Fix StackOverflowError in Display.setCurrent off-EDT (#4811) by liannacasper · Pull Request #4812 · codenameone/CodenameOne

liannacasper · 2026-04-25T18:41:16Z

Summary

Fixes stack overflow in edt #4811 — Display.setCurrent invoked from a non-EDT thread recursed infinitely into callSerially -> RunnableWrapper.run -> setCurrent until the JVM stack overflowed (the SOH happened to surface in getDefaultVirtualKeyboard/setShowVirtualKeyboard because those frames sit on top of the loop).
Root cause: when codenameOneRunning is false (e.g. before init has fully completed or after deinitialize), callSerially falls back to executing the runnable synchronously on the calling thread, which re-enters setCurrent in the same off-EDT state.
Move the !isEdt() dispatch ahead of any UI work in setCurrent (so VKB folding, revalidate/repaint, and editing-text branches always execute on the EDT) and fail fast with a clear IllegalStateException when the EDT cannot accept the call.

Test plan

mvn -pl core compile -Plocal-dev-javase succeeds (verified locally).
Existing JavaSE tests pass (ant test-javase / mvn test -Plocal-dev-javase).
Manual: invoking Display.getInstance().setCurrent(form, false) from a background thread before init (or after deinitialize) now throws IllegalStateException with a clear message instead of crashing with StackOverflowError.
Normal off-EDT setCurrent calls (during a running app) continue to dispatch through callSerially and show the form.

🤖 Generated with Claude Code

When setCurrent was invoked from a non-EDT thread while Codename One was not running, callSerially's synchronous fallback re-entered setCurrent on the same thread and recursed until the stack overflowed. Move the EDT dispatch ahead of the UI work and fail fast with a clear IllegalStateException when the EDT cannot accept the call. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

github-actions · 2026-04-25T18:49:34Z

✅ Continuous Quality Report

Test & Coverage

✅ Tests: 2407 total, 0 failed, 0 skipped
📊 Line coverage: 53.27% [HTML preview] [Download]
- Lowest covered classes
  - com.codename1.ui.Display$EdtException – 0.00%
  - com.codename1.ui.plaf.CSSBorder$LinearGradient – 0.00%
  - com.codename1.util.EasyThread$InQueueRunnable – 0.00%
  - com.codename1.components.FloatingActionButton$ReleaseActionListener – 0.00%
  - com.codename1.io.Oauth2$ShowAuthenticationActionListener – 0.00%
  - com.codename1.io.Oauth2$RefreshTokenActionListener – 0.00%
  - com.codename1.util.EasyThread$RunAndWaitRunnable – 0.00%
  - com.codename1.components.ToastBar$FlushAnimationCallback – 0.00%
  - com.codename1.ui.plaf.CSSBorder$ColorStop – 0.00%
  - com.codename1.ui.ElevationComparator – 0.00%

Static Analysis

SpotBugs [Report archive]
- ✅ ByteCodeTranslator: 0 findings (no issues)
- ✅ android: 0 findings (no issues)
- ✅ codenameone-maven-plugin: 0 findings (no issues)
- ✅ core-unittests: 0 findings (no issues)
- ✅ ios: 0 findings (no issues)
✅ PMD: 0 findings (no issues) [Report archive]
✅ Checkstyle: 0 findings (no issues) [Report archive]

Generated automatically by the PR CI workflow.

shai-almog · 2026-04-25T18:56:19Z

Compared 37 screenshots: 37 matched.

Native Android coverage

📊 Line coverage: 7.94% (4213/53043 lines covered) [HTML preview] (artifact android-coverage-report, jacocoAndroidReport/html/index.html)
- Other counters: instruction 6.22% (20744/333558), branch 3.03% (976/32174), complexity 3.70% (1137/30766), method 6.50% (933/14344), class 10.68% (203/1900)
- Lowest covered classes
  - kotlin.collections.kotlin.collections.ArraysKt___ArraysKt – 0.00% (0/6327 lines covered)
  - kotlin.collections.unsigned.kotlin.collections.unsigned.UArraysKt___UArraysKt – 0.00% (0/2384 lines covered)
  - org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.ClassReader – 0.00% (0/1519 lines covered)
  - kotlin.collections.kotlin.collections.CollectionsKt___CollectionsKt – 0.00% (0/1148 lines covered)
  - org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.MethodWriter – 0.00% (0/923 lines covered)
  - kotlin.sequences.kotlin.sequences.SequencesKt___SequencesKt – 0.00% (0/730 lines covered)
  - kotlin.text.kotlin.text.StringsKt___StringsKt – 0.00% (0/623 lines covered)
  - org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.Frame – 0.00% (0/564 lines covered)
  - kotlin.collections.kotlin.collections.ArraysKt___ArraysJvmKt – 0.00% (0/495 lines covered)
  - kotlinx.coroutines.kotlinx.coroutines.JobSupport – 0.00% (0/423 lines covered)

✅ Native Android screenshot tests passed.

