First step into a new block allocation strategy for the block_cache

(right now, it's still malloc/free, just encapsulated in an allocator class).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@12662 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/block_cache.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2005, Axel Dörfler, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _KERNEL_BLOCK_CACHE_H
+#define _KERNEL_BLOCK_CACHE_H
+
+
+#include <SupportDefs.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern status_t block_cache_init(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _KRENEL_BLOCK_CACHE_H */

src/system/kernel/cache/BlockAllocator.cpp

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2005, Axel Dörfler, [email protected]. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "BlockAllocator.h"
+
+#include <KernelExport.h>
+#include <util/AutoLock.h>
+
+
+BlockAllocator::AllocatorList BlockAllocator::sList;
+mutex BlockAllocator::sMutex;
+
+
+BlockAllocator::BlockAllocator(size_t size)
+	:
+	fSize(size)
+{
+}
+
+
+BlockAllocator::~BlockAllocator()
+{
+}
+
+
+void *
+BlockAllocator::Get()
+{
+	return malloc(fSize);
+}
+
+
+void
+BlockAllocator::Put(void *block)
+{
+	free(block);
+}
+
+
+void
+BlockAllocator::Acquire()
+{
+	fRefCount++;
+}
+
+
+int32
+BlockAllocator::Release()
+{
+	return --fRefCount;
+}
+
+
+//	#pragma mark - static
+
+
+// static
+BlockAllocator *
+BlockAllocator::GetAllocator(size_t size)
+{
+	MutexLocker locker(&sMutex);
+
+	// search for allocator in list
+
+	AllocatorList::Iterator iterator = sList.GetIterator();
+	while (iterator.HasNext()) {
+		BlockAllocator *allocator = iterator.Next();
+
+		if (allocator->Size() == size) {
+			allocator->Acquire();
+			return allocator;
+		}
+	}
+
+	// it's not yet there, create new one
+
+	BlockAllocator *allocator = new BlockAllocator(size);
+	if (allocator == NULL)
+		return NULL;
+
+	sList.Add(allocator);
+	return allocator;
+}
+
+
+// static
+void
+BlockAllocator::PutAllocator(BlockAllocator *allocator)
+{
+	MutexLocker locker(&sMutex);
+
+	if (!allocator->Release()) {
+		sList.Remove(allocator);
+		delete allocator;
+	}
+}
+
+
+//	#pragma mark -
+
+
+extern "C" status_t
+init_block_allocator(void)
+{
+	status_t status = mutex_init(&BlockAllocator::sMutex, "block allocator");
+	if (status < B_OK)
+		return status;
+
+	new(&BlockAllocator::sList) DoublyLinkedList<BlockAllocator>;
+		// static initializers do not work in the kernel,
+		// so we have to do it here, manually
+	return B_OK;
+}
+

src/system/kernel/cache/BlockAllocator.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2005, Axel Dörfler, [email protected]. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef BLOCK_ALLOCATOR_H
+#define BLOCK_ALLOCATOR_H
+
+
+#include <util/DoublyLinkedList.h>
+#include <lock.h>
+
+
+class BlockAllocator : public DoublyLinkedListLinkImpl<BlockAllocator> {
+	public:
+		void *Get();
+		void Put(void *block);
+
+		static BlockAllocator *GetAllocator(size_t size);
+		static void PutAllocator(BlockAllocator *allocator);
+
+	protected:
+		BlockAllocator(size_t size);
+		~BlockAllocator();
+
+		size_t Size() const { return fSize; }
+
+		void Acquire();
+		int32 Release();
+
+	private:
+		typedef DoublyLinkedList<BlockAllocator> AllocatorList;
+
+		size_t	fSize;
+		int32	fRefCount;
+
+	public:
+		static AllocatorList sList;
+		static mutex sMutex;
+};
+
+extern "C" status_t init_block_allocator(void);
+
+#endif	/* BLOCK_ALLOCATOR_H */

src/system/kernel/cache/Jamfile

@@ -1,6 +1,7 @@
 SubDir OBOS_TOP src system kernel cache ;
 
