src/memory.c - haproxy - Gitiles

 /*
  * Memory management functions.
  *
  * Copyright 2000-2007 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  *
  */

 #include <types/applet.h>
 #include <types/cli.h>
 #include <types/global.h>
 #include <types/stats.h>

 #include <common/config.h>
 #include <common/debug.h>
 #include <common/memory.h>
 #include <common/mini-clist.h>
 #include <common/standard.h>

 #include <proto/applet.h>
 #include <proto/cli.h>
 #include <proto/channel.h>
 #include <proto/log.h>
 #include <proto/stream_interface.h>
 #include <proto/stats.h>

 static struct list pools = LIST_HEAD_INIT(pools);
 int mem_poison_byte = -1;

 /* Try to find an existing shared pool with the same characteristics and
  * returns it, otherwise creates this one. NULL is returned if no memory
  * is available for a new creation. Two flags are supported :
  *   - MEM_F_SHARED to indicate that the pool may be shared with other users
  *   - MEM_F_EXACT to indicate that the size must not be rounded up
  */
 struct pool_head *create_pool(char *name, unsigned int size, unsigned int flags)
 {
 	struct pool_head *pool;
 	struct pool_head *entry;
 	struct list *start;
 	unsigned int align;

 	/* We need to store a (void *) at the end of the chunks. Since we know
 	 * that the malloc() function will never return such a small size,
 	 * let's round the size up to something slightly bigger, in order to
 	 * ease merging of entries. Note that the rounding is a power of two.
 	 * This extra (void *) is not accounted for in the size computation
 	 * so that the visible parts outside are not affected.
 	 */

 	if (!(flags & MEM_F_EXACT)) {
 		align = 16;
 		size  = ((size + POOL_EXTRA + align - 1) & -align) - POOL_EXTRA;
 	}

 	/* TODO: thread: we do not lock pool list for now because all pools are
 	 * created during HAProxy startup (so before threads creation) */
 	start = &pools;
 	pool = NULL;

 	list_for_each_entry(entry, &pools, list) {
 		if (entry->size == size) {
 			/* either we can share this place and we take it, or
 			 * we look for a sharable one or for the next position
 			 * before which we will insert a new one.
 			 */
 			if (flags & entry->flags & MEM_F_SHARED) {
 				/* we can share this one */
 				pool = entry;
 				DPRINTF(stderr, "Sharing %s with %s\n", name, pool->name);
 				break;
 			}
 		}
 		else if (entry->size > size) {
 			/* insert before this one */
 			start = &entry->list;
 			break;
 		}
 	}

 	if (!pool) {
 		pool = calloc(1, sizeof(*pool));
 		if (!pool)
 			return NULL;
 		if (name)
 			strlcpy2(pool->name, name, sizeof(pool->name));
 		pool->size = size;
 		pool->flags = flags;
 		LIST_ADDQ(start, &pool->list);
 	}
 	pool->users++;
 	HA_SPIN_INIT(&pool->lock);
 	return pool;
 }

 /* Allocates new entries for pool <pool> until there are at least <avail> + 1
  * available, then returns the last one for immediate use, so that at least
  * <avail> are left available in the pool upon return. NULL is returned if the
  * last entry could not be allocated. It's important to note that at least one
  * allocation is always performed even if there are enough entries in the pool.
  * A call to the garbage collector is performed at most once in case malloc()
  * returns an error, before returning NULL.
  */
 void *__pool_refill_alloc(struct pool_head *pool, unsigned int avail)
 {
 	void *ptr = NULL;
 	int failed = 0;

 	/* stop point */
 	avail += pool->used;

 	while (1) {
 		if (pool->limit && pool->allocated >= pool->limit)
 			return NULL;

 		ptr = pool_alloc_area(pool->size + POOL_EXTRA);
 		if (!ptr) {
 			pool->failed++;
 			if (failed)
 				return NULL;
 			failed++;
 			pool_gc(pool);
 			continue;
 		}
 		if (++pool->allocated > avail)
 			break;

