| /* |
| * Copyright © 2010 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| * DEALINGS IN THE SOFTWARE. |
| */ |
| |
| #include <assert.h> |
| #include <stdarg.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "util/list.h" |
| #include "util/macros.h" |
| #include "util/u_math.h" |
| #include "util/u_printf.h" |
| |
| #include "ralloc.h" |
| |
| #define CANARY 0x5A1106 |
| |
| #if defined(__LP64__) || defined(_WIN64) |
| #define HEADER_ALIGN 16 |
| #else |
| #define HEADER_ALIGN 8 |
| #endif |
| |
| /* Align the header's size so that ralloc() allocations will return with the |
| * same alignment as a libc malloc would have (8 on 32-bit GLIBC, 16 on |
| * 64-bit), avoiding performance penalities on x86 and alignment faults on |
| * ARM. |
| */ |
| struct ralloc_header |
| { |
| alignas(HEADER_ALIGN) |
| |
| #ifndef NDEBUG |
| /* A canary value used to determine whether a pointer is ralloc'd. */ |
| unsigned canary; |
| unsigned size; |
| #endif |
| |
| struct ralloc_header *parent; |
| |
| /* The first child (head of a linked list) */ |
| struct ralloc_header *child; |
| |
| /* Linked list of siblings */ |
| struct ralloc_header *prev; |
| struct ralloc_header *next; |
| |
| void (*destructor)(void *); |
| }; |
| |
| typedef struct ralloc_header ralloc_header; |
| |
| static void unlink_block(ralloc_header *info); |
| static void unsafe_free(ralloc_header *info); |
| |
| static ralloc_header * |
| get_header(const void *ptr) |
| { |
| ralloc_header *info = (ralloc_header *) (((char *) ptr) - |
| sizeof(ralloc_header)); |
| assert(info->canary == CANARY); |
| return info; |
| } |
| |
| #define PTR_FROM_HEADER(info) (((char *) info) + sizeof(ralloc_header)) |
| |
| static void |
| add_child(ralloc_header *parent, ralloc_header *info) |
| { |
| if (parent != NULL) { |
| info->parent = parent; |
| info->next = parent->child; |
| parent->child = info; |
| |
| if (info->next != NULL) |
| info->next->prev = info; |
| } |
| } |
| |
| void * |
| ralloc_context(const void *ctx) |
| { |
| return ralloc_size(ctx, 0); |
| } |
| |
| void * |
| ralloc_size(const void *ctx, size_t size) |
| { |
| /* Some malloc allocation doesn't always align to 16 bytes even on 64 bits |
| * system, from Android bionic/tests/malloc_test.cpp: |
| * - Allocations of a size that rounds up to a multiple of 16 bytes |
| * must have at least 16 byte alignment. |
| * - Allocations of a size that rounds up to a multiple of 8 bytes and |
| * not 16 bytes, are only required to have at least 8 byte alignment. |
| */ |
| void *block = malloc(align64(size + sizeof(ralloc_header), |
| alignof(ralloc_header))); |
| ralloc_header *info; |
| ralloc_header *parent; |
| |
| if (unlikely(block == NULL)) |
| return NULL; |
| |
| info = (ralloc_header *) block; |
| /* measurements have shown that calloc is slower (because of |
| * the multiplication overflow checking?), so clear things |
| * manually |
| */ |
| info->parent = NULL; |
| info->child = NULL; |
| info->prev = NULL; |
| info->next = NULL; |
| info->destructor = NULL; |
| |
| parent = ctx != NULL ? get_header(ctx) : NULL; |
| |
| add_child(parent, info); |
| |
| #ifndef NDEBUG |
| info->canary = CANARY; |
| info->size = size; |
| #endif |
| |
| return PTR_FROM_HEADER(info); |
| } |
| |
| void * |
| rzalloc_size(const void *ctx, size_t size) |
| { |
| void *ptr = ralloc_size(ctx, size); |
| |
| if (likely(ptr)) |
| memset(ptr, 0, size); |
| |
| return ptr; |
| } |
| |
| /* helper function - assumes ptr != NULL */ |
| static void * |
| resize(void *ptr, size_t size) |
| { |
| ralloc_header *child, *old, *info; |
| |
| old = get_header(ptr); |
| info = realloc(old, align64(size + sizeof(ralloc_header), |
| alignof(ralloc_header))); |
| |
| if (info == NULL) |
| return NULL; |
| |
| /* Update parent and sibling's links to the reallocated node. */ |
| if (info != old && info->parent != NULL) { |
| if (info->parent->child == old) |
| info->parent->child = info; |
| |
| if (info->prev != NULL) |
| info->prev->next = info; |
| |
| if (info->next != NULL) |
| info->next->prev = info; |
| } |
| |
| /* Update child->parent links for all children */ |
| for (child = info->child; child != NULL; child = child->next) |
| child->parent = info; |
| |
| return PTR_FROM_HEADER(info); |
| } |
| |
| void * |
| reralloc_size(const void *ctx, void *ptr, size_t size) |
| { |
| if (unlikely(ptr == NULL)) |
| return ralloc_size(ctx, size); |
| |
| assert(ralloc_parent(ptr) == ctx); |
| return resize(ptr, size); |
| } |
| |
| void * |
| rerzalloc_size(const void *ctx, void *ptr, size_t old_size, size_t new_size) |
| { |
