* [PATCH 3/6] qspawn: shorten lifetime of circular references
2019-09-17 8:31 7% [PATCH 0/6] qspawn-related cleanups, comments, and minor fix Eric Wong
@ 2019-09-17 8:31 7% ` Eric Wong
0 siblings, 0 replies; 2+ results
From: Eric Wong @ 2019-09-17 8:31 UTC (permalink / raw)
To: meta
All of these circular references are designed to clear
themselves, but these will make actual errors from Devel::Cycle
easier-to-spot.
The circular reference in the limiter {run_queue} is not a real
problem, but we can avoid storing the circular reference until
we actually need to spawn the child, reducing the size of the
Qspawn object while it's in the queue, slightly.
We also do not need to have redundant checks to spawn new
processes, we should only spawn new processes when they're
->start-ed or after waitpid reaps them.
---
lib/PublicInbox/Qspawn.pm | 28 +++++++++-------------------
1 file changed, 9 insertions(+), 19 deletions(-)
diff --git a/lib/PublicInbox/Qspawn.pm b/lib/PublicInbox/Qspawn.pm
index 844d50f..10fe534 100644
--- a/lib/PublicInbox/Qspawn.pm
+++ b/lib/PublicInbox/Qspawn.pm
@@ -44,11 +44,11 @@ sub new ($$$;) {
}
sub _do_spawn {
- my ($self, $cb) = @_;
+ my ($self, $cb, $limiter) = @_;
my $err;
my ($cmd, $env, $opts) = @{$self->{args}};
my %opts = %{$opts || {}};
- my $limiter = $self->{limiter};
+ $self->{limiter} = $limiter;
foreach my $k (PublicInbox::Spawn::RLIMITS()) {
if (defined(my $rlimit = $limiter->{$k})) {
$opts{$k} = $rlimit;
@@ -94,21 +94,21 @@ sub waitpid_err ($$) {
$err = "W: waitpid($xpid, 0) => $pid: $!";
} # else should not be called with pid == 0
+ my $env = delete $self->{env};
+
# done, spawn whatever's in the queue
my $limiter = $self->{limiter};
my $running = --$limiter->{running};
- # limiter->{max} may change dynamically
- if (($running || $limiter->{running}) < $limiter->{max}) {
- if (my $next = shift @{$limiter->{run_queue}}) {
- _do_spawn(@$next);
+ if ($running < $limiter->{max}) {
+ if (my $next = shift(@{$limiter->{run_queue}})) {
+ _do_spawn(@$next, $limiter);
}
}
return unless $err;
$self->{err} = $err;
- my $env = $self->{env} or return;
- if (!$env->{'qspawn.quiet'}) {
+ if ($env && !$env->{'qspawn.quiet'}) {
log_err($env, join(' ', @{$self->{args}}) . ": $err");
}
}
@@ -132,22 +132,12 @@ sub finish ($;$) {
if (delete $self->{rpipe}) {
do_waitpid($self, $env);
}
-
- # limiter->{max} may change dynamically
- my $limiter = $self->{limiter};
- if ($limiter->{running} < $limiter->{max}) {
- if (my $next = shift @{$limiter->{run_queue}}) {
- _do_spawn(@$next);
- }
- }
}
sub start {
my ($self, $limiter, $cb) = @_;
- $self->{limiter} = $limiter;
-
if ($limiter->{running} < $limiter->{max}) {
- _do_spawn($self, $cb);
+ _do_spawn($self, $cb, $limiter);
} else {
push @{$limiter->{run_queue}}, [ $self, $cb ];
}
--
EW
^ permalink raw reply related [relevance 7%]
* [PATCH 0/6] qspawn-related cleanups, comments, and minor fix
@ 2019-09-17 8:31 7% Eric Wong
2019-09-17 8:31 7% ` [PATCH 3/6] qspawn: shorten lifetime of circular references Eric Wong
0 siblings, 1 reply; 2+ results
From: Eric Wong @ 2019-09-17 8:31 UTC (permalink / raw)
To: meta
Still haven't found anything which is causing problems on korg,
but found a bunch of worthwhile cleanups, clarifications
and perhaps minor efficiency improvements that I'm comfortable
putting on 'master'.
Eric Wong (6):
qspawn: remove return value from ->finish
qspawn: log errors for generic PSGI server users
qspawn: shorten lifetime of circular references
qspawn: improve variable naming and commenting
http: drop unused `$env' variable after delete
http: remove unnecessary delete
lib/PublicInbox/GitHTTPBackend.pm | 2 +-
lib/PublicInbox/HTTP.pm | 6 ++--
lib/PublicInbox/Qspawn.pm | 48 ++++++++++++-------------------
t/qspawn.t | 17 +++++++----
4 files changed, 33 insertions(+), 40 deletions(-)
--
EW
^ permalink raw reply [relevance 7%]
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