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-rw-r--r--app/nginx/src/core/ngx_slab.c806
1 files changed, 806 insertions, 0 deletions
diff --git a/app/nginx/src/core/ngx_slab.c b/app/nginx/src/core/ngx_slab.c
new file mode 100644
index 0000000..1d4ce2b
--- /dev/null
+++ b/app/nginx/src/core/ngx_slab.c
@@ -0,0 +1,806 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) Nginx, Inc.
+ */
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+#define NGX_SLAB_PAGE_MASK 3
+#define NGX_SLAB_PAGE 0
+#define NGX_SLAB_BIG 1
+#define NGX_SLAB_EXACT 2
+#define NGX_SLAB_SMALL 3
+
+#if (NGX_PTR_SIZE == 4)
+
+#define NGX_SLAB_PAGE_FREE 0
+#define NGX_SLAB_PAGE_BUSY 0xffffffff
+#define NGX_SLAB_PAGE_START 0x80000000
+
+#define NGX_SLAB_SHIFT_MASK 0x0000000f
+#define NGX_SLAB_MAP_MASK 0xffff0000
+#define NGX_SLAB_MAP_SHIFT 16
+
+#define NGX_SLAB_BUSY 0xffffffff
+
+#else /* (NGX_PTR_SIZE == 8) */
+
+#define NGX_SLAB_PAGE_FREE 0
+#define NGX_SLAB_PAGE_BUSY 0xffffffffffffffff
+#define NGX_SLAB_PAGE_START 0x8000000000000000
+
+#define NGX_SLAB_SHIFT_MASK 0x000000000000000f
+#define NGX_SLAB_MAP_MASK 0xffffffff00000000
+#define NGX_SLAB_MAP_SHIFT 32
+
+#define NGX_SLAB_BUSY 0xffffffffffffffff
+
+#endif
+
+
+#define ngx_slab_slots(pool) \
+ (ngx_slab_page_t *) ((u_char *) (pool) + sizeof(ngx_slab_pool_t))
+
+#define ngx_slab_page_type(page) ((page)->prev & NGX_SLAB_PAGE_MASK)
+
+#define ngx_slab_page_prev(page) \
+ (ngx_slab_page_t *) ((page)->prev & ~NGX_SLAB_PAGE_MASK)
+
+#define ngx_slab_page_addr(pool, page) \
+ ((((page) - (pool)->pages) << ngx_pagesize_shift) \
+ + (uintptr_t) (pool)->start)
+
+
+#if (NGX_DEBUG_MALLOC)
+
+#define ngx_slab_junk(p, size) ngx_memset(p, 0xA5, size)
+
+#elif (NGX_HAVE_DEBUG_MALLOC)
+
+#define ngx_slab_junk(p, size) \
+ if (ngx_debug_malloc) ngx_memset(p, 0xA5, size)
+
+#else
+
+#define ngx_slab_junk(p, size)
+
+#endif
+
+static ngx_slab_page_t *ngx_slab_alloc_pages(ngx_slab_pool_t *pool,
+ ngx_uint_t pages);
+static void ngx_slab_free_pages(ngx_slab_pool_t *pool, ngx_slab_page_t *page,
+ ngx_uint_t pages);
+static void ngx_slab_error(ngx_slab_pool_t *pool, ngx_uint_t level,
+ char *text);
+
+
+static ngx_uint_t ngx_slab_max_size;
+static ngx_uint_t ngx_slab_exact_size;
+static ngx_uint_t ngx_slab_exact_shift;
+
+
+void
+ngx_slab_init(ngx_slab_pool_t *pool)
+{
+ u_char *p;
+ size_t size;
+ ngx_int_t m;
+ ngx_uint_t i, n, pages;
+ ngx_slab_page_t *slots, *page;
+
+ /* STUB */
+ if (ngx_slab_max_size == 0) {
+ ngx_slab_max_size = ngx_pagesize / 2;
+ ngx_slab_exact_size = ngx_pagesize / (8 * sizeof(uintptr_t));
+ for (n = ngx_slab_exact_size; n >>= 1; ngx_slab_exact_shift++) {
+ /* void */
+ }
+ }
+ /**/
+
+ pool->min_size = (size_t) 1 << pool->min_shift;