Native Android coverage

📊 Line coverage: 7.94% (4213/53043 lines covered) [HTML preview] (artifact android-coverage-report, jacocoAndroidReport/html/index.html)
- Other counters: instruction 6.22% (20744/333558), branch 3.03% (976/32174), complexity 3.70% (1137/30766), method 6.50% (933/14344), class 10.68% (203/1900)
- Lowest covered classes
  - kotlin.collections.kotlin.collections.ArraysKt___ArraysKt – 0.00% (0/6327 lines covered)
  - kotlin.collections.unsigned.kotlin.collections.unsigned.UArraysKt___UArraysKt – 0.00% (0/2384 lines covered)
  - org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.ClassReader – 0.00% (0/1519 lines covered)
  - kotlin.collections.kotlin.collections.CollectionsKt___CollectionsKt – 0.00% (0/1148 lines covered)
  - org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.MethodWriter – 0.00% (0/923 lines covered)
  - kotlin.sequences.kotlin.sequences.SequencesKt___SequencesKt – 0.00% (0/730 lines covered)
  - kotlin.text.kotlin.text.StringsKt___StringsKt – 0.00% (0/623 lines covered)
  - org.jacoco.agent.rt.internal_b6258fc.asm.org.jacoco.agent.rt.internal_b6258fc.asm.Frame – 0.00% (0/564 lines covered)
  - kotlin.collections.kotlin.collections.ArraysKt___ArraysJvmKt – 0.00% (0/495 lines covered)
  - kotlinx.coroutines.kotlinx.coroutines.JobSupport – 0.00% (0/423 lines covered)

Benchmark Results

Detailed Performance Metrics

Metric	Duration
Base64 payload size	8192 bytes
Base64 benchmark iterations	6000
Base64 native encode	747.000 ms
Base64 CN1 encode	174.000 ms
Base64 encode ratio (CN1/native)	0.233x (76.7% faster)
Base64 native decode	1129.000 ms
Base64 CN1 decode	292.000 ms
Base64 decode ratio (CN1/native)	0.259x (74.1% faster)
Image encode benchmark status	skipped (SIMD unsupported)

shai-almog · 2026-04-25T19:18:38Z

Compared 37 screenshots: 37 matched.
✅ Native iOS screenshot tests passed.

Benchmark Results

VM Translation Time: 0 seconds
Compilation Time: 123 seconds

Build and Run Timing

Metric	Duration
Simulator Boot	91000 ms
Simulator Boot (Run)	2000 ms
App Install	17000 ms
App Launch	9000 ms
Test Execution	158000 ms

Detailed Performance Metrics

Metric	Duration
Base64 payload size	8192 bytes
Base64 benchmark iterations	6000
Base64 native encode	2344.000 ms
Base64 CN1 encode	1599.000 ms
Base64 encode ratio (CN1/native)	0.682x (31.8% faster)
Base64 native decode	1404.000 ms
Base64 CN1 decode	1414.000 ms
Base64 decode ratio (CN1/native)	1.007x (0.7% slower)
Base64 SIMD encode	571.000 ms
Base64 encode ratio (SIMD/native)	0.244x (75.6% faster)
Base64 encode ratio (SIMD/CN1)	0.357x (64.3% faster)
Base64 SIMD decode	694.000 ms
Base64 decode ratio (SIMD/native)	0.494x (50.6% faster)
Base64 decode ratio (SIMD/CN1)	0.491x (50.9% faster)
Image encode benchmark iterations	100
Image createMask (SIMD off)	122.000 ms
Image createMask (SIMD on)	16.000 ms
Image createMask ratio (SIMD on/off)	0.131x (86.9% faster)
Image applyMask (SIMD off)	347.000 ms
Image applyMask (SIMD on)	164.000 ms
Image applyMask ratio (SIMD on/off)	0.473x (52.7% faster)
Image modifyAlpha (SIMD off)	123.000 ms
Image modifyAlpha (SIMD on)	107.000 ms
Image modifyAlpha ratio (SIMD on/off)	0.870x (13.0% faster)
Image modifyAlpha removeColor (SIMD off)	373.000 ms
Image modifyAlpha removeColor (SIMD on)	170.000 ms
Image modifyAlpha removeColor ratio (SIMD on/off)	0.456x (54.4% faster)
Image PNG encode (SIMD off)	1370.000 ms
Image PNG encode (SIMD on)	975.000 ms
Image PNG encode ratio (SIMD on/off)	0.712x (28.8% faster)
Image JPEG encode	875.000 ms

shai-almog merged commit 3f33dab into master Apr 25, 2026
14 of 15 checks passed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Fix StackOverflowError in Display.setCurrent off-EDT (#4811)#4812

Fix StackOverflowError in Display.setCurrent off-EDT (#4811)#4812
shai-almog merged 1 commit into
masterfrom
fix-4811-setcurrent-stack-overflow

liannacasper commented Apr 25, 2026

Uh oh!

github-actions Bot commented Apr 25, 2026

Uh oh!

shai-almog commented Apr 25, 2026 •

edited

Loading

Uh oh!

shai-almog commented Apr 25, 2026 •

edited

Loading

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Conversation

liannacasper commented Apr 25, 2026

Summary

Test plan

Uh oh!

github-actions Bot commented Apr 25, 2026

✅ Continuous Quality Report

Test & Coverage

Static Analysis

Uh oh!

shai-almog commented Apr 25, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Native Android coverage

Native Android coverage

Benchmark Results

Detailed Performance Metrics

Uh oh!

shai-almog commented Apr 25, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Benchmark Results

Build and Run Timing

Detailed Performance Metrics

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

shai-almog commented Apr 25, 2026 •

edited

Loading

shai-almog commented Apr 25, 2026 •

edited

Loading