This patch adds support for LZO compression when storing the register cache. The initial register defaults cache is marked as __devinitconst and the only change required for a driver to use LZO compression is to set the compress_type member in codec->driver to SND_SOC_LZO_COMPRESSION.

For a typical device whose register map would normally occupy 25kB or 50kB by using the LZO compression technique, one can get down to ~3-5kB. There might be a performance penalty associated with each individual read/write due to decompressing/compressing the underlying cache, however that should not be noticeable. The memory benefits depend on whether the target architecture can get rid of the memory occupied by the original register defaults cache which is marked as __devinitconst.

Signed-off-by: Dimitris Papastamos dp@opensource.wolfsonmicro.com --- include/sound/soc.h | 3 +- sound/soc/soc-cache.c | 413 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 415 insertions(+), 1 deletions(-)

diff --git a/include/sound/soc.h b/include/sound/soc.h index 90a9b60..8135b3c 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -255,7 +255,8 @@ enum snd_soc_control_type { };

enum snd_soc_compress_type { - SND_SOC_NO_COMPRESSION + SND_SOC_NO_COMPRESSION, + SND_SOC_LZO_COMPRESSION };

int snd_soc_register_platform(struct device *dev, diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c index c5d05b8..63b7fe9 100644 --- a/sound/soc/soc-cache.c +++ b/sound/soc/soc-cache.c @@ -14,6 +14,8 @@ #include <linux/i2c.h> #include <linux/spi/spi.h> #include <sound/soc.h> +#include <linux/lzo.h> +#include <linux/bitmap.h>

/* serialize access to *cache_read() and *cache_write() */ static DEFINE_MUTEX(cache_rw_mutex); @@ -757,6 +759,409 @@ int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec, } EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);