| if (unlikely(ptr == NULL)) |
| return rzalloc_size(ctx, new_size); |
| |
| assert(ralloc_parent(ptr) == ctx); |
| ptr = resize(ptr, new_size); |
| |
| if (new_size > old_size) |
| memset((char *)ptr + old_size, 0, new_size - old_size); |
| |
| return ptr; |
| } |
| |
| void * |
| ralloc_array_size(const void *ctx, size_t size, unsigned count) |
| { |
| if (count > SIZE_MAX/size) |
| return NULL; |
| |
| return ralloc_size(ctx, size * count); |
| } |
| |
| void * |
| rzalloc_array_size(const void *ctx, size_t size, unsigned count) |
| { |
| if (count > SIZE_MAX/size) |
| return NULL; |
| |
| return rzalloc_size(ctx, size * count); |
| } |
| |
| void * |
| reralloc_array_size(const void *ctx, void *ptr, size_t size, unsigned count) |
| { |
| if (count > SIZE_MAX/size) |
| return NULL; |
| |
| return reralloc_size(ctx, ptr, size * count); |
| } |
| |
| void * |
| rerzalloc_array_size(const void *ctx, void *ptr, size_t size, |
| unsigned old_count, unsigned new_count) |
| { |
| if (new_count > SIZE_MAX/size) |
| return NULL; |
| |
| return rerzalloc_size(ctx, ptr, size * old_count, size * new_count); |
| } |
| |
| void |
| ralloc_free(void *ptr) |
| { |
| ralloc_header *info; |
| |
| if (ptr == NULL) |
| return; |
| |
| info = get_header(ptr); |
| unlink_block(info); |
| unsafe_free(info); |
| } |
| |
| static void |
| unlink_block(ralloc_header *info) |
| { |
| /* Unlink from parent & siblings */ |
| if (info->parent != NULL) { |
| if (info->parent->child == info) |
| info->parent->child = info->next; |
| |
| if (info->prev != NULL) |
| info->prev->next = info->next; |
| |
| if (info->next != NULL) |
| info->next->prev = info->prev; |
| } |
| info->parent = NULL; |
| info->prev = NULL; |
| info->next = NULL; |
| } |
| |
| static void |
| unsafe_free(ralloc_header *info) |
| { |
| /* Recursively free any children...don't waste time unlinking them. */ |
| ralloc_header *temp; |
| while (info->child != NULL) { |
| temp = info->child; |
| info->child = temp->next; |
| unsafe_free(temp); |
| } |
| |
| /* Free the block itself. Call the destructor first, if any. */ |
| if (info->destructor != NULL) |
| info->destructor(PTR_FROM_HEADER(info)); |
| |
| free(info); |
| } |
| |
| void |
| ralloc_steal(const void *new_ctx, void *ptr) |
| { |
| ralloc_header *info, *parent; |
| |
| if (unlikely(ptr == NULL)) |
| return; |
| |
| info = get_header(ptr); |
| parent = new_ctx ? get_header(new_ctx) : NULL; |
| |
| unlink_block(info); |
| |
| add_child(parent, info); |
| } |
| |
| void |
| ralloc_adopt(const void *new_ctx, void *old_ctx) |
| { |
| ralloc_header *new_info, *old_info, *child; |
| |
| if (unlikely(old_ctx == NULL)) |
| return; |
| |
| old_info = get_header(old_ctx); |
| new_info = get_header(new_ctx); |
| |
| /* If there are no children, bail. */ |
| if (unlikely(old_info->child == NULL)) |
| return; |
| |
| /* Set all the children's parent to new_ctx; get a pointer to the last child. */ |
| for (child = old_info->child; child->next != NULL; child = child->next) { |
| child->parent = new_info; |
| } |
| child->parent = new_info; |
| |
| /* Connect the two lists together; parent them to new_ctx; make old_ctx empty. */ |
| child->next = new_info->child; |
| if (child->next) |
| child->next->prev = child; |
| new_info->child = old_info->child; |
| old_info->child = NULL; |
| } |
| |
| void * |
| ralloc_parent(const void *ptr) |
| { |
| ralloc_header *info; |
| |
| if (unlikely(ptr == NULL)) |
| return NULL; |
| |
| info = get_header(ptr); |
| return info->parent ? PTR_FROM_HEADER(info->parent) : NULL; |
| } |
| |
| void |
| ralloc_set_destructor(const void *ptr, void(*destructor)(void *)) |
| { |
| ralloc_header *info = get_header(ptr); |
| info->destructor = destructor; |
| } |
| |
| void * |
| ralloc_memdup(const void *ctx, const void *mem, size_t n) |
| { |
| void *ptr = ralloc_size(ctx, n); |
| |
| if (unlikely(ptr == NULL)) |
| return NULL; |
| |
| memcpy(ptr, mem, n); |
| return ptr; |
| } |
| |
| char * |
| ralloc_strdup(const void *ctx, const char *str) |
| { |
| size_t n; |
| char *ptr; |
| |
| if (unlikely(str == NULL)) |
| return NULL; |
| |
| n = strlen(str); |
| ptr = ralloc_array(ctx, char, n + 1); |
| memcpy(ptr, str, n); |
| ptr[n] = '\0'; |
| return ptr; |
| } |
| |
| char * |
| ralloc_strndup(const void *ctx, const char *str, size_t max) |
| { |
| size_t n; |
| char *ptr; |
| |
| if (unlikely(str == NULL)) |
| return NULL; |
| |
| n = strnlen(str, max); |
| ptr = ralloc_array(ctx, char, n + 1); |
| memcpy(ptr, str, n); |
| ptr[n] = '\0'; |
| return ptr; |
| } |
| |
| /* helper routine for strcat/strncat - n is the exact amount to copy */ |
