The fact that queryPathInfo() is synchronous meant that we needed a
thread for every concurrent binary cache lookup, even though they end
up being handled by the same download thread. Requiring hundreds of
threads is not a good idea. So now there is an asynchronous version of
queryPathInfo() that takes a callback function to process the
result. Similarly, enqueueDownload() now takes a callback rather than
returning a future.
Thus, a command like
nix path-info --store https://cache.nixos.org/ -r /nix/store/slljrzwmpygy1daay14kjszsr9xix063-nixos-16.09beta231.dccf8c5
that returns 4941 paths now takes 1.87s using only 2 threads (the main
thread and the downloader thread). (This is with a prewarmed
CloudFront.)
It's a slight misnomer now because it actually limits *all* downloads,
not just binary cache lookups.
Also add a "enable-http2" option to allow disabling use of HTTP/2
(enabled by default).
The binary cache store can now use HTTP/2 to do lookups. This is much
more efficient than HTTP/1.1 due to multiplexing: we can issue many
requests in parallel over a single TCP connection. Thus it's no longer
necessary to use a bunch of concurrent TCP connections (25 by
default).
For example, downloading 802 .narinfo files from
https://cache.nixos.org/, using a single TCP connection, takes 11.8s
with HTTP/1.1, but only 0.61s with HTTP/2.
This did require a fairly substantial rewrite of the Downloader class
to use the curl multi interface, because otherwise curl wouldn't be
able to do multiplexing for us. As a bonus, we get connection reuse
even with HTTP/1.1. All downloads are now handled by a single worker
thread. Clients call Downloader::enqueueDownload() to tell the worker
thread to start the download, getting a std::future to the result.
This largely reverts c68e5913c7. Running
builds as root breaks "cp -p", since when running as root, "cp -p"
assumes that it can succesfully chown() files. But that's not actually
the case since the user namespace doesn't provide a complete uid
mapping. So it barfs with a fatal error message ("cp: failed to
preserve ownership for 'foo': Invalid argument").
BASH_ENV causes all non-interactive shells called via eg. /etc/bashrc to
remove the rc-file before the main shell gets to run it. Completion
scripts will often do this. Fixes#976.
Adapted from and fixes#1034.
* exwm-floating.el (exwm-floating--set-floating):
* exwm-workspace.el (exwm-workspace-move-window):
Buffers visible on other frames should be treated as invisible. One
side effect is visible buffers on the current frame is also taken into
account.
This is a small change that improves the behavior of
`exwm-workspace-move-window` in the following situation:
0. `exwm-workspace-show-all-buffers` and `exwm-layout-show-all-buffers`
are `nil`*.
1. On active workspace `i`, there is X window `a` in the selected Emacs
window.
2. On workspace `j`, there is X window `b` in the selected Emacs window
on that workspace frame.
3. While workspace `i` is active, use `exwm-workspace-move-window` to
move `a` to workspace `j`.
4. Switch to workspace `j` and use `exwm-workspace-move-window` to move
`a` back to workspace `i`.
Expected behavior: X window `a` is once again shown in the selected
Emacs window on workspace `i` and X window `b` is once again shown in
the selected Emacs window on workspace `j`.
What is observed: `a` is OK but the selected Emacs window on workspace
`j` does not show `b`. However, `b` is the first candidate when doing a
`switch-to-buffer` in that Emacs window on workspace `j`.
I'm not sure if this is the correct and complete change required, but it
is working well so far.
*The expected behavior is observed with EXWM 0.10 if
exwm-{workspace,layout}-show-all-buffers are non-nil.
This fixes an assertion failure in "assert(goal);" in
Worker::waitForInput() after a substitution goal is cancelled by the
termination of another goal. The problem was the line
//worker.childTerminated(shared_from_this()); // FIXME
in the SubstitutionGoal destructor. This was disabled because
shared_from_this() obviously doesn't work from a destructor. So we now
use a real pointer for object identity.
The implementation of "partition" in Nixpkgs is O(n^2) (because of the
use of ++), and for some reason was causing stack overflows in
multi-threaded evaluation (not sure why).
This reduces "nix-env -qa --drv-path" runtime by 0.197s and memory
usage by 298 MiB (in non-Boehm mode).
