| /* |
| * Copyright (C) 2023 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #define LOG_TAG "audio_utils::threads" |
| |
| #include <audio_utils/threads.h> |
| |
| #include <algorithm> // std::clamp |
| #include <errno.h> |
| #include <sched.h> // scheduler |
| #include <sys/resource.h> |
| #include <utils/Errors.h> // status_t |
| #include <utils/Log.h> |
| |
| namespace android::audio_utils { |
| |
| /** |
| * Sets the unified priority of the tid. |
| */ |
| status_t set_thread_priority(pid_t tid, int priority) { |
| if (is_realtime_priority(priority)) { |
| // audio processes are designed to work with FIFO, not RR. |
| constexpr int new_policy = SCHED_FIFO; |
| const int rtprio = unified_priority_to_rtprio(priority); |
| struct sched_param param { |
| .sched_priority = rtprio, |
| }; |
| if (sched_setscheduler(tid, new_policy, ¶m) != 0) { |
| ALOGW("%s: Cannot set FIFO priority for tid %d to policy %d rtprio %d %s", |
| __func__, tid, new_policy, rtprio, strerror(errno)); |
| return -errno; |
| } |
| return NO_ERROR; |
| } else if (is_cfs_priority(priority)) { |
| const int policy = sched_getscheduler(tid); |
| const int nice = unified_priority_to_nice(priority); |
| if (policy != SCHED_OTHER) { |
| struct sched_param param{}; |
| constexpr int new_policy = SCHED_OTHER; |
| if (sched_setscheduler(tid, new_policy, ¶m) != 0) { |
| ALOGW("%s: Cannot set CFS priority for tid %d to policy %d nice %d %s", |
| __func__, tid, new_policy, nice, strerror(errno)); |
| return -errno; |
| } |
| } |
| if (setpriority(PRIO_PROCESS, tid, nice) != 0) return -errno; |
| return NO_ERROR; |
| } else { |
| return BAD_VALUE; |
| } |
| } |
| |
| /** |
| * Returns the unified priority of the tid. |
| * |
| * A negative number represents error. |
| */ |
| int get_thread_priority(int tid) { |
| const int policy = sched_getscheduler(tid); |
| if (policy < 0) return -errno; |
| |
| if (policy == SCHED_OTHER) { |
| errno = 0; // negative return value valid, so check errno change. |
| const int nice = getpriority(PRIO_PROCESS, tid); |
| if (errno != 0) return -errno; |
| return nice_to_unified_priority(nice); |
| } else if (policy == SCHED_FIFO || policy == SCHED_RR) { |
| struct sched_param param{}; |
| if (sched_getparam(tid, ¶m) < 0) return -errno; |
| return rtprio_to_unified_priority(param.sched_priority); |
| } else { |
| return INVALID_OPERATION; |
| } |
| } |
| |
| } // namespace android::audio_utils |