| static bool |
| cat(char **dest, const char *str, size_t n) |
| { |
| char *both; |
| size_t existing_length; |
| assert(dest != NULL && *dest != NULL); |
| |
| existing_length = strlen(*dest); |
| both = resize(*dest, existing_length + n + 1); |
| if (unlikely(both == NULL)) |
| return false; |
| |
| memcpy(both + existing_length, str, n); |
| both[existing_length + n] = '\0'; |
| |
| *dest = both; |
| return true; |
| } |
| |
| |
| bool |
| ralloc_strcat(char **dest, const char *str) |
| { |
| return cat(dest, str, strlen(str)); |
| } |
| |
| bool |
| ralloc_strncat(char **dest, const char *str, size_t n) |
| { |
| return cat(dest, str, strnlen(str, n)); |
| } |
| |
| bool |
| ralloc_str_append(char **dest, const char *str, |
| size_t existing_length, size_t str_size) |
| { |
| char *both; |
| assert(dest != NULL && *dest != NULL); |
| |
| both = resize(*dest, existing_length + str_size + 1); |
| if (unlikely(both == NULL)) |
| return false; |
| |
| memcpy(both + existing_length, str, str_size); |
| both[existing_length + str_size] = '\0'; |
| |
| *dest = both; |
| |
| return true; |
| } |
| |
| char * |
| ralloc_asprintf(const void *ctx, const char *fmt, ...) |
| { |
| char *ptr; |
| va_list args; |
| va_start(args, fmt); |
| ptr = ralloc_vasprintf(ctx, fmt, args); |
| va_end(args); |
| return ptr; |
| } |
| |
| char * |
| ralloc_vasprintf(const void *ctx, const char *fmt, va_list args) |
| { |
| size_t size = u_printf_length(fmt, args) + 1; |
| |
| char *ptr = ralloc_size(ctx, size); |
| if (ptr != NULL) |
| vsnprintf(ptr, size, fmt, args); |
| |
| return ptr; |
| } |
| |
| bool |
| ralloc_asprintf_append(char **str, const char *fmt, ...) |
| { |
| bool success; |
| va_list args; |
| va_start(args, fmt); |
| success = ralloc_vasprintf_append(str, fmt, args); |
| va_end(args); |
| return success; |
| } |
| |
| bool |
| ralloc_vasprintf_append(char **str, const char *fmt, va_list args) |
| { |
| size_t existing_length; |
| assert(str != NULL); |
| existing_length = *str ? strlen(*str) : 0; |
| return ralloc_vasprintf_rewrite_tail(str, &existing_length, fmt, args); |
| } |
| |
| bool |
| ralloc_asprintf_rewrite_tail(char **str, size_t *start, const char *fmt, ...) |
| { |
| bool success; |
| va_list args; |
| va_start(args, fmt); |
| success = ralloc_vasprintf_rewrite_tail(str, start, fmt, args); |
| va_end(args); |
| return success; |
| } |
| |
| bool |
| ralloc_vasprintf_rewrite_tail(char **str, size_t *start, const char *fmt, |
| va_list args) |
| { |
| size_t new_length; |
| char *ptr; |
| |
| assert(str != NULL); |
| |
| if (unlikely(*str == NULL)) { |
| // Assuming a NULL context is probably bad, but it's expected behavior. |
| *str = ralloc_vasprintf(NULL, fmt, args); |
| *start = strlen(*str); |
| return true; |
| } |
| |
| new_length = u_printf_length(fmt, args); |
| |
| ptr = resize(*str, *start + new_length + 1); |
| if (unlikely(ptr == NULL)) |
| return false; |
| |
| vsnprintf(ptr + *start, new_length + 1, fmt, args); |
| *str = ptr; |
| *start += new_length; |
| return true; |
| } |
| |
| /*************************************************************************** |
| * GC context. |
| *************************************************************************** |
| */ |
| |
| /* The maximum size of an object that will be allocated specially. |
| */ |
| #define MAX_FREELIST_SIZE 512 |
| |
| /* Allocations small enough to be allocated from a freelist will be aligned up |
| * to this size. |
| */ |
| #define FREELIST_ALIGNMENT 32 |
| |
| #define NUM_FREELIST_BUCKETS (MAX_FREELIST_SIZE / FREELIST_ALIGNMENT) |
| |
| /* The size of a slab. */ |
| #define SLAB_SIZE (32 * 1024) |
| |
| #define GC_CONTEXT_CANARY 0xAF6B6C83 |
| #define GC_CANARY 0xAF6B5B72 |
| |
| enum gc_flags { |
| IS_USED = (1 << 0), |
| CURRENT_GENERATION = (1 << 1), |
| IS_PADDING = (1 << 7), |
| }; |
| |
| typedef struct |
| { |
| #ifndef NDEBUG |
| /* A canary value used to determine whether a pointer is allocated using gc_alloc. */ |
| unsigned canary; |
| #endif |
| |
| uint16_t slab_offset; |
| uint8_t bucket; |
| uint8_t flags; |
| |
| /* The last padding byte must have IS_PADDING set and is used to store the amount of padding. If |
| * there is no padding, the IS_PADDING bit of "flags" is unset and "flags" is checked instead. |
| * Because of this, "flags" must be the last member of this struct. |
| */ |
| uint8_t padding[]; |
| } gc_block_header; |
| |
| /* This structure is at the start of the slab. Objects inside a slab are |
| * allocated using a freelist backed by a simple linear allocator. |
| */ |