 		*POOL_LINK(pool, ptr) = (void *)pool->free_list;
 		pool->free_list = ptr;
 	}
 	pool->used++;
 #ifdef DEBUG_MEMORY_POOLS
 	/* keep track of where the element was allocated from */
 	*POOL_LINK(pool, ptr) = (void *)pool;
 #endif
 	return ptr;
 }
 void *pool_refill_alloc(struct pool_head *pool, unsigned int avail)
 {
 	void *ptr;

 	HA_SPIN_LOCK(POOL_LOCK, &pool->lock);
 	ptr = __pool_refill_alloc(pool, avail);
 	HA_SPIN_UNLOCK(POOL_LOCK, &pool->lock);
 	return ptr;
 }
 /*
  * This function frees whatever can be freed in pool <pool>.
  */
 void pool_flush(struct pool_head *pool)
 {
 	void *temp, *next;
 	if (!pool)
 		return;

 	HA_SPIN_LOCK(POOL_LOCK, &pool->lock);
 	next = pool->free_list;
 	while (next) {
 		temp = next;
 		next = *POOL_LINK(pool, temp);
 		pool->allocated--;
 		pool_free_area(temp, pool->size + POOL_EXTRA);
 	}
 	pool->free_list = next;
 	HA_SPIN_UNLOCK(POOL_LOCK, &pool->lock);
 	/* here, we should have pool->allocate == pool->used */
 }

 /*
  * This function frees whatever can be freed in all pools, but respecting
  * the minimum thresholds imposed by owners. It takes care of avoiding
  * recursion because it may be called from a signal handler.
  *
  * <pool_ctx> is used when pool_gc is called to release resources to allocate
  * an element in __pool_refill_alloc. It is important because <pool_ctx> is
  * already locked, so we need to skip the lock here.
  */
 void pool_gc(struct pool_head *pool_ctx)
 {
 	static int recurse;
 	int cur_recurse = 0;
 	struct pool_head *entry;

 	if (recurse || !HA_ATOMIC_CAS(&recurse, &cur_recurse, 1))
 		return;

 	list_for_each_entry(entry, &pools, list) {
 		void *temp, *next;
 		//qfprintf(stderr, "Flushing pool %s\n", entry->name);
 		if (entry != pool_ctx)
 			HA_SPIN_LOCK(POOL_LOCK, &entry->lock);
 		next = entry->free_list;
 		while (next &&
 		       (int)(entry->allocated - entry->used) > (int)entry->minavail) {
 			temp = next;
 			next = *POOL_LINK(entry, temp);
 			entry->allocated--;
 			pool_free_area(temp, entry->size + POOL_EXTRA);
 		}
 		entry->free_list = next;
 		if (entry != pool_ctx)
 			HA_SPIN_UNLOCK(POOL_LOCK, &entry->lock);
 	}

 	HA_ATOMIC_STORE(&recurse, 0);
 }

 /*
  * This function destroys a pool by freeing it completely, unless it's still
  * in use. This should be called only under extreme circumstances. It always
  * returns NULL if the resulting pool is empty, easing the clearing of the old
  * pointer, otherwise it returns the pool.
  * .
  */
 void *pool_destroy(struct pool_head *pool)
 {
 	if (pool) {
 		pool_flush(pool);
 		if (pool->used)
 			return pool;
 		pool->users--;
 		if (!pool->users) {
 			LIST_DEL(&pool->list);
 			HA_SPIN_DESTROY(&pool->lock);
 			free(pool);
 		}
 	}
 	return NULL;
 }

 /* This function dumps memory usage information into the trash buffer. */
 void dump_pools_to_trash()
 {
 	struct pool_head *entry;
 	unsigned long allocated, used;
 	int nbpools;

 	allocated = used = nbpools = 0;
 	chunk_printf(&trash, "Dumping pools usage. Use SIGQUIT to flush them.\n");
 	list_for_each_entry(entry, &pools, list) {
 		HA_SPIN_LOCK(POOL_LOCK, &entry->lock);
 		chunk_appendf(&trash, "  - Pool %s (%d bytes) : %d allocated (%u bytes), %d used, %d failures, %d users%s\n",
 			 entry->name, entry->size, entry->allocated,
 		         entry->size * entry->allocated, entry->used, entry->failed,
 			 entry->users, (entry->flags & MEM_F_SHARED) ? " [SHARED]" : "");

 		allocated += entry->allocated * entry->size;
 		used += entry->used * entry->size;
 		nbpools++;
 		HA_SPIN_UNLOCK(POOL_LOCK, &entry->lock);
 	}
 	chunk_appendf(&trash, "Total: %d pools, %lu bytes allocated, %lu used.\n",
 		 nbpools, allocated, used);
 }

