LibGfx: Make Gfx::Bitmap::set_nonvolatile() report allocation failure

Making a bitmap non-volatile after being volatile may fail to allocate
physical pages after the kernel stole the old pages in a purge.

This is different from the pages being purged, but reallocated. In that
case, they are simply replaced with zero-fill-on-demand pages as if
they were freshly allocated.

Userland/Libraries/LibGUI/Window.cpp

@@ -410,8 +410,9 @@ void Window::handle_multi_paint_event(MultiPaintEvent& event)
         m_back_store = create_backing_store(event.window_size());
         VERIFY(m_back_store);
     } else if (m_double_buffering_enabled) {
-        bool still_has_pixels = m_back_store->bitmap().set_nonvolatile();
-        if (!still_has_pixels) {
+        bool was_purged = false;
+        bool bitmap_has_memory = m_back_store->bitmap().set_nonvolatile(was_purged);
+        if (!bitmap_has_memory || was_purged) {
             m_back_store = create_backing_store(event.window_size());
             VERIFY(m_back_store);
             created_new_backing_store = true;
@@ -1015,7 +1016,9 @@ void Window::notify_state_changed(Badge<WindowServerConnection>, bool minimized,
     if (minimized || occluded) {
         store->bitmap().set_volatile();
     } else {
-        if (!store->bitmap().set_nonvolatile()) {
+        bool was_purged = false;
+        bool bitmap_has_memory = store->bitmap().set_nonvolatile(was_purged);
+        if (!bitmap_has_memory || was_purged) {
             store = nullptr;
             update();
         }

Userland/Libraries/LibGfx/BMPLoader.cpp

@@ -1367,11 +1367,11 @@ void BMPImageDecoderPlugin::set_volatile()
         m_context->bitmap->set_volatile();
 }
 
-bool BMPImageDecoderPlugin::set_nonvolatile()
+bool BMPImageDecoderPlugin::set_nonvolatile(bool& was_purged)
 {
     if (!m_context->bitmap)
         return false;
-    return m_context->bitmap->set_nonvolatile();
+    return m_context->bitmap->set_nonvolatile(was_purged);
 }
 
 bool BMPImageDecoderPlugin::sniff()

Userland/Libraries/LibGfx/BMPLoader.h

@@ -24,7 +24,7 @@ public:
     virtual IntSize size() override;
     virtual RefPtr<Gfx::Bitmap> bitmap() override;
     virtual void set_volatile() override;
-    [[nodiscard]] virtual bool set_nonvolatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
     virtual bool sniff() override;
     virtual bool is_animated() override;
     virtual size_t loop_count() override;

Userland/Libraries/LibGfx/Bitmap.cpp

@@ -22,7 +22,7 @@
 #include <LibGfx/PNGLoader.h>
 #include <LibGfx/PPMLoader.h>
 #include <LibGfx/ShareableBitmap.h>
-#include <fcntl.h>
+#include <errno.h>
 #include <stdio.h>
 #include <sys/mman.h>
 
@@ -533,21 +533,27 @@ void Bitmap::set_volatile()
     m_volatile = true;
 }
 
-[[nodiscard]] bool Bitmap::set_nonvolatile()
+[[nodiscard]] bool Bitmap::set_nonvolatile(bool& was_purged)
 {
-    if (!m_volatile)
+    if (!m_volatile) {
+        was_purged = false;
         return true;
+    }
+
 #ifdef __serenity__
     int rc = madvise(m_data, size_in_bytes(), MADV_SET_NONVOLATILE);
     if (rc < 0) {
+        if (errno == ENOMEM) {
+            was_purged = was_purged_int;
+            return false;
+        }
+
         perror("madvise(MADV_SET_NONVOLATILE)");
-        VERIFY_NOT_REACHED();
     }
-#else
-    int rc = 0;
+    was_purged = rc != 0;
 #endif
     m_volatile = false;
-    return rc == 0;
+    return true;
 }
 
 ShareableBitmap Bitmap::to_shareable_bitmap() const
@@ -600,5 +606,4 @@ Vector<RGBA32> Bitmap::palette_to_vector() const
         vector.unchecked_append(palette_color(i).value());
     return vector;
 }
-
 }

Userland/Libraries/LibGfx/Bitmap.h

@@ -227,7 +227,10 @@ public:
 
     [[nodiscard]] bool is_volatile() const { return m_volatile; }
     void set_volatile();
-    [[nodiscard]] bool set_nonvolatile();
+
+    // Returns true if making the bitmap non-volatile succeeded. `was_purged` indicates status of contents.
+    // Returns false if there was not enough memory.
+    [[nodiscard]] bool set_nonvolatile(bool& was_purged);
 
     [[nodiscard]] Core::AnonymousBuffer& anonymous_buffer() { return m_buffer; }
     [[nodiscard]] Core::AnonymousBuffer const& anonymous_buffer() const { return m_buffer; }