| typedef struct gc_slab { |
| alignas(HEADER_ALIGN) |
| |
| gc_ctx *ctx; |
| |
| /* Objects are allocated using either linear or freelist allocation. "next_available" is the |
| * pointer used for linear allocation, while "freelist" is the next free object for freelist |
| * allocation. |
| */ |
| char *next_available; |
| gc_block_header *freelist; |
| |
| /* Slabs that handle the same-sized objects. */ |
| struct list_head link; |
| |
| /* Free slabs that handle the same-sized objects. */ |
| struct list_head free_link; |
| |
| /* Number of allocated and free objects, recorded so that we can free the slab if it |
| * becomes empty or add one to the freelist if it's no longer full. |
| */ |
| unsigned num_allocated; |
| unsigned num_free; |
| } gc_slab; |
| |
| struct gc_ctx { |
| #ifndef NDEBUG |
| unsigned canary; |
| #endif |
| |
| /* Array of slabs for fixed-size allocations. Each slab tracks allocations |
| * of specific sized blocks. User allocations are rounded up to the nearest |
| * fixed size. slabs[N] contains allocations of size |
| * FREELIST_ALIGNMENT * (N + 1). |
| */ |
| struct { |
| /* List of slabs in this bucket. */ |
| struct list_head slabs; |
| |
| /* List of slabs with free space in this bucket, so we can quickly choose one when |
| * allocating. |
| */ |
| struct list_head free_slabs; |
| } slabs[NUM_FREELIST_BUCKETS]; |
| |
| uint8_t current_gen; |
| void *rubbish; |
| }; |
| |
| static gc_block_header * |
| get_gc_header(const void *ptr) |
| { |
| uint8_t *c_ptr = (uint8_t *)ptr; |
| |
| /* Adjust for padding added to ensure alignment of the allocation. There might also be padding |
| * added by the compiler into gc_block_header, but that isn't counted in the IS_PADDING byte. |
| */ |
| if (c_ptr[-1] & IS_PADDING) |
| c_ptr -= c_ptr[-1] & ~IS_PADDING; |
| |
| c_ptr -= sizeof(gc_block_header); |
| |
| gc_block_header *info = (gc_block_header *)c_ptr; |
| assert(info->canary == GC_CANARY); |
| return info; |
| } |
| |
| static gc_block_header * |
| get_gc_freelist_next(gc_block_header *ptr) |
| { |
| gc_block_header *next; |
| /* work around possible strict aliasing bug using memcpy */ |
| memcpy(&next, (void*)(ptr + 1), sizeof(next)); |
| return next; |
| } |
| |
| static void |
| set_gc_freelist_next(gc_block_header *ptr, gc_block_header *next) |
| { |
| memcpy((void*)(ptr + 1), &next, sizeof(next)); |
| } |
| |
| static gc_slab * |
| get_gc_slab(gc_block_header *header) |
| { |
| return (gc_slab *)((char *)header - header->slab_offset); |
| } |
| |
| gc_ctx * |
| gc_context(const void *parent) |
| { |
| gc_ctx *ctx = rzalloc(parent, gc_ctx); |
| for (unsigned i = 0; i < NUM_FREELIST_BUCKETS; i++) { |
| list_inithead(&ctx->slabs[i].slabs); |
| list_inithead(&ctx->slabs[i].free_slabs); |
| } |
| #ifndef NDEBUG |
| ctx->canary = GC_CONTEXT_CANARY; |
| #endif |
| return ctx; |
| } |
| |
| static_assert(UINT32_MAX >= MAX_FREELIST_SIZE, "Freelist sizes use uint32_t"); |
| |
| static uint32_t |
| gc_bucket_obj_size(uint32_t bucket) |
| { |
| return (bucket + 1) * FREELIST_ALIGNMENT; |
| } |
| |
| static uint32_t |
| gc_bucket_for_size(uint32_t size) |
| { |
| return (size - 1) / FREELIST_ALIGNMENT; |
| } |
| |
| static_assert(UINT32_MAX >= SLAB_SIZE, "SLAB_SIZE use uint32_t"); |
| |
| static uint32_t |
| gc_bucket_num_objs(uint32_t bucket) |
| { |
| return (SLAB_SIZE - sizeof(gc_slab)) / gc_bucket_obj_size(bucket); |
| } |
| |
| static gc_block_header * |
| alloc_from_slab(gc_slab *slab, uint32_t bucket) |
| { |
| uint32_t size = gc_bucket_obj_size(bucket); |
| gc_block_header *header; |
| if (slab->freelist) { |
| /* Prioritize already-allocated chunks, since they probably have a page |
| * backing them. |
| */ |
| header = slab->freelist; |
| slab->freelist = get_gc_freelist_next(slab->freelist); |
| } else if (slab->next_available + size <= ((char *) slab) + SLAB_SIZE) { |
| header = (gc_block_header *) slab->next_available; |
| header->slab_offset = (char *) header - (char *) slab; |
| header->bucket = bucket; |
| slab->next_available += size; |
| } else { |
| return NULL; |
| } |
| |
| slab->num_allocated++; |
| slab->num_free--; |
| if (!slab->num_free) |
| list_del(&slab->free_link); |
| return header; |
| } |
| |
| static void |
| free_slab(gc_slab *slab) |
| { |
| if (list_is_linked(&slab->free_link)) |
| list_del(&slab->free_link); |
| list_del(&slab->link); |
| ralloc_free(slab); |
| } |
| |
| static void |
| free_from_slab(gc_block_header *header, bool keep_empty_slabs) |
| { |
| gc_slab *slab = get_gc_slab(header); |
| |
| if (slab->num_allocated == 1 && !(keep_empty_slabs && list_is_singular(&slab->free_link))) { |