 /* Dump statistics on pools usage. */
 void dump_pools(void)
 {
 	dump_pools_to_trash();
 	qfprintf(stderr, "%s", trash.str);
 }

 /* This function returns the total number of failed pool allocations */
 int pool_total_failures()
 {
 	struct pool_head *entry;
 	int failed = 0;

 	list_for_each_entry(entry, &pools, list)
 		failed += entry->failed;
 	return failed;
 }

 /* This function returns the total amount of memory allocated in pools (in bytes) */
 unsigned long pool_total_allocated()
 {
 	struct pool_head *entry;
 	unsigned long allocated = 0;

 	list_for_each_entry(entry, &pools, list)
 		allocated += entry->allocated * entry->size;
 	return allocated;
 }

 /* This function returns the total amount of memory used in pools (in bytes) */
 unsigned long pool_total_used()
 {
 	struct pool_head *entry;
 	unsigned long used = 0;

 	list_for_each_entry(entry, &pools, list)
 		used += entry->used * entry->size;
 	return used;
 }

 /* This function dumps memory usage information onto the stream interface's
  * read buffer. It returns 0 as long as it does not complete, non-zero upon
  * completion. No state is used.
  */
 static int cli_io_handler_dump_pools(struct appctx *appctx)
 {
 	struct stream_interface *si = appctx->owner;

 	dump_pools_to_trash();
 	if (ci_putchk(si_ic(si), &trash) == -1) {
 		si_applet_cant_put(si);
 		return 0;
 	}
 	return 1;
 }

 /* register cli keywords */
 static struct cli_kw_list cli_kws = {{ },{
 	{ { "show", "pools",  NULL }, "show pools     : report information about the memory pools usage", NULL, cli_io_handler_dump_pools },
 	{{},}
 }};

 __attribute__((constructor))
 static void __memory_init(void)
 {
 	cli_register_kw(&cli_kws);
 }

 /*
  * Local variables:
  *  c-indent-level: 8
  *  c-basic-offset: 8
  * End:
  */
	/*
	* Memory management functions.
	*
	* Copyright 2000-2007 Willy Tarreau <w@1wt.eu>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	*/

	#include <types/applet.h>
	#include <types/cli.h>
	#include <types/global.h>
	#include <types/stats.h>

	#include <common/config.h>
	#include <common/debug.h>
	#include <common/memory.h>
	#include <common/mini-clist.h>
	#include <common/standard.h>

	#include <proto/applet.h>
	#include <proto/cli.h>
	#include <proto/channel.h>
	#include <proto/log.h>
	#include <proto/stream_interface.h>
	#include <proto/stats.h>

	static struct list pools = LIST_HEAD_INIT(pools);
	int mem_poison_byte = -1;

	/* Try to find an existing shared pool with the same characteristics and
	* returns it, otherwise creates this one. NULL is returned if no memory
	* is available for a new creation. Two flags are supported :
	* - MEM_F_SHARED to indicate that the pool may be shared with other users
	* - MEM_F_EXACT to indicate that the size must not be rounded up
	*/
	struct pool_head create_pool(char name, unsigned int size, unsigned int flags)
	{
	struct pool_head *pool;
	struct pool_head *entry;
	struct list *start;
	unsigned int align;

	/* We need to store a (void *) at the end of the chunks. Since we know
	* that the malloc() function will never return such a small size,
	* let's round the size up to something slightly bigger, in order to
	* ease merging of entries. Note that the rounding is a power of two.
	* This extra (void *) is not accounted for in the size computation
	* so that the visible parts outside are not affected.
	*/

	if (!(flags & MEM_F_EXACT)) {
	align = 16;
	size = ((size + POOL_EXTRA + align - 1) & -align) - POOL_EXTRA;
	}

