ADFA-5514: plot the Gradle daemon, the process that actually holds the build - #1798
ADFA-5514: plot the Gradle daemon, the process that actually holds the build#1798davidschachterADFA wants to merge 6 commits into
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ToolingApiServerImplTest has not compiled since InitializeProjectParams gained a required buildId: every test in :subprojects:tooling-api-impl has been unrunnable, not failing. BuildId.Unknown already exists for callers that have no real build to name, which is exactly this case. Spotless reformats the file on the way past, since touching it enrols it in the ratchet. Separated from the change that needed it so the feature commit is only the feature. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j
…e build BaseEditorActivity has always had a colour ready for PROC_GRADLE_DAEMON and nothing ever passed it: watchProcess was called with the IDE and the tooling server and never the daemon, so the branch colouring it green was unreachable and the legend showed two entries. Measured on a Pixel 6 Pro during a build, the one it left out is the big one -- IDE 702 MB, tooling server 165 MB, daemon 779 MB. The process that runs the compiler, holds the most memory, and is the likeliest reason a build is slow or gets killed on a small device was the one the chart could not show. The client has no handle on the daemon, but the server does: it is the tooling server's own child, which killDescendantProcesses already relies on. So the pid is pushed from the server rather than discovered by scanning, over two new client notifications beside the build events that already exist. Three things the ticket left open, settled by measurement rather than assumption: - Which descendant. Matched on the GradleDaemon main class, not "the only child": this build runs Kotlin compilation with kotlin.compiler.execution.strategy=daemon, so a second JVM is a sibling of the one holding the build's heap. - When to stop. Not on build finish, which is what the ticket assumed. A daemon outlives the build that spawned it -- still resident at 777 MB 144 s after one finished, despite daemon.forceKill -- and an idle daemon holding that much is exactly what a user on a 4 GB phone needs to see. It is unwatched when the process exits, off ProcessHandle.onExit. - Whether it is readable at all. It is, with no new mechanism: same uid as the app, and an ordinary child JVM like the tooling server, which the existing Debug.getMemoryInfo reflection path already reads. Also guards readUsages against a pid that has gone away. Debug.getMemoryInfo leaves its output untouched for a dead process, so sampling one repeats its last reading forever -- a flat line at 800 MB for a daemon that is gone. The IDE and the tooling server live as long as the editor, so this was unreachable until something that comes and goes was plotted. Verified on a Pixel 6 Pro: the daemon was identified within 10 s of the build starting, the chart drew three lines -- Gradle Tooling 163.70MB, Gradle Daemon 795.86MB, IDE 583.18MB, against a measured RSS of 797296 kB -- and killing the daemon fired the exit event and dropped the line without leaving a frozen one behind. Ten unit tests, seven for which descendant is the daemon and when the client hears about it, three for the dead-pid guard; the two guard tests that can fail were run against the unguarded code to confirm they do. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j
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WalkthroughThe change detects Gradle daemon processes, reports their lifecycle through the tooling API, and connects those events to editor memory monitoring. Dead process samples now record zero usage, and PID-specific unwatching preserves replacement daemon tracking. ChangesGradle daemon tracking
Estimated code review effort: 4 (Complex) | ~45 minutes Merge Risk: 🟡 Moderate · up to Gradle daemon memory plotting may stop tracking a replacement daemon when the prior daemon exits, leaving the process chart inaccurate until monitoring is restored. This should be resolved before merge. Sequence Diagram(s)sequenceDiagram
participant ToolingApiServerImpl
participant GradleDaemonWatcher
participant IToolingApiClient
participant GradleBuildService
participant EditorBuildEventListener
participant BaseEditorActivity
participant MemoryUsageWatcher
ToolingApiServerImpl->>GradleDaemonWatcher: onBuildStarted()
GradleDaemonWatcher->>IToolingApiClient: onGradleDaemonStarted(pid)
IToolingApiClient->>GradleBuildService: forward daemon start
GradleBuildService->>EditorBuildEventListener: onGradleDaemonStarted(pid)
EditorBuildEventListener->>BaseEditorActivity: watchGradleDaemon(pid)
BaseEditorActivity->>MemoryUsageWatcher: watchProcess(pid, PROC_GRADLE_DAEMON)
GradleDaemonWatcher->>IToolingApiClient: onGradleDaemonExited(pid)
EditorBuildEventListener->>BaseEditorActivity: unwatchGradleDaemon(pid)
BaseEditorActivity->>MemoryUsageWatcher: unwatchProcess(pid)
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✅ Passed checks (4 passed)
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🧪 Generate unit tests (beta)
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app/src/main/java/com/itsaky/androidide/activities/editor/BaseEditorActivity.kt (1)
1048-1050: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick winRecord font-scale verification in the PR.
