Mercurial > hg > nginx-quic
view src/core/ngx_slab.c @ 2682:4756333f31bd
release-0.7.50 tag
author | Igor Sysoev <igor@sysoev.ru> |
---|---|
date | Mon, 06 Apr 2009 11:44:35 +0000 |
parents | 2bce3f6416c6 |
children | 6b87e875e87a |
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/* * Copyright (C) Igor Sysoev */ #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 #if (NGX_DEBUG_MALLOC) #define ngx_slab_junk(p, size) ngx_memset(p, 0xD0, size) #else #if (NGX_FREEBSD) #define ngx_slab_junk(p, size) \ if (ngx_freebsd_debug_malloc) ngx_memset(p, 0xD0, size) #else #define ngx_slab_junk(p, size) #endif #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; /* 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 = 1 << pool->min_shift; p = (u_char *) pool + sizeof(ngx_slab_pool_t); size = pool->end - p; ngx_slab_junk(p, size); slots = (ngx_slab_page_t *) p; n = ngx_pagesize_shift - pool->min_shift; for (i = 0; i < n; i++) { slots[i].slab = 0; slots[i].next = &slots[i]; slots[i].prev = 0; } p += n * sizeof(ngx_slab_page_t); pages = (ngx_uint_t) (size / (ngx_pagesize + sizeof(ngx_slab_page_t))); ngx_memzero(p, pages * sizeof(ngx_slab_page_t)); pool->pages = (ngx_slab_page_t *) p; pool->free.prev = 0; pool->free.next = (ngx_slab_page_t *) p; pool->pages->slab = pages; pool->pages->next = &pool->free; pool->pages->prev = (uintptr_t) &pool->free; pool->start = (u_char *) ngx_align_ptr((uintptr_t) p + pages * sizeof(ngx_slab_page_t), ngx_pagesize); m = pages - (pool->end - pool->start) / ngx_pagesize; if (m > 0) { pages -= m; pool->pages->slab = pages; } 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 - 1) >> ngx_pagesize_shift); if (page) { p = (page - pool->pages) << ngx_pagesize_shift; p += (uintptr_t) pool->start; } 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 { size = pool->min_size; shift = pool->min_shift; slot = 0; } ngx_log_debug2(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab alloc: %uz slot: %ui", size, slot); slots = (ngx_slab_page_t *) ((u_char *) pool + sizeof(ngx_slab_pool_t)); page = slots[slot].next; if (page->next != page) { if (shift < ngx_slab_exact_shift) { do { p = (page - pool->pages) << ngx_pagesize_shift; bitmap = (uintptr_t *) (pool->start + p); map = (1 << (ngx_pagesize_shift - 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) << shift) + (i << shift); if (bitmap[n] == NGX_SLAB_BUSY) { for (n = n + 1; n < map; n++) { if (bitmap[n] != NGX_SLAB_BUSY) { p = (uintptr_t) bitmap + i; goto done; } } prev = (ngx_slab_page_t *) (page->prev & ~NGX_SLAB_PAGE_MASK); prev->next = page->next; page->next->prev = page->prev; page->next = NULL; page->prev = NGX_SLAB_SMALL; } p = (uintptr_t) bitmap + i; goto done; } } } page = page->next; } while (page); } else if (shift == ngx_slab_exact_shift) { do { if (page->slab != NGX_SLAB_BUSY) { 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_t *) (page->prev & ~NGX_SLAB_PAGE_MASK); prev->next = page->next; page->next->prev = page->prev; page->next = NULL; page->prev = NGX_SLAB_EXACT; } p = (page - pool->pages) << ngx_pagesize_shift; p += i << shift; p += (uintptr_t) pool->start; goto done; } } page = page->next; } while (page); } else { /* shift > ngx_slab_exact_shift */ n = ngx_pagesize_shift - (page->slab & NGX_SLAB_SHIFT_MASK); n = 1 << n; n = ((uintptr_t) 1 << n) - 1; mask = n << NGX_SLAB_MAP_SHIFT; do { if ((page->slab & NGX_SLAB_MAP_MASK) != mask) { 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_t *) (page->prev & ~NGX_SLAB_PAGE_MASK); prev->next = page->next; page->next->prev = page->prev; page->next = NULL; page->prev = NGX_SLAB_BIG; } p = (page - pool->pages) << ngx_pagesize_shift; p += i << shift; p += (uintptr_t) pool->start; goto done; } } page = page->next; } while (page); } } page = ngx_slab_alloc_pages(pool, 1); if (page) { if (shift < ngx_slab_exact_shift) { p = (page - pool->pages) << ngx_pagesize_shift; bitmap = (uintptr_t *) (pool->start + p); s = 1 << shift; n = (1 << (ngx_pagesize_shift - shift)) / 8 / s; if (n == 0) { n = 1; } bitmap[0] = (2 << n) - 1; map = (1 << (ngx_pagesize_shift - 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; p = ((page - pool->pages) << ngx_pagesize_shift) + s * n; p += (uintptr_t) pool->start; 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; p = (page - pool->pages) << ngx_pagesize_shift; p += (uintptr_t) pool->start; 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; p = (page - pool->pages) << ngx_pagesize_shift; p += (uintptr_t) pool->start; goto done; } } p = 0; done: ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, ngx_cycle->log, 0, "slab alloc: %p", p); return (void *) 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 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 = page->prev & NGX_SLAB_PAGE_MASK; switch (type) { case NGX_SLAB_SMALL: shift = slab & NGX_SLAB_SHIFT_MASK; size = 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 - 1)); n /= (sizeof(uintptr_t) * 8); bitmap = (uintptr_t *) ((uintptr_t) p & ~(ngx_pagesize - 1)); if (bitmap[n] & m) { if (page->next == NULL) { slots = (ngx_slab_page_t *) ((u_char *) pool + sizeof(ngx_slab_pool_t)); slot = shift - pool->min_shift; 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 = (1 << (ngx_pagesize_shift - shift)) / 8 / (1 << shift); if (n == 0) { n = 1; } if (bitmap[0] & ~(((uintptr_t) 1 << n) - 1)) { goto done; } map = (1 << (ngx_pagesize_shift - shift)) / (sizeof(uintptr_t) * 8); for (n = 1; n < map; n++) { if (bitmap[n]) { goto done; } } ngx_slab_free_pages(pool, page, 1); 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) { if (slab == NGX_SLAB_BUSY) { slots = (ngx_slab_page_t *) ((u_char *) pool + sizeof(ngx_slab_pool_t)); slot = ngx_slab_exact_shift - pool->min_shift; 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); goto done; } goto chunk_already_free; case NGX_SLAB_BIG: shift = slab & NGX_SLAB_SHIFT_MASK; size = 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) { if (page->next == NULL) { slots = (ngx_slab_page_t *) ((u_char *) pool + sizeof(ngx_slab_pool_t)); slot = shift - pool->min_shift; 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); 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_FREE) { 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); size <<= ngx_pagesize_shift; goto done; } /* not reached */ return; done: 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[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; 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; } } 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; page->slab = pages--; if (pages) { ngx_memzero(&page[1], pages * sizeof(ngx_slab_page_t)); } if (page->next) { prev = (ngx_slab_page_t *) (page->prev & ~NGX_SLAB_PAGE_MASK); prev->next = page->next; page->next->prev = page->prev; } 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); }