+
+ slots = ngx_slab_slots(pool);
+
+ p = (u_char *) slots;
+ size = pool->end - p;
+
+ ngx_slab_junk(p, size);
+
+ n = ngx_pagesize_shift - pool->min_shift;
+
+ for (i = 0; i < n; i++) {
+ /* only "next" is used in list head */
+ slots[i].slab = 0;
+ slots[i].next = &slots[i];
+ slots[i].prev = 0;
+ }
+
+ p += n * sizeof(ngx_slab_page_t);
+
+ pool->stats = (ngx_slab_stat_t *) p;
+ ngx_memzero(pool->stats, n * sizeof(ngx_slab_stat_t));
+
+ p += n * sizeof(ngx_slab_stat_t);
+
+ size -= n * (sizeof(ngx_slab_page_t) + sizeof(ngx_slab_stat_t));
+
+ pages = (ngx_uint_t) (size / (ngx_pagesize + sizeof(ngx_slab_page_t)));
+
+ pool->pages = (ngx_slab_page_t *) p;
+ ngx_memzero(pool->pages, pages * sizeof(ngx_slab_page_t));
+
+ page = pool->pages;
+
+ /* only "next" is used in list head */
+ pool->free.slab = 0;
+ pool->free.next = page;
+ pool->free.prev = 0;
+
+ page->slab = pages;
+ page->next = &pool->free;
+ page->prev = (uintptr_t) &pool->free;
+
+ pool->start = ngx_align_ptr(p + pages * sizeof(ngx_slab_page_t),
+ ngx_pagesize);
+
+ m = pages - (pool->end - pool->start) / ngx_pagesize;
+ if (m > 0) {
+ pages -= m;
+ page->slab = pages;
+ }
+
+ pool->last = pool->pages + pages;
+ pool->pfree = pages;
+
+ pool->log_nomem = 1;
+ pool->log_ctx = &pool->zero;
+ pool->zero = '\0';
+}
+
+
+void *
+ngx_slab_alloc(ngx_slab_pool_t *pool, size_t size)
+{
+ void *p;
+
+ ngx_shmtx_lock(&pool->mutex);
+
+ p = ngx_slab_alloc_locked(pool, size);
+
+ ngx_shmtx_unlock(&pool->mutex);
+
+ return p;
+}
+
+
+void *
+ngx_slab_alloc_locked(ngx_slab_pool_t *pool, size_t size)
+{
+ size_t s;
+ uintptr_t p, n, m, mask, *bitmap;
+ ngx_uint_t i, slot, shift, map;
+ ngx_slab_page_t *page, *prev, *slots;
+
+ if (size > ngx_slab_max_size) {
+
+ ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0,
+ "slab alloc: %uz", size);
+
+ page = ngx_slab_alloc_pages(pool, (size >> ngx_pagesize_shift)
+ + ((size % ngx_pagesize) ? 1 : 0));
+ if (page) {
+ p = ngx_slab_page_addr(pool, page);
+
+ } else {
+ p = 0;
+ }
+
+ goto done;
+ }
+
+ if (size > pool->min_size) {
+ shift = 1;
+ for (s = size - 1; s >>= 1; shift++) { /* void */ }
+ slot = shift - pool->min_shift;
+
+ } else {
+ shift = pool->min_shift;
+ slot = 0;
+ }
+
+ pool->stats[slot].reqs++;
+
+ ngx_log_debug2(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0,
+ "slab alloc: %uz slot: %ui", size, slot);
+
+ slots = ngx_slab_slots(pool);
+ page = slots[slot].next;
+
+ if (page->next != page) {
+
+ if (shift < ngx_slab_exact_shift) {
+
+ bitmap = (uintptr_t *) ngx_slab_page_addr(pool, page);
+
+ map = (ngx_pagesize >> shift) / (sizeof(uintptr_t) * 8);
+
+ for (n = 0; n < map; n++) {
+
+ if (bitmap[n] != NGX_SLAB_BUSY) {
