--- /dev/null
+/*
+ * util/alloc.c - memory allocation service.
+ *
+ * Copyright (c) 2007, NLnet Labs. All rights reserved.
+ *
+ * This software is open source.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of the NLNET LABS nor the names of its contributors may
+ * be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * \file
+ *
+ * This file contains memory allocation functions.
+ */
+
+#include "config.h"
+#include "util/alloc.h"
+
--- /dev/null
+/*
+ * util/alloc.h - memory allocation service.
+ *
+ * Copyright (c) 2007, NLnet Labs. All rights reserved.
+ *
+ * This software is open source.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of the NLNET LABS nor the names of its contributors may
+ * be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * \file
+ *
+ * This file contains memory allocation functions.
+ *
+ * The reasons for this service are:
+ * o Avoid locking costs of getting global lock to call malloc().
+ * o The packed rrset type needs to be kept on special freelists,
+ * so that they are reused for other packet rrset allocations.
+ * o This service is not there to improve speed of malloc.
+ * Some caching is performed to help avoid locking costs.
+ * o This service does not prevent fragmentation.
+ * The caching will help somewhat for this.
+ *
+ * Design choices:
+ * o The global malloc/free is used to handle fragmentation, etc.
+ * If freelists become very large, it is returned to the system.
+ * o Only 1k and smaller is cached, bigger uses malloc.
+ * Because DNS fragments are mostly this size.
+ * o On startup preallocated memory can be given, so threads can
+ * avoid contention in the startup phase.
+ */
+
+#ifndef UTIL_ALLOC_H
+#define UTIL_ALLOC_H
+
+#include "util/locks.h"
+
+/** all allocations are in multiples of this size */
+#define ALLOC_ALIGN 32 /* bytes */
+
+/**
+ * This size and smaller is kept in cached lists by size.
+ * Must be a multiple of ALLOC_ALIGN.
+ */
+#define ALLOC_LARGESIZE 1024 /* bytes */
+
+/** number of bins */
+#define ALLOC_BINS (ALLOC_LARGESIZE / ALLOC_ALIGN)
+
+/** The special type, packed rrset. Not allowed to be used for other memory */
+typedef uint64_t alloc_special_t;
+/** clean the special type. Pass pointer. */
+#define alloc_special_clean(x) memset(x, 0, sizeof(alloc_special_t))
+/** access next pointer. (in available spot). Pass pointer. */
+#define alloc_special_next(x) ((alloc_special_t*)(*(x)))
+
+/** The number of cached items. */
+#define ALLOC_CACHENUM 10 /* memory blocks */
+
+/** Preallocated per thread. This number for every size. */
+#define ALLOC_PREALLOC 32 /* memory blocks */
+
+/** shorthand */
+typedef struct alloc_cache alloc_t;
+/**
+ * Structure that provides caching based on size. Used one per thread.
+ */
+struct alloc_cache {
+ /** global allocator above this one. NULL for none (malloc/free) */
+ struct alloc_super* super;
+ /** singly linked lists per size: [0]32, [1]64, ... [n-1]LARGESIZE */
+ void* bins[ALLOC_BINS];
+ /** the number of items per bin. */
+ size_t nums[ALLOC_BINS];
+ /** singly linked lists of special type. These are free for use. */
+ alloc_special_t* quar;
+ /** number of items in quarantine. */
+ size_t num_quar;
+
+ /* some statistics */
+ /** amount allocated. */
+ size_t bytes_allocated;
+ /** number of items allocated. */
+ size_t items_allocated;
+ /** wasted space due to assigning oversized aligned blocks. */
+ size_t internal_frag;
+ /** amount in cache. */
+ size_t bytes_in_bins;
+ /** number of special type allocated */
+ size_t special_allocated;
+};
+
+/**
+ * Structure with lock to provide global cache of special items and allocs.
+ */
+struct alloc_super {
+ /** lock for single access. */
+ lock_quick_t lock;
+ /** singly linked lists of special type. These are free for use. */
+ alloc_special_t* quar;
+ /** number of items in quarantine. */
+ size_t num_quar;
+};
+
+/**
+ * Init super alloc. (zeroes the struct, inits the lock).
+ * @param super: to init.
+ */
+void asuper_init(struct alloc_super* super);
+
+/**
+ * Init alloc (zeroes the struct).
+ * @param alloc: this parameter is allocated by the caller.
+ * @param super: super to use (init that before with super_init).
+ */
+void alloc_init(alloc_t* alloc, struct alloc_super* super);
+
+/**
+ * Free the alloc. Pushes all the cached items into the super structure.
+ * @param alloc: is almost zeroed on exit (except some stats).
+ */
+void alloc_delete(alloc_t* alloc);
+
+/**
+ * Allocate memory
+ * @param alloc: where to alloc it.
+ * @param size: how much.
+ * @return: memory block. Will not return NULL (instead fatal_exit).
+ */
+void* alloc_alloc(alloc_t* alloc, size_t size);
+
+/**
+ * Free memory.
+ * @param alloc: where to alloc it.
+ * @param mem: block to free.
+ */
+void alloc_free(alloc_t* alloc, void* mem);
+
+/**
+ * Get a new special_t element.
+ * @param alloc: where to alloc it.
+ * @return: memory block. Will not return NULL (instead fatal_exit).
+ */
+alloc_special_t* alloc_special_alloc(alloc_t* alloc);
+
+/**
+ * Return special_t back to pool.
+ * @param alloc: where to alloc it.
+ * @param mem: block to free.
+ */
+void alloc_special_free(alloc_t* alloc, alloc_special_t* mem);
+
+
+#endif /* UTIL_ALLOC_H */
projects / thirdparty / unbound.git / commitdiff