| /* Free the slab if this is the last object. */ |
| free_slab(slab); |
| return; |
| } else if (slab->num_free == 0) { |
| list_add(&slab->free_link, &slab->ctx->slabs[header->bucket].free_slabs); |
| } else { |
| /* Keep the free list sorted by the number of free objects in ascending order. By prefering to |
| * allocate from the slab with the fewest free objects, we help free the slabs with many free |
| * objects. |
| */ |
| while (slab->free_link.next != &slab->ctx->slabs[header->bucket].free_slabs && |
| slab->num_free > list_entry(slab->free_link.next, gc_slab, free_link)->num_free) { |
| gc_slab *next = list_entry(slab->free_link.next, gc_slab, free_link); |
| |
| /* Move "slab" to after "next". */ |
| list_move_to(&slab->free_link, &next->free_link); |
| } |
| } |
| |
| set_gc_freelist_next(header, slab->freelist); |
| slab->freelist = header; |
| |
| slab->num_allocated--; |
| slab->num_free++; |
| } |
| |
| static uint32_t |
| get_slab_size(uint32_t bucket) |
| { |
| /* SLAB_SIZE rounded down to a multiple of the object size so that it's not larger than what can |
| * be used. |
| */ |
| uint32_t obj_size = gc_bucket_obj_size(bucket); |
| uint32_t num_objs = gc_bucket_num_objs(bucket); |
| return align((uint32_t)sizeof(gc_slab) + num_objs * obj_size, alignof(gc_slab)); |
| } |
| |
| static gc_slab * |
| create_slab(gc_ctx *ctx, unsigned bucket) |
| { |
| gc_slab *slab = ralloc_size(ctx, get_slab_size(bucket)); |
| if (unlikely(!slab)) |
| return NULL; |
| |
| slab->ctx = ctx; |
| slab->freelist = NULL; |
| slab->next_available = (char*)(slab + 1); |
| slab->num_allocated = 0; |
| slab->num_free = gc_bucket_num_objs(bucket); |
| |
| list_addtail(&slab->link, &ctx->slabs[bucket].slabs); |
| list_addtail(&slab->free_link, &ctx->slabs[bucket].free_slabs); |
| |
| return slab; |
| } |
| |
| void * |
| gc_alloc_size(gc_ctx *ctx, size_t size, size_t alignment) |
| { |
| assert(ctx); |
| assert(util_is_power_of_two_nonzero_uintptr(alignment)); |
| |
| alignment = MAX2(alignment, alignof(gc_block_header)); |
| |
| /* Alignment will add at most align-alignof(gc_block_header) bytes of padding to the header, and |
| * the IS_PADDING byte can only encode up to 127. |
| */ |
| assert((alignment - alignof(gc_block_header)) <= 127); |
| |
| /* We can only align as high as the slab is. */ |
| assert(alignment <= HEADER_ALIGN); |
| |
| size_t header_size = align64(sizeof(gc_block_header), alignment); |
| size = align64(size, alignment); |
| size += header_size; |
| |
| gc_block_header *header = NULL; |
| if (size <= MAX_FREELIST_SIZE) { |
| uint32_t bucket = gc_bucket_for_size((uint32_t)size); |
| if (list_is_empty(&ctx->slabs[bucket].free_slabs) && !create_slab(ctx, bucket)) |
| return NULL; |
| gc_slab *slab = list_first_entry(&ctx->slabs[bucket].free_slabs, gc_slab, free_link); |
| header = alloc_from_slab(slab, bucket); |
| } else { |
| header = ralloc_size(ctx, size); |
| if (unlikely(!header)) |
| return NULL; |
| /* Mark the header as allocated directly, so we know to actually free it. */ |
| header->bucket = NUM_FREELIST_BUCKETS; |
| } |
| |
| header->flags = ctx->current_gen | IS_USED; |
| #ifndef NDEBUG |
| header->canary = GC_CANARY; |
| #endif |
| |
| uint8_t *ptr = (uint8_t *)header + header_size; |
| if ((header_size - 1) != offsetof(gc_block_header, flags)) |
| ptr[-1] = IS_PADDING | (header_size - sizeof(gc_block_header)); |
| |
| assert(((uintptr_t)ptr & (alignment - 1)) == 0); |
| return ptr; |
| } |
| |
| void * |
| gc_zalloc_size(gc_ctx *ctx, size_t size, size_t alignment) |
| { |
| void *ptr = gc_alloc_size(ctx, size, alignment); |
| |
| if (likely(ptr)) |
| memset(ptr, 0, size); |
| |
| return ptr; |
| } |
| |
| void |
| gc_free(void *ptr) |
| { |
| if (!ptr) |
| return; |
| |
| gc_block_header *header = get_gc_header(ptr); |
| header->flags &= ~IS_USED; |
| |
| if (header->bucket < NUM_FREELIST_BUCKETS) |
| free_from_slab(header, true); |
| else |
| ralloc_free(header); |
| } |
| |
| gc_ctx *gc_get_context(void *ptr) |
| { |
| gc_block_header *header = get_gc_header(ptr); |
| |
| if (header->bucket < NUM_FREELIST_BUCKETS) |
| return get_gc_slab(header)->ctx; |
| else |
| return ralloc_parent(header); |
| } |
| |
| void |
| gc_sweep_start(gc_ctx *ctx) |
| { |
| ctx->current_gen ^= CURRENT_GENERATION; |
| |
| ctx->rubbish = ralloc_context(NULL); |
| ralloc_adopt(ctx->rubbish, ctx); |
| } |
| |
| void |
| gc_mark_live(gc_ctx *ctx, const void *mem) |
| { |
| gc_block_header *header = get_gc_header(mem); |
| if (header->bucket < NUM_FREELIST_BUCKETS) |
| header->flags ^= CURRENT_GENERATION; |