Verify the editor memory chart, its legend, and surrounding controls at font scales 1.0 and 2.0. Record both scales and checks for clipping, overflow, inaccessible actions, and overlapping content.
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Inline comments:
In
`@app/src/main/java/com/itsaky/androidide/handlers/EditorBuildEventListener.kt`:
- Line 87: Update the daemon exit handling in EditorBuildEventListener to pass
the exiting pid to activity.unwatchGradleDaemon(pid), and make
unwatchGradleDaemon use memoryUsageWatcher.unwatchProcess(pid) so only that
daemon is removed. Add a regression test covering start(A), start(B), then
exit(A), verifying daemon B remains watched.
In `@app/src/main/java/com/itsaky/androidide/utils/MemoryUsageWatcher.kt`:
- Line 158: Update the sampling coroutine’s history update to use the already
captured proc value rather than re-reading memoryUsage[pid] with a force unwrap,
preventing a concurrent unwatchProcess removal from throwing. Keep the existing
update behavior for the captured process and ensure any coroutine-local failure
is handled so it cannot terminate the sampling coroutine.
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app/src/main/java/com/itsaky/androidide/activities/editor/BaseEditorActivity.ktapp/src/main/java/com/itsaky/androidide/handlers/EditorBuildEventListener.ktapp/src/main/java/com/itsaky/androidide/services/builder/GradleBuildService.ktapp/src/main/java/com/itsaky/androidide/utils/MemoryUsageWatcher.ktapp/src/test/java/com/itsaky/androidide/utils/MemoryUsageWatcherLivenessTest.ktsubprojects/tooling-api-impl/src/main/java/com/itsaky/androidide/tooling/impl/GradleDaemonWatcher.ktsubprojects/tooling-api-impl/src/main/java/com/itsaky/androidide/tooling/impl/ToolingApiServerImpl.ktsubprojects/tooling-api-impl/src/test/java/com/itsaky/androidide/tooling/impl/GradleDaemonWatcherTest.ktsubprojects/tooling-api-impl/src/test/java/com/itsaky/androidide/tooling/impl/ToolingApiServerImplTest.ktsubprojects/tooling-api/src/main/java/com/itsaky/androidide/tooling/api/ForwardingToolingApiClient.ktsubprojects/tooling-api/src/main/java/com/itsaky/androidide/tooling/api/IToolingApiClient.kttesting/tooling/src/main/java/com/itsaky/androidide/testing/tooling/ToolingApiTestLauncher.kt
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| override fun onGradleDaemonExited(pid: Int) { | ||
| checkActivity("onGradleDaemonExited") ?: return | ||
| activity.unwatchGradleDaemon() |
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🎯 Functional Correctness | 🟠 Major | ⚡ Quick win
Use the exit PID when removing the daemon watch.
Line 87 removes whichever watched process has the PROC_GRADLE_DAEMON name. If daemon A exits after daemon B starts, this removes daemon B from the chart. Pass pid to unwatchGradleDaemon(pid) and call memoryUsageWatcher.unwatchProcess(pid). Add a regression test for start(A), start(B), exit(A).
