ADFA-5514: plot the Gradle daemon, the process that actually holds the build - #1798
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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) <[email protected]> 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) <[email protected]> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j
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Included review availability: Your plan provides up to 2 included reviews per hour; 1 remains after this review. 📝 Summary
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)
🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
✨ Finishing Touches 💡 1📝 Generate docstrings 💡
🧪 Generate unit tests (beta)
A rabbit tracks the daemon’s trail, Comment |
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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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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 <[email protected]> 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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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 <[email protected]> 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 <[email protected]> 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 <[email protected]> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j
Daniel-ADFA
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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 |
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GradleDaemonWatcher.shutdown() had no caller. Reported by hal-eisen-adfa on PR #1812, where the code is in the base commit rather than the diff -- it came in with ADFA-5514 via #1798, so it is live on stage. - the watcher's thread outlived server shutdown, and an in-flight poll chain went on scanning ProcessHandle.descendants() for up to a minute - onExit().thenRun { client?.onGradleDaemonExited(pid) } could fire into a client whose RPC channel was being torn down; shutdown() sets client to null, so that was a race rather than a guaranteed no-op - shutdown() was dead code, which made onBuildStarted's note about the scheduler rejecting work after shutdown describe an unreachable state Two details that are easy to get wrong, both found in review of the version of this fix that rides ADFA-5589: It is called after DefaultGradleConnector.close(), not before. Stopping the daemons is what produces the exit, and the exit is reported through scheduler.execute { ... } -- a scheduler already shut down rejects it and merely logs, so the client never hears that the daemon it is plotting has gone. For the same reason the client is cleared after the wait rather than before it; best effort even then, since the client's own channel is going away at the same time. It goes through the lazy delegate rather than the property, or a server that never ran a build constructs a watcher, and its scheduler, purely to shut it down again. This is carried out of PR #1813, which is a draft while the review queue drains, so the fix does not wait on it. Tests: 9 in GradleDaemonWatcherTest, one new -- shutdown reaches scheduler.shutdownNow(). Co-Authored-By: Claude Opus 5 <[email protected]> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j
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* ADFA-5659: shut the Gradle daemon watcher down with the server GradleDaemonWatcher.shutdown() had no caller. Reported by hal-eisen-adfa on PR #1812, where the code is in the base commit rather than the diff -- it came in with ADFA-5514 via #1798, so it is live on stage. - the watcher's thread outlived server shutdown, and an in-flight poll chain went on scanning ProcessHandle.descendants() for up to a minute - onExit().thenRun { client?.onGradleDaemonExited(pid) } could fire into a client whose RPC channel was being torn down; shutdown() sets client to null, so that was a race rather than a guaranteed no-op - shutdown() was dead code, which made onBuildStarted's note about the scheduler rejecting work after shutdown describe an unreachable state Two details that are easy to get wrong, both found in review of the version of this fix that rides ADFA-5589: It is called after DefaultGradleConnector.close(), not before. Stopping the daemons is what produces the exit, and the exit is reported through scheduler.execute { ... } -- a scheduler already shut down rejects it and merely logs, so the client never hears that the daemon it is plotting has gone. For the same reason the client is cleared after the wait rather than before it; best effort even then, since the client's own channel is going away at the same time. It goes through the lazy delegate rather than the property, or a server that never ran a build constructs a watcher, and its scheduler, purely to shut it down again. This is carried out of PR #1813, which is a draft while the review queue drains, so the fix does not wait on it. Tests: 9 in GradleDaemonWatcherTest, one new -- shutdown reaches scheduler.shutdownNow(). Co-Authored-By: Claude Opus 5 <[email protected]> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j * ADFA-5659: pin the fix at the caller, and stop claiming the exit is delivered Review of the first version found three problems with it, all mine. The only test passed against the unfixed code. GradleDaemonWatcher .shutdown() already read { scheduler.shutdownNow() } on stage -- what was missing was anything calling it -- so a test of the watcher in isolation pinned nothing, and deleting the new block