[Libguestfs] [nbdkit PATCH] errors: Use lighter-weight locking
Commit d02d9c9d used pthread_mutex to avoid interleaving output.
However, the standard provides flockfile() for grouping related
FILE* I/O that must not be interleaved; and that may be
lighter-weight than rolling our own locking.
Signed-off-by: Eric Blake <eblake(a)redhat.com>
---
Pushing this one; as a related conversation on another mailing list
reminded me about flockfile().
src/errors.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/src/errors.c b/src/errors.c
index c1efae6..471e3ea 100644
--- a/src/errors.c
+++ b/src/errors.c
@@ -1,5 +1,5 @@
/* nbdkit
- * Copyright (C) 2013-2017 Red Hat Inc.
+ * Copyright (C) 2013-2018 Red Hat Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -44,21 +44,16 @@
#include "nbdkit-plugin.h"
#include "internal.h"
-/* Used to group piecemeal message construction into atomic output. */
-static pthread_mutex_t errors_lock = PTHREAD_MUTEX_INITIALIZER;
-
static void
lock (void)
{
- int r = pthread_mutex_lock (&errors_lock);
- assert (!r);
+ flockfile (stderr);
}
static void
unlock (void)
{
- int r = pthread_mutex_unlock (&errors_lock);
- assert (!r);
+ funlockfile (stderr);
}
/* Called with lock taken. */
--
2.14.3