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In `@app/src/main/java/com/itsaky/androidide/handlers/EditorBuildEventListener.kt`
at line 87, Update the daemon exit handling in EditorBuildEventListener to pass
the exiting pid to activity.unwatchGradleDaemon(pid), and make
unwatchGradleDaemon use memoryUsageWatcher.unwatchProcess(pid) so only that
daemon is removed. Add a regression test covering start(A), start(B), then
exit(A), verifying daemon B remains watched.
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Agreed on the change, with one correction to the failure you describe.
unwatchProcess(PROC_GRADLE_DAEMON) removing "whichever process holds the name" is the wrong operation to be performing, and passing the pid costs nothing. I'll take it.
But start(A), start(B), exit(A) is not reachable as the code stands, so the regression test you suggest would be asserting against a state the server cannot produce. GradleDaemonWatcher holds a single watched pid: report only fires when it is NO_PID, onBuildStarted returns immediately while it is set, and the onExit callback clears it before reporting the exit. So B cannot be reported until A's exit has been. The two notifications also arrive over one JSON-RPC connection and both hop to the UI thread through runOnUiThread, so their order is preserved.
That makes this defence in depth rather than a live bug — worth doing because the single-generation invariant lives in a different module from the code that depends on it, and nothing enforces the coupling. What I'd write instead of your test is one that pins the invariant where it is actually kept: that a second daemon is not reported while the first is still watched. There is already a test for that (the daemon is reported once, not once per build).
Flagging one thing your suggested signature would hide: if the client is ever asked to unwatch a pid it is not watching, the right behaviour is to do nothing rather than to fall back to the name. I'll make sure the fix does not quietly re-introduce the name lookup as a fallback.
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@davidschachterADFA, agreed. The start(A), start(B), exit(A) sequence is not reachable under the current GradleDaemonWatcher contract. The suggested regression test does not match that contract.
The PID-based removal remains useful defence in depth. unwatchGradleDaemon(pid) should remove only that PID. If the PID is not watched, it should do nothing and must not fall back to PROC_GRADLE_DAEMON.
Thank you for the correction. 🐇
✏️ Learnings added
Learnt from: davidschachterADFA
Repo: appdevforall/CodeOnTheGo PR: 1798
File: app/src/main/java/com/itsaky/androidide/handlers/EditorBuildEventListener.kt:87-87
Timestamp: 2026-09-07T09:25:18.253Z
Learning: In the Gradle daemon tracking flow, `GradleDaemonWatcher` maintains one watched PID. It does not report another daemon while a PID is watched, and its `onExit` callback clears the watched PID before it reports the exit. Consequently, the client cannot receive `onGradleDaemonStarted(B)` before `onGradleDaemonExited(A)` for the previously watched daemon A. PID-based unwatching in `EditorBuildEventListener` remains defence in depth; an unknown exit PID must be a no-op and must not fall back to a process-name lookup.
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Correcting myself: you were right and I was wrong. The interleaving I said the server cannot produce is reachable, and start(A), start(B), exit(A) is exactly it.
I claimed "B cannot be reported until A's exit has been". Look at the order inside the exit callback:
handle.onExit().thenRun {
if (watched.compareAndSet(pid, NO_PID)) { // <- slot freed here
log.info("Gradle daemon {} exited", pid)
runCatching { onExited(pid) } // <- notification sent here
}
}The slot is freed before the notification goes out, and those are two different threads — the exit callback runs on a ProcessHandle completion thread, the discovery poll on the watcher's scheduler. Preempt between those two statements and the poll thread's compareAndSet(NO_PID, B) succeeds, so onStarted(B) reaches the client first. Then:
- client watches B under the name (
unique = trueevicts A, correctly) - the delayed
onExited(A)arrives unwatchProcess("Gradle Daemon")removes B, the live daemon
No green line until B dies and another build starts. Ordered delivery over the one RPC connection does not save it, because the two notifications are sent out of order at the source.