 KernelMergeObject kernel_cache.o :
+	BlockAllocator.cpp
 	block_cache.cpp
 	file_cache.cpp
 	vnode_store.cpp

src/system/kernel/cache/block_cache.cpp

@@ -4,10 +4,12 @@
  */
 
 
+#include "BlockAllocator.h"
+
 #include <KernelExport.h>
 #include <fs_cache.h>
 
-#include <cache.h>
+#include <block_cache.h>
 #include <lock.h>
 #include <util/kernel_cpp.h>
 #include <util/DoublyLinkedList.h>
@@ -41,6 +43,7 @@ struct cache_transaction;
 struct cached_block;
 typedef DoublyLinkedListLink<cached_block> block_link;
 
+
 struct cached_block {
 	cached_block	*next;			// next in hash
 	cached_block	*transaction_next;
@@ -66,6 +69,7 @@ struct block_cache {
 	size_t		block_size;
 	int32		next_transaction_id;
 	hash_table	*transaction_hash;
+	BlockAllocator *allocator;
 };
 
 typedef DoublyLinkedList<cached_block,
@@ -132,7 +136,7 @@ class BenaphoreLocker {
 static status_t write_cached_block(block_cache *cache, cached_block *block, bool deleteTransaction = true);
 
 
-//	private transaction functions
+//	#pragma mark - private transaction
 
 
 static int
@@ -173,8 +177,7 @@ lookup_transaction(block_cache *cache, int32 id)
 }
 
 
-//	#pragma mark -
+//	#pragma mark - private block_cache
-//	private cached block functions
 
 
 static int
@@ -201,13 +204,14 @@ cached_block_hash(void *_cacheEntry, const void *_block, uint32 range)
 
 
 static void
-free_cached_block(cached_block *block)
+free_cached_block(block_cache *cache, cached_block *block)
 {
-	free(block->data);
+	cache->allocator->Put(block->data);
-	free(block->original);
+	cache->allocator->Put(block->original);
 #ifdef DEBUG_CHANGED
-	free(block->compare);
+	cache->allocator->Put(block->compare);
 #endif
+
 	free(block);
 }
 
@@ -220,7 +224,7 @@ new_cached_block(block_cache *cache, off_t blockNumber, bool cleared = false)
 		return NULL;
 
 	if (!cleared) {
-		block->data = malloc(cache->block_size);
+		block->data = cache->allocator->Get();
 		if (block->data == NULL) {
 			free(block);
 			return NULL;
@@ -297,7 +301,7 @@ put_cached_block(block_cache *cache, cached_block *block)
 		write_cached_block(cache, block);
 		panic("block_cache: supposed to be clean block was changed!\n");
 
-		free(block->compare);
+		cache->allocator->Put(block->compare);
 		block->compare = NULL;
 	}
 #endif
@@ -332,7 +336,7 @@ get_cached_block(block_cache *cache, off_t blockNumber, bool cleared = false)
 	
 	if (!allocated && block->data == NULL && !cleared) {
 		// there is no block yet, but we need one
-		block->data = malloc(cache->block_size);
+		block->data = cache->allocator->Get();
 		if (block->data == NULL)
 			return NULL;
 
@@ -343,7 +347,7 @@ get_cached_block(block_cache *cache, off_t blockNumber, bool cleared = false)
 		int32 blockSize = cache->block_size;
 
 		if (read_pos(cache->fd, blockNumber * blockSize, block->data, blockSize) < blockSize) {
-			free_cached_block(block);
+			free_cached_block(cache, block);
 			return NULL;
 		}
 	}
@@ -368,7 +372,7 @@ get_writable_cached_block(block_cache *cache, off_t blockNumber, off_t base, off
 	// if there is no transaction support, we just return the current block
 	if (transactionID == -1) {
 		if (cleared && block->data == NULL) {
-			block->data = malloc(cache->block_size);
+			block->data = cache->allocator->Get();
 			if (block->data == NULL) {
 				put_cached_block(cache, block);
 				return NULL;
@@ -414,7 +418,7 @@ get_writable_cached_block(block_cache *cache, off_t blockNumber, off_t base, off
 