+
+ for (m = 1, i = 0; m; m <<= 1, i++) {
+ if (bitmap[n] & m) {
+ continue;
+ }
+
+ bitmap[n] |= m;
+
+ i = (n * sizeof(uintptr_t) * 8 + i) << shift;
+
+ p = (uintptr_t) bitmap + i;
+
+ pool->stats[slot].used++;
+
+ if (bitmap[n] == NGX_SLAB_BUSY) {
+ for (n = n + 1; n < map; n++) {
+ if (bitmap[n] != NGX_SLAB_BUSY) {
+ goto done;
+ }
+ }
+
+ prev = ngx_slab_page_prev(page);
+ prev->next = page->next;
+ page->next->prev = page->prev;
+
+ page->next = NULL;
+ page->prev = NGX_SLAB_SMALL;
+ }
+
+ goto done;
+ }
+ }
+ }
+
+ } else if (shift == ngx_slab_exact_shift) {
+
+ for (m = 1, i = 0; m; m <<= 1, i++) {
+ if (page->slab & m) {
+ continue;
+ }
+
+ page->slab |= m;
+
+ if (page->slab == NGX_SLAB_BUSY) {
+ prev = ngx_slab_page_prev(page);
+ prev->next = page->next;
+ page->next->prev = page->prev;
+
+ page->next = NULL;
+ page->prev = NGX_SLAB_EXACT;
+ }
+
+ p = ngx_slab_page_addr(pool, page) + (i << shift);
+
+ pool->stats[slot].used++;
+
+ goto done;
+ }
+
+ } else { /* shift > ngx_slab_exact_shift */
+
+ mask = ((uintptr_t) 1 << (ngx_pagesize >> shift)) - 1;
+ mask <<= NGX_SLAB_MAP_SHIFT;
+
+ for (m = (uintptr_t) 1 << NGX_SLAB_MAP_SHIFT, i = 0;
+ m & mask;
+ m <<= 1, i++)
+ {
+ if (page->slab & m) {
+ continue;
+ }
+
+ page->slab |= m;
+
+ if ((page->slab & NGX_SLAB_MAP_MASK) == mask) {
+ prev = ngx_slab_page_prev(page);
+ prev->next = page->next;
+ page->next->prev = page->prev;
+
+ page->next = NULL;
+ page->prev = NGX_SLAB_BIG;
+ }
+
+ p = ngx_slab_page_addr(pool, page) + (i << shift);
+
+ pool->stats[slot].used++;
+
+ goto done;
+ }
+ }
+
+ ngx_slab_error(pool, NGX_LOG_ALERT, "ngx_slab_alloc(): page is busy");
+ ngx_debug_point();
+ }
+
+ page = ngx_slab_alloc_pages(pool, 1);
+
+ if (page) {
+ if (shift < ngx_slab_exact_shift) {
+ bitmap = (uintptr_t *) ngx_slab_page_addr(pool, page);
+
+ n = (ngx_pagesize >> shift) / ((1 << shift) * 8);
+
+ if (n == 0) {
+ n = 1;
+ }
+
+ /* "n" elements for bitmap, plus one requested */
+ bitmap[0] = ((uintptr_t) 2 << n) - 1;
+
+ map = (ngx_pagesize >> shift) / (sizeof(uintptr_t) * 8);
+
+ for (i = 1; i < map; i++) {
+ bitmap[i] = 0;
+ }
+
+ page->slab = shift;
+ page->next = &slots[slot];
+ page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_SMALL;
+
+ slots[slot].next = page;
+
+ pool->stats[slot].total += (ngx_pagesize >> shift) - n;
+
+ p = ngx_slab_page_addr(pool, page) + (n << shift);
+
+ pool->stats[slot].used++;
+
+ goto done;
+
+ } else if (shift == ngx_slab_exact_shift) {
+
+ page->slab = 1;
+ page->next = &slots[slot];
+ page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_EXACT;
+
+ slots[slot].next = page;
+
+ pool->stats[slot].total += sizeof(uintptr_t) * 8;
+
