NGX_HTTP_SUBREQUEST_WAITED argument to ngx_http_subrequest?

[Brian Moran]

What does the NGX_HTTP_SUBREQUEST_WAITED argument indicate to 
ngx_http_subrequest?

I am using the ngx_zip_module, and experimenting with generating a file 
that is composed of hundreds of sub-requests.

I *think* that many of the subrequests are being executed (or at least 
started) in parallel; I'd like to be able to limit or serialize the 
subrequests, and ran across this flag....

Thanks,

Brian Moran