From e54626f4c1b5cb4de0b5dc86d820bb36c1d6499f Mon Sep 17 00:00:00 2001 From: Andrew Leech Date: Mon, 1 Jun 2020 16:16:25 +1000 Subject: [PATCH] docs/reference: Add note about multiple exceptions when heap is locked. --- docs/reference/isr_rules.rst | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/docs/reference/isr_rules.rst b/docs/reference/isr_rules.rst index 57690ac212..7f466ab42f 100644 --- a/docs/reference/isr_rules.rst +++ b/docs/reference/isr_rules.rst @@ -43,6 +43,11 @@ for the purpose. Debugging is simplified if the following code is included in an import micropython micropython.alloc_emergency_exception_buf(100) +The emergency exception buffer can only hold one exception stack trace. This means that if a second exception is +thrown during the handling of an exception while the heap is locked, that second exception's stack trace will +replace the original one - even if the second exception is cleanly handled. This can lead to confusing exception +messages if the buffer is later printed. + Simplicity ~~~~~~~~~~