+ p = ngx_slab_page_addr(pool, page);
+
+ pool->stats[slot].used++;
+
+ goto done;
+
+ } else { /* shift > ngx_slab_exact_shift */
+
+ page->slab = ((uintptr_t) 1 << NGX_SLAB_MAP_SHIFT) | shift;
+ page->next = &slots[slot];
+ page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_BIG;
+
+ slots[slot].next = page;
+
+ pool->stats[slot].total += ngx_pagesize >> shift;
+
+ p = ngx_slab_page_addr(pool, page);
+
+ pool->stats[slot].used++;
+
+ goto done;
+ }
+ }
+
+ p = 0;
+
+ pool->stats[slot].fails++;
+
+done:
+
+ ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0,
+ "slab alloc: %p", (void *) p);
+
+ return (void *) p;
+}
+
+
+void *
+ngx_slab_calloc(ngx_slab_pool_t *pool, size_t size)
+{
+ void *p;
+
+ ngx_shmtx_lock(&pool->mutex);
+
+ p = ngx_slab_calloc_locked(pool, size);
+
+ ngx_shmtx_unlock(&pool->mutex);
+
+ return p;
+}
+
+
+void *
+ngx_slab_calloc_locked(ngx_slab_pool_t *pool, size_t size)
+{
+ void *p;
+
+ p = ngx_slab_alloc_locked(pool, size);
+ if (p) {
+ ngx_memzero(p, size);
+ }
+
+ return p;
+}
+
+
+void
+ngx_slab_free(ngx_slab_pool_t *pool, void *p)
+{
+ ngx_shmtx_lock(&pool->mutex);
+
+ ngx_slab_free_locked(pool, p);
+
+ ngx_shmtx_unlock(&pool->mutex);
+}
+
+
+void
+ngx_slab_free_locked(ngx_slab_pool_t *pool, void *p)
+{
+ size_t size;
+ uintptr_t slab, m, *bitmap;
+ ngx_uint_t i, n, type, slot, shift, map;
+ ngx_slab_page_t *slots, *page;
+
+ ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab free: %p", p);
+
+ if ((u_char *) p < pool->start || (u_char *) p > pool->end) {
+ ngx_slab_error(pool, NGX_LOG_ALERT, "ngx_slab_free(): outside of pool");
+ goto fail;
+ }
+
+ n = ((u_char *) p - pool->start) >> ngx_pagesize_shift;
+ page = &pool->pages[n];
+ slab = page->slab;
+ type = ngx_slab_page_type(page);
+
+ switch (type) {
+
+ case NGX_SLAB_SMALL:
+
+ shift = slab & NGX_SLAB_SHIFT_MASK;
+ size = (size_t) 1 << shift;
+
+ if ((uintptr_t) p & (size - 1)) {
+ goto wrong_chunk;
+ }
+
+ n = ((uintptr_t) p & (ngx_pagesize - 1)) >> shift;
+ m = (uintptr_t) 1 << (n % (sizeof(uintptr_t) * 8));
+ n /= sizeof(uintptr_t) * 8;
+ bitmap = (uintptr_t *)
+ ((uintptr_t) p & ~((uintptr_t) ngx_pagesize - 1));
+
+ if (bitmap[n] & m) {
+ slot = shift - pool->min_shift;
+
+ if (page->next == NULL) {
+ slots = ngx_slab_slots(pool);
+
+ page->next = slots[slot].next;
+ slots[slot].next = page;
+
+ page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_SMALL;
+ page->next->prev = (uintptr_t) page | NGX_SLAB_SMALL;
+ }
+
+ bitmap[n] &= ~m;
+
+ n = (ngx_pagesize >> shift) / ((1 << shift) * 8);
+
+ if (n == 0) {
+ n = 1;
+ }
+
+ if (bitmap[0] & ~(((uintptr_t) 1 << n) - 1)) {
+ goto done;
+ }
+
+ map = (ngx_pagesize >> shift) / (sizeof(uintptr_t) * 8);
+
