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From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: [PATCH 3/7] ipc: more consistent behavior between worker types
Date: Fri, 29 Jan 2021 12:42:56 +0500	[thread overview]
Message-ID: <20210129074300.14475-4-e@80x24.org> (raw)
In-Reply-To: <20210129074300.14475-1-e@80x24.org>

Localize signals inside the respective worker loops
in case there's circular references.

We'll also rely on OnDestroy to trigger exits from the
ipc_worker_loop like we do with wq_worker_loop.  And
also add some more developer documentation to help future
developers.

The default signals remain different, for now.
Cleanup some unnecessary "use" statements while we're
loading OnDestroy.
---
 lib/PublicInbox/IPC.pm | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/lib/PublicInbox/IPC.pm b/lib/PublicInbox/IPC.pm
index 838f9530..ece0e8b8 100644
--- a/lib/PublicInbox/IPC.pm
+++ b/lib/PublicInbox/IPC.pm
@@ -2,16 +2,20 @@
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 
 # base class for remote IPC calls and workqueues, requires Storable or Sereal
+# - ipc_do and ipc_worker_* is for a single worker/producer and uses pipes
+# - wq_do and wq_worker* is for a single producer and multiple workers,
+#   using SOCK_SEQPACKET for work distribution
+# use ipc_do when you need work done on a certain process
+# use wq_do when your work can be done on any idle worker
 package PublicInbox::IPC;
 use strict;
 use v5.10.1;
 use Carp qw(confess croak);
 use PublicInbox::DS qw(dwaitpid);
 use PublicInbox::Spawn;
-use POSIX qw(mkfifo WNOHANG);
+use PublicInbox::OnDestroy;
 use Socket qw(AF_UNIX MSG_EOR SOCK_STREAM);
 use Errno qw(EMSGSIZE);
-use File::Temp 0.19 (); # 0.19 for ->newdir
 my $SEQPACKET = eval { Socket::SOCK_SEQPACKET() }; # portable enough?
 use constant PIPE_BUF => $^O eq 'linux' ? 4096 : POSIX::_POSIX_PIPE_BUF();
 my $WQ_MAX_WORKERS = 4096;
@@ -107,16 +111,22 @@ sub ipc_worker_spawn {
 	if ($pid == 0) {
 		srand($seed);
 		eval { PublicInbox::DS->Reset };
-		delete @$self{qw(-wq_s1 -wq_workers -wq_ppid)};
+		delete @$self{qw(-wq_s1 -wq_s2 -wq_workers -wq_ppid)};
 		$w_req = $r_res = undef;
 		$w_res->autoflush(1);
 		$SIG{$_} = 'IGNORE' for (qw(TERM INT QUIT));
 		local $0 = $ident;
 		PublicInbox::DS::sig_setmask($sigset);
+		# ensure we properly exit even if warn() dies:
+		my $end = PublicInbox::OnDestroy->new($$, sub { exit(!!$@) });
 		my $on_destroy = $self->ipc_atfork_child;
-		eval { ipc_worker_loop($self, $r_req, $w_res) };
+		eval {
+			local %SIG = %SIG;
+			ipc_worker_loop($self, $r_req, $w_res);
+		};
 		die "worker $ident PID:$$ died: $@\n" if $@;
-		exit;
+		undef $on_destroy;
+		undef $end; # trigger exit
 	}
 	PublicInbox::DS::sig_setmask($sigset) unless $oldset;
 	$r_req = $w_res = undef;
@@ -320,14 +330,17 @@ sub _wq_worker_start ($$$) {
 		eval { PublicInbox::DS->Reset };
 		delete @$self{qw(-wq_s1 -wq_workers -wq_ppid)};
 		@$self{keys %$fields} = values(%$fields) if $fields;
-		$SIG{$_} = 'IGNORE' for (qw(PIPE TTOU TTIN));
-		$SIG{$_} = 'DEFAULT' for (qw(TERM QUIT INT CHLD));
+		$SIG{$_} = 'IGNORE' for (qw(PIPE));
+		$SIG{$_} = 'DEFAULT' for (qw(TTOU TTIN TERM QUIT INT CHLD));
 		local $0 = $self->{-wq_ident};
 		PublicInbox::DS::sig_setmask($oldset);
 		# ensure we properly exit even if warn() dies:
 		my $end = PublicInbox::OnDestroy->new($$, sub { exit(!!$@) });
 		my $on_destroy = $self->ipc_atfork_child;
-		eval { wq_worker_loop($self) };
+		eval {
+			local %SIG = %SIG;
+			wq_worker_loop($self);
+		};
 		warn "worker $self->{-wq_ident} PID:$$ died: $@" if $@;
 		undef $on_destroy;
 		undef $end; # trigger exit

  parent reply	other threads:[~2021-01-29  7:43 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-29  7:42 [PATCH 0/7] lei: more half-baked updates Eric Wong
2021-01-29  7:42 ` [PATCH 1/7] ipc: wq: support passing fields to workers Eric Wong
2021-01-29  7:42 ` [PATCH 2/7] lei_xsearch: drop repeated "Xapian" in error message Eric Wong
2021-01-29  7:42 ` Eric Wong [this message]
2021-01-29  7:42 ` [PATCH 4/7] lei: less error-prone FD mapping Eric Wong
2021-01-29  7:42 ` [PATCH 5/7] git: synchronous cat_file may return type and OID Eric Wong
2021-01-29  7:42 ` [PATCH 6/7] ipc: move on_destroy scope to inside the eval Eric Wong
2021-01-29  7:43 ` [PATCH 7/7] shared_kv: simplify PID+object guard for cleanup Eric Wong

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