| else |
| ralloc_steal(ctx, header); |
| } |
| |
| void |
| gc_sweep_end(gc_ctx *ctx) |
| { |
| assert(ctx->rubbish); |
| |
| for (unsigned i = 0; i < NUM_FREELIST_BUCKETS; i++) { |
| unsigned obj_size = gc_bucket_obj_size(i); |
| list_for_each_entry_safe(gc_slab, slab, &ctx->slabs[i].slabs, link) { |
| if (!slab->num_allocated) { |
| free_slab(slab); |
| continue; |
| } |
| |
| for (char *ptr = (char*)(slab + 1); ptr != slab->next_available; ptr += obj_size) { |
| gc_block_header *header = (gc_block_header *)ptr; |
| if (!(header->flags & IS_USED)) |
| continue; |
| if ((header->flags & CURRENT_GENERATION) == ctx->current_gen) |
| continue; |
| |
| bool last = slab->num_allocated == 1; |
| |
| header->flags &= ~IS_USED; |
| free_from_slab(header, false); |
| |
| if (last) |
| break; |
| } |
| } |
| } |
| |
| for (unsigned i = 0; i < NUM_FREELIST_BUCKETS; i++) { |
| list_for_each_entry(gc_slab, slab, &ctx->slabs[i].slabs, link) { |
| assert(slab->num_allocated > 0); /* free_from_slab() should free it otherwise */ |
| ralloc_steal(ctx, slab); |
| } |
| } |
| |
| ralloc_free(ctx->rubbish); |
| ctx->rubbish = NULL; |
| } |
| |
| /*************************************************************************** |
| * Linear allocator for short-lived allocations. |
| *************************************************************************** |
| * |
| * The allocator consists of a parent node (2K buffer), which requires |
| * a ralloc parent, and child nodes (allocations). Child nodes can't be freed |
| * directly, because the parent doesn't track them. You have to release |
| * the parent node in order to release all its children. |
| * |
| * The allocator uses a fixed-sized buffer with a monotonically increasing |
| * offset after each allocation. If the buffer is all used, another buffer |
| * is allocated, using the linear parent node as ralloc parent. |
| * |
| * The linear parent node is always the first buffer and keeps track of all |
| * other buffers. |
| */ |
| |
| #define SUBALLOC_ALIGNMENT 8 |
| #define LMAGIC_CONTEXT 0x87b9c7d3 |
| #define LMAGIC_NODE 0x87b910d3 |
| |
| struct linear_ctx { |
| |
| alignas(HEADER_ALIGN) |
| |
| #ifndef NDEBUG |
| unsigned magic; /* for debugging */ |
| #endif |
| unsigned min_buffer_size; |
| |
| unsigned offset; /* points to the first unused byte in the latest buffer */ |
| unsigned size; /* size of the latest buffer */ |
| void *latest; /* the only buffer that has free space */ |
| }; |
| |
| typedef struct linear_ctx linear_ctx; |
| |
| #ifndef NDEBUG |
| struct linear_node_canary { |
| alignas(HEADER_ALIGN) |
| unsigned magic; |
| unsigned offset; /* points to the first unused byte in *this* buffer */ |
| }; |
| |
| typedef struct linear_node_canary linear_node_canary; |
| |
| static linear_node_canary * |
| get_node_canary(void *ptr) |
| { |
| return (void *)((char *)ptr - sizeof(linear_node_canary)); |
| } |
| #endif |
| |
| static unsigned |
| get_node_canary_size() |
| { |
| #ifndef NDEBUG |
| return sizeof(linear_node_canary); |
| #else |
| return 0; |
| #endif |
| } |
| |
| void * |
| linear_alloc_child(linear_ctx *ctx, unsigned size) |
| { |
| assert(ctx->magic == LMAGIC_CONTEXT); |
| assert(get_node_canary(ctx->latest)->magic == LMAGIC_NODE); |
| assert(get_node_canary(ctx->latest)->offset == ctx->offset); |
| |
| size = ALIGN_POT(size, SUBALLOC_ALIGNMENT); |
| |
| if (unlikely(ctx->offset + size > ctx->size)) { |
| /* allocate a new node */ |
| unsigned node_size = size; |
| if (likely(node_size < ctx->min_buffer_size)) |
| node_size = ctx->min_buffer_size; |
| |
| const unsigned canary_size = get_node_canary_size(); |
| const unsigned full_size = canary_size + node_size; |
| |
| /* linear context is also a ralloc context */ |
| char *ptr = ralloc_size(ctx, full_size); |
| if (unlikely(!ptr)) |
| return NULL; |
| |
| #ifndef NDEBUG |
| linear_node_canary *canary = (void *) ptr; |
| canary->magic = LMAGIC_NODE; |
| canary->offset = 0; |
| #endif |
| |
| /* If the new buffer is going to be full, don't update `latest` |
| * pointer. Either the current one is also full, so doesn't |
| * matter, or the current one is not full, so there's still chance |
| * to use that space. |
| */ |
| if (unlikely(size == node_size)) { |
| #ifndef NDEBUG |
| canary->offset = size; |
| #endif |
| assert((uintptr_t)(ptr + canary_size) % SUBALLOC_ALIGNMENT == 0); |
| return ptr + canary_size; |
| } |
| |
| ctx->offset = 0; |
| ctx->size = node_size; |
| ctx->latest = ptr + canary_size; |
| } |
| |
| void *ptr = (char *)ctx->latest + ctx->offset; |
| ctx->offset += size; |
| |
