Temporarily move taskq+util to libzpool until that directory is broken in to lib...

[zfs.git] / zfs / lib / libumem / umem_fork.c

diff --git a/zfs/lib/libumem/umem_fork.c b/zfs/lib/libumem/umem_fork.c
index 2f70102..4cbe81d 100644 (file)
--- a/zfs/lib/libumem/umem_fork.c
+++ b/zfs/lib/libumem/umem_fork.c
@@ -2,9 +2,8 @@
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
- * Common Development and Distribution License, Version 1.0 only
- * (the "License").  You may not use this file except in compliance
- * with the License.
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
@@ -19,26 +18,22 @@
  *
  * CDDL HEADER END
  */
+
 /*
- * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
-/*
- * Portions Copyright 2006 OmniTI, Inc.
- */
 
-/* #pragma ident       "@(#)umem_fork.c        1.3     05/06/08 SMI" */
+#pragma ident  "%Z%%M% %I%     %E% SMI"
 
-#include "config.h"
-/* #include "mtlib.h" */
 #include "umem_base.h"
 #include "vmem_base.h"
 
-#ifndef _WIN32
 #include <unistd.h>
 
 /*
- * The following functions are for pre- and post-fork1(2) handling.
+ * The following functions are for pre- and post-fork1(2) handling.  See
+ * "Lock Ordering" in lib/libumem/common/umem.c for the lock ordering used.
  */
 
 static void
@@ -108,6 +103,10 @@ umem_lockup(void)
                (void) umem_init();
                (void) mutex_lock(&umem_init_lock);
        }
+
+       vmem_lockup();
+       vmem_sbrk_lockup();
+
        (void) mutex_lock(&umem_cache_lock);
        (void) mutex_lock(&umem_update_lock);
        (void) mutex_lock(&umem_flags_lock);
@@ -124,46 +123,30 @@ umem_lockup(void)
 
        (void) cond_broadcast(&umem_update_cv);
 
-       vmem_sbrk_lockup();
-       vmem_lockup();
 }
 
 static void
-umem_release(void)
-{
-       umem_cache_t *cp;
-
-       vmem_release();
-       vmem_sbrk_release();
-
-       umem_release_log_header(umem_slab_log);
-       umem_release_log_header(umem_failure_log);
-       umem_release_log_header(umem_content_log);
-       umem_release_log_header(umem_transaction_log);
-
-       for (cp = umem_null_cache.cache_next; cp != &umem_null_cache;
-           cp = cp->cache_next)
-               umem_release_cache(cp);
-       umem_release_cache(&umem_null_cache);
-
-       (void) mutex_unlock(&umem_flags_lock);
-       (void) mutex_unlock(&umem_update_lock);
-       (void) mutex_unlock(&umem_cache_lock);
-       (void) mutex_unlock(&umem_init_lock);
-}
-
-static void
-umem_release_child(void)
+umem_do_release(int as_child)
 {
        umem_cache_t *cp;
+       int cleanup_update = 0;
 
        /*
-        * Clean up the update state
+        * Clean up the update state if we are the child process and
+        * another thread was processing updates.
         */
-       umem_update_thr = 0;
+       if (as_child) {
+               if (umem_update_thr != thr_self()) {
+                       umem_update_thr = 0;
+                       cleanup_update = 1;
+               }
+               if (umem_st_update_thr != thr_self()) {
+                       umem_st_update_thr = 0;
+                       cleanup_update = 1;
+               }
+       }
 
-       if (umem_st_update_thr != thr_self()) {
-               umem_st_update_thr = 0;
+       if (cleanup_update) {
                umem_reaping = UMEM_REAP_DONE;
 
                for (cp = umem_null_cache.cache_next; cp != &umem_null_cache;
@@ -196,19 +179,45 @@ umem_release_child(void)
                }
        }
 
-       umem_release();
+       umem_release_log_header(umem_slab_log);
+       umem_release_log_header(umem_failure_log);
+       umem_release_log_header(umem_content_log);
+       umem_release_log_header(umem_transaction_log);
+
+       for (cp = umem_null_cache.cache_next; cp != &umem_null_cache;
+           cp = cp->cache_next)
+               umem_release_cache(cp);
+       umem_release_cache(&umem_null_cache);
+
+       (void) mutex_unlock(&umem_flags_lock);
+       (void) mutex_unlock(&umem_update_lock);
+       (void) mutex_unlock(&umem_cache_lock);
+
+       vmem_sbrk_release();
+       vmem_release();
+
+       (void) mutex_unlock(&umem_init_lock);
+}
+
+static void
+umem_release(void)
+{
+       umem_do_release(0);
+}
+
+static void
+umem_release_child(void)
+{
+       umem_do_release(1);
 }
-#endif
 
 void
 umem_forkhandler_init(void)
 {
-#ifndef _WIN32
        /*
         * There is no way to unregister these atfork functions,
         * but we don't need to.  The dynamic linker and libc take
         * care of unregistering them if/when the library is unloaded.
         */
        (void) pthread_atfork(umem_lockup, umem_release, umem_release_child);
-#endif
 }