xref: /aosp_15_r20/system/chre/util/include/chre/util/throttle.h (revision 84e339476a462649f82315436d70fd732297a399)
1 /*
2  * Copyright (C) 2024 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 CHRE_UTIL_THROTTLE_H_
18 #define CHRE_UTIL_THROTTLE_H_
19 
20 /**
21  * Throttles an action to a given interval and maximum number of times.
22  * The action will be called at most maxCount in every interval.
23  *
24  * @param action The action to throttle
25  * @param interval The interval between actions
26  * @param maxCount The maximum number of times to call the action
27  * @param getTime A function to get the current time
28  */
29 #define CHRE_THROTTLE(action, interval, maxCount, getTime)       \
30   do {                                                           \
31     static uint32_t _count = 0;                                  \
32     static bool _hasLastCallTime = false;                        \
33     static Nanoseconds _lastCallTime;                            \
34     Nanoseconds _now = getTime;                                  \
35     if (!_hasLastCallTime || _now - _lastCallTime >= interval) { \
36       _hasLastCallTime = true;                                   \
37       _count = 0;                                                \
38       _lastCallTime = _now;                                      \
39     }                                                            \
40     if (++_count > maxCount) {                                   \
41       break;                                                     \
42     }                                                            \
43     action;                                                      \
44   } while (0)
45 
46 #endif  // CHRE_UTIL_THROTTLE_H_
47