1 /* 2 * Copyright (C) 2021 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_NATIVE_PERFORMANCE_HINT_H 18 #define ANDROID_NATIVE_PERFORMANCE_HINT_H 19 20 #include <sys/cdefs.h> 21 22 /****************************************************************** 23 * 24 * IMPORTANT NOTICE: 25 * 26 * This file is part of Android's set of stable system headers 27 * exposed by the Android NDK (Native Development Kit). 28 * 29 * Third-party source AND binary code relies on the definitions 30 * here to be FROZEN ON ALL UPCOMING PLATFORM RELEASES. 31 * 32 * - DO NOT MODIFY ENUMS (EXCEPT IF YOU ADD NEW 32-BIT VALUES) 33 * - DO NOT MODIFY CONSTANTS OR FUNCTIONAL MACROS 34 * - DO NOT CHANGE THE SIGNATURE OF FUNCTIONS IN ANY WAY 35 * - DO NOT CHANGE THE LAYOUT OR SIZE OF STRUCTURES 36 */ 37 38 #include <android/api-level.h> 39 #include <stdint.h> 40 41 __BEGIN_DECLS 42 43 struct APerformanceHintManager; 44 struct APerformanceHintSession; 45 46 /** 47 * An opaque type representing a handle to a performance hint manager. 48 * It must be released after use. 49 * 50 * <p>To use:<ul> 51 * <li>Obtain the performance hint manager instance by calling 52 * {@link APerformanceHint_getManager} function.</li> 53 * <li>Create an {@link APerformanceHintSession} with 54 * {@link APerformanceHint_createSession}.</li> 55 * <li>Get the preferred update rate in nanoseconds with 56 * {@link APerformanceHint_getPreferredUpdateRateNanos}.</li> 57 */ 58 typedef struct APerformanceHintManager APerformanceHintManager; 59 60 /** 61 * An opaque type representing a handle to a performance hint session. 62 * A session can only be acquired from a {@link APerformanceHintManager} 63 * with {@link APerformanceHint_getPreferredUpdateRateNanos}. It must be 64 * freed with {@link APerformanceHint_closeSession} after use. 65 * 66 * A Session represents a group of threads with an inter-related workload such that hints for 67 * their performance should be considered as a unit. The threads in a given session should be 68 * long-life and not created or destroyed dynamically. 69 * 70 * <p>Each session is expected to have a periodic workload with a target duration for each 71 * cycle. The cycle duration is likely greater than the target work duration to allow other 72 * parts of the pipeline to run within the available budget. For example, a renderer thread may 73 * work at 60hz in order to produce frames at the display's frame but have a target work 74 * duration of only 6ms.</p> 75 * 76 * <p>After each cycle of work, the client is expected to use 77 * {@link APerformanceHint_reportActualWorkDuration} to report the actual time taken to 78 * complete.</p> 79 * 80 * <p>To use:<ul> 81 * <li>Update a sessions target duration for each cycle of work 82 * with {@link APerformanceHint_updateTargetWorkDuration}.</li> 83 * <li>Report the actual duration for the last cycle of work with 84 * {@link APerformanceHint_reportActualWorkDuration}.</li> 85 * <li>Release the session instance with 86 * {@link APerformanceHint_closeSession}.</li></ul></p> 87 */ 88 typedef struct APerformanceHintSession APerformanceHintSession; 89 90 /** 91 * Acquire an instance of the performance hint manager. 92 * 93 * @return manager instance on success, nullptr on failure. 94 */ 95 APerformanceHintManager* APerformanceHint_getManager() __INTRODUCED_IN(__ANDROID_API_T__); 96 97 /** 98 * Creates a session for the given set of threads and sets their initial target work 99 * duration. 100 * @param manager The performance hint manager instance. 101 * @param threadIds The list of threads to be associated with this session. They must be part of 102 * this app's thread group. 103 * @param size the size of threadIds. 104 * @param initialTargetWorkDurationNanos The desired duration in nanoseconds for the new session. 105 * This must be positive. 106 * @return manager instance on success, nullptr on failure. 107 */ 108 APerformanceHintSession* APerformanceHint_createSession( 109 APerformanceHintManager* manager, 110 const int32_t* threadIds, size_t size, 111 int64_t initialTargetWorkDurationNanos) __INTRODUCED_IN(__ANDROID_API_T__); 112 113 /** 114 * Get preferred update rate information for this device. 115 * 116 * @param manager The performance hint manager instance. 117 * @return the preferred update rate supported by device software. 118 */ 119 int64_t APerformanceHint_getPreferredUpdateRateNanos( 120 APerformanceHintManager* manager) __INTRODUCED_IN(__ANDROID_API_T__); 121 122 /** 123 * Updates this session's target duration for each cycle of work. 124 * 125 * @param session The performance hint session instance to update. 126 * @param targetDurationNanos the new desired duration in nanoseconds. This must be positive. 127 * @return 0 on success 128 * EINVAL if targetDurationNanos is not positive. 129 * EPIPE if communication with the system service has failed. 130 */ 131 int APerformanceHint_updateTargetWorkDuration( 132 APerformanceHintSession* session, 133 int64_t targetDurationNanos) __INTRODUCED_IN(__ANDROID_API_T__); 134 135 /** 136 * Reports the actual duration for the last cycle of work. 137 * 138 * <p>The system will attempt to adjust the core placement of the threads within the thread 139 * group and/or the frequency of the core on which they are run to bring the actual duration 140 * close to the target duration.</p> 141 * 142 * @param session The performance hint session instance to update. 143 * @param actualDurationNanos how long the thread group took to complete its last task in 144 * nanoseconds. This must be positive. 145 * @return 0 on success 146 * EINVAL if actualDurationNanos is not positive. 147 * EPIPE if communication with the system service has failed. 148 */ 149 int APerformanceHint_reportActualWorkDuration( 150 APerformanceHintSession* session, 151 int64_t actualDurationNanos) __INTRODUCED_IN(__ANDROID_API_T__); 152 153 /** 154 * Release the performance hint manager pointer acquired via 155 * {@link APerformanceHint_createSession}. 156 * 157 * @param session The performance hint session instance to release. 158 */ 159 void APerformanceHint_closeSession( 160 APerformanceHintSession* session) __INTRODUCED_IN(__ANDROID_API_T__); 161 162 __END_DECLS 163 164 #endif // ANDROID_NATIVE_PERFORMANCE_HINT_H 165