+struct snd_soc_lzo_ctx { + void *wmem; + void *dst; + const void *src; + size_t src_len; + size_t dst_len; + size_t decompressed_size; + unsigned long *sync_bmp; + int sync_bmp_nbits; +}; + +#define LZO_BLOCK_NUM 8 +static int snd_soc_lzo_block_count(void) +{ + return LZO_BLOCK_NUM; +} + +static int snd_soc_lzo_prepare(struct snd_soc_lzo_ctx *lzo_ctx) +{ + lzo_ctx->wmem = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); + if (!lzo_ctx->wmem) + return -ENOMEM; + return 0; +} + +static int snd_soc_lzo_compress(struct snd_soc_lzo_ctx *lzo_ctx) +{ + size_t compress_size; + int ret; + + ret = lzo1x_1_compress(lzo_ctx->src, lzo_ctx->src_len, + lzo_ctx->dst, &compress_size, lzo_ctx->wmem); + if (ret != LZO_E_OK || compress_size > lzo_ctx->dst_len) + return -EINVAL; + lzo_ctx->dst_len = compress_size; + return 0; +} + +static int snd_soc_lzo_decompress(struct snd_soc_lzo_ctx *lzo_ctx) +{ + size_t dst_len; + int ret; + + dst_len = lzo_ctx->dst_len; + ret = lzo1x_decompress_safe(lzo_ctx->src, lzo_ctx->src_len, + lzo_ctx->dst, &dst_len); + if (ret != LZO_E_OK || dst_len != lzo_ctx->dst_len) + return -EINVAL; + return 0; +} + +static int snd_soc_lzo_compress_cache_block(struct snd_soc_codec *codec, + struct snd_soc_lzo_ctx *lzo_ctx) +{ + int ret; + + lzo_ctx->dst_len = lzo1x_worst_compress(PAGE_SIZE); + lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL); + if (!lzo_ctx->dst) { + lzo_ctx->dst_len = 0; + return -ENOMEM; + } + + ret = snd_soc_lzo_compress(lzo_ctx); + if (ret < 0) + return ret; + return 0; +} + +static int snd_soc_lzo_decompress_cache_block(struct snd_soc_codec *codec, + struct snd_soc_lzo_ctx *lzo_ctx) +{ + int ret; + + lzo_ctx->dst_len = lzo_ctx->decompressed_size; + lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL); + if (!lzo_ctx->dst) { + lzo_ctx->dst_len = 0; + return -ENOMEM; + } + + ret = snd_soc_lzo_decompress(lzo_ctx); + if (ret < 0) + return ret; + return 0; +} + +static inline int snd_soc_lzo_get_blkindex(struct snd_soc_codec *codec, + unsigned int reg) +{ + struct snd_soc_codec_driver *codec_drv; + size_t reg_size; + + codec_drv = codec->driver; + reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size; + return (reg * codec_drv->reg_word_size) / + DIV_ROUND_UP(reg_size, snd_soc_lzo_block_count()); +} + +static inline int snd_soc_lzo_get_blkpos(struct snd_soc_codec *codec, + unsigned int reg) +{ + struct snd_soc_codec_driver *codec_drv; + size_t reg_size; + + codec_drv = codec->driver; + reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size; + return reg % (DIV_ROUND_UP(reg_size, snd_soc_lzo_block_count()) / + codec_drv->reg_word_size); +} + +static inline int snd_soc_lzo_get_blksize(struct snd_soc_codec *codec) +{ + struct snd_soc_codec_driver *codec_drv; + size_t reg_size; + + codec_drv = codec->driver; + reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size; + return DIV_ROUND_UP(reg_size, snd_soc_lzo_block_count()); +} + +static int snd_soc_lzo_cache_sync(struct snd_soc_codec *codec) +{ + struct snd_soc_lzo_ctx **lzo_blocks; + unsigned int val; + int i; + + lzo_blocks = codec->reg_cache; + for_each_set_bit(i, lzo_blocks[0]->sync_bmp, lzo_blocks[0]->sync_bmp_nbits) { + snd_soc_cache_read(codec, i, &val); + snd_soc_write(codec, i, val); + dev_dbg(codec->dev, "Synced register %#x, value = %#x\n", + i, val); + } + + return 0; +} + +static int snd_soc_lzo_cache_write(struct snd_soc_codec *codec, + unsigned int reg, unsigned int value) +{ + struct snd_soc_lzo_ctx *lzo_block, **lzo_blocks; + int