AMDG
On 10/05/2017 08:12 PM, Stefan Seefeld via Boost-build wrote:
<snip>
I'm looking at
https://github.com/boostorg/build/blob/develop/src/engine/make1.c#L326, and
wonder why, despite the inline comment above the referenced line, this is not
the first statement to be executed in the make1a function. I understand that the
make1a function may be called multiple times from different locations, but
should be ignored (i.e., should be a noop) in all but one case.
However, each time the function is called, its parent's async counter is
incremented (as long as this target 's progress is not yet RUNNING).
Example:
A depends on C
B depends on C
We enter make1a for C twice, once with each parent,
A and B. A and B both need to wait for C to complete,
hence we increment the async counter both times.
We only skip this if C has already completed, and
no waiting is required.