| #ifndef NDEBUG |
| linear_node_canary *canary = get_node_canary(ctx->latest); |
| canary->offset += size; |
| #endif |
| |
| assert((uintptr_t)ptr % SUBALLOC_ALIGNMENT == 0); |
| return ptr; |
| } |
| |
| linear_ctx * |
| linear_context(void *ralloc_ctx) |
| { |
| const linear_opts opts = {0}; |
| return linear_context_with_opts(ralloc_ctx, &opts); |
| } |
| |
| linear_ctx * |
| linear_context_with_opts(void *ralloc_ctx, const linear_opts *opts) |
| { |
| linear_ctx *ctx; |
| |
| if (unlikely(!ralloc_ctx)) |
| return NULL; |
| |
| const unsigned default_min_buffer_size = 2048; |
| const unsigned min_buffer_size = |
| MAX2(ALIGN_POT(opts->min_buffer_size, default_min_buffer_size), |
| default_min_buffer_size); |
| |
| const unsigned size = min_buffer_size; |
| const unsigned canary_size = get_node_canary_size(); |
| const unsigned full_size = |
| sizeof(linear_ctx) + canary_size + size; |
| |
| ctx = ralloc_size(ralloc_ctx, full_size); |
| if (unlikely(!ctx)) |
| return NULL; |
| |
| ctx->min_buffer_size = min_buffer_size; |
| |
| ctx->offset = 0; |
| ctx->size = size; |
| ctx->latest = (char *)&ctx[1] + canary_size; |
| #ifndef NDEBUG |
| ctx->magic = LMAGIC_CONTEXT; |
| linear_node_canary *canary = get_node_canary(ctx->latest); |
| canary->magic = LMAGIC_NODE; |
| canary->offset = 0; |
| #endif |
| |
| return ctx; |
| } |
| |
| void * |
| linear_zalloc_child(linear_ctx *ctx, unsigned size) |
| { |
| void *ptr = linear_alloc_child(ctx, size); |
| |
| if (likely(ptr)) |
| memset(ptr, 0, size); |
| return ptr; |
| } |
| |
| void |
| linear_free_context(linear_ctx *ctx) |
| { |
| if (unlikely(!ctx)) |
| return; |
| |
| assert(ctx->magic == LMAGIC_CONTEXT); |
| |
| /* Linear context is also the ralloc parent of extra nodes. */ |
| ralloc_free(ctx); |
| } |
| |
| void |
| ralloc_steal_linear_context(void *new_ralloc_ctx, linear_ctx *ctx) |
| { |
| if (unlikely(!ctx)) |
| return; |
| |
| assert(ctx->magic == LMAGIC_CONTEXT); |
| |
| /* Linear context is also the ralloc parent of extra nodes. */ |
| ralloc_steal(new_ralloc_ctx, ctx); |
| } |
| |
| void * |
| ralloc_parent_of_linear_context(linear_ctx *ctx) |
| { |
| assert(ctx->magic == LMAGIC_CONTEXT); |
| return PTR_FROM_HEADER(get_header(ctx)->parent); |
| } |
| |
| /* All code below is pretty much copied from ralloc and only the alloc |
| * calls are different. |
| */ |
| |
| char * |
| linear_strdup(linear_ctx *ctx, const char *str) |
| { |
| unsigned n; |
| char *ptr; |
| |
| if (unlikely(!str)) |
| return NULL; |
| |
| n = strlen(str); |
| ptr = linear_alloc_child(ctx, n + 1); |
| if (unlikely(!ptr)) |
| return NULL; |
| |
| memcpy(ptr, str, n); |
| ptr[n] = '\0'; |
| return ptr; |
| } |
| |
| char * |
| linear_asprintf(linear_ctx *ctx, const char *fmt, ...) |
| { |
| char *ptr; |
| va_list args; |
| va_start(args, fmt); |
| ptr = linear_vasprintf(ctx, fmt, args); |
| va_end(args); |
| return ptr; |
| } |
| |
| char * |
| linear_vasprintf(linear_ctx *ctx, const char *fmt, va_list args) |
| { |
| unsigned size = u_printf_length(fmt, args) + 1; |
| |
| char *ptr = linear_alloc_child(ctx, size); |
| if (ptr != NULL) |
| vsnprintf(ptr, size, fmt, args); |
| |
| return ptr; |
| } |
| |
| bool |
| linear_asprintf_append(linear_ctx *ctx, char **str, const char *fmt, ...) |
| { |
| bool success; |
| va_list args; |
| va_start(args, fmt); |
| success = linear_vasprintf_append(ctx, str, fmt, args); |
| va_end(args); |
| return success; |
| } |
| |
| bool |
| linear_vasprintf_append(linear_ctx *ctx, char **str, const char *fmt, va_list args) |
| { |
| size_t existing_length; |
| assert(str != NULL); |
| existing_length = *str ? strlen(*str) : 0; |
| return linear_vasprintf_rewrite_tail(ctx, str, &existing_length, fmt, args); |
| } |
| |
| bool |
| linear_asprintf_rewrite_tail(linear_ctx *ctx, char **str, size_t *start, |
| const char *fmt, ...) |
| { |
| bool success; |
| va_list args; |
| va_start(args, fmt); |
| success = linear_vasprintf_rewrite_tail(ctx, str, start, fmt, args); |
| va_end(args); |
| return success; |
| } |
| |
| bool |
| linear_vasprintf_rewrite_tail(linear_ctx *ctx, char **str, size_t *start, |
| const char *fmt, va_list args) |
| { |
| size_t new_length; |
| char *ptr; |
| |
| assert(str != NULL); |
| |
| if (unlikely(*str == NULL)) { |
| *str = linear_vasprintf(ctx, fmt, args); |
| *start = strlen(*str); |
| return true; |
| } |
| |
| new_length = u_printf_length(fmt, args); |
| |
| ptr = linear_alloc_child(ctx, *start + new_length + 1); |
| if (unlikely(ptr == NULL)) |
| return false; |
| |
| memcpy(ptr, *str, *start); |
| |
| vsnprintf(ptr + *start, new_length + 1, fmt, args); |
