Issue 0449: What is the value of TSS_DTOR_ITERATIONS for implementations with no maximum?

This issue has been automatically converted from the original issue lists and some formatting may not have been preserved.

Authors: WG 14, Douglas Walls
Date: 2013-08-24
Reference document: N1744
Submitted against: C11 / C17
Status: Closed
Converted from: n2396.htm

Summary

Suggested Technical Corrigendum

Comment from WG14 on 2015-04-17:

Oct 2013 meeting

Committee Discussion

• The committee notes that existing practice in all cases has provided a small integer value for this definition.
• Allowing no restrictions is likely to break existing practice.

Apr 2014 meeting

Committee Discussion

The question posed should be answered.

Proposed Committee Response

The standard intentionally does not define a value of TSS_DTOR_ITERATIONS for implementations with no maximum.

The TSS_DTOR_ITERATIONS macro is used to limit recursion at thread termination. The issue is that existing practice allows the creation of new tss bindings during the destructor call, and one destructor might reincarnate the original, thus forming an infinite recursive destructor loop. This loop may appear non-deterministically and is difficult to detect. The purpose of TSS_DTOR_ITERATIONS is as a bound to such recursion.

It is possible monitor the recursion depth with careful defensive programming and in those cases the value of TSS_DTOR_ITERATIONS is useful as that bound.