817202 - asyncOpen of jar:file:// does blocking I/O on main thread

Status: RESOLVED DUPLICATE of bug 1373708

(Core :: Networking: JAR, defect)

Description

[Jason Duell]

CreateJarInput() winds up calling (via the zipcache) all the way down to nsZipHandle::Init(), which does OpenNSPRFileDesc() and PR_MemMap().  No particular reason this needs to block main thread AFAICT--we're already past the point in AsyncOpen where we're committed to returning NS_OK and returning errors via OnStopRequest.

Comment 1

[Jason Duell]

CreateJarInput call:

   http://mxr.mozilla.org/mozilla-central/source/modules/libjar/nsJARChannel.cpp?rev=736e9f98d97a#711

and comment that says we're no longer returning errors synchronously:

   http://mxr.mozilla.org/mozilla-central/source/modules/libjar/nsJARChannel.cpp?rev=736e9f98d97a#692

Comment 2

[Jason Duell]

Note that with jar caching this only happens once per jarfile in the common case, not per channel.

Comment 3

[Dietrich Ayala (:dietrich)]

Jason is this worth pursuing? What kind of win?

Comment 4

[David Teller [:Yoric] - still alive but not very active]

Well, main thread I/O is always bad. I believe that this is worth pursuing.