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	Thu, 26 Dec 2019 07:53:07 +0000 (UTC)
Date: Thu, 26 Dec 2019 07:53:07 +0000
From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: Re: [PATCH 02/30] httpd/async: support passing arg to callbacks
Message-ID: <20191226075307.GA4890@dcvr>
References: <20191225075104.22184-1-e@80x24.org>
 <20191225075104.22184-3-e@80x24.org>
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Eric Wong <e@80x24.org> wrote:
> index eea59b6d..d59320bc 100644
> --- a/lib/PublicInbox/SolverGit.pm
> +++ b/lib/PublicInbox/SolverGit.pm
> @@ -363,18 +363,13 @@ sub do_step ($) {
>  	}
>  }
>  
> -sub step_cb ($) {
> -	my ($self) = @_;
> -	sub { do_step($self) };
> -}
> -
>  sub next_step ($) {
>  	my ($self) = @_;
>  	# if outside of public-inbox-httpd, caller is expected to be
> -	# looping step_cb, anyways
> +	# looping do_step, anyways
>  	my $async = $self->{psgi_env}->{'pi-httpd.async'} or return;
>  	# PublicInbox::HTTPD::Async->new
> -	$async->(undef, step_cb($self));
> +	$async->(undef, \&do_step, $self);
>  }
>  
>  sub mark_found ($$$) {
> @@ -598,12 +593,11 @@ sub solve ($$$$$) {
>  	$self->{tmp} = File::Temp->newdir("solver.$oid_want-XXXXXXXX", TMPDIR => 1);
>  
>  	dbg($self, "solving $oid_want ...");
> -	my $step_cb = step_cb($self);
>  	if (my $async = $env->{'pi-httpd.async'}) {
>  		# PublicInbox::HTTPD::Async->new
> -		$async->(undef, $step_cb);
> +		$async->(undef, \&do_step, $self);
>  	} else {
> -		$step_cb->() while $self->{user_cb};
> +		do_step($self) while $self->{user_cb};
>  	}
>  }
>  

Those calls to $async->(...) were wrong, given how
HTTPD::Async->new works in the '!defined($io)' path.
Failures were exposed using the async API:

  https://public-inbox.org/meta/20191226064804.23024-4-e@80x24.org/

So we'll rename do_step to event_step and rely on DS::requeue to
call it, instead:

diff --git a/lib/PublicInbox/HTTPD/Async.pm b/lib/PublicInbox/HTTPD/Async.pm
index 70769bba..d182c118 100644
--- a/lib/PublicInbox/HTTPD/Async.pm
+++ b/lib/PublicInbox/HTTPD/Async.pm
@@ -23,7 +23,7 @@ sub new {
 	# no $io? call $cb at the top of the next event loop to
 	# avoid recursion:
 	unless (defined($io)) {
-		PublicInbox::DS::requeue($cb);
+		PublicInbox::DS::requeue($cb ? $cb : $arg);
 		die '$end unsupported w/o $io' if $end;
 		return;
 	}
diff --git a/lib/PublicInbox/SolverGit.pm b/lib/PublicInbox/SolverGit.pm
index d59320bc..b3fc5bef 100644
--- a/lib/PublicInbox/SolverGit.pm
+++ b/lib/PublicInbox/SolverGit.pm
@@ -327,7 +327,7 @@ sub do_finish ($$) {
 	$user_cb->(undef);
 }
 
-sub do_step ($) {
+sub event_step ($) {
 	my ($self) = @_;
 	eval {
 		# step 1: resolve blobs to patches in the todo queue
@@ -366,10 +366,10 @@ sub do_step ($) {
 sub next_step ($) {
 	my ($self) = @_;
 	# if outside of public-inbox-httpd, caller is expected to be
-	# looping do_step, anyways
+	# looping event_step, anyways
 	my $async = $self->{psgi_env}->{'pi-httpd.async'} or return;
 	# PublicInbox::HTTPD::Async->new
-	$async->(undef, \&do_step, $self);
+	$async->(undef, undef, $self);
 }
 
 sub mark_found ($$$) {
@@ -595,9 +595,9 @@ sub solve ($$$$$) {
 	dbg($self, "solving $oid_want ...");
 	if (my $async = $env->{'pi-httpd.async'}) {
 		# PublicInbox::HTTPD::Async->new
-		$async->(undef, \&do_step, $self);
+		$async->(undef, undef, $self);
 	} else {
-		do_step($self) while $self->{user_cb};
+		event_step($self) while $self->{user_cb};
 	}
 }