	/* TODO: thread: we do not lock pool list for now because all pools are
	* created during HAProxy startup (so before threads creation) */
	start = &pools;
	pool = NULL;

	list_for_each_entry(entry, &pools, list) {
	if (entry->size == size) {
	/* either we can share this place and we take it, or
	* we look for a sharable one or for the next position
	* before which we will insert a new one.
	*/
	if (flags & entry->flags & MEM_F_SHARED) {
	/* we can share this one */
	pool = entry;
	DPRINTF(stderr, "Sharing %s with %s\n", name, pool->name);
	break;
	}
	}
	else if (entry->size > size) {
	/* insert before this one */
	start = &entry->list;
	break;
	}
	}

	if (!pool) {
	pool = calloc(1, sizeof(*pool));
	if (!pool)
	return NULL;
	if (name)
	strlcpy2(pool->name, name, sizeof(pool->name));
	pool->size = size;
	pool->flags = flags;
	LIST_ADDQ(start, &pool->list);
	}
	pool->users++;
	HA_SPIN_INIT(&pool->lock);
	return pool;
	}

	/* Allocates new entries for pool <pool> until there are at least <avail> + 1
	* available, then returns the last one for immediate use, so that at least
	* <avail> are left available in the pool upon return. NULL is returned if the
	* last entry could not be allocated. It's important to note that at least one
	* allocation is always performed even if there are enough entries in the pool.
	* A call to the garbage collector is performed at most once in case malloc()
	* returns an error, before returning NULL.
	*/
	void __pool_refill_alloc(struct pool_head pool, unsigned int avail)
	{
	void *ptr = NULL;
	int failed = 0;

	/* stop point */
	avail += pool->used;

	while (1) {
	if (pool->limit && pool->allocated >= pool->limit)
	return NULL;

	ptr = pool_alloc_area(pool->size + POOL_EXTRA);
	if (!ptr) {
	pool->failed++;
	if (failed)
	return NULL;
	failed++;
	pool_gc(pool);
	continue;
	}
	if (++pool->allocated > avail)
	break;

	POOL_LINK(pool, ptr) = (void )pool->free_list;
	pool->free_list = ptr;
	}
	pool->used++;
	#ifdef DEBUG_MEMORY_POOLS
	/* keep track of where the element was allocated from */
	POOL_LINK(pool, ptr) = (void )pool;
	#endif
	return ptr;
	}
	void pool_refill_alloc(struct pool_head pool, unsigned int avail)
	{
	void *ptr;

	HA_SPIN_LOCK(POOL_LOCK, &pool->lock);
	ptr = __pool_refill_alloc(pool, avail);
	HA_SPIN_UNLOCK(POOL_LOCK, &pool->lock);
	return ptr;
	}
	/*
	* This function frees whatever can be freed in pool <pool>.
	*/
	void pool_flush(struct pool_head *pool)
	{
	void temp, next;
	if (!pool)
	return;

	HA_SPIN_LOCK(POOL_LOCK, &pool->lock);
	next = pool->free_list;
	while (next) {
	temp = next;
	next = *POOL_LINK(pool, temp);
	pool->allocated--;
	pool_free_area(temp, pool->size + POOL_EXTRA);
	}
	pool->free_list = next;
	HA_SPIN_UNLOCK(POOL_LOCK, &pool->lock);
	/* here, we should have pool->allocate == pool->used */
	}

	/*
	* This function frees whatever can be freed in all pools, but respecting
	* the minimum thresholds imposed by owners. It takes care of avoiding
	* recursion because it may be called from a signal handler.
	*
	* <pool_ctx> is used when pool_gc is called to release resources to allocate
	* an element in __pool_refill_alloc. It is important because <pool_ctx> is
	* already locked, so we need to skip the lock here.
	*/
	void pool_gc(struct pool_head *pool_ctx)
	{
	static int recurse;
	int cur_recurse = 0;
	struct pool_head *entry;

	if (recurse \|\| !HA_ATOMIC_CAS(&recurse, &cur_recurse, 1))
	return;

	list_for_each_entry(entry, &pools, list) {
	void temp, next;
	//qfprintf(stderr, "Flushing pool %s\n", entry->name);
	if (entry != pool_ctx)
	HA_SPIN_LOCK(POOL_LOCK, &entry->lock);
	next = entry->free_list;
	while (next &&
	(int)(entry->allocated - entry->used) > (int)entry->minavail) {
	temp = next;
	next = *POOL_LINK(entry, temp);
	entry->allocated--;
	pool_free_area(temp, entry->size + POOL_EXTRA);
	}
	entry->free_list = next;
	if (entry != pool_ctx)
	HA_SPIN_UNLOCK(POOL_LOCK, &entry->lock);
	}

