We've recently updated a view which displays photos via a CoreImage chain from a NSOpenGLView subclass to a NSView with a backing CAMetalLayer. Things are mostly working fine, but we occasionally hit a deadlock involving CALayer and CIMetalCommandQueue. I've made a spindump, it appears none of our code is involved in the locked threads. Despite this, I'm assuming the problem is ours 😅 I saw the mention in the CAMetalLayer documentation about releasing drawables with an @autoreleasepool in drawRect, we have done this and I can't find any places we're retaining a drawable outside drawRect. https://developer.apple.com/documentation/quartzcore/cametallayer?language=objc I am seeing this on macOS 15.0.1, M2 Max MacBookPro. We haven't seen it on macOS 14.x but it may be luck as we have not tested much on that OS. I don't know how to move forward debugging this, any help much appreciated! The two locking threads in the spindump are MainThread and CI::RenderCompletionQueue. Thread 0xb3b0f8 DispatchQueue "com.apple.main-thread"(1) … CA::Layer::commit_if_needed(CA::Transaction*, void (CA::Layer*, unsigned int, unsigned int) block_pointer) + 364 (QuartzCore + 178484) [0x1a5dba934] invocation function for block in CA::Context::commit_transaction(CA::Transaction*, double, double*) + 176 (QuartzCore + 1782676) [0x1a5f42394] -[CALayer(CALayerPrivate) _copyRenderLayer:layerFlags:commitFlags:] + 720 (QuartzCore + 179304) [0x1a5dbac68] -[NSImage(CALayerSupport) CA_copyRenderValue] + 52 (AppKit + 1517960) [0x1a0fe0988] -[NSImage CGImageForProposedRect:context:hints:] + 440 (AppKit + 1246368) [0x1a0f9e4a0] -[NSImage _usingBestRepresentationForRect:context:hints:body:] + 148 (AppKit + 1247980) [0x1a0f9eaec] __48-[NSImage CGImageForProposedRect:context:hints:]_block_invoke + 80 (AppKit + 1248792) [0x1a0f9ee18] -[NSCIImageRep CGImageForProposedRect:context:hints:] + 112 (AppKit + 6200292) [0x1a1457be4] +[CIContext contextWithOptions:] + 40 (CoreImage + 549532) [0x1a8df129c] -[CIContext initWithOptions:] + 588 (CoreImage + 65744) [0x1a8d7b0d0] +[CIContext(Internal) internalContextWithMTLDevice:options:] + 76 (CoreImage + 66568) [0x1a8d7b408] CIMetalCommandQueueCreate + 52 (CoreImage + 66692) [0x1a8d7b484] -[CaptureMTLDevice newCommandQueue] + 168 (GPUToolsCapture + 130200) [0x1029e7c98] -[CaptureMTLCommandQueue initWithBaseObject:captureDevice:] + 204 (GPUToolsCapture + 799812) [0x102a8b444] GTMTLGuestAppClientAddMTLCommandQueueInfo + 108 (GPUToolsCapture + 313572) [0x102a148e4] __ulock_wait2 + 8 (libsystem_kernel.dylib + 60540) [0x19d24bc7c] *??? (kernel.release.t6020 + 6102048) [0xfffffe0008cd5c20] (blocked by turnstile waiting for Phocus [11343] [unique pid 1001657] thread 0xb41b08 - part of a deadlock) and Thread 0xb41b08 DispatchQueue "CI::RenderCompletionQueue"(535) 1000 samples (1-1000) priority 46 (base 46) start_wqthread + 8 (libsystem_pthread.dylib + 52464) [0x1035f4cf0] _pthread_wqthread + 288 (libsystem_pthread.dylib + 20736) [0x1035ed100] _dispatch_workloop_worker_thread + 580 (libdispatch.dylib + 129956) [0x1026afba4] _dispatch_root_queue_drain_deferred_wlh + 652 (libdispatch.dylib + 133360) [0x1026b08f0] _dispatch_lane_invoke + 468 (libdispatch.dylib + 68516) [0x1026a0ba4] _dispatch_lane_serial_drain + 860 (libdispatch.dylib + 64160) [0x10269faa0] _dispatch_client_callout + 20 (libdispatch.dylib + 26788) [0x1026968a4] _dispatch_call_block_and_release + 32 (libdispatch.dylib + 19300) [0x102694b64] CI::Object::unref() const + 120 (CoreImage + 35360) [0x1a8d73a20] CI::MetalContext::~MetalContext() + 16 (CoreImage + 192260) [0x1a8d99f04] CI::MetalContext::~MetalContext() + 236 (CoreImage + 192536) [0x1a8d9a018] -[CaptureMTLCommandQueue dealloc] + 44 (GPUToolsCapture + 797916) [0x102a8acdc] GTMTLGuestAppClientRemoveMTLCommandQueueInfo + 236 (GPUToolsCapture + 314240) [0x102a14b80] GTMTLGuestAppClient_allCaptureObjectsUnsafe + 392 (GPUToolsCapture + 298776) [0x102a10f18] AllMetalLayers + 64 (GPUToolsCapture + 518224) [0x102a46850] MakeLayerInfos + 320 (GPUToolsCapture + 518608) [0x102a469d0] -[CALayer frame] + 88 (QuartzCore + 74624) [0x1a5da1380] __ulock_wait2 + 8 (libsystem_kernel.dylib + 60540) [0x19d24bc7c] *??? (kernel.release.t6020 + 6102048) [0xfffffe0008cd5c20] (blocked by turnstile waiting for Phocus [11343] [unique pid 1001657] thread 0xb3b0f8 - part of a deadlock)

Hi all,We're developing an app which involves BTLE communication between Android and iOS.We have Android5.0+ in Peripheral mode and iOS in Central.We've been developing this for a few months, I've been testing the iOS side on phones from 4S to 6S from iOS8.1 to the iOS10.0.1 release. All was good.This week we got our first iPhone 7. It's lovely, but to my horror, we're unable to complete our data transfer to the Android BTLE Peripherals. After scanning and successfully connecting to the peripheral we set the delegate and call -discoverServices as normal but the delegate method never gets called back.I tested both iOS10.0 14A346 (that it shipped with) and current 10.0.1 14A403.My didConnectPeripheral implementation looks like:func centralManager(central: CBCentralManager, didConnectPeripheral peripheral: CBPeripheral) { DLog("Connected: \(peripheral)") self.lastPeripheral = peripheral if peripheral.services == nil { peripheral.discoverServices([lockServiceUUIDBase]) assert(peripheral.delegate != nil) } else { DLog("Services already exist, shortcutting") self.peripheral(peripheral, didDiscoverServices: nil) } }Nothing too fancy. This method gets called, the assert doesn't throw, but -didDiscoverServices never gets called. I have tried removing the specific service UUID's but it made no difference.Has anyone else run into this?Thanks in advance.Alex Kent