8313697: [XWayland][Screencast] consequent getPixelColor calls are slow

src/java.desktop/unix/classes/sun/awt/screencast/ScreencastHelper.java

@@ -35,6 +35,8 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Set;
+import java.util.Timer;
+import java.util.TimerTask;
 import java.util.stream.IntStream;
 
 /**
@@ -54,6 +56,13 @@ public class ScreencastHelper {
     private static final int DENIED = -11;
     private static final int OUT_OF_BOUNDS = -12;
 
+    private static final int DELAY_BEFORE_SESSION_CLOSE = 2000;
+
+    private static volatile TimerTask timerTask = null;
+    private static final Timer timerCloseSession
+            = new Timer("auto-close screencast session", true);
+
+
     private ScreencastHelper() {
     }
 
@@ -105,11 +114,30 @@ private static List<Rectangle> getSystemScreensBounds() {
                 ).toList();
     }
 
+    private static synchronized native void closeSession();
+
+    private static void timerCloseSessionRestart() {
+        if (timerTask != null) {
+            timerTask.cancel();
+        }
+
+        timerTask = new TimerTask() {
+            @Override
+            public void run() {
+                closeSession();
+            }
+        };
+
+        timerCloseSession.schedule(timerTask, DELAY_BEFORE_SESSION_CLOSE);
+    }
+
     public static synchronized void getRGBPixels(
             int x, int y, int width, int height, int[] pixelArray
     ) {
         if (!IS_NATIVE_LOADED) return;
 
+        timerCloseSessionRestart();
+
         Rectangle captureArea = new Rectangle(x, y, width, height);
 
         List<Rectangle> affectedScreenBounds = getSystemScreensBounds()

src/java.desktop/unix/classes/sun/awt/screencast/TokenStorage.java

@@ -324,6 +324,10 @@ static Set<TokenItem> getTokens(List<Rectangle> affectedScreenBounds) {
                         return tokenItem;
                     })
                     .filter(Objects::nonNull)
+                    .sorted((t1, t2) -> //Token with more screens preferred
+                            t2.allowedScreensBounds.size()
+                            - t1.allowedScreensBounds.size()
+                    )
                     .toList();
         }
 

src/java.desktop/unix/native/libawt_xawt/awt/gtk3_interface.c

@@ -604,6 +604,7 @@ GtkApi* gtk3_load(JNIEnv *env, const char* lib_name)
 
         fp_g_string_new = dl_symbol("g_string_new");
         fp_g_string_erase = dl_symbol("g_string_erase");
+        fp_g_string_set_size = dl_symbol("g_string_set_size");
         fp_g_string_free = dl_symbol("g_string_free");
 
         glib_version_2_68 = !fp_glib_check_version(2, 68, 0);
@@ -3110,6 +3111,7 @@ static void gtk3_init(GtkApi* gtk) {
 
     gtk->g_string_new = fp_g_string_new;
     gtk->g_string_erase = fp_g_string_erase;
+    gtk->g_string_set_size = fp_g_string_set_size;
     gtk->g_string_free = fp_g_string_free;
     gtk->g_string_replace = fp_g_string_replace;
     gtk->g_string_printf = fp_g_string_printf;

src/java.desktop/unix/native/libawt_xawt/awt/gtk3_interface.h

@@ -758,6 +758,9 @@ static GString *(*fp_g_string_erase)(GString *string,
                                      gssize pos,
                                      gssize len);
 
+static GString *(*fp_g_string_set_size)(GString* string,
+                                        gsize len);
+
 static gchar *(*fp_g_string_free)(GString *string,
                                   gboolean free_segment);
 

src/java.desktop/unix/native/libawt_xawt/awt/gtk_interface.h

@@ -716,6 +716,10 @@ typedef struct GtkApi {
                                gssize pos,
                                gssize len);
 
+    GString *(*g_string_set_size)(GString* string,
+                                  gsize len);
+
+
     gchar *(*g_string_free)(GString *string,
                             gboolean free_segment);
 

src/java.desktop/unix/native/libawt_xawt/awt/screencast_pipewire.c

@@ -43,6 +43,9 @@ int DEBUG_SCREENCAST_ENABLED = FALSE;
                                       (*env)->ExceptionDescribe(env); \
                                    }
 
+static volatile gboolean sessionClosed = TRUE;
+static GString *activeSessionToken;
+
 struct ScreenSpace screenSpace = {0};
 static struct PwLoopData pw = {0};
 