ret, blkindex, blkpos; + size_t blksize, tmp_dst_len; + void *tmp_dst; + + /* index of the compressed lzo block */ + blkindex = snd_soc_lzo_get_blkindex(codec, reg); + /* register index within the decompressed block */ + blkpos = snd_soc_lzo_get_blkpos(codec, reg); + /* size of the compressed block */ + blksize = snd_soc_lzo_get_blksize(codec); + lzo_blocks = codec->reg_cache; + lzo_block = lzo_blocks[blkindex]; + + /* save the pointer and length of the compressed block */ + tmp_dst = lzo_block->dst; + tmp_dst_len = lzo_block->dst_len; + + /* prepare the source to be the compressed block */ + lzo_block->src = lzo_block->dst; + lzo_block->src_len = lzo_block->dst_len; + + /* decompress the block */ + ret = snd_soc_lzo_decompress_cache_block(codec, lzo_block); + if (ret < 0) { + kfree(lzo_block->dst); + goto out; + } + + /* write the new value to the cache */ + switch (codec->driver->reg_word_size) { + case 1: { + u8 *cache; + cache = lzo_block->dst; + if (cache[blkpos] == value) { + kfree(lzo_block->dst); + goto out; + } + cache[blkpos] = value; + } + break; + case 2: { + u16 *cache; + cache = lzo_block->dst; + if (cache[blkpos] == value) { + kfree(lzo_block->dst); + goto out; + } + cache[blkpos] = value; + } + break; + default: + return -EINVAL; + } + + /* prepare the source to be the decompressed block */ + lzo_block->src = lzo_block->dst; + lzo_block->src_len = lzo_block->dst_len; + + /* compress the block */ + ret = snd_soc_lzo_compress_cache_block(codec, lzo_block); + if (ret < 0) { + kfree(lzo_block->dst); + kfree(lzo_block->src); + goto out; + } + + /* set the bit so we know we have to sync this register */ + set_bit(reg, lzo_block->sync_bmp); + kfree(tmp_dst); + kfree(lzo_block->src); + return 0; +out: + lzo_block->dst = tmp_dst; + lzo_block->dst_len = tmp_dst_len; + return ret; +} + +static int snd_soc_lzo_cache_read(struct snd_soc_codec *codec, + unsigned int reg, unsigned int *value) +{ + struct snd_soc_lzo_ctx *lzo_block, **lzo_blocks; + int ret, blkindex, blkpos; + size_t blksize, tmp_dst_len; + void *tmp_dst; + + *value = 0; + /* index of the compressed lzo block */ + blkindex = snd_soc_lzo_get_blkindex(codec, reg); + /* register index within the decompressed block */ + blkpos = snd_soc_lzo_get_blkpos(codec, reg); + /* size of the compressed block */ + blksize = snd_soc_lzo_get_blksize(codec); + lzo_blocks = codec->reg_cache; + lzo_block = lzo_blocks[blkindex]; + + /* save the pointer and length of the compressed block */ + tmp_dst = lzo_block->dst; + tmp_dst_len = lzo_block->dst_len; + + /* prepare the source to be the compressed block */ + lzo_block->src = lzo_block->dst; + lzo_block->src_len = lzo_block->dst_len; + + /* decompress the block */ + ret = snd_soc_lzo_decompress_cache_block(codec, lzo_block); + if (ret >= 0) { + /* fetch the value from the cache */ + switch (codec->driver->reg_word_size) { + case 1: { + u8 *cache; + cache = lzo_block->dst; + *value = cache[blkpos]; + } + break; + case 2: { + u16 *cache; + cache = lzo_block->dst; + *value = cache[blkpos]; + } + break; + default: + return -EINVAL; + } + } + + kfree(lzo_block->dst); + /* restore the pointer and length of the compressed block */ + lzo_block->dst = tmp_dst; + lzo_block->dst_len = tmp_dst_len; + return 0; +} + +static int snd_soc_lzo_cache_exit(struct snd_soc_codec *codec) +{ + struct snd_soc_lzo_ctx **lzo_blocks; + int i, blkcount; + + lzo_blocks = codec->reg_cache; + if (!lzo_blocks) + return 0; + + blkcount = snd_soc_lzo_block_count(); + /* + * the