Fix DesktopMode iOS screenshot late-present race (700ms -> 1500ms settle) by shai-almog · Pull Request #5316 · codenameone/CodenameOne

shai-almog · 2026-06-30T11:44:57Z

Problem

The DesktopMode iOS screenshot test intermittently captures the wrong form — observed in CI capturing the preceding MutableImageClip form under the DesktopMode name. This is the documented iOS Metal late-present race: the heavy 30-row scrollable form's first frame is presented just after Display.screenshot() reads the framebuffer, so the grab returns the previous test's pixels.

It surfaced repeatedly on the device-input PR (#5309) CI as a build-ios / packaging failure that "cleared on re-run" — i.e. a real timing bug, not noise.

Root cause

DesktopModeScreenshotTest already opts into the sanctioned extraSettleBeforeCaptureMillis() mitigation (repaint + wait for GPU present before capture), but its 700ms value still loses the race on a starved CI runner.

Fix

Raise the settle to 1500ms — the same post-present margin OrientationLockScreenshotTest already relies on. The captured form is unchanged, so the reference image is unaffected; only the wait before the grab is longer.

🤖 Generated with Claude Code

…tle) The DesktopMode capture intermittently shipped the preceding test's framebuffer (observed: it captured the MutableImageClip form) -- the documented iOS Metal late-present race where the heavy 30-row form's first frame is presented just after Display.screenshot() reads the framebuffer. The test already opts into the extraSettleBeforeCaptureMillis repaint-and-wait mitigation, but 700ms still lost the race on a starved CI runner. Raise it to the same 1500ms post-present margin the OrientationLock test already relies on. The captured form is unchanged, so the reference image is unaffected -- only the settle before the grab is longer.

shai-almog · 2026-06-30T12:02:42Z

Compared 139 screenshots: 139 matched.

Native Android coverage

📊 Line coverage: 9.14% (9115/99743 lines covered) [HTML preview] (artifact android-coverage-report, jacocoAndroidReport/html/index.html)
- Other counters: instruction 8.05% (44780/556236), branch 3.71% (1878/50588), complexity 4.00% (2151/53777), method 6.23% (1746/28022), class 10.16% (404/3978)
- 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)
  - com.google.common.cache.com.google.common.cache.LocalCache$Segment – 0.00% (0/726 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)

✅ Native Android screenshot tests passed.

Native Android coverage

📊 Line coverage: 9.14% (9115/99743 lines covered) [HTML preview] (artifact android-coverage-report, jacocoAndroidReport/html/index.html)
- Other counters: instruction 8.05% (44780/556236), branch 3.71% (1878/50588), complexity 4.00% (2151/53777), method 6.23% (1746/28022), class 10.16% (404/3978)
- 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)
  - com.google.common.cache.com.google.common.cache.LocalCache$Segment – 0.00% (0/726 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)

Benchmark Results

Detailed Performance Metrics

Metric	Duration
SIMD kernel backend	scalar fallback (no native SIMD)
SIMD int-add (64K x300)	java 192ms / native 135ms = 1.4x speedup
SIMD float-mul (64K x300)	java 125ms / native 48ms = 2.6x speedup
SIMD kernel correctness	PASS (native result == scalar reference)
Base64 payload size	8192 bytes
Base64 benchmark iterations	6000
Base64 SIMD byte path	gated to scalar (CPU autovectorizes scalar; explicit SIMD not beneficial here)
Base64 CN1 encode	210.000 ms
Base64 CN1 decode	159.000 ms
Base64 native encode	1410.000 ms
Base64 encode ratio (CN1/native)	0.149x (85.1% faster)
Base64 native decode	929.000 ms
Base64 decode ratio (CN1/native)	0.171x (82.9% faster)
Image encode benchmark status	skipped (SIMD unsupported)

shai-almog · 2026-06-30T12:07:59Z

Compared 131 screenshots: 131 matched.
✅ JavaScript-port screenshot tests passed.

shai-almog · 2026-06-30T12:08:58Z

Compared 135 screenshots: 135 matched.
Native Windows port, REAL shipping pipeline: the hellocodenameone screenshot suite rendered by a binary CROSS-COMPILED on Linux (clang-cl + xwin, WebView2 linked) and RUN on a Windows x64 runner. Compared against the in-repo baseline in scripts/windows/screenshots.

