Fix deadlock on OpenGL on window dispose. (#301)

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/SkiaLayer.jvm.kt

@@ -212,7 +212,7 @@ actual open class SkiaLayer internal constructor(
     @Volatile
     private var isDisposed = false
     internal var redrawer: Redrawer? = null
-    private var contextHandler: ContextHandler? = null
+    internal var contextHandler: ContextHandler? = null
     private val fallbackRenderApiQueue = SkikoProperties.fallbackRenderApiQueue.toMutableList()
     private var renderApi_ = fallbackRenderApiQueue[0]
     actual var renderApi: GraphicsApi

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/context/OpenGLContextHandler.kt

@@ -73,4 +73,13 @@ internal class OpenGLContextHandler(layer: SkiaLayer) : ContextHandler(layer) {
             "Model: ${gl.glGetString(gl.GL_RENDERER)}\n" +
             "Total VRAM: ${gl.glGetIntegerv(gl.GL_TOTAL_MEMORY) / 1024} MB\n"
     }
+
+    fun disposeInOpenGLContext() {
+        super.dispose()
+    }
+
+    // dispose should be called only in the OpenGL context.
+    // TODO remove in https://github.com/JetBrains/skiko/pull/300
+    override open fun dispose() {
+    }
 }

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/LinuxOpenGLRedrawer.kt

@@ -3,6 +3,7 @@ package org.jetbrains.skiko.redrawer
 import kotlinx.coroutines.*
 import kotlinx.coroutines.swing.Swing
 import org.jetbrains.skiko.*
+import org.jetbrains.skiko.context.OpenGLContextHandler
 
 internal class LinuxOpenGLRedrawer(
     private val layer: SkiaLayer,
@@ -51,6 +52,8 @@ internal class LinuxOpenGLRedrawer(
             // makeCurrent is mandatory to destroy context, otherwise, OpenGL will destroy wrong context (from another window).
             // see the official example: https://www.khronos.org/opengl/wiki/Tutorial:_OpenGL_3.0_Context_Creation_(GLX)
             it.makeCurrent(context)
+            // TODO remove in https://github.com/JetBrains/skiko/pull/300
+            (layer.contextHandler as OpenGLContextHandler).disposeInOpenGLContext()
             it.destroyContext(context)
         }
         runBlocking {

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/WindowsOpenGLRedrawer.kt

@@ -5,6 +5,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.swing.Swing
 import kotlinx.coroutines.withContext
 import org.jetbrains.skiko.*
+import org.jetbrains.skiko.context.OpenGLContextHandler
 
 internal class WindowsOpenGLRedrawer(
     private val layer: SkiaLayer,
@@ -34,6 +35,8 @@ internal class WindowsOpenGLRedrawer(
     override fun dispose() {
         check(!isDisposed) { "WindowsOpenGLRedrawer is disposed" }
         makeCurrent()
+        // TODO remove in https://github.com/JetBrains/skiko/pull/300
+        (layer.contextHandler as OpenGLContextHandler).disposeInOpenGLContext()
         deleteContext(context)
         isDisposed = true
     }