RFR: 8358452: JNI exception pending in Java_sun_awt_screencast_ScreencastHelper_remoteDesktopKeyImpl of screencast_pipewire.c:1214 (ID: 51119) [v2]

[Alexander Zvegintsev]

On Wed, 4 Jun 2025 03:49:05 GMT, Prasanta Sadhukhan <psadhukhan at openjdk.org> wrote:

> We call AWT_UNLOCK in awt_Robot.c, gtk3_interface.c, awt_GraphicsEnv.c where there's no ExceptionCheck after the call.

Neither awt_Robot.c nor gtk3_interface.c calls any JNI functions afterwards.
I'm not sure why the tool didn't trigger regarding the awt_GraphicsEnv.c case.

> Normally we do ExceptionCheck after GetStringUTFChars

I added it just in case, but the GetStringUTFChars [documentation](https://docs.oracle.com/en/java/javase/21/docs/specs/jni/functions.html#getstringutfchars) doesn't mention any exceptions being thrown.

> Did you verify the warning goes off only by this PR change? 

it is the only reported line by the tool:

`JNI exception pending in Java_sun_awt_screencast_ScreencastHelper_remoteDesktopKeyImpl of screencast_pipewire.c:1214`

so it should resolve the issue.

But now I think it might be a false positive:

1. `AWT_LOCK()` clears all exceptions:
https://github.com/openjdk/jdk/blob/78a392aa3b0cda52cfacfa15250fa61010519424/src/java.desktop/unix/native/common/awt/awt.h#L86-L95
2. `awt_getX11KeySym` doesn't call JNI at all
3. `AWT_UNLOCK()`  also clears an exception,  and rethrows a previously pending exception, if any.
https://github.com/openjdk/jdk/blob/78a392aa3b0cda52cfacfa15250fa61010519424/src/java.desktop/unix/native/common/awt/awt.h#L97-L110

Since neither 1. nor 2. produces an exception, no exception will be thrown.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25605#discussion_r2125687104