From: Yusuke ENDOH <mame@...>
Date: 2010-07-15T22:16:12+09:00
Subject: [ruby-core:31299] Re: [Bug #3566] memory leak when spawning+joining 	Threads in a loop

Hi,

2010/7/14 Eric Wong <redmine@ruby-lang.org>:
> The following loop causes Ruby 1.9.2-rc2 memory usage to grow without bounds:
>
> �loop { Thread.new {}.join }


I think the following patch fixes this issue.
Even with the patch applied, memory usage seems to grow slowly.
But it will stop eventually, as long as I investigated.
I guess it is due to conservative GC.


diff --git a/thread_pthread.c b/thread_pthread.c
index e974b73..4db1226 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -213,22 +213,18 @@ get_stack(void **addr, size_t *size)
     CHECK_ERR(pthread_attr_getstackaddr(&attr, addr));
     CHECK_ERR(pthread_attr_getstacksize(&attr, size));
 #   endif
-    if (pthread_attr_getguardsize(&attr, &guard) == 0) {
-	STACK_GROW_DIR_DETECTION;
-	STACK_DIR_UPPER((void)0, (void)(*addr = (char *)*addr + guard));
-	*size -= guard;
-    }
 # else
     CHECK_ERR(pthread_attr_init(&attr));
     CHECK_ERR(pthread_attr_get_np(pthread_self(), &attr));
     CHECK_ERR(pthread_attr_getstackaddr(&attr, addr));
     CHECK_ERR(pthread_attr_getstacksize(&attr, size));
 # endif
-    CHECK_ERR(pthread_attr_getguardsize(&attr, &guard));
-    *size -= guard;
-# ifndef HAVE_PTHREAD_GETATTR_NP
+    if (pthread_attr_getguardsize(&attr, &guard) == 0) {
+	STACK_GROW_DIR_DETECTION;
+	STACK_DIR_UPPER((void)0, (void)(*addr = (char *)*addr + guard));
+	*size -= guard;
+    }
     pthread_attr_destroy(&attr);
-# endif
 #elif defined HAVE_PTHREAD_GET_STACKADDR_NP && defined
HAVE_PTHREAD_GET_STACKSIZE_NP
     pthread_t th = pthread_self();
     *addr = pthread_get_stackaddr_np(th);

-- 
Yusuke Endoh <mame@tsg.ne.jp>