So this is a live bug, not defence in depth, and passing the pid is the fix rather than a tidy-up — unwatchProcess(pid) makes the late notification a no-op instead of a deletion. Your suggested regression test is also the right one after all; I said it would assert against an unreachable state, and it would not.
Worth adding that the narrow fix leaves a second-order version: the server would still be reporting a start and an exit out of order, so anything else that ever keys off the pair sees them reversed. Sending onExited before clearing the slot would fix it at the source, and is a one-line reorder. I'd do both.
My apologies for the confident dismissal — I reasoned about the invariant I intended rather than reading the order I wrote.
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@davidschachterADFA, your correction is correct.
watched.compareAndSet(pid, NO_PID) releases the slot before onExited(pid) sends the exit notification. The scheduler can then report daemon B before the client receives the exit notification for daemon A. The current name-based unwatch can remove daemon B.
Both changes are appropriate:
- Pass
pidthroughonGradleDaemonExitedand remove only that PID. An unknown PID must be a no-op. - Invoke
onExited(pid)before clearingwatched. This preserves lifecycle notification order at the source.
The start(A), start(B), exit(A) regression test is valid and should verify that daemon B remains watched.
Thanks for the detailed correction. The earlier learning contains the obsolete ordering assumption. Please confirm if you want it deleted from the CodeRabbit learnings page.
🐇
✏️ Learnings added
Learnt from: davidschachterADFA
Repo: appdevforall/CodeOnTheGo PR: 1798
File: app/src/main/java/com/itsaky/androidide/handlers/EditorBuildEventListener.kt:87-87
Timestamp: 2026-09-07T09:46:35.359Z
Learning: In `subprojects/tooling-api-impl/src/main/java/com/itsaky/androidide/tooling/impl/GradleDaemonWatcher.kt`, the `ProcessHandle.onExit` completion callback and daemon-discovery polling can interleave. If the callback clears `watched` before it invokes `onExited(pid)`, a new daemon can be reported before the prior daemon's exit notification. Invoke `onExited(pid)` before clearing `watched` to preserve lifecycle notification order. In `app/src/main/java/com/itsaky/androidide/handlers/EditorBuildEventListener.kt`, forward the exiting PID to the activity and unwatch only that PID; an unknown exit PID must be a no-op.
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🧠 Learnings used
Learnt from: davidschachterADFA
Repo: appdevforall/CodeOnTheGo PR: 1798
File: app/src/main/java/com/itsaky/androidide/handlers/EditorBuildEventListener.kt:87-87
Timestamp: 2026-09-07T09:25:21.105Z
Learning: In the Gradle daemon tracking flow, `GradleDaemonWatcher` maintains one watched PID. It does not report another daemon while a PID is watched, and its `onExit` callback clears the watched PID before it reports the exit. Consequently, the client cannot receive `onGradleDaemonStarted(B)` before `onGradleDaemonExited(A)` for the previously watched daemon A. PID-based unwatching in `EditorBuildEventListener` remains defence in depth; an unknown exit PID must be a no-op and must not fall back to a process-name lookup.