Userland/Libraries/LibGfx/DDSLoader.cpp

@@ -1014,11 +1014,11 @@ void DDSImageDecoderPlugin::set_volatile()
         m_context->bitmap->set_volatile();
 }
 
-bool DDSImageDecoderPlugin::set_nonvolatile()
+bool DDSImageDecoderPlugin::set_nonvolatile(bool& was_purged)
 {
     if (!m_context->bitmap)
         return false;
-    return m_context->bitmap->set_nonvolatile();
+    return m_context->bitmap->set_nonvolatile(was_purged);
 }
 
 bool DDSImageDecoderPlugin::sniff()

Userland/Libraries/LibGfx/DDSLoader.h

@@ -245,7 +245,7 @@ public:
     virtual IntSize size() override;
     virtual RefPtr<Gfx::Bitmap> bitmap() override;
     virtual void set_volatile() override;
-    [[nodiscard]] virtual bool set_nonvolatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
     virtual bool sniff() override;
     virtual bool is_animated() override;
     virtual size_t loop_count() override;

Userland/Libraries/LibGfx/GIFLoader.cpp

@@ -655,12 +655,11 @@ void GIFImageDecoderPlugin::set_volatile()
     }
 }
 
-bool GIFImageDecoderPlugin::set_nonvolatile()
+bool GIFImageDecoderPlugin::set_nonvolatile(bool& was_purged)
 {
-    if (!m_context->frame_buffer) {
-        return true;
-    }
-    return m_context->frame_buffer->set_nonvolatile();
+    if (!m_context->frame_buffer)
+        return false;
+    return m_context->frame_buffer->set_nonvolatile(was_purged);
 }
 
 bool GIFImageDecoderPlugin::sniff()

Userland/Libraries/LibGfx/GIFLoader.h

@@ -24,7 +24,7 @@ public:
     virtual IntSize size() override;
     virtual RefPtr<Gfx::Bitmap> bitmap() override;
     virtual void set_volatile() override;
-    [[nodiscard]] virtual bool set_nonvolatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
     virtual bool sniff() override;
     virtual bool is_animated() override;
     virtual size_t loop_count() override;

Userland/Libraries/LibGfx/ICOLoader.cpp

@@ -352,11 +352,11 @@ void ICOImageDecoderPlugin::set_volatile()
         m_context->images[0].bitmap->set_volatile();
 }
 
-bool ICOImageDecoderPlugin::set_nonvolatile()
+bool ICOImageDecoderPlugin::set_nonvolatile(bool& was_purged)
 {
     if (!m_context->images[0].bitmap)
         return false;
-    return m_context->images[0].bitmap->set_nonvolatile();
+    return m_context->images[0].bitmap->set_nonvolatile(was_purged);
 }
 
 bool ICOImageDecoderPlugin::sniff()

Userland/Libraries/LibGfx/ICOLoader.h

@@ -24,7 +24,7 @@ public:
     virtual IntSize size() override;
     virtual RefPtr<Gfx::Bitmap> bitmap() override;
     virtual void set_volatile() override;
-    [[nodiscard]] virtual bool set_nonvolatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
     virtual bool sniff() override;
     virtual bool is_animated() override;
     virtual size_t loop_count() override;

Userland/Libraries/LibGfx/ImageDecoder.h

@@ -33,7 +33,7 @@ public:
     virtual RefPtr<Gfx::Bitmap> bitmap() = 0;
 
     virtual void set_volatile() = 0;
-    [[nodiscard]] virtual bool set_nonvolatile() = 0;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) = 0;
 
     virtual bool sniff() = 0;
 
@@ -63,7 +63,7 @@ public:
         if (m_plugin)
             m_plugin->set_volatile();
     }
-    [[nodiscard]] bool set_nonvolatile() { return m_plugin ? m_plugin->set_nonvolatile() : false; }
+    [[nodiscard]] bool set_nonvolatile(bool& was_purged) { return m_plugin ? m_plugin->set_nonvolatile(was_purged) : false; }
     bool sniff() const { return m_plugin ? m_plugin->sniff() : false; }
     bool is_animated() const { return m_plugin ? m_plugin->is_animated() : false; }
     size_t loop_count() const { return m_plugin ? m_plugin->loop_count() : 0; }

Userland/Libraries/LibGfx/JPGLoader.cpp

@@ -1295,11 +1295,11 @@ void JPGImageDecoderPlugin::set_volatile()
         m_context->bitmap->set_volatile();
 }
 
-bool JPGImageDecoderPlugin::set_nonvolatile()
+bool JPGImageDecoderPlugin::set_nonvolatile(bool& was_purged)
 {
     if (!m_context->bitmap)
         return false;
-    return m_context->bitmap->set_nonvolatile();
+    return m_context->bitmap->set_nonvolatile(was_purged);
 }
 
 bool JPGImageDecoderPlugin::sniff()

