From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 21 Aug 2022 10:19:17 +0000 (+0100)
Subject: prefork-interp: properly handle EINTR in monitor
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=689f49612660745b546017187c8cbdea6bb4fd3e;p=chiark-utils.git

prefork-interp: properly handle EINTR in monitor

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/pm/Proc/Prefork/Interp.pm b/pm/Proc/Prefork/Interp.pm
index 3b38ffa..d1d99ee 100644
--- a/pm/Proc/Prefork/Interp.pm
+++ b/pm/Proc/Prefork/Interp.pm
@@ -65,11 +65,16 @@ sub become_monitor () {
 
   #---- monitor [2] ----
 
-  my $rbits = '';
-  vec($rbits, fileno(CALL), 1) = 1;
-  vec($rbits, fileno(EXECTERM), 1) = 1;
-  my $ebits = $rbits;
-  my $nfound = select($rbits, '', $ebits, undef);
+  for (;;) {
+    my $rbits = '';
+    vec($rbits, fileno(CALL), 1) = 1;
+    vec($rbits, fileno(EXECTERM), 1) = 1;
+    my $ebits = $rbits;
+    my $nfound = select($rbits, '', $ebits, undef);
+    last if $nfound > 0;
+    next if $! == EINTR;
+    fail_log("monitor select() failed: $!");
+  }
 
   # Either the child has just died, or the caller has gone away