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Sampler NPE. readUsages looked the process up twice and asserted on the second read. unwatchProcess runs on the main thread from a build event, so the entry can go between them -- and the daemon is the process that gets unwatched. Use the value already in hand. Exit and start could cross. ProcessHandle.onExit fires on a process-reaper thread while starts are reported from the poll, and freeing the slot is what lets the next poll find a replacement daemon. So a start for the new daemon could reach the client ahead of the exit for the old one, and the client, which unwatched by name, would drop the line it had just been told to draw. Both reports now come off the watcher's own thread, and the client unwatches by pid, so a late exit for a dead pid is a no-op rather than wrong. That means onBuildStarted can no longer skip the scan when a daemon is already known: the answer differs precisely in the window where an exit is still queued, and skipping there would leave a fresh daemon unplotted until the build after next. The poll makes the test instead, on the thread that owns the state. Its initial schedule is now guarded, since it is submitted from the build's thread and the scheduler rejects work after shutdown. Lost lines on a configuration change. A rotation replaces the activity and its MemoryUsageWatcher but not the service or the processes it drives, and both pids arrive on one-shot callbacks the replacement has already missed -- the tooling server's on the start it did not request, the daemon's on the build that spawned it. The chart came back plotting the IDE alone. The service remembers both pids and the activity re-adopts them on connect. The tooling server half is pre-existing, not new to this ticket; it is the same defect and one line to fix here. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j
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Actionable comments posted: 1
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Inline comments:
In
`@app/src/main/java/com/itsaky/androidide/services/builder/GradleBuildService.kt`:
- Line 132: Mark GradleBuildService.gradleDaemonPid as `@Volatile` so writes from
daemon callbacks are visible to ProjectHandlerActivity during service
connection, preserving daemon monitoring restoration after activity recreation.
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📒 Files selected for processing (8)
app/src/main/java/com/itsaky/androidide/activities/editor/BaseEditorActivity.ktapp/src/main/java/com/itsaky/androidide/activities/editor/ProjectHandlerActivity.ktapp/src/main/java/com/itsaky/androidide/handlers/EditorBuildEventListener.ktapp/src/main/java/com/itsaky/androidide/services/builder/GradleBuildService.ktapp/src/main/java/com/itsaky/androidide/utils/MemoryUsageWatcher.ktapp/src/test/java/com/itsaky/androidide/utils/MemoryUsageWatcherLivenessTest.ktsubprojects/tooling-api-impl/src/main/java/com/itsaky/androidide/tooling/impl/GradleDaemonWatcher.ktsubprojects/tooling-api-impl/src/test/java/com/itsaky/androidide/tooling/impl/GradleDaemonWatcherTest.kt
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- app/src/main/java/com/itsaky/androidide/utils/MemoryUsageWatcher.kt
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The re-adoption has no unit test -- its call site is an activity's service callback -- so this is what makes it checkable on device, and it says which pids the chart is about to plot after the editor comes back. Silent when there is nothing to re-adopt, which is every cold start. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j
… a clinit The dead-pid test asserted a zero, which is also what a watcher that read nothing at all would hold -- so it did not distinguish the guard working from the setup never taking effect. It now reads the stale figure back first, with the same process called alive, so the zero that follows is a decision. (The stale read does happen: the control passes at 800MB.) LIVE_PID parsed /proc/self in a companion initialiser, so a platform without /proc took the whole class down with an ExceptionInInitializerError -- four unrelated tests failing for a reason none of them is about. Only one test needs a pid /proc really has; it reads one itself and skips if there is none. The others just need a second pid, since they replace the liveness check anyway. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j
Review found gradleDaemonPid written on the tooling API's RPC reader thread and read on the main thread while the activity binds. Without a memory barrier a recreated editor can read a stale null and leave the daemon off the chart -- the exact failure the field was added to prevent. ToolingServerRunner.pid has the same shape and was not flagged: startAsync writes it from a coroutine on runnerScope, and the same re-adoption reads it on the main thread. Both are volatile now, since fixing one and leaving the other would fix half of one feature. No test: a missing happens-before edge is not reproducible on demand, and a test that passes either way would pin nothing. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j
The daemon plot and the carousel stack do not merge cleanlyI built a throwaway integration of #1798 (ADFA-5514) and the carousel stack tip #1801 (ADFA-5526) to get one APK showing every metric at once. It worked — all three lines on one chart, Three files conflict textually
Take the carousel side as the base in all three and port ADFA-5514's additions onto it. The carousel side is the structural superset, and ADFA-5514's captured-
Two defects the merge creates, neither of which is a conflict marker1. The daemon callbacks reopen a hole #1792 deliberately closed. ADFA-5509 removed every default from fun onGradleDaemonStarted(pid: Int) = Unit
fun onGradleDaemonExited(pid: Int) = UnitMerged as-is this compiles and fails 2. The liveness guard silently zeroes ADFA-5531's alignment tests.