+ for (i = 1; i < map; i++) {
+ if (bitmap[i]) {
+ goto done;
+ }
+ }
+
+ ngx_slab_free_pages(pool, page, 1);
+
+ pool->stats[slot].total -= (ngx_pagesize >> shift) - n;
+
+ goto done;
+ }
+
+ goto chunk_already_free;
+
+ case NGX_SLAB_EXACT:
+
+ m = (uintptr_t) 1 <<
+ (((uintptr_t) p & (ngx_pagesize - 1)) >> ngx_slab_exact_shift);
+ size = ngx_slab_exact_size;
+
+ if ((uintptr_t) p & (size - 1)) {
+ goto wrong_chunk;
+ }
+
+ if (slab & m) {
+ slot = ngx_slab_exact_shift - pool->min_shift;
+
+ if (slab == NGX_SLAB_BUSY) {
+ slots = ngx_slab_slots(pool);
+
+ page->next = slots[slot].next;
+ slots[slot].next = page;
+
+ page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_EXACT;
+ page->next->prev = (uintptr_t) page | NGX_SLAB_EXACT;
+ }
+
+ page->slab &= ~m;
+
+ if (page->slab) {
+ goto done;
+ }
+
+ ngx_slab_free_pages(pool, page, 1);
+
+ pool->stats[slot].total -= sizeof(uintptr_t) * 8;
+
+ goto done;
+ }
+
+ goto chunk_already_free;
+
+ case NGX_SLAB_BIG:
+
+ shift = slab & NGX_SLAB_SHIFT_MASK;
+ size = (size_t) 1 << shift;
+
+ if ((uintptr_t) p & (size - 1)) {
+ goto wrong_chunk;
+ }
+
+ m = (uintptr_t) 1 << ((((uintptr_t) p & (ngx_pagesize - 1)) >> shift)
+ + NGX_SLAB_MAP_SHIFT);
+
+ if (slab & m) {
+ slot = shift - pool->min_shift;
+
+ if (page->next == NULL) {
+ slots = ngx_slab_slots(pool);
+
+ page->next = slots[slot].next;
+ slots[slot].next = page;
+
+ page->prev = (uintptr_t) &slots[slot] | NGX_SLAB_BIG;
+ page->next->prev = (uintptr_t) page | NGX_SLAB_BIG;
+ }
+
+ page->slab &= ~m;
+
+ if (page->slab & NGX_SLAB_MAP_MASK) {
+ goto done;
+ }
+
+ ngx_slab_free_pages(pool, page, 1);
+
+ pool->stats[slot].total -= ngx_pagesize >> shift;
+
+ goto done;
+ }
+
+ goto chunk_already_free;
+
+ case NGX_SLAB_PAGE:
+
+ if ((uintptr_t) p & (ngx_pagesize - 1)) {
+ goto wrong_chunk;
+ }
+
+ if (!(slab & NGX_SLAB_PAGE_START)) {
+ ngx_slab_error(pool, NGX_LOG_ALERT,
+ "ngx_slab_free(): page is already free");
+ goto fail;
+ }
+
+ if (slab == NGX_SLAB_PAGE_BUSY) {
+ ngx_slab_error(pool, NGX_LOG_ALERT,
+ "ngx_slab_free(): pointer to wrong page");
+ goto fail;
+ }
+
+ n = ((u_char *) p - pool->start) >> ngx_pagesize_shift;
+ size = slab & ~NGX_SLAB_PAGE_START;
+
+ ngx_slab_free_pages(pool, &pool->pages[n], size);
+
+ ngx_slab_junk(p, size << ngx_pagesize_shift);
+
+ return;
+ }
+
+ /* not reached */
+
+ return;
+
+done:
+
+ pool->stats[slot].used--;
+
+ ngx_slab_junk(p, size);
+
+ return;
+
+wrong_chunk:
+
+ ngx_slab_error(pool, NGX_LOG_ALERT,
+ "ngx_slab_free(): pointer to wrong chunk");
+
+ goto fail;
+
+chunk_already_free:
+
+ ngx_slab_error(pool, NGX_LOG_ALERT,
+ "ngx_slab_free(): chunk is already free");
+
+fail:
+
+ return;
+}
+
+
+static ngx_slab_page_t *