Benchmark Results

Detailed Performance Metrics

Metric	Duration
SIMD kernel backend	SSE2 (x64) / NEON (arm64) native kernels
SIMD int-add (64K x300)	java 63ms / native 3ms = 21.0x speedup
SIMD float-mul (64K x300)	java 61ms / native 3ms = 20.3x speedup
SIMD kernel correctness	PASS (native result == scalar reference)

shai-almog · 2026-06-30T12:17:24Z

Compared 137 screenshots: 137 matched.
Native Linux port (x64), GTK3/Cairo/Pango, ParparVM bytecode-to-C (no JVM): the hellocodenameone screenshot suite rendered by a native ELF built + run on the GitHub x64 runner. Baseline: scripts/linux/screenshots.

shai-almog · 2026-06-30T12:17:29Z

Compared 137 screenshots: 137 matched.
Native Linux port (arm64), GTK3/Cairo/Pango, ParparVM bytecode-to-C (no JVM): the hellocodenameone screenshot suite rendered by a native ELF built + run on the GitHub arm64 runner. Baseline: scripts/linux/screenshots-arm.

shai-almog · 2026-06-30T12:28:13Z

Compared 138 screenshots: 138 matched.
✅ Native iOS Metal screenshot tests passed.

Benchmark Results

VM Translation Time: 0 seconds
Compilation Time: 224 seconds

Build and Run Timing

Metric	Duration
Simulator Boot	53000 ms
Simulator Boot (Run)	1000 ms
App Install	11000 ms
App Launch	1000 ms
Test Execution	301000 ms

Detailed Performance Metrics

Metric	Duration
SIMD kernel backend	SSE2 (x64) / NEON (arm64) native kernels
SIMD int-add (64K x300)	java 52ms / native 3ms = 17.3x speedup
SIMD float-mul (64K x300)	java 72ms / native 2ms = 36.0x speedup
SIMD kernel correctness	PASS (native result == scalar reference)
Base64 payload size	8192 bytes
Base64 benchmark iterations	6000
Base64 SIMD byte path	active (NEON-accelerated)
Base64 CN1 encode	427.000 ms
Base64 CN1 decode	208.000 ms
Base64 native encode	423.000 ms
Base64 encode ratio (CN1/native)	1.009x (0.9% slower)
Base64 native decode	262.000 ms
Base64 decode ratio (CN1/native)	0.794x (20.6% faster)
Base64 SIMD encode	52.000 ms
Base64 encode ratio (SIMD/CN1)	0.122x (87.8% faster)
Base64 SIMD decode	45.000 ms
Base64 decode ratio (SIMD/CN1)	0.216x (78.4% faster)
Base64 encode ratio (SIMD/native)	0.123x (87.7% faster)
Base64 decode ratio (SIMD/native)	0.172x (82.8% faster)
Image encode benchmark iterations	100
Image createMask (SIMD off)	16.000 ms
Image createMask (SIMD on)	2.000 ms
Image createMask ratio (SIMD on/off)	0.125x (87.5% faster)
Image applyMask (SIMD off)	42.000 ms
Image applyMask (SIMD on)	27.000 ms
Image applyMask ratio (SIMD on/off)	0.643x (35.7% faster)
Image modifyAlpha (SIMD off)	60.000 ms
Image modifyAlpha (SIMD on)	25.000 ms
Image modifyAlpha ratio (SIMD on/off)	0.417x (58.3% faster)
Image modifyAlpha removeColor (SIMD off)	62.000 ms
Image modifyAlpha removeColor (SIMD on)	24.000 ms
Image modifyAlpha removeColor ratio (SIMD on/off)	0.387x (61.3% faster)

shai-almog · 2026-06-30T12:59:35Z

iOS screenshot updates

Compared 134 screenshots: 132 matched, 2 updated.

DesktopMode — updated screenshot. Screenshot differs (1179x2556 px, bit depth 8).

Preview info: JPEG preview quality 70; JPEG preview quality 70; downscaled to 825x1789.
Full-resolution PNG saved as DesktopMode.png in workflow artifacts.
landscape — updated screenshot. Screenshot differs (1179x2556 px, bit depth 8).

Preview info: JPEG preview quality 70; JPEG preview quality 70; downscaled to 825x1789.
Full-resolution PNG saved as landscape.png in workflow artifacts.