@@ -89,8 +92,8 @@ static void doCleanup() {
         struct ScreenProps *screenProps = &screenSpace.screens[i];
         if (screenProps->data) {
             if (screenProps->data->stream) {
-                fp_pw_thread_loop_lock(pw.loop);
                 fp_pw_stream_disconnect(screenProps->data->stream);
+                fp_pw_thread_loop_lock(pw.loop);
                 fp_pw_stream_destroy(screenProps->data->stream);
                 fp_pw_thread_loop_unlock(pw.loop);
                 screenProps->data->stream = NULL;
@@ -123,7 +126,11 @@ static void doCleanup() {
     if (screenSpace.screens) {
         free(screenSpace.screens);
         screenSpace.screens = NULL;
+        screenSpace.screenCount = 0;
     }
+
+    gtk->g_string_set_size(activeSessionToken, 0);
+    sessionClosed = TRUE;
 }
 
 /**
@@ -132,6 +139,24 @@ static void doCleanup() {
 static gboolean initScreencast(const gchar *token,
                                GdkRectangle *affectedBounds,
                                gint affectedBoundsLength) {
+    gboolean isSameToken = !token
+            ? FALSE
+            : strcmp(token, activeSessionToken->str) == 0;
+
+    if (!sessionClosed) {
+        if (isSameToken) {
+            DEBUG_SCREENCAST("Reusing active session.\n", NULL);
+            return TRUE;
+        } else {
+            DEBUG_SCREENCAST(
+                    "Active session has a different token |%s| -> |%s|,"
+                    " closing current session.\n",
+                    activeSessionToken->str, token
+            );
+            doCleanup();
+        }
+    }
+
     fp_pw_init(NULL, NULL);
 
     pw.pwFd = RESULT_ERROR;
@@ -145,6 +170,8 @@ static gboolean initScreencast(const gchar *token,
         return FALSE;
     }
 
+    gtk->g_string_printf(activeSessionToken, "%s", token);
+    sessionClosed = FALSE;
     return TRUE;
 }
 
@@ -386,8 +413,19 @@ static gboolean connectStream(int index) {
 
     data->screenProps = &screenSpace.screens[index];
 
-    data->hasFormat = FALSE;
+    if (!sessionClosed && data->stream) {
+        fp_pw_thread_loop_lock(pw.loop);
+        int result = fp_pw_stream_set_active(data->stream, TRUE);
+        fp_pw_thread_loop_unlock(pw.loop);
+
+        DEBUG_SCREEN_PREFIX(data->screenProps,
+                            "stream %p: activate result |%i|\n",
+                            data->stream, result);
+
+        return result == 0; // 0 - success
+    };
 
+    data->hasFormat = FALSE;
 
     data->stream = fp_pw_stream_new(
             pw.core,
@@ -505,60 +543,64 @@ static const struct pw_core_events coreEvents = {
  * @return TRUE on success
  */
 static gboolean doLoop(GdkRectangle requestedArea) {
-    pw.loop = fp_pw_thread_loop_new("AWT Pipewire Thread", NULL);
-
-    if (!pw.loop) {
-        DEBUG_SCREENCAST("!!! Could not create a loop\n", NULL);
-        doCleanup();
-        return FALSE;
-    }
-
-    pw.context = fp_pw_context_new(
-            fp_pw_thread_loop_get_loop(pw.loop),
-            NULL,
-            0
-    );
+    if (!pw.loop && !sessionClosed) {
+        pw.loop = fp_pw_thread_loop_new("AWT Pipewire Thread", NULL);
 
-    if (!pw.context) {
-        DEBUG_SCREENCAST("!!! Could not create a pipewire context\n", NULL);
-        doCleanup();
-        return FALSE;
-    }
+        if (!pw.loop) {
+            DEBUG_SCREENCAST("!!! Could not create a loop\n", NULL);
+            doCleanup();
+            return FALSE;
+        }
 
-    if (fp_pw_thread_loop_start(pw.loop) != 0) {
-        DEBUG_SCREENCAST("!!! Could not start pipewire thread loop\n", NULL);
-        doCleanup();
-        return FALSE;
-    }
+        pw.context = fp_pw_context_new(
+                fp_pw_thread_loop_get_loop(pw.loop),
+                NULL,
+                0
+        );
 
-    fp_pw_thread_loop_lock(pw.loop);
+        if (!pw.context) {
+            DEBUG_SCREENCAST("!!! Could not create a pipewire context\n", NULL);
+            doCleanup();
+            return FALSE;
+        }
 
-    pw.core = fp_pw_context_connect_fd(
-            pw.context,
-            pw.pwFd,
-            NULL,
-            0
-    );
+        if (fp_pw_thread_loop_start(pw.loop) != 0) {
+            DEBUG_SCREENCAST("!!! Could not start pipewire thread loop\n", NULL);
+            doCleanup();
+            return FALSE;
+        }
 
