--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/MTLTexurePool.m	Fri Jun 21 12:08:37 2019 +0530
@@ -0,0 +1,92 @@
+#import "MTLTexturePool.h"
+#import "Trace.h"
+
+@implementation MTLTexturePoolItem
+
+@synthesize texture;
+@synthesize isBusy;
+
+- (id) initWithTexture:(id<MTLTexture>)tex {
+    self = [super init];
+    if (self == nil) return self;
+    self.texture = tex;
+    isBusy = NO;
+    return self;
+}
+@end
+
+@implementation MTLTexturePool
+
+@synthesize device;
+@synthesize pool;
+
+- (id) initWithDevice:(id<MTLDevice>)dev {
+    self = [super init];
+    if (self == nil) return self;
+
+    self.device = dev;
+    self.pool = [NSMutableArray arrayWithCapacity:10];
+    return self;
+}
+
+// NOTE: called from RQ-thread (on blit operations)
+- (id<MTLTexture>) getTexture:(int)width height:(int)height format:(MTLPixelFormat)format {
+    @synchronized (self) {
+        // 1. find free item
+        // TODO: optimize search, use Map<(w,h,pf), TexPoolItem>
+        const int count = [self.pool count];
+        for (int c = 0; c < count; ++c) {
+            MTLTexturePoolItem *tpi = [self.pool objectAtIndex:c];
+            if (tpi == nil)
+                continue;
+            // TODO: use checks tpi.texture.width <= width && tpi.texture.height <= height
+            if (tpi.texture.width == width && tpi.texture.height == height && tpi.texture.pixelFormat == format &&
+                !tpi.isBusy) {
+                tpi.isBusy = YES;
+                return tpi.texture;
+            }
+        }
+
+        // 2. create
+        MTLTextureDescriptor *textureDescriptor = [MTLTextureDescriptor texture2DDescriptorWithPixelFormat:format width:width height:height mipmapped:NO];
+        id <MTLTexture> tex = [self.device newTextureWithDescriptor:textureDescriptor];
+        MTLTexturePoolItem *tpi = [[MTLTexturePoolItem alloc] initWithTexture:tex];
+        [self.pool addObject:tpi];
+        J2dTraceLn4(J2D_TRACE_VERBOSE, "MTLTexturePool: created pool item: tex=%p, w=%d h=%d, pf=%d", tex, width, height, format);
+        return tpi.texture;
+    }
+};
+
+// NOTE: called from completion-handler (pooled thread)
+- (void) markTextureFree:(id<MTLTexture>)texture {
+    // TODO: optimize search, use Map<(w,h,pf), TexPoolItem>
+    @synchronized (self) {
+        const int count = [self.pool count];
+        for (int c = 0; c < count; ++c) {
+            MTLTexturePoolItem * tpi = [self.pool objectAtIndex:c];
+            if (tpi == nil)
+                continue;
+            if (tpi.texture == texture) {
+                tpi.isBusy = NO;
+                return;
+            }
+        }
+        J2dTraceLn1(J2D_TRACE_ERROR, "MTLTexturePool: can't find item with texture %p", texture);
+    }
+}
+
+// NOTE: called from completion-handler (pooled thread)
+- (void) markAllTexturesFree {
+    @synchronized (self) {
+        const int count = [self.pool count];
+        for (int c = 0; c < count; ++c) {
+            MTLTexturePoolItem *tpi = [self.pool objectAtIndex:c];
+            if (tpi == nil)
+                continue;
+            tpi.isBusy = NO;
+        }
+    }
+}
+
+
+@end
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