in ToolingApiServerImpl left the suite green. CLAUDE.md asks for the opposite and I checked it on the sibling change and not on this one. There is now a seam (newDaemonWatcher, defaulted, the shape GradleDaemonWatcher itself uses for descendants and scheduler) and two tests at the caller: shutting the server down stops the watcher, and a server that never ran a build does not construct one just to stop it. Both fail against their own mutation. The "after the daemons, not before" ordering did not do what it claimed. The exit arrives through handle.onExit().thenRun { scheduler.execute { ... } }, and onExit completes on a process-reaper thread only once the OS has reaped the daemon -- strictly after DefaultGradleConnector.close() returns. There is no point in the sequence where the scheduler still accepts work and the daemon has already been reaped, so the report is not deliverable at shutdown under any ordering. The call goes back early, where it ends the scanning thread soonest and no late poll can report into a channel being torn down, and the comment says plainly that the shutdown-time exit is not delivered. Moving `client = null` after the wait made consequence #2 worse rather than better: it left the client non-null for the whole daemon-stopping window instead of none of it, so a late callback could reach a half-torn-down channel. It goes back where stage had it. GradleDaemonWatcher.shutdown() is now graceful then forceful -- a report already queued still runs, a poll wedged mid-scan cannot hold the process open. That part is a real improvement and is tested both ways. What remains true is consequence #1, which was always the defect: an unstopped watcher goes on scanning ProcessHandle.descendants() for up to a minute after the server is gone. Tests: 17 in the module, four new. Each fails against the mutation it is named for -- removing the call, dropping the isInitialized guard, reverting shutdown() to shutdownNow() alone. Co-Authored-By: Claude Opus 5 <[email protected]> Claude-Session: https://claude.ai/code/session_017CCQUU7tBzZL61EmQhJP8j * ADFA-5659: serialise building the daemon watcher against stopping it `shutdown()` asked `lazyDaemonWatcher.isInitialized()` while `runBuild` touched `daemonWatcher`, with nothing between them. Both bodies run on the common pool, so a build submitted just before a shutdown can construct the watcher, and its scheduler, after shutdown has already looked and found none -- the leak this PR's shutdown call exists to prevent, arriving by the one route that check cannot see. One lock now covers the construction and a shutdown flag. Shutdown first means the build skips building a watcher at all; build first means shutdown sees it and stops it. The lock spans only the construction: `shutdown()` and `onBuildStarted()` both run outside it, so neither blocks the other, and a watcher stopped in between hits the scheduler rejection `onBuildStarted` already guards. Severity, since the reported finding overstated it: the scheduler's thread is a daemon thread and `Main` ends with `exitProcess(0)`, so a leaked watcher costs extra `descendants()` scans during teardown rather than holding the JVM open. The same is true of the defect this PR started from. Tests, both proved against the unfixed code: - a build that starts after shutdown does not build a watcher -> without the flag: expected 0 but was 1 - shutdown waits for a watcher a concurrent build is building -> without the lock: shutdown completed while the watcher was still being constructed The second asserts a bounded negative -- shutdown did not conclude within a second, against an unlocked shutdown that returns in milliseconds -- and its comment says so. Found by CodeRabbit on #1816. * ADFA-5659: restore the interrupt only for an actual interrupt `shutdown()` wrapped `awaitTermination` in `runCatching`, which catches `Throwable`, and re-interrupted the calling thread for anything it caught. Only an `InterruptedException` says anything about that thread's cancellation state; for any other failure the flag is set on a thread that was never cancelled. That matters because of where the flag lands. `shutdown()` runs as a teardown step on a `ForkJoinPool.commonPool` worker, and its caller's next act is `connectionCloseFuture.get()` in `ToolingApiServerImpl.shutdown()`. A set flag makes that `get()` throw immediately, so `connector.disconnect()` is never waited on, and the worker carries a stale interrupt into whatever the pool runs next. The catch stays `Throwable`: narrowing it would let a non-interrupt propagate out of `shutdown()` and skip `scheduler.shutdownNow()`, leaving the scheduler merely graceful. A failure still counts as "not drained", so the forceful stop still runs -- pinned by the first test below. This addresses the reported "any Throwable sets the flag" half only. A genuine interrupt still sets it and still aborts the connection-close wait; that half is left as reported, deliberately. Tests, both against the unfixed code: - a wait that fails for another reason does not mark the thread interrupted -> without the narrowing: interrupted() expected to be false - an interrupted wait still marks the thread interrupted -> pins that the narrowing did not overshoot Reported by @jatezzz on #1816. --------- Co-authored-by: Claude Opus 5 <[email protected]> Co-authored-by: Hal Eisen <[email protected]>
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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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