+ngx_slab_alloc_pages(ngx_slab_pool_t *pool, ngx_uint_t pages)
+{
+ ngx_slab_page_t *page, *p;
+
+ for (page = pool->free.next; page != &pool->free; page = page->next) {
+
+ if (page->slab >= pages) {
+
+ if (page->slab > pages) {
+ page[page->slab - 1].prev = (uintptr_t) &page[pages];
+
+ page[pages].slab = page->slab - pages;
+ page[pages].next = page->next;
+ page[pages].prev = page->prev;
+
+ p = (ngx_slab_page_t *) page->prev;
+ p->next = &page[pages];
+ page->next->prev = (uintptr_t) &page[pages];
+
+ } else {
+ p = (ngx_slab_page_t *) page->prev;
+ p->next = page->next;
+ page->next->prev = page->prev;
+ }
+
+ page->slab = pages | NGX_SLAB_PAGE_START;
+ page->next = NULL;
+ page->prev = NGX_SLAB_PAGE;
+
+ pool->pfree -= pages;
+
+ if (--pages == 0) {
+ return page;
+ }
+
+ for (p = page + 1; pages; pages--) {
+ p->slab = NGX_SLAB_PAGE_BUSY;
+ p->next = NULL;
+ p->prev = NGX_SLAB_PAGE;
+ p++;
+ }
+
+ return page;
+ }
+ }
+
+ if (pool->log_nomem) {
+ ngx_slab_error(pool, NGX_LOG_CRIT,
+ "ngx_slab_alloc() failed: no memory");
+ }
+
+ return NULL;
+}
+
+
+static void
+ngx_slab_free_pages(ngx_slab_pool_t *pool, ngx_slab_page_t *page,
+ ngx_uint_t pages)
+{
+ ngx_slab_page_t *prev, *join;
+
+ pool->pfree += pages;
+
+ page->slab = pages--;
+
+ if (pages) {
+ ngx_memzero(&page[1], pages * sizeof(ngx_slab_page_t));
+ }
+
+ if (page->next) {
+ prev = ngx_slab_page_prev(page);
+ prev->next = page->next;
+ page->next->prev = page->prev;
+ }
+
+ join = page + page->slab;
+
+ if (join < pool->last) {
+
+ if (ngx_slab_page_type(join) == NGX_SLAB_PAGE) {
+
+ if (join->next != NULL) {
+ pages += join->slab;
+ page->slab += join->slab;
+
+ prev = ngx_slab_page_prev(join);
+ prev->next = join->next;
+ join->next->prev = join->prev;
+
+ join->slab = NGX_SLAB_PAGE_FREE;
+ join->next = NULL;
+ join->prev = NGX_SLAB_PAGE;
+ }
+ }
+ }
+
+ if (page > pool->pages) {
+ join = page - 1;
+
+ if (ngx_slab_page_type(join) == NGX_SLAB_PAGE) {
+
+ if (join->slab == NGX_SLAB_PAGE_FREE) {
+ join = ngx_slab_page_prev(join);
+ }
+
+ if (join->next != NULL) {
+ pages += join->slab;
+ join->slab += page->slab;
+
+ prev = ngx_slab_page_prev(join);
+ prev->next = join->next;
+ join->next->prev = join->prev;
+
+ page->slab = NGX_SLAB_PAGE_FREE;
+ page->next = NULL;
+ page->prev = NGX_SLAB_PAGE;
+
+ page = join;
+ }
+ }
+ }
+
+ if (pages) {
+ page[pages].prev = (uintptr_t) page;
+ }
+
+ page->prev = (uintptr_t) &pool->free;
+ page->next = pool->free.next;
+
+ page->next->prev = (uintptr_t) page;
+
+ pool->free.next = page;
+}
+
+
+static void
+ngx_slab_error(ngx_slab_pool_t *pool, ngx_uint_t level, char *text)
+{
+ ngx_log_error(level, ngx_cycle->log, 0, "%s%s", text, pool->log_ctx);
+}