Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 208 insertions, 0 deletions

diff --git a/src/libs/xpcom18a4/xpcom/ds/nsRecyclingAllocator.h b/src/libs/xpcom18a4/xpcom/ds/nsRecyclingAllocator.h
new file mode 100644
index 00000000..4266b1b8
--- /dev/null
+++ b/src/libs/xpcom18a4/xpcom/ds/nsRecyclingAllocator.h
@@ -0,0 +1,208 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2001, 2002
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *	Suresh Duddi <dp@netscape.com>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+/*
+ * nsRecyclingAllocator
+ *
+ * This allocator is useful when we cycle through a small set of allocations
+ * repeatedly with minimal overlap. For eg. something we do for every gif
+ * file read (or) buffers required for decompression of every file from jar.
+ *
+ * What this does is keeps around the first set of memory allocated and
+ * reuses it subsequently. If all buckets are full, this falls back to
+ * malloc/free
+ *
+ * Uses a timer to release all memory allocated if not used for more than
+ * 10 secs automatically.
+ *
+ * Also there is a 4 byte maintenance overhead on every allocation.
+ *
+ * This allocator is thread safe.
+ *
+ * CAVEATS: As the number of buckets increases, this allocators performance
+ *          will drop. As a general guideline, dont use this for more
+ *          than NS_MAX_BLOCKS
+ */
+
+#ifndef nsRecyclingAllocator_h__
+#define nsRecyclingAllocator_h__
+
+#include "nscore.h"
+#include "pratom.h"
+#include "prlock.h"
+#include "nsIRecyclingAllocator.h"
+#include "nsIGenericFactory.h"
+
+#define NS_DEFAULT_RECYCLE_TIMEOUT 10  // secs
+#define NS_MAX_BLOCKS              24
+#define NS_ALLOCATOR_OVERHEAD_BYTES (sizeof(Block)) // bytes
+
+class nsITimer;
+class nsIMemory;
+
+class NS_COM nsRecyclingAllocator {
+ protected:
+    struct Block {
+      PRSize bytes;
+    };
+
+    // Make |BlockStoreNode| a |friend| so it can access |Block|.
+    struct BlockStoreNode;
+    friend struct BlockStoreNode;
+
+    struct BlockStoreNode {
+      BlockStoreNode() : bytes(0), block(nsnull), next(nsnull) {};
+      PRSize bytes;
+      Block *block;
+      BlockStoreNode *next;
+    };
+
+#define DATA(block) ((void *)(((char *)block) + NS_ALLOCATOR_OVERHEAD_BYTES))
+#define DATA_TO_BLOCK(data) ((Block *)((char *)(data) - NS_ALLOCATOR_OVERHEAD_BYTES))
+
+    // mMaxBlocks: Maximum number of blocks that can be allocated
+    PRUint32 mMaxBlocks;
+
+    // mBlocks:
+    //  All blocks used or not.
+    BlockStoreNode *mBlocks;
+
+    // mFreeList
+    //  A linked list of free blocks sorted by increasing order of size
+    BlockStoreNode* mFreeList;
+
+    // mNotUsedList
+    //  A linked list of BlockStoreNodes that are not used to store
+    //  any block information. When we add blocks into mFreeList, we
+    //  take BlockStoreNode from here.
+    BlockStoreNode* mNotUsedList;
+
+    // mLock: Thread safety of mFreeList and mNotUsedList
+    PRLock *mLock;
+
+    // Timer for freeing unused memory
+    nsITimer *mRecycleTimer;
+
+    // mRecycleAfter:
+    //  Allocator should be untouched for this many seconds for freeing
+    //  unused Blocks.
+    PRUint32 mRecycleAfter;
+
+    // mTouched:
+    //  says if the allocator touched any bucket. If allocator didn't touch
+    //  any bucket over a time time interval, timer will call FreeUnusedBuckets()
+    PRInt32 mTouched;
+
+    // mId:
+    //  a string for identifying the user of nsRecyclingAllocator
+    //  User mainly for debug prints
+    const char *mId;
+
+#ifdef DEBUG
+    // mNAllocated: Number of blocks allocated
+    PRInt32 mNAllocated;
+#endif
+
+ public:
+
+    // nbucket : number of buckets to hold. Capped at NS_MAX_BUCKET
+    // recycleAfter : Try recycling allocated buckets after this many seconds
+    // id : a string used to identify debug prints. Will not be released.
+    nsRecyclingAllocator(PRUint32 nbucket = 0, PRUint32 recycleAfter = NS_DEFAULT_RECYCLE_TIMEOUT,
+                         const char *id = NULL);
+    ~nsRecyclingAllocator();
+
+    nsresult Init(PRUint32 nbucket, PRUint32 recycleAfter, const char *id);
+
+    // Allocation and free routines
+    void* Malloc(PRSize size, PRBool zeroit = PR_FALSE);
+    void  Free(void *ptr);
+
+    void* Calloc(PRUint32 items, PRSize size)
+    {
+        return Malloc(items * size, PR_TRUE);
+    }
+
+    // FreeUnusedBuckets - Frees any bucket memory that isn't in use
+    void FreeUnusedBuckets();
+
+ protected:
+
+    // Timer callback to trigger unused memory
+    static void nsRecycleTimerCallback(nsITimer *aTimer, void *aClosure);
+
+    // Freelist management
+    // FindFreeBlock: return a free block that can hold bytes (best fit)
+    Block* FindFreeBlock(PRSize bytes);
+    // AddToFreeList: adds block into our freelist for future retrieval.
+    //  Returns PR_TRUE is addition was successful. PR_FALSE otherewise.
+    PRBool AddToFreeList(Block* block);
+
+    // Touch will mark that someone used this allocator
+    // Timer based release will free unused memory only if allocator
+    // was not touched for mRecycleAfter seconds.
+    void Touch() {
+        if (!mTouched)
+            PR_AtomicSet(&mTouched, 1);
+    }
+    void Untouch() {
+        PR_AtomicSet(&mTouched, 0);
+    }
+
+    friend void nsRecycleTimerCallback(nsITimer *aTimer, void *aClosure);
+};
+
+// ----------------------------------------------------------------------
+// Wrapping the recyling allocator with nsIMemory
+// ----------------------------------------------------------------------
+
+// Wrapping the nsRecyclingAllocator with nsIMemory
+class nsRecyclingAllocatorImpl : public nsRecyclingAllocator, public nsIRecyclingAllocator {
+public:
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIMEMORY
+    NS_DECL_NSIRECYCLINGALLOCATOR
+
+    nsRecyclingAllocatorImpl()
+    {
+    }
+
+private:
+    ~nsRecyclingAllocatorImpl() {}
+};
+#endif // nsRecyclingAllocator_h__