From 9908d834bed5996b1634f15e92a84b51a99c54df Mon Sep 17 00:00:00 2001
From: Ingo Weinhold <ingo_weinhold@gmx.de>
Date: Wed, 3 Feb 2010 18:55:52 +0000
Subject: [PATCH] Forgot to add this one in the previous commit: The
 PageCacheLocker does have its own source file now that the page daemon source
 file is gone.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35394 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/system/kernel/vm/PageCacheLocker.cpp | 54 ++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 src/system/kernel/vm/PageCacheLocker.cpp

diff --git a/src/system/kernel/vm/PageCacheLocker.cpp b/src/system/kernel/vm/PageCacheLocker.cpp
new file mode 100644
index 0000000000..0fbd226841
--- /dev/null
+++ b/src/system/kernel/vm/PageCacheLocker.cpp
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2007, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "PageCacheLocker.h"
+
+#include <vm/VMCache.h>
+
+
+bool
+PageCacheLocker::_IgnorePage(vm_page* page)
+{
+	if (page->busy || page->state == PAGE_STATE_WIRED
+		|| page->state == PAGE_STATE_FREE || page->state == PAGE_STATE_CLEAR
+		|| page->state == PAGE_STATE_UNUSED || page->wired_count > 0)
+		return true;
+
+	return false;
+}
+
+
+bool
+PageCacheLocker::Lock(vm_page* page, bool dontWait)
+{
+	if (_IgnorePage(page))
+		return false;
+
+	// Grab a reference to this cache.
+	VMCache* cache = vm_cache_acquire_locked_page_cache(page, dontWait);
+	if (cache == NULL)
+		return false;
+
+	if (_IgnorePage(page)) {
+		cache->ReleaseRefAndUnlock();
+		return false;
+	}
+
+	fPage = page;
+	return true;
+}
+
+
+void
+PageCacheLocker::Unlock()
+{
+	if (fPage == NULL)
+		return;
+
+	fPage->Cache()->ReleaseRefAndUnlock();
+
+	fPage = NULL;
+}