pointer to the bitmap used for syncing the cache + * is shared amongst all lzo_blocks. Ensure it is freed + * only once. + */ + if (lzo_blocks[0]) + kfree(lzo_blocks[0]->sync_bmp); + for (i = 0; i < blkcount; ++i) { + if (lzo_blocks[i]) { + kfree(lzo_blocks[i]->wmem); + kfree(lzo_blocks[i]->dst); + } + /* each lzo_block is a pointer returned by kmalloc or NULL */ + kfree(lzo_blocks[i]); + } + kfree(lzo_blocks); + codec->reg_cache = NULL; + return 0; +} + +static int snd_soc_lzo_cache_init(struct snd_soc_codec *codec) +{ + struct snd_soc_lzo_ctx **lzo_blocks; + size_t reg_size, bmp_size; + struct snd_soc_codec_driver *codec_drv; + int ret, tofree, i, blksize, blkcount; + const char *p, *end; + unsigned long *sync_bmp; + + ret = 0; + codec_drv = codec->driver; + reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size; + + /* + * If we have not been given a default register cache + * then allocate a dummy zero-ed out region, compress it + * and remember to free it afterwards. + */ + tofree = 0; + if (!codec_drv->reg_cache_default) + tofree = 1; + + if (!codec_drv->reg_cache_default) { + codec_drv->reg_cache_default = kzalloc(reg_size, + GFP_KERNEL); + if (!codec_drv->reg_cache_default) + return -ENOMEM; + } + + blkcount = snd_soc_lzo_block_count(); + codec->reg_cache = kzalloc(blkcount * sizeof(*lzo_blocks), + GFP_KERNEL); + if (!codec->reg_cache) { + ret = -ENOMEM; + goto err_tofree; + } + lzo_blocks = codec->reg_cache; + + /* + * allocate a bitmap to be used when syncing the cache with + * the hardware. Each time a register is modified, the corresponding + * bit is set in the bitmap, so we know that we have to sync + * that register. + */ + bmp_size = codec_drv->reg_cache_size; + sync_bmp = kmalloc(BITS_TO_LONGS(bmp_size) * sizeof(unsigned long), + GFP_KERNEL); + if (!sync_bmp) { + ret = -ENOMEM; + goto err; + } + bitmap_zero(sync_bmp, reg_size); + + /* allocate the lzo blocks and initialize them */ + for (i = 0; i < blkcount; ++i) { + lzo_blocks[i] = kzalloc(sizeof **lzo_blocks, + GFP_KERNEL); + if (!lzo_blocks[i]) { + kfree(sync_bmp); + ret = -ENOMEM; + goto err; + } + lzo_blocks[i]->sync_bmp = sync_bmp; + lzo_blocks[i]->sync_bmp_nbits = reg_size; + /* alloc the working space for the compressed block */ + ret = snd_soc_lzo_prepare(lzo_blocks[i]); + if (ret < 0) + goto err; + } + + blksize = snd_soc_lzo_get_blksize(codec); + p = codec_drv->reg_cache_default; + end = codec_drv->reg_cache_default + reg_size; + /* compress the register map and fill the lzo blocks */ + for (i = 0; i < blkcount; ++i, p += blksize) { + lzo_blocks[i]->src = p; + if (p + blksize > end) + lzo_blocks[i]->src_len = end - p; + else + lzo_blocks[i]->src_len = blksize; + ret = snd_soc_lzo_compress_cache_block(codec, + lzo_blocks[i]); + if (ret < 0) + goto err; + lzo_blocks[i]->decompressed_size = + lzo_blocks[i]->src_len; + } + + if (tofree) + kfree(codec_drv->reg_cache_default); + return 0; +err: + snd_soc_cache_exit(codec); +err_tofree: + if (tofree) + kfree(codec_drv->reg_cache_default); + return ret; +} + static int snd_soc_flat_cache_sync(struct snd_soc_codec *codec) { int i; @@ -879,6 +1284,14 @@ static const struct snd_soc_cache_ops cache_types[] = { .read = snd_soc_flat_cache_read, .write = snd_soc_flat_cache_write, .sync = snd_soc_flat_cache_sync + }, + { + .id = SND_SOC_LZO_COMPRESSION, + .init = snd_soc_lzo_cache_init, + .exit = snd_soc_lzo_cache_exit, + .read = snd_soc_lzo_cache_read, + .write = snd_soc_lzo_cache_write, + .sync = snd_soc_lzo_cache_sync } };

