Re: forcing valgrind dumps

[Hallvard B Furuseth]

I wrote:
> Next we need a patch to filter old
> allocations out from new one, leaving recent allocations.

Like this enhancement to valgrind 3.5.0 for dumping "delta leaks":
http://bugs.kde.org/show_bug.cgi?id=206802
Then instead of VALGRIND_DO_LEAK_CHECK in my patch, use
VALGRIND_DO_ADDED_LEAK_CHECK or VALGRIND_DO_CHANGED_LEAK_CHECK.

And quoting the author, Philippe Waroquiers:
  "If you use the patch, it would be nice to give some feedback (how
  it is working, enhancements/changes you think would be good, ...)."

-- 
Hallvard

Re: forcing valgrind dumps

[Bill MacAllister]

Thanks for the patch.  I will be testing with it later this week.

Bill

--On Thursday, November 19, 2009 12:25:30 AM +0100 Hallvard B Furuseth 
 wrote:


Here is a patch to force valgrind to dump memory leaks or all
allocations while running.  Next we need a patch to filter old
allocations out from new one, leaving recent allocations.

Dunno if it belongs in the source code or not... IIRC we do have #ifdefs
for some external malloc debug stuff already, but I didn't find that
now:-(


Index: servers/slapd/daemon.c
===
RCS file: /repo/OpenLDAP/pkg/ldap/servers/slapd/daemon.c,v
retrieving revision 1.442
diff -u -2 -r1.442 daemon.c
--- servers/slapd/daemon.c  13 Nov 2009 22:48:51 -  1.442
+++ servers/slapd/daemon.c  18 Nov 2009 23:18:29 -
@@ -36,4 +36,22 @@
 #include 

+#ifdef USE_VALGRIND
+/*
+ * When running under valgrind, make kill -USR1 force a leak/alloc dump
+ * to stderr, in addition to its usual "wake listener" function.
+ * After SIGUSR1 there will also be a dump before shutdown.
+ *
+ * Usage:
+ *   valgrind --leak-check=yes --show-reachable=yes slapd -d0 2>slapd.out &
+ *   kill -USR1 
+ *
+ * For recent leaks/allocs only, do kill -USR1 after startup and again
+ * sometime later.  Then filter out from the 2nd dump the occurrences of
+ * allocs from the 1st dump.
+ */
+#include 
+#include 
+#endif /* USE_VALGRIND */
+
 #include "slap.h"
 #include "ldap_pvt_thread.h"
@@ -664,4 +682,25 @@
 #endif /* ! epoll && ! /dev/poll */

+#ifdef USE_VALGRIND
+static sig_atomic_t slap_valgrind_requested = 0;
+#define slap_valgrind_request() ((void) (slap_valgrind_requested = 2))
+static void
+slap_valgrind_check( int when, const char *msg )
+{
+   if ( slap_valgrind_requested >= when && RUNNING_ON_VALGRIND ) {
+   Debug( LDAP_DEBUG_TRACE, "Valgrind dump %s\n", msg, 0, 0 );
+   /* Needed for terminator between valgrind -q dumps */
+   VALGRIND_PRINTF( "==> Valgrind dump %s\n", msg );
+   VALGRIND_DO_LEAK_CHECK;
+   VALGRIND_PRINTF( "<== Valgrind dump %s\n", msg );
+   slap_valgrind_requested = 1;
+   }
+}
+
+#else /* !USE_VALGRIND */
+#define slap_valgrind_check(when, msg) ((void) 0)
+#define slap_valgrind_request() ((void) 0)
+#endif /* USE_VALGRIND */
+
 #ifdef HAVE_SLP
 /*
@@ -2308,4 +2347,6 @@
struct re_s*rtask;

+   slap_valgrind_check( 2, "while running" );
+
now = slap_get_time();

@@ -2760,4 +2801,6 @@
}

+   slap_valgrind_check( 1, "before shutdown" );
+
if ( slapd_gentle_shutdown != 2 ) close_listeners ( 0 );

@@ -2942,4 +2985,6 @@
int save_errno = errno;

+   slap_valgrind_request();
+
WAKE_LISTENER(1);





--

Bill MacAllister, System Software Programmer
Unix Systems Group, Stanford University