| *str = ptr; |
| *start += new_length; |
| return true; |
| } |
| |
| /* helper routine for strcat/strncat - n is the exact amount to copy */ |
| static bool |
| linear_cat(linear_ctx *ctx, char **dest, const char *str, unsigned n) |
| { |
| char *both; |
| unsigned existing_length; |
| assert(dest != NULL && *dest != NULL); |
| |
| existing_length = strlen(*dest); |
| both = linear_alloc_child(ctx, existing_length + n + 1); |
| if (unlikely(both == NULL)) |
| return false; |
| |
| memcpy(both, *dest, existing_length); |
| memcpy(both + existing_length, str, n); |
| both[existing_length + n] = '\0'; |
| |
| *dest = both; |
| return true; |
| } |
| |
| bool |
| linear_strcat(linear_ctx *ctx, char **dest, const char *str) |
| { |
| return linear_cat(ctx, dest, str, strlen(str)); |
| } |
| |
| void * |
| linear_alloc_child_array(linear_ctx *ctx, size_t size, unsigned count) |
| { |
| if (count > SIZE_MAX/size) |
| return NULL; |
| |
| return linear_alloc_child(ctx, size * count); |
| } |
| |
| void * |
| linear_zalloc_child_array(linear_ctx *ctx, size_t size, unsigned count) |
| { |
| if (count > SIZE_MAX/size) |
| return NULL; |
| |
| return linear_zalloc_child(ctx, size * count); |
| } |
| |
| typedef struct { |
| FILE *f; |
| unsigned indent; |
| |
| unsigned ralloc_count; |
| unsigned linear_count; |
| unsigned gc_count; |
| |
| /* These don't include padding or metadata from suballocators. */ |
| unsigned content_bytes; |
| unsigned ralloc_metadata_bytes; |
| unsigned linear_metadata_bytes; |
| unsigned gc_metadata_bytes; |
| |
| bool inside_linear; |
| bool inside_gc; |
| } ralloc_print_info_state; |
| |
| static void |
| ralloc_print_info_helper(ralloc_print_info_state *state, const ralloc_header *info) |
| { |
| FILE *f = state->f; |
| |
| if (f) { |
| for (unsigned i = 0; i < state->indent; i++) fputc(' ', f); |
| fprintf(f, "%p", info); |
| } |
| |
| /* TODO: Account for padding used in various places. */ |
| |
| #ifndef NDEBUG |
| assert(info->canary == CANARY); |
| if (f) fprintf(f, " (%d bytes)", info->size); |
| state->content_bytes += info->size; |
| state->ralloc_metadata_bytes += sizeof(ralloc_header); |
| |
| const void *ptr = PTR_FROM_HEADER(info); |
| const linear_ctx *lin_ctx = ptr; |
| const gc_ctx *gc_ctx = ptr; |
| |
| if (lin_ctx->magic == LMAGIC_CONTEXT) { |
| if (f) fprintf(f, " (linear context)"); |
| assert(!state->inside_gc && !state->inside_linear); |
| state->inside_linear = true; |
| state->linear_metadata_bytes += sizeof(linear_ctx); |
| state->content_bytes -= sizeof(linear_ctx); |
| state->linear_count++; |
| } else if (gc_ctx->canary == GC_CONTEXT_CANARY) { |
| if (f) fprintf(f, " (gc context)"); |
| assert(!state->inside_gc && !state->inside_linear); |
| state->inside_gc = true; |
| state->gc_metadata_bytes += sizeof(gc_block_header); |
| } else if (state->inside_linear) { |
| const linear_node_canary *lin_node = ptr; |
| if (lin_node->magic == LMAGIC_NODE) { |
| if (f) fprintf(f, " (linear node buffer)"); |
| state->content_bytes -= sizeof(linear_node_canary); |
| state->linear_metadata_bytes += sizeof(linear_node_canary); |
| state->linear_count++; |
| } |
| } else if (state->inside_gc) { |
| if (f) fprintf(f, " (gc slab or large block)"); |
| state->gc_count++; |
| } |
| #endif |
| |
| state->ralloc_count++; |
| if (f) fprintf(f, "\n"); |
| |
| const ralloc_header *c = info->child; |
| state->indent += 2; |
| while (c != NULL) { |
| ralloc_print_info_helper(state, c); |
| c = c->next; |
| } |
| state->indent -= 2; |
| |
| #ifndef NDEBUG |
| if (lin_ctx->magic == LMAGIC_CONTEXT) state->inside_linear = false; |
| else if (gc_ctx->canary == GC_CONTEXT_CANARY) state->inside_gc = false; |
| #endif |
| } |
| |
| void |
| ralloc_print_info(FILE *f, const void *p, unsigned flags) |
| { |
| ralloc_print_info_state state = { |
| .f = ((flags & RALLOC_PRINT_INFO_SUMMARY_ONLY) == 1) ? NULL : f, |
| }; |
| |
| const ralloc_header *info = get_header(p); |
| ralloc_print_info_helper(&state, info); |
| |
| fprintf(f, "==== RALLOC INFO ptr=%p info=%p\n" |
| "ralloc allocations = %d\n" |
| " - linear = %d\n" |
| " - gc = %d\n" |
| " - other = %d\n", |
| p, info, |
| state.ralloc_count, |
| state.linear_count, |
| state.gc_count, |
| state.ralloc_count - state.linear_count - state.gc_count); |
| |
| if (state.content_bytes) { |
| fprintf(f, |
| "content bytes = %d\n" |
| "ralloc metadata bytes = %d\n" |
| "linear metadata bytes = %d\n", |
| state.content_bytes, |
| state.ralloc_metadata_bytes, |
| state.linear_metadata_bytes); |
| } |
| |
| fprintf(f, "====\n"); |
| } |
| |