This patch adds support for rbtree compression when storing the register cache. It does this by not adding any uninitialized registers (those whose value is 0). If any of those registers is written with a nonzero value they get added into the rbtree.

Consider a sample device with a large sparse register map. The register indices are between [0, 0x31ff]. An array of 12800 registers is thus created each of which is 2 bytes. This results in a 25kB region. This array normally lives outside soc-core, normally in the driver itself. The original soc-core code would kmemdup this region resulting in 50kB total memory. When using the rbtree compression technique and __devinitconst on the original array the figures are as follows. For this typical device, you might have 100 initialized registers, that is registers that are nonzero by default. We build an rbtree with 100 nodes, each of which is 21 bytes. This results in ~2kB of memory. Assuming that the target arch can freeup the memory used by the initial __devinitconst array, we end up using about ~2kB bytes of actual memory. The memory footprint will increase as uninitialized registers get written and thus new nodes created in the rbtree. In practice, most of those registers are never changed. If the target arch can't freeup the __devinitconst array, we end up using a total of ~27kB. The difference between the rbtree and the LZO caching techniques, is that if using the LZO technique the size of the cache will increase slower as more uninitialized registers get changed.

Signed-off-by: Dimitris Papastamos dp@opensource.wolfsonmicro.com --- include/sound/soc.h | 3 +- sound/soc/soc-cache.c | 233 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 235 insertions(+), 1 deletions(-)

diff --git a/include/sound/soc.h b/include/sound/soc.h index 8135b3c..6e9f511 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -256,7 +256,8 @@ enum snd_soc_control_type {

enum snd_soc_compress_type { SND_SOC_NO_COMPRESSION, - SND_SOC_LZO_COMPRESSION + SND_SOC_LZO_COMPRESSION, + SND_SOC_RBTREE_COMPRESSION };

int snd_soc_register_platform(struct device *dev, diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c index 63b7fe9..3d85ac0 100644 --- a/sound/soc/soc-cache.c +++ b/sound/soc/soc-cache.c @@ -16,6 +16,7 @@ #include <sound/soc.h> #include <linux/lzo.h> #include <linux/bitmap.h> +#include <linux/rbtree.h>

/* serialize access to *cache_read() and *cache_write() */ static DEFINE_MUTEX(cache_rw_mutex); @@ -759,6 +760,230 @@ int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec, } EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);

