From 46c433aabd33454271cd5e2890f1171acd6d7fa3 Mon Sep 17 00:00:00 2001
From: Mikhail Naganov <mnaganov@google.com>
Date: Wed, 6 Mar 2024 17:57:28 +0000
Subject: [PATCH] audio: Set correct priority for the SPATIALIZER stream thread

To align with the framework, the thread serving SPATIALIZER
stream I/O must use SCHED_FIFO and realtime priority.
The latter can be set via `audio.spatializer.priority`
property.

Bug: 321233946
Test: adb shell ps -Tl -p <HAL PID>
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:81a14293f4f26bf3af740cc1682c1111d7e1e29d)
Merged-In: I80107c9aa7d86cbfc2f79c2ad05959fc9f7913f7
Change-Id: I80107c9aa7d86cbfc2f79c2ad05959fc9f7913f7
---
 audio/aidl/default/Stream.cpp | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/audio/aidl/default/Stream.cpp b/audio/aidl/default/Stream.cpp
index 807348fad7..697ff0d0f0 100644
--- a/audio/aidl/default/Stream.cpp
+++ b/audio/aidl/default/Stream.cpp
@@ -21,6 +21,7 @@
 #include <Utils.h>
 #include <android-base/logging.h>
 #include <android/binder_ibinder_platform.h>
+#include <cutils/properties.h>
 #include <utils/SystemClock.h>
 #include <utils/Trace.h>
 
@@ -652,16 +653,34 @@ ndk::ScopedAStatus StreamCommonImpl::initInstance(
          isBitPositionFlagSet(flags.template get<AudioIoFlags::Tag::input>(),
                               AudioInputFlags::FAST)) ||
         (flags.getTag() == AudioIoFlags::Tag::output &&
-         isBitPositionFlagSet(flags.template get<AudioIoFlags::Tag::output>(),
-                              AudioOutputFlags::FAST))) {
+         (isBitPositionFlagSet(flags.template get<AudioIoFlags::Tag::output>(),
+                               AudioOutputFlags::FAST) ||
+          isBitPositionFlagSet(flags.template get<AudioIoFlags::Tag::output>(),
+                               AudioOutputFlags::SPATIALIZER)))) {
         // FAST workers should be run with a SCHED_FIFO scheduler, however the host process
         // might be lacking the capability to request it, thus a failure to set is not an error.
         pid_t workerTid = mWorker->getTid();
         if (workerTid > 0) {
-            struct sched_param param;
-            param.sched_priority = 3;  // Must match SchedulingPolicyService.PRIORITY_MAX (Java).
+            constexpr int32_t kRTPriorityMin = 1;  // SchedulingPolicyService.PRIORITY_MIN (Java).
+            constexpr int32_t kRTPriorityMax = 3;  // SchedulingPolicyService.PRIORITY_MAX (Java).
+            int priorityBoost = kRTPriorityMax;
+            if (flags.getTag() == AudioIoFlags::Tag::output &&
+                isBitPositionFlagSet(flags.template get<AudioIoFlags::Tag::output>(),
+                                     AudioOutputFlags::SPATIALIZER)) {
+                const int32_t sptPrio =
+                        property_get_int32("audio.spatializer.priority", kRTPriorityMin);
+                if (sptPrio >= kRTPriorityMin && sptPrio <= kRTPriorityMax) {
+                    priorityBoost = sptPrio;
+                } else {
+                    LOG(WARNING) << __func__ << ": invalid spatializer priority: " << sptPrio;
+                    return ndk::ScopedAStatus::ok();
+                }
+            }
+            struct sched_param param = {
+                    .sched_priority = priorityBoost,
+            };
             if (sched_setscheduler(workerTid, SCHED_FIFO | SCHED_RESET_ON_FORK, &param) != 0) {
-                PLOG(WARNING) << __func__ << ": failed to set FIFO scheduler for a fast thread";
+                PLOG(WARNING) << __func__ << ": failed to set FIFO scheduler and priority";
             }
         } else {
             LOG(WARNING) << __func__ << ": invalid worker tid: " << workerTid;