.also { it.isProcessAlive = { true } }Practical noteInserting the With those two changes the full |
2 participants
BaseEditorActivityhas always had a colour ready forPROC_GRADLE_DAEMONand nothing ever passed it.watchProcesswas called with the IDE and the tooling server and never the daemon, so the branch colouring it green was unreachable and the legend showed two entries.Measured on a Pixel 6 Pro during a build, the one it left out is the big one:
com.itsaky.androididetooling-api-all.jarGradleDaemonThe process that runs the compiler, holds the most memory, and is the likeliest reason a build is slow or gets killed on a small device was the one the chart could not show.
Approach
The client has no handle on the daemon, but the server does — it is the tooling server's own child, which
Main.killDescendantProcessesalready relies on. So the pid is pushed from the server over two newIToolingApiClientnotifications beside the build events that already exist, rather than discovered by scanning/procor parsing Gradle's daemon registry.The three open questions in the ticket, settled by measurement
Which descendant. Matched on the
GradleDaemonmain class, not "the only child". This build runs Kotlin compilation withkotlin.compiler.execution.strategy=daemon(visible in the build args it logs), so a second JVM can be a sibling of the one holding the build's heap.When to stop watching. Not on build finish, which is what the ticket assumed. A daemon outlives the build that spawned it — I measured one still resident at 777 MB 144 s after the build finished, despite
-Dide.tooling.daemon.forceKill=true, which only fires at tooling-server shutdown. An idle daemon holding that much is exactly what a user on a 4 GB phone needs to see, so it is unwatched when the process actually exits, offProcessHandle.onExit().Whether it is readable at all. It is, with no new mechanism: same uid as the app (
u0_a367), and an ordinary child JVM just like the tooling server, which the existingDebug.getMemoryInforeflection path already reads successfully today.One defensive fix included
readUsagessampled every watched pid unconditionally.Debug.getMemoryInfoleaves its output untouched for a dead process, so sampling one repeats its last reading forever — a flat line at 800 MB for a daemon that is gone. The IDE and the tooling server live as long as the editor does, so this was unreachable until something that comes and goes was plotted. A dead pid now records zero, which is both true and visibly the end of that process.Verification
On a Pixel 6 Pro (Android 17, arm64), against a real build of a Compose project:
GradleDaemonWatcher: Gradle daemon identified: pid 26243);Gradle Tooling - 163.70MB,Gradle Daemon - 795.86MB,IDE - 583.18MB— against a measured RSS of 797296 kB for that pid;Ten unit tests at the time of the first commits: seven in
GradleDaemonWatcherTestfor which descendant is the daemon and when the client hears about it (including a Kotlin compile daemon as a decoy, a dead child, report-once-per-daemon-not-per-build, and a replacement daemon after an exit), three inMemoryUsageWatcherLivenessTestfor the dead-pid guard. The two guard tests that can fail were run against the unguarded code to confirm they do; the third is a guard on the guard and passes either way by design. Full:appunit suite,:subprojects:tooling-api-impl:testandspotlessCheckgreen.Two things to know
The first commit is a prerequisite, not part of the feature.
ToolingApiServerImplTesthas not compiled sinceInitializeProjectParamsgained a requiredbuildId, so every test in:subprojects:tooling-api-implwas unrunnable rather than failing. One line,BuildId.Unknown, committed separately with the Spotless reformat it drags in.A pre-existing cosmetic defect this makes easier to hit.
resetMemUsageChart()rebuilds the datasets zero-filled and relies on the next sample to refill them. While the editor is paused there is no next sample, so if a reset lands then — e.g. the daemon exits while the install prompt is up — the chart sits empty with a y axis reading-1MB, -1MB, 0MB, 0MB, 1MB, 1MB(the%dMBformatter rounding a sub-1MB label interval into duplicates) until the editor resumes. It recovers on resume, verified. This predates the change —watchMemory()resets the same way on every editor open — but the daemon adds a new reset that can land while paused. Worth its own ticket; not fixed here to keep this PR to its subject.Three defects found reviewing this, fixed in the last commit
The sampler could NPE.