Benchmark Results

VM Translation Time: 0 seconds
Compilation Time: 256 seconds

Build and Run Timing

Metric	Duration
Simulator Boot	97000 ms
Simulator Boot (Run)	0 ms
App Install	14000 ms
App Launch	3000 ms
Test Execution	471000 ms

Detailed Performance Metrics

Metric	Duration
SIMD kernel backend	SSE2 (x64) / NEON (arm64) native kernels
SIMD int-add (64K x300)	java 120ms / native 4ms = 30.0x speedup
SIMD float-mul (64K x300)	java 78ms / native 3ms = 26.0x speedup
SIMD kernel correctness	PASS (native result == scalar reference)
Base64 payload size	8192 bytes
Base64 benchmark iterations	6000
Base64 SIMD byte path	active (NEON-accelerated)
Base64 CN1 encode	489.000 ms
Base64 CN1 decode	411.000 ms
Base64 native encode	1206.000 ms
Base64 encode ratio (CN1/native)	0.405x (59.5% faster)
Base64 native decode	408.000 ms
Base64 decode ratio (CN1/native)	1.007x (0.7% slower)
Base64 SIMD encode	137.000 ms
Base64 encode ratio (SIMD/CN1)	0.280x (72.0% faster)
Base64 SIMD decode	110.000 ms
Base64 decode ratio (SIMD/CN1)	0.268x (73.2% faster)
Base64 encode ratio (SIMD/native)	0.114x (88.6% faster)
Base64 decode ratio (SIMD/native)	0.270x (73.0% faster)
Image encode benchmark iterations	100
Image createMask (SIMD off)	42.000 ms
Image createMask (SIMD on)	9.000 ms
Image createMask ratio (SIMD on/off)	0.214x (78.6% faster)
Image applyMask (SIMD off)	607.000 ms
Image applyMask (SIMD on)	578.000 ms
Image applyMask ratio (SIMD on/off)	0.952x (4.8% faster)
Image modifyAlpha (SIMD off)	280.000 ms
Image modifyAlpha (SIMD on)	244.000 ms
Image modifyAlpha ratio (SIMD on/off)	0.871x (12.9% faster)
Image modifyAlpha removeColor (SIMD off)	321.000 ms
Image modifyAlpha removeColor (SIMD on)	294.000 ms
Image modifyAlpha removeColor ratio (SIMD on/off)	0.916x (8.4% faster)

shai-almog · 2026-06-30T13:14:02Z

Compared 137 screenshots: 137 matched.
✅ Native Mac screenshot tests passed.

Benchmark Results

VM Translation Time: 0 seconds
Compilation Time: 235 seconds

Detailed Performance Metrics

Metric	Duration
SIMD kernel backend	SSE2 (x64) / NEON (arm64) native kernels
SIMD int-add (64K x300)	java 86ms / native 4ms = 21.5x speedup
SIMD float-mul (64K x300)	java 83ms / native 4ms = 20.7x speedup
SIMD kernel correctness	PASS (native result == scalar reference)
Base64 payload size	8192 bytes
Base64 benchmark iterations	6000
Base64 SIMD byte path	active (NEON-accelerated)
Base64 CN1 encode	478.000 ms
Base64 CN1 decode	419.000 ms
Base64 native encode	818.000 ms
Base64 encode ratio (CN1/native)	0.584x (41.6% faster)
Base64 native decode	717.000 ms
Base64 decode ratio (CN1/native)	0.584x (41.6% faster)
Base64 SIMD encode	113.000 ms
Base64 encode ratio (SIMD/CN1)	0.236x (76.4% faster)
Base64 SIMD decode	96.000 ms
Base64 decode ratio (SIMD/CN1)	0.229x (77.1% faster)
Base64 encode ratio (SIMD/native)	0.138x (86.2% faster)
Base64 decode ratio (SIMD/native)	0.134x (86.6% faster)
Image encode benchmark iterations	100
Image createMask (SIMD off)	35.000 ms
Image createMask (SIMD on)	5.000 ms
Image createMask ratio (SIMD on/off)	0.143x (85.7% faster)
Image applyMask (SIMD off)	287.000 ms
Image applyMask (SIMD on)	227.000 ms
Image applyMask ratio (SIMD on/off)	0.791x (20.9% faster)
Image modifyAlpha (SIMD off)	198.000 ms
Image modifyAlpha (SIMD on)	120.000 ms
Image modifyAlpha ratio (SIMD on/off)	0.606x (39.4% faster)
Image modifyAlpha removeColor (SIMD off)	139.000 ms
Image modifyAlpha removeColor (SIMD on)	82.000 ms
Image modifyAlpha removeColor ratio (SIMD on/off)	0.590x (41.0% faster)

shai-almog · 2026-06-30T13:21:55Z

Compared 214 screenshots: 214 matched.
✅ Native Apple Watch (watchOS, Core Graphics) screenshot tests passed.

shai-almog · 2026-06-30T13:29:09Z

Compared 136 screenshots: 136 matched.
✅ Native Apple TV (tvOS, Metal) screenshot tests passed.

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Fix DesktopMode iOS screenshot late-present race (700ms -> 1500ms settle)#5316

Fix DesktopMode iOS screenshot late-present race (700ms -> 1500ms settle)#5316
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fix/desktopmode-late-present-settle

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iOS screenshot updates

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