	HA_ATOMIC_STORE(&recurse, 0);
	}

	/*
	* This function destroys a pool by freeing it completely, unless it's still
	* in use. This should be called only under extreme circumstances. It always
	* returns NULL if the resulting pool is empty, easing the clearing of the old
	* pointer, otherwise it returns the pool.
	* .
	*/
	void pool_destroy(struct pool_head pool)
	{
	if (pool) {
	pool_flush(pool);
	if (pool->used)
	return pool;
	pool->users--;
	if (!pool->users) {
	LIST_DEL(&pool->list);
	HA_SPIN_DESTROY(&pool->lock);
	free(pool);
	}
	}
	return NULL;
	}

	/* This function dumps memory usage information into the trash buffer. */
	void dump_pools_to_trash()
	{
	struct pool_head *entry;
	unsigned long allocated, used;
	int nbpools;

	allocated = used = nbpools = 0;
	chunk_printf(&trash, "Dumping pools usage. Use SIGQUIT to flush them.\n");
	list_for_each_entry(entry, &pools, list) {
	HA_SPIN_LOCK(POOL_LOCK, &entry->lock);
	chunk_appendf(&trash, " - Pool %s (%d bytes) : %d allocated (%u bytes), %d used, %d failures, %d users%s\n",
	entry->name, entry->size, entry->allocated,
	entry->size * entry->allocated, entry->used, entry->failed,
	entry->users, (entry->flags & MEM_F_SHARED) ? " [SHARED]" : "");

	allocated += entry->allocated * entry->size;
	used += entry->used * entry->size;
	nbpools++;
	HA_SPIN_UNLOCK(POOL_LOCK, &entry->lock);
	}
	chunk_appendf(&trash, "Total: %d pools, %lu bytes allocated, %lu used.\n",
	nbpools, allocated, used);
	}

	/* Dump statistics on pools usage. */
	void dump_pools(void)
	{
	dump_pools_to_trash();
	qfprintf(stderr, "%s", trash.str);
	}

	/* This function returns the total number of failed pool allocations */
	int pool_total_failures()
	{
	struct pool_head *entry;
	int failed = 0;

	list_for_each_entry(entry, &pools, list)
	failed += entry->failed;
	return failed;
	}

	/* This function returns the total amount of memory allocated in pools (in bytes) */
	unsigned long pool_total_allocated()
	{
	struct pool_head *entry;
	unsigned long allocated = 0;

	list_for_each_entry(entry, &pools, list)
	allocated += entry->allocated * entry->size;
	return allocated;
	}

	/* This function returns the total amount of memory used in pools (in bytes) */
	unsigned long pool_total_used()
	{
	struct pool_head *entry;
	unsigned long used = 0;

	list_for_each_entry(entry, &pools, list)
	used += entry->used * entry->size;
	return used;
	}

	/* This function dumps memory usage information onto the stream interface's
	* read buffer. It returns 0 as long as it does not complete, non-zero upon
	* completion. No state is used.
	*/
	static int cli_io_handler_dump_pools(struct appctx *appctx)
	{
	struct stream_interface *si = appctx->owner;

	dump_pools_to_trash();
	if (ci_putchk(si_ic(si), &trash) == -1) {
	si_applet_cant_put(si);
	return 0;
	}
	return 1;
	}

	/* register cli keywords */
	static struct cli_kw_list cli_kws = {{ },{
	{ { "show", "pools", NULL }, "show pools : report information about the memory pools usage", NULL, cli_io_handler_dump_pools },
	{{},}
	}};

	__attribute__((constructor))
	static void __memory_init(void)
	{
	cli_register_kw(&cli_kws);
	}

	/*
	* Local variables:
	* c-indent-level: 8
	* c-basic-offset: 8
	* End:
	*/