 	if (block->data != NULL && block->original == NULL) {
 		// we already have data, so we need to save it
-		block->original = malloc(cache->block_size);
+		block->original = cache->allocator->Get();
 		if (block->original == NULL) {
 			put_cached_block(cache, block);
 			return NULL;
@@ -425,7 +429,7 @@ get_writable_cached_block(block_cache *cache, off_t blockNumber, off_t base, off
 
 	if (block->data == NULL && cleared) {
 		// there is no data yet, we need a clean new block
-		block->data = malloc(cache->block_size);
+		block->data = cache->allocator->Get();
 		if (block->data == NULL) {
 			put_cached_block(cache, block);
 			return NULL;
@@ -479,8 +483,14 @@ write_cached_block(block_cache *cache, cached_block *block, bool deleteTransacti
 }
 
 
-//	#pragma mark -
+extern "C" status_t
-//	Transactions
+block_cache_init(void)
+{
+	return init_block_allocator();
+}
+
+
+//	#pragma mark - public transaction
 
 
 extern "C" int32
@@ -567,7 +577,7 @@ cache_end_transaction(void *_cache, int32 id, transaction_notification_hook hook
 		}
 
 		if (block->original != NULL) {
-			free(block->original);
+			cache->allocator->Put(block->original);
 			block->original = NULL;
 		}
 
@@ -649,7 +659,7 @@ cache_next_block_in_transaction(void *_cache, int32 id, uint32 *_cookie, off_t *
 }
 
 
-//	#pragma mark -
+//	#pragma mark - public block cache
 //	public interface
 
 
@@ -666,7 +676,7 @@ block_cache_delete(void *_cache, bool allowWrites)
 	uint32 cookie = 0;
 	cached_block *block;
 	while ((block = (cached_block *)hash_remove_first(cache->hash, &cookie)) != NULL) {
-		free_cached_block(block);
+		free_cached_block(cache, block);
 	}
 	
 	// free all transactions (they will all be aborted)	
@@ -679,6 +689,7 @@ block_cache_delete(void *_cache, bool allowWrites)
 
 	hash_uninit(cache->hash);
 	hash_uninit(cache->transaction_hash);
+	BlockAllocator::PutAllocator(cache->allocator);
 	benaphore_destroy(&cache->lock);
 
 	delete cache;
@@ -700,9 +711,13 @@ block_cache_create(int fd, off_t numBlocks, size_t blockSize)
 	if (cache->transaction_hash == NULL)
 		goto err2;
 
-	if (benaphore_init(&cache->lock, "block cache") < B_OK)
+	cache->allocator = BlockAllocator::GetAllocator(blockSize);
+	if (cache->allocator == NULL)
 		goto err3;
 
+	if (benaphore_init(&cache->lock, "block cache") < B_OK)
+		goto err4;
+
 	cache->fd = fd;
 	cache->max_blocks = numBlocks;
 	cache->block_size = blockSize;
@@ -710,6 +725,8 @@ block_cache_create(int fd, off_t numBlocks, size_t blockSize)
 
 	return cache;
 
+err4:
+	BlockAllocator::PutAllocator(cache->allocator);
 err3:
 	hash_uninit(cache->transaction_hash);
 err2:
@@ -801,7 +818,7 @@ block_cache_get_etc(void *_cache, off_t blockNumber, off_t base, off_t length)
 
 #ifdef DEBUG_CHANGED
 	if (block->compare == NULL)
-		block->compare = malloc(cache->block_size);
+		block->compare = cache->allocator->Get();
 	if (block->compare != NULL)
 		memcpy(block->compare, block->data, cache->block_size);
 #endif

src/system/kernel/fs/vfs.cpp

@@ -26,6 +26,7 @@
 #include <vm.h>
 #include <vm_cache.h>
 #include <file_cache.h>
+#include <block_cache.h>
 #include <khash.h>
 #include <lock.h>
 #include <fd.h>
@@ -2841,6 +2842,9 @@ vfs_init(kernel_args *args)
 	if (mutex_init(&sVnodeMutex, "vfs_vnode_lock") < 0)
 		panic("vfs_init: error allocating vnode lock\n");
 
+	if (block_cache_init() != B_OK)
+		return B_ERROR;
+
 	return file_cache_init();
 }