Userland/Libraries/LibGfx/JPGLoader.h

@@ -25,7 +25,7 @@ public:
     virtual IntSize size() override;
     virtual RefPtr<Gfx::Bitmap> bitmap() override;
     virtual void set_volatile() override;
-    [[nodiscard]] virtual bool set_nonvolatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
     virtual bool sniff() override;
     virtual bool is_animated() override;
     virtual size_t loop_count() override;

Userland/Libraries/LibGfx/PBMLoader.cpp

@@ -156,12 +156,12 @@ void PBMImageDecoderPlugin::set_volatile()
         m_context->bitmap->set_volatile();
 }
 
-bool PBMImageDecoderPlugin::set_nonvolatile()
+bool PBMImageDecoderPlugin::set_nonvolatile(bool& was_purged)
 {
     if (!m_context->bitmap)
         return false;
 
-    return m_context->bitmap->set_nonvolatile();
+    return m_context->bitmap->set_nonvolatile(was_purged);
 }
 
 bool PBMImageDecoderPlugin::sniff()

Userland/Libraries/LibGfx/PBMLoader.h

@@ -25,7 +25,7 @@ public:
     virtual RefPtr<Gfx::Bitmap> bitmap() override;
 
     virtual void set_volatile() override;
-    [[nodiscard]] virtual bool set_nonvolatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
 
     virtual bool sniff() override;
 

Userland/Libraries/LibGfx/PGMLoader.cpp

@@ -159,12 +159,12 @@ void PGMImageDecoderPlugin::set_volatile()
         m_context->bitmap->set_volatile();
 }
 
-bool PGMImageDecoderPlugin::set_nonvolatile()
+bool PGMImageDecoderPlugin::set_nonvolatile(bool& was_purged)
 {
     if (!m_context->bitmap)
         return false;
 
-    return m_context->bitmap->set_nonvolatile();
+    return m_context->bitmap->set_nonvolatile(was_purged);
 }
 
 bool PGMImageDecoderPlugin::sniff()

Userland/Libraries/LibGfx/PGMLoader.h

@@ -25,7 +25,7 @@ public:
     virtual RefPtr<Gfx::Bitmap> bitmap() override;
 
     virtual void set_volatile() override;
-    [[nodiscard]] virtual bool set_nonvolatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
 
     virtual bool sniff() override;
 

Userland/Libraries/LibGfx/PNGLoader.cpp

@@ -984,11 +984,11 @@ void PNGImageDecoderPlugin::set_volatile()
         m_context->bitmap->set_volatile();
 }
 
-bool PNGImageDecoderPlugin::set_nonvolatile()
+bool PNGImageDecoderPlugin::set_nonvolatile(bool& was_purged)
 {
     if (!m_context->bitmap)
         return false;
-    return m_context->bitmap->set_nonvolatile();
+    return m_context->bitmap->set_nonvolatile(was_purged);
 }
 
 bool PNGImageDecoderPlugin::sniff()

Userland/Libraries/LibGfx/PNGLoader.h

@@ -24,7 +24,7 @@ public:
     virtual IntSize size() override;
     virtual RefPtr<Gfx::Bitmap> bitmap() override;
     virtual void set_volatile() override;
-    [[nodiscard]] virtual bool set_nonvolatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
     virtual bool sniff() override;
     virtual bool is_animated() override;
     virtual size_t loop_count() override;

Userland/Libraries/LibGfx/PPMLoader.cpp

@@ -161,12 +161,12 @@ void PPMImageDecoderPlugin::set_volatile()
         m_context->bitmap->set_volatile();
 }
 
-bool PPMImageDecoderPlugin::set_nonvolatile()
+bool PPMImageDecoderPlugin::set_nonvolatile(bool& was_purged)
 {
     if (!m_context->bitmap)
         return false;
 
-    return m_context->bitmap->set_nonvolatile();
+    return m_context->bitmap->set_nonvolatile(was_purged);
 }
 
 bool PPMImageDecoderPlugin::sniff()

Userland/Libraries/LibGfx/PPMLoader.h

@@ -25,7 +25,7 @@ public:
     virtual RefPtr<Gfx::Bitmap> bitmap() override;
 
     virtual void set_volatile() override;
-    [[nodiscard]] virtual bool set_nonvolatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
 
     virtual bool sniff() override;
 

Userland/Libraries/LibWeb/Loader/ImageResource.cpp

@@ -97,8 +97,9 @@ void ImageResource::update_volatility()
         if (!frame.bitmap) {
             still_has_decoded_image = false;
         } else {
-            bool still_has_frame = frame.bitmap->set_nonvolatile();
-            if (!still_has_frame)
+            bool was_purged = false;
+            bool bitmap_has_memory = frame.bitmap->set_nonvolatile(was_purged);
+            if (!bitmap_has_memory || was_purged)
                 still_has_decoded_image = false;
         }
     }