readUsageslooked each process up twice and asserted on the second read.unwatchProcessruns on the main thread from a build event, so the entry can be dropped between the two -- and the daemon is precisely the process that gets unwatched, which is what made a pre-existing window reachable. It uses the value already in hand. A test that unwatches from inside the liveness hook NPEs against the old code.An exit and a start could cross.
ProcessHandle.onExitfires on a process-reaper thread while starts are reported from the poll, and freeing the slot is what lets the next poll find a replacement daemon. So a start for the new daemon could reach the client ahead of the exit for the old one -- and the client, which unwatched by name, would drop the line it had just been told to draw. Two halves:watchProcess'suniquehas dropped the old pid by then, so this is a no-op in exactly the case where the name would have been wrong.That has a corollary worth flagging:
onBuildStartedcan no longer skip the scan when a daemon is already known, because the answer differs precisely in the window where an exit is still queued, and skipping there would leave a fresh daemon unplotted until the build after next. The poll makes the test instead, on the thread that owns the state. Cost is one scheduled task per build start that reads an int and returns. Its initial schedule is now guarded, since it is submitted from the build's thread and the scheduler rejects work aftershutdown.A recreated editor lost the line. A new editor activity brings a new
MemoryUsageWatcher, but the service and the processes it drives are still there. Both pids arrive on one-shot callbacks a replacement listener has already missed -- the tooling server's on the start it did not request, the daemon's on the build that spawned it -- so the chart came back plotting the IDE alone, the smallest of the three.I first wrote this up as a rotation bug and it is not:
EditorActivityKtdeclaresorientation|screenSize|screenLayout|smallestScreenSize|fontScale, so it handles a rotation itself. The triggers are leaving the editor and coming back to a live daemon (the common one), a night-mode or locale change, and "don't keep activities". The service remembers both pids; the activity re-adopts them on connect.The tooling-server half of that is pre-existing, not new to this ticket:
onGradleBuildServiceConnectedreturns early when the server is already up, and that early return is what skips thewatchProcesscall. It is the same defect and one line to fix here, so it is fixed rather than filed.What is tested and what is not
a process unwatched while it is being sampled does not take the sampler down with itNullPointerExceptionan exit is handed to the watcher's own thread rather than reported from the reaper'sexpected to be empty, but was [3]unwatching a daemon by pid leaves the one that replaced it aloneunwatchProcess(Int)already behaved this way, the fix was choosing itThirteen unit tests in total now (eight in
GradleDaemonWatcherTest, five inMemoryUsageWatcherLivenessTest). Full:appunit suite,:subprojects:tooling-api-impl:testandspotlessCheckgreen.Sibling sweep:
watchProcess/unwatchProcesshave four production call sites, all in the two editor activities, and all four now pass a pid or a name deliberately.memoryUsageis read twice nowhere else.GradleDaemonWatcheris the only user of its scheduler.On device
Pixel 6 Pro, Android 17, arm64. Built a project, left the editor, came back to it while the daemon was still up:
Both pids, both real, on a fresh activity. The last commit adds that log line -- the re-adoption is the one fix here with no unit test, so this is what makes it checkable, and it names the pids the chart is about to plot. It is silent when there is nothing to re-adopt, which is every cold start. That
readoptWatchedProcessesis the only other path that re-watches either pid is a code-level fact:onGradleBuildServiceConnectedreturns early when the server is already started, and that early return is what skipswatchProcess.The daemon exit in that trace also shows the reordered path working end to end, off the watcher's thread.
Font scale
No layout changes. The legend gains a third entry, which is the one thing here that could crowd at 2x on a small screen; verified at 1.0, not re-verified at 2.0.
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