From 2a72ad4071b3b5612492f85ee6bd50e35c90128b Mon Sep 17 00:00:00 2001
From: "A. Unique TensorFlower" <gardener@tensorflow.org>
Date: Mon, 27 Apr 2020 20:10:17 -0700
Subject: [PATCH] TFLite Metal delegate: Memory leak when aggressive wait mode
 is used has been fixed.

PiperOrigin-RevId: 308749950
Change-Id: I5786e1673984df9c22399726b2b638670f9b1d5c
---
 .../lite/delegates/gpu/metal_delegate.mm      | 28 ++++++++++---------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/tensorflow/lite/delegates/gpu/metal_delegate.mm b/tensorflow/lite/delegates/gpu/metal_delegate.mm
index 47155e045d7..8b8bfe147c3 100644
--- a/tensorflow/lite/delegates/gpu/metal_delegate.mm
+++ b/tensorflow/lite/delegates/gpu/metal_delegate.mm
@@ -120,19 +120,21 @@ class GpuAlarmClock {
       alarm_thread_ = std::thread([this]() {
         id<MTLCommandBuffer> prev_command_buffer;
         while (!release_thread_) {
-          if (active_alarms_ == total_alarms_) {
-            id<MTLCommandBuffer> command_buffer = [command_queue_ commandBuffer];
-            id<MTLComputeCommandEncoder> encoder = [command_buffer computeCommandEncoder];
-            [encoder setComputePipelineState:stub_program_];
-            [encoder setBuffer:stub_buffer_ offset:0 atIndex:0];
-            [encoder dispatchThreadgroups:MTLSizeMake(1, 1, 1)
-                    threadsPerThreadgroup:MTLSizeMake(1, 1, 1)];
-            [encoder endEncoding];
-            [command_buffer commit];
-            if (prev_command_buffer != nil) [prev_command_buffer waitUntilScheduled];
-            prev_command_buffer = command_buffer;
-          } else {
-            std::this_thread::sleep_for(std::chrono::milliseconds(1));
+          @autoreleasepool {
+            if (active_alarms_ == total_alarms_) {
+              id<MTLCommandBuffer> command_buffer = [command_queue_ commandBuffer];
+              id<MTLComputeCommandEncoder> encoder = [command_buffer computeCommandEncoder];
+              [encoder setComputePipelineState:stub_program_];
+              [encoder setBuffer:stub_buffer_ offset:0 atIndex:0];
+              [encoder dispatchThreadgroups:MTLSizeMake(1, 1, 1)
+                      threadsPerThreadgroup:MTLSizeMake(1, 1, 1)];
+              [encoder endEncoding];
+              [command_buffer commit];
+              if (prev_command_buffer != nil) [prev_command_buffer waitUntilScheduled];
+              prev_command_buffer = command_buffer;
+            } else {
+              std::this_thread::sleep_for(std::chrono::milliseconds(1));
+            }
           }
         }
       });