-    if (!pw.core) {
-        DEBUG_SCREENCAST("!!! Could not create pipewire core\n", NULL);
-        goto fail;
-    }
+        fp_pw_thread_loop_lock(pw.loop);
 
-    pw_core_add_listener(pw.core, &pw.coreListener, &coreEvents, NULL);
+        pw.core = fp_pw_context_connect_fd(
+                pw.context,
+                pw.pwFd,
+                NULL,
+                0
+        );
 
-    for (int i = 0; i < screenSpace.screenCount; ++i) {
-        struct PwStreamData *data =
-                (struct PwStreamData*) malloc(sizeof (struct PwStreamData));
-        if (!data) {
-            ERR("failed to allocate memory\n");
+        if (!pw.core) {
+            DEBUG_SCREENCAST("!!! Could not create pipewire core\n", NULL);
             goto fail;
         }
 
-        memset(data, 0, sizeof (struct PwStreamData));
+        pw_core_add_listener(pw.core, &pw.coreListener, &coreEvents, NULL);
+    }
 
+    for (int i = 0; i < screenSpace.screenCount; ++i) {
         struct ScreenProps *screen = &screenSpace.screens[i];
-        screen->data = data;
+        if (!screen->data && !sessionClosed) {
+            struct PwStreamData *data =
+                    (struct PwStreamData*) malloc(sizeof (struct PwStreamData));
+            if (!data) {
+                ERR("failed to allocate memory\n");
+                goto fail;
+            }
+
+            memset(data, 0, sizeof (struct PwStreamData));
+
+            screen->data = data;
+        }
 
         DEBUG_SCREEN_PREFIX(screen, "@@@ adding screen %i\n", i);
         if (checkScreen(i, requestedArea)) {
@@ -746,6 +788,8 @@ JNIEXPORT jboolean JNICALL Java_sun_awt_screencast_ScreencastHelper_loadPipewire
         return JNI_FALSE;
     }
 
+    activeSessionToken = gtk->g_string_new("");
+
     gboolean usable = initXdgDesktopPortal();
     portalScreenCastCleanup();
     return usable;
@@ -783,6 +827,17 @@ static void arrayToRectangles(JNIEnv *env,
     (*env)->ReleaseIntArrayElements(env, boundsArray, body, 0);
 }
 
+/*
+ * Class:     sun_awt_screencast_ScreencastHelper
+ * Method:    closeSession
+ * Signature: ()V
+ */
+JNIEXPORT void JNICALL
+Java_sun_awt_screencast_ScreencastHelper_closeSession(JNIEnv *env, jclass cls) {
+    DEBUG_SCREENCAST("closing screencast session\n\n", NULL);
+    doCleanup();
+}
+
 /*
  * Class:     sun_awt_screencast_ScreencastHelper
  * Method:    getRGBPixelsImpl
@@ -805,7 +860,7 @@ JNIEXPORT jint JNICALL Java_sun_awt_screencast_ScreencastHelper_getRGBPixelsImpl
         boundsLen = (*env)->GetArrayLength(env, affectedScreensBoundsArray);
         EXCEPTION_CHECK_DESCRIBE();
         if (boundsLen % 4 != 0) {
-            DEBUG_SCREENCAST("%s:%i incorrect array length\n", __FUNCTION__, __LINE__);
+            DEBUG_SCREENCAST("incorrect array length\n", NULL);
             return RESULT_ERROR;
         }
         affectedBoundsLength = boundsLen / 4;
@@ -896,11 +951,12 @@ JNIEXPORT jint JNICALL Java_sun_awt_screencast_ScreencastHelper_getRGBPixelsImpl
 
             fp_pw_thread_loop_lock(pw.loop);
             fp_pw_stream_set_active(screenProps->data->stream, FALSE);
-            fp_pw_stream_disconnect(screenProps->data->stream);
             fp_pw_thread_loop_unlock(pw.loop);
+
+            screenProps->captureDataReady = FALSE;
         }
     }
-    doCleanup();
+
     releaseToken(env, jtoken, token);
     return 0;
 }

src/java.desktop/unix/native/libawt_xawt/awt/screencast_portal.c

@@ -777,6 +777,10 @@ int portalScreenCastOpenPipewireRemote() {
 }
 
 void portalScreenCastCleanup() {
+    if (!portal) {
+        return;
+    }
+
     if (portal->screenCastSessionHandle) {
         gtk->g_dbus_connection_call_sync(
                 portal->connection,
@@ -796,9 +800,6 @@ void portalScreenCastCleanup() {
         portal->screenCastSessionHandle = NULL;
     }
 
-    if (!portal) {
-        return;
-    }
     if (portal->connection) {
         gtk->g_object_unref(portal->connection);
         portal->connection = NULL;