From f3e7d10d076bf53516fcb9a2aa11b00a01ed3bb6 Mon Sep 17 00:00:00 2001 From: Martin Ling Date: Mon, 16 Dec 2024 21:19:12 +0000 Subject: [PATCH 25/75] Add comment about constraints on locking primitives. --- firmware/common/locking.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/firmware/common/locking.h b/firmware/common/locking.h index 80fbf12f..392b689d 100644 --- a/firmware/common/locking.h +++ b/firmware/common/locking.h @@ -26,6 +26,12 @@ #include +/* Primitives for implementing locking. + * + * Must always be used in a pair, with a call to load_exclusive being + * followed immediately or near-immediately by a call to store_exclusive(). + * Failure to observe this rule may lead to undefined results. */ + // Use ldrex and strex directly if available. // Otherwise, disable interrupts to ensure exclusivity. #if defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7EM__) -- 2.47.3