+struct snd_soc_rbtree_node { + struct rb_node node; + unsigned int dirty:1; + unsigned int reg; + unsigned int value; +} __attribute__ ((packed)); + +struct snd_soc_rbtree_ctx { + struct rb_root root; +}; + +static struct snd_soc_rbtree_node *snd_soc_rbtree_lookup( + struct rb_root *root, unsigned int reg) +{ + struct rb_node *node; + struct snd_soc_rbtree_node *rbnode; + + node = root->rb_node; + while (node) { + rbnode = container_of(node, struct snd_soc_rbtree_node, node); + if (rbnode->reg < reg) + node = node->rb_left; + else if (rbnode->reg > reg) + node = node->rb_right; + else + return rbnode; + } + + return NULL; +} + + +static int snd_soc_rbtree_insert(struct rb_root *root, + struct snd_soc_rbtree_node *rbnode) +{ + struct rb_node **new, *parent; + struct snd_soc_rbtree_node *rbnode_tmp; + + parent = NULL; + new = &root->rb_node; + while (*new) { + rbnode_tmp = container_of(*new, struct snd_soc_rbtree_node, + node); + parent = *new; + if (rbnode_tmp->reg < rbnode->reg) + new = &((*new)->rb_left); + else if (rbnode_tmp->reg > rbnode->reg) + new = &((*new)->rb_right); + else + return 0; + } + + /* insert the node into the rbtree */ + rb_link_node(&rbnode->node, parent, new); + rb_insert_color(&rbnode->node, root); + + return 1; +} + +static int snd_soc_rbtree_cache_sync(struct snd_soc_codec *codec) +{ + struct snd_soc_rbtree_ctx *rbtree_ctx; + struct rb_node *node; + struct snd_soc_rbtree_node *rbnode; + unsigned int val; + + rbtree_ctx = codec->reg_cache; + for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) { + rbnode = rb_entry(node, struct snd_soc_rbtree_node, node); + if (!rbnode->dirty) + continue; + snd_soc_cache_read(codec, rbnode->reg, &val); + snd_soc_write(codec, rbnode->reg, val); + dev_dbg(codec->dev, "Synced register %#x, value = %#x\n", + rbnode->reg, val); + } + + return 0; +} + +static int snd_soc_rbtree_cache_write(struct snd_soc_codec *codec, + unsigned int reg, unsigned int value) +{ + struct snd_soc_rbtree_ctx *rbtree_ctx; + struct snd_soc_rbtree_node *rbnode; + + rbtree_ctx = codec->reg_cache; + rbnode = snd_soc_rbtree_lookup(&rbtree_ctx->root, reg); + if (rbnode) { + if (rbnode->value == value) + return 0; + rbnode->value = value; + } else { + /* bail out early, no need to create the rbnode yet */ + if (!value) + return 0; + /* + * for uninitialized registers whose value is changed + * from the default zero, create an rbnode and insert + * it into the tree. + */ + rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL); + if (!rbnode) + return -ENOMEM; + rbnode->reg = reg; + rbnode->value = value; + snd_soc_rbtree_insert(&rbtree_ctx->root, rbnode); + } + /* remember that we have to sync this register */ + rbnode->dirty = 1; + + return 0; +} + +static int snd_soc_rbtree_cache_read(struct snd_soc_codec *codec, + unsigned int reg, unsigned int *value) +{ + struct snd_soc_rbtree_ctx *rbtree_ctx; + struct snd_soc_rbtree_node *rbnode; + + rbtree_ctx = codec->reg_cache; + rbnode = snd_soc_rbtree_lookup(&rbtree_ctx->root, reg); + if (rbnode) { + *value = rbnode->value; + } else { + /* uninitialized registers default to 0 */ + *value = 0; + } + + return 0; +} + +static int snd_soc_rbtree_cache_exit(struct snd_soc_codec *codec) +{ + struct rb_node *next; + struct snd_soc_rbtree_ctx *rbtree_ctx; + struct snd_soc_rbtree_node *rbtree_node; + + /* if we've already been called then just return */ + rbtree_ctx = codec->reg_cache; + if (!rbtree_ctx) + return 0; + + /* free up the rbtree */ + next = rb_first(&rbtree_ctx->root); + while (next) { + rbtree_node = rb_entry(next, struct snd_soc_rbtree_node, node); + next = rb_next(&rbtree_node->node); + rb_erase(&rbtree_node->node, &rbtree_ctx->root); + kfree(rbtree_node); + } + + /* release the resources */ + kfree(codec->reg_cache); + codec->reg_cache = NULL; + + return 0; +} + +static int snd_soc_rbtree_cache_init(struct snd_soc_codec *codec) +{ + struct snd_soc_rbtree_ctx *rbtree_ctx; + + codec->reg_cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL); + if (!codec->reg_cache) + return -ENOMEM; + + rbtree_ctx = codec->reg_cache; + rbtree_ctx->root = RB_ROOT; + + if (!codec->driver->reg_cache_default) + return 0; + +/* + * populate the rbtree with the initialized registers. All other + * registers will be inserted into the tree when they are first written. + * + * The reasoning behind this, is that we need to step through and + * dereference the cache in u8/u16 increments without sacrificing + * portability. This could also be done using memcpy() but that would + * be slightly more cryptic. + */ +#define snd_soc_rbtree_populate(cache) \ +({ \ + int ret, i; \ + struct snd_soc_rbtree_node *rbtree_node; \ + \ + ret = 0; \ + cache = codec->driver->reg_cache_default; \ + for (i = 0; i < codec->driver->reg_cache_size; ++i) { \ + if (!cache[i]) \ + continue; \ + rbtree_node = kzalloc(sizeof *rbtree_node, GFP_KERNEL); \ + if (!rbtree_node) { \ + ret = -ENOMEM; \ + snd_soc_cache_exit(codec); \ + break; \ + } \ + rbtree_node->reg = i; \ + rbtree_node->value = cache[i]; \ + snd_soc_rbtree_insert(&rbtree_ctx->root, \ + rbtree_node); \ + } \ + ret; \ +}) + + switch (codec->driver->reg_word_size) { + case 1: { + const u8 *cache; + + return snd_soc_rbtree_populate(cache); + } + case 2: { + const u16 *cache; + + return snd_soc_rbtree_populate(cache); + } + default: + return -EINVAL; + } + + return 0; +} + struct snd_soc_lzo_ctx { void *wmem; void *dst; @@ -1292,6 +1517,14 @@ static const struct snd_soc_cache_ops cache_types[] = { .read = snd_soc_lzo_cache_read, .write = snd_soc_lzo_cache_write, .sync = snd_soc_lzo_cache_sync + }, + { + .id = SND_SOC_RBTREE_COMPRESSION, + .init = snd_soc_rbtree_cache_init, + .exit = snd_soc_rbtree_cache_exit, + .read = snd_soc_rbtree_cache_read, + .write = snd_soc_rbtree_cache_write, + .sync = snd_soc_rbtree_cache_sync } };