_t getFlattenedSize() const; 83 size_t getFdCount() const; 84 status_t flatten(void* buffer, size_t size, 85 int fds[], size_t count) const; 86 status_t unflatten(void const* buffer, size_t size, 87 int fds[], size_t count); 88 89private: 90 // Only allow instantiation using ref counting. 91 friend class LightRefBase<Fence>; 92 virtual ~Fence(); 93 94 // Disallow copying 95 Fence(const Fence& rhs); 96 Fence& operator = (const Fence& rhs); 97 const Fence& operator = (const Fence& rhs) const; 98 99 int mFenceFd; 100}; 101 102}; // namespace android 103 104#endif // ANDROID_FENCE_H 105