From 797d6d3fe0c5b14feb41d6352654254368ba889c Mon Sep 17 00:00:00 2001
From: Alexander Schneider <aschneider1@meta.com>
Date: Fri, 13 Dec 2024 14:22:00 -0800
Subject: [PATCH] add isEmpty() method to and fix bug in Ocean::ThreadPool

Reviewed By: janherling

Differential Revision: D67174302

fbshipit-source-id: 1201715719507ffa5d803de656c82f05ec353d4a
---
 impl/ocean/base/ThreadPool.cpp |  2 +-
 impl/ocean/base/ThreadPool.h   | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/impl/ocean/base/ThreadPool.cpp b/impl/ocean/base/ThreadPool.cpp
index 3663d8a4c..67bc6f1b1 100644
--- a/impl/ocean/base/ThreadPool.cpp
+++ b/impl/ocean/base/ThreadPool.cpp
@@ -175,7 +175,7 @@ void ThreadPool::threadRun()
 				}
 			}
 
-			while (capacity_ < busyPoolThreads_.size() + idlePoolThreads_.size() && idlePoolThreads_.empty())
+			while (capacity_ < busyPoolThreads_.size() + idlePoolThreads_.size() && !idlePoolThreads_.empty())
 			{
 				// we have an idle pool thread and we have more threads than the specified capacity (e.g., because the capacity has been reduced lately)
 
diff --git a/impl/ocean/base/ThreadPool.h b/impl/ocean/base/ThreadPool.h
index fb9e5307c..acab73eea 100644
--- a/impl/ocean/base/ThreadPool.h
+++ b/impl/ocean/base/ThreadPool.h
@@ -145,6 +145,12 @@ class OCEAN_BASE_EXPORT ThreadPool : protected Thread
 		 */
 		inline size_t pending() const;
 
+		/**
+		 * Returns whether the ThreadPool has completed all jobs that have been submitted
+		 * @return True, if the results of size() and pending() are atomically both 0
+		 */
+		inline bool isEmpty() const;
+
 	protected:
 
 		/**
@@ -220,6 +226,13 @@ inline size_t ThreadPool::pending() const
 	return pendingFunctions_.size();
 }
 
+inline bool ThreadPool::isEmpty() const
+{
+	const ScopedLock scopedLock(lock_);
+
+	return (pendingFunctions_.size() + busyPoolThreads_.size()) == 0;
+}
+
 }
 
 #endif // META_OCEAN_BASE_THREAD_POOL_H