From: Pavel Rochnyack <pavel2000@ngs.ru>
Date: Fri, 13 May 2016 08:50:31 +0000 (+0600)
Subject: perl plugin: lock base thread interpreter in perl_init() too.
X-Git-Tag: collectd-5.6.0~291^2~4
X-Git-Url: https://git.octo.it/?a=commitdiff_plain;h=e58ebe6738bd29699619010484e085c0bb1f0b68;hp=aee1cc1a20b3e7f131835fe5d3ba0f5a51cb6731;p=collectd.git

perl plugin: lock base thread interpreter in perl_init() too.
Avoid race conditions with c_ithread_create() called from threads of already-initialized plugins.
Fix for https://github.com/collectd/collectd/issues/1706.
---

diff --git a/src/perl.c b/src/perl.c
index 945e2258..0b5debe6 100644
--- a/src/perl.c
+++ b/src/perl.c
@@ -1,4 +1,4 @@
-/**
+/*
  * collectd - src/perl.c
  * Copyright (C) 2007-2009  Sebastian Harl
  *
@@ -1911,6 +1911,7 @@ static XS (Collectd_call_by_name)
 
 static int perl_init (void)
 {
+	int status;
 	dTHX;
 
 	if (NULL == perl_threads)
@@ -1928,7 +1929,19 @@ static int perl_init (void)
 
 	log_debug ("perl_init: c_ithread: interp = %p (active threads: %i)",
 			aTHX, perl_threads->number_of_threads);
-	return pplugin_call_all (aTHX_ PLUGIN_INIT);
+
+	/* Lock the base thread to avoid race conditions with c_ithread_create().
+	 * See https://github.com/collectd/collectd/issues/9 and
+	 *     https://github.com/collectd/collectd/issues/1706 for details. */
+
+	assert (aTHX == perl_threads->head->interp);
+	pthread_mutex_lock (&perl_threads->mutex);
+
+	status = pplugin_call_all (aTHX_ PLUGIN_INIT);
+
+	pthread_mutex_unlock (&perl_threads->mutex);
+
+	return status;
 } /* static int perl_init (void) */
 
 static int perl_read (void)