From cb6d9d4d80079a76c7821836c73ade0a675cad99 Mon Sep 17 00:00:00 2001
From: "Alexander A. Klimov" <alexander.klimov@icinga.com>
Date: Mon, 25 Aug 2025 15:04:17 +0200
Subject: [PATCH] Make IoEngine#m_CpuBoundSemaphore unsigned

---
 lib/base/io-engine.cpp | 6 +++---
 lib/base/io-engine.hpp | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/base/io-engine.cpp b/lib/base/io-engine.cpp
index ce531923a..0c0be835e 100644
--- a/lib/base/io-engine.cpp
+++ b/lib/base/io-engine.cpp
@@ -77,10 +77,10 @@ bool CpuBoundWork::TryAcquireSlot()
 	auto& ie (IoEngine::Get());
 	auto freeSlots (ie.m_CpuBoundSemaphore.load());
 
-	while (freeSlots > 0) {
+	while (freeSlots > 0u) {
 		// If ie.m_CpuBoundSemaphore was changed after the last load,
 		// compare_exchange_weak() will load its latest value into freeSlots for us to retry until...
-		if (ie.m_CpuBoundSemaphore.compare_exchange_weak(freeSlots, freeSlots - 1)) {
+		if (ie.m_CpuBoundSemaphore.compare_exchange_weak(freeSlots, freeSlots - 1u)) {
 			// ... either we successfully decrement ie.m_CpuBoundSemaphore by one, ...
 			return true;
 		}
@@ -106,7 +106,7 @@ void CpuBoundWork::Done()
 		// The constructor takes the slow path only if the semaphore is full,
 		// so we only have to wake up constructors if the semaphore was full.
 		// This works because after fetch_add(), TryAcquireSlot() (fast path) will succeed.
-		if (ie.m_CpuBoundSemaphore.fetch_add(1) == 0) {
+		if (ie.m_CpuBoundSemaphore.fetch_add(1) == 0u) {
 			// So now there are only slow path subscribers from just before the fetch_add() to be woken up.
 			// Precisely, only subscribers from just before the fetch_add() which turned 0 to 1.
 
diff --git a/lib/base/io-engine.hpp b/lib/base/io-engine.hpp
index 23be1a146..b48ae6012 100644
--- a/lib/base/io-engine.hpp
+++ b/lib/base/io-engine.hpp
@@ -157,7 +157,7 @@ private:
 	std::vector<std::thread> m_Threads;
 	boost::asio::deadline_timer m_AlreadyExpiredTimer;
 
-	std::atomic_int_fast32_t m_CpuBoundSemaphore;
+	std::atomic_uint_fast32_t m_CpuBoundSemaphore;
 	std::mutex m_CpuBoundWaitingMutex;
 	std::vector<std::pair<boost::asio::io_context::strand, Shared<AsioConditionVariable>::Ptr>> m_CpuBoundWaiting;
 };