Fix cancelling hints when refreshing expiring hints.

When choose a new throttle option, we:
1. Send the new hints.
2. Cancel the old hints.

After b/230316778, we also sometimes do this when the hint *doesn't
change*, so we can "refresh" the hint if it's about to expire.

This send & immediately cancels the same hints, which essentially just
cancels the hint.

The solution is to only do step #1 from above when refreshing the hint.

Bug: 232782573
Test: manual
Change-Id: I2a6d83a29b683d7e1f8d71b8fff700b51d1839cf

1 files changed, 20 insertions, 13 deletions

diff --git a/power-libperfmgr/adaptivecpu/AdaptiveCpu.cpp b/power-libperfmgr/adaptivecpu/AdaptiveCpu.cpp
index 16b4028..0ad9639 100644
--- a/power-libperfmgr/adaptivecpu/AdaptiveCpu.cpp
+++ b/power-libperfmgr/adaptivecpu/AdaptiveCpu.cpp
@@ -177,22 +177,29 @@ void AdaptiveCpu::RunMainLoop() {
         LOG(VERBOSE) << "Model decision: " << static_cast<uint32_t>(throttleDecision);
         ATRACE_INT("AdaptiveCpu_throttleDecision", static_cast<uint32_t>(throttleDecision));
 
-        const auto now = mTimeSource.GetTime();
-        // Resend the throttle hints, even if they've not changed, if the previous send is close to
-        // timing out. We define "close to" as half the hint timeout, as we can't guarantee we will
-        // run again before the actual timeout.
-        const bool throttleHintMayTimeout = now - mLastThrottleHintTime > mConfig.hintTimeout / 2;
-        if (throttleDecision != previousThrottleDecision || throttleHintMayTimeout) {
-            mLastThrottleHintTime = now;
+        {
             ATRACE_NAME("sendHints");
-            for (const auto &hintName : THROTTLE_DECISION_TO_HINT_NAMES.at(throttleDecision)) {
-                HintManager::GetInstance()->DoHint(hintName, mConfig.hintTimeout);
+            const auto now = mTimeSource.GetTime();
+            // Resend the throttle hints, even if they've not changed, if the previous send is close
+            // to timing out. We define "close to" as half the hint timeout, as we can't guarantee
+            // we will run again before the actual timeout.
+            const bool throttleHintMayTimeout =
+                    now - mLastThrottleHintTime > mConfig.hintTimeout / 2;
+            if (throttleDecision != previousThrottleDecision || throttleHintMayTimeout) {
+                ATRACE_NAME("sendNewHints");
+                mLastThrottleHintTime = now;
+                for (const auto &hintName : THROTTLE_DECISION_TO_HINT_NAMES.at(throttleDecision)) {
+                    HintManager::GetInstance()->DoHint(hintName, mConfig.hintTimeout);
+                }
             }
-            for (const auto &hintName :
-                 THROTTLE_DECISION_TO_HINT_NAMES.at(previousThrottleDecision)) {
-                HintManager::GetInstance()->EndHint(hintName);
+            if (throttleDecision != previousThrottleDecision) {
+                ATRACE_NAME("endOldHints");
+                for (const auto &hintName :
+                     THROTTLE_DECISION_TO_HINT_NAMES.at(previousThrottleDecision)) {
+                    HintManager::GetInstance()->EndHint(hintName);
+                }
+                previousThrottleDecision = throttleDecision;
             }
-            previousThrottleDecision = throttleDecision;
         }
 
         mAdaptiveCpuStats.RegisterSuccessfulRun(previousThrottleDecision, throttleDecision,