/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Copyright by The HDF Group. * * All rights reserved. * * * * This file is part of HDF5. The full HDF5 copyright notice, including * * terms governing use, modification, and redistribution, is contained in * * the COPYING file, which can be found at the root of the source code * * distribution tree, or in https://www.hdfgroup.org/licenses. * * If you do not have access to either file, you may request a copy from * * help@hdfgroup.org. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /*------------------------------------------------------------------------- * * Created: H5MP.c * May 2 2005 * Quincey Koziol * * Purpose: Implements memory pools. (Similar to Apache's APR * memory pools) * * Please see the documentation in: * doc/html/TechNotes/MemoryPools.html for a full description * of how they work, etc. * *------------------------------------------------------------------------- */ #include "H5MPmodule.h" /* This source code file is part of the H5MP module */ /* Private headers */ #include "H5private.h" /* Generic Functions */ #include "H5Eprivate.h" /* Error handling */ #include "H5MMprivate.h" /* Memory management */ #include "H5MPpkg.h" /* Memory Pools */ /****************/ /* Local Macros */ /****************/ /* Minimum sized block */ #define H5MP_MIN_BLOCK (H5MP_BLOCK_ALIGN(sizeof(H5MP_page_blk_t)) + H5MP_BLOCK_ALIGNMENT) /* First block in page */ #define H5MP_PAGE_FIRST_BLOCK(p) \ (H5MP_page_blk_t *)((void *)((unsigned char *)(p) + H5MP_BLOCK_ALIGN(sizeof(H5MP_page_t)))) /******************/ /* Local Typedefs */ /******************/ /********************/ /* Local Prototypes */ /********************/ /********************************/ /* Package Variable Definitions */ /********************************/ /* Package initialization variable */ hbool_t H5_PKG_INIT_VAR = FALSE; /********************/ /* Static Variables */ /********************/ /* Declare a free list to manage the H5MP_pool_t struct */ H5FL_DEFINE(H5MP_pool_t); /*------------------------------------------------------------------------- * Function: H5MP_create * * Purpose: Create a new memory pool * * Return: Pointer to the memory pool "header" on success/NULL on failure * * Programmer: Quincey Koziol * May 2 2005 * *------------------------------------------------------------------------- */ H5MP_pool_t * H5MP_create(size_t page_size, unsigned flags) { H5MP_pool_t *mp = NULL; /* New memory pool header */ H5MP_pool_t *ret_value = NULL; /* Return value */ FUNC_ENTER_NOAPI(NULL) /* Allocate space for the pool header */ if (NULL == (mp = H5FL_MALLOC(H5MP_pool_t))) HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for memory pool header") /* Assign information */ mp->page_size = H5MP_BLOCK_ALIGN(page_size); mp->flags = flags; /* Initialize information */ mp->free_size = 0; mp->first = NULL; mp->max_size = mp->page_size - H5MP_BLOCK_ALIGN(sizeof(H5MP_page_t)); /* Create factory for pool pages */ if (NULL == (mp->page_fac = H5FL_fac_init(page_size))) HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, NULL, "can't create page factory") /* Set return value */ ret_value = mp; done: if (NULL == ret_value && mp) if (H5MP_close(mp) < 0) HDONE_ERROR(H5E_RESOURCE, H5E_CANTFREE, NULL, "unable to free memory pool header") FUNC_LEAVE_NOAPI(ret_value) } /* end H5MP_create() */ /*------------------------------------------------------------------------- * Function: H5MP__new_page * * Purpose: Allocate new page for a memory pool * * Return: Pointer to the page allocated on success/NULL on failure * * Programmer: Quincey Koziol * May 4 2005 * *------------------------------------------------------------------------- */ static H5MP_page_t * H5MP__new_page(H5MP_pool_t *mp, size_t page_size) { H5MP_page_t *new_page; /* New page created */ H5MP_page_blk_t *first_blk; /* Pointer to first block in page */ H5MP_page_t *ret_value = NULL; /* Return value */ FUNC_ENTER_STATIC /* Sanity check */ HDassert(mp); HDassert(page_size >= mp->page_size); /* Allocate page */ if (page_size > mp->page_size) { if (NULL == (new_page = (H5MP_page_t *)H5MM_malloc(page_size))) HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for page") new_page->free_size = page_size - H5MP_BLOCK_ALIGN(sizeof(H5MP_page_t)); new_page->fac_alloc = FALSE; } /* end if */ else { if (NULL == (new_page = (H5MP_page_t *)H5FL_FAC_MALLOC(mp->page_fac))) HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for page") new_page->free_size = mp->max_size; new_page->fac_alloc = TRUE; } /* end else */ /* Initialize page information */ first_blk = H5MP_PAGE_FIRST_BLOCK(new_page); first_blk->size = new_page->free_size; first_blk->page = new_page; first_blk->is_free = TRUE; first_blk->prev = NULL; first_blk->next = NULL; /* Insert into page list */ new_page->prev = NULL; new_page->next = mp->first; if (mp->first) mp->first->prev = new_page; mp->first = new_page; /* Account for new free space */ new_page->free_blk = first_blk; mp->free_size += new_page->free_size; /* Assign return value */ ret_value = new_page; done: FUNC_LEAVE_NOAPI(ret_value) } /* end H5MP__new_page() */ /*------------------------------------------------------------------------- * Function: H5MP_malloc * * Purpose: Allocate space in a memory pool * * Return: Pointer to the space allocated on success/NULL on failure * * Programmer: Quincey Koziol * May 2 2005 * *------------------------------------------------------------------------- */ void * H5MP_malloc(H5MP_pool_t *mp, size_t request) { H5MP_page_t *alloc_page = NULL; /* Page to allocate space from */ H5MP_page_blk_t *alloc_free; /* Pointer to free space in page */ size_t needed; /* Size requested, plus block header and alignment */ void *ret_value = NULL; /* Return value */ FUNC_ENTER_NOAPI(NULL) /* Sanity check */ HDassert(mp); HDassert(request > 0); /* Compute actual size needed */ needed = H5MP_BLOCK_ALIGN(request) + H5MP_BLOCK_ALIGN(sizeof(H5MP_page_blk_t)); /* See if the request can be handled by existing free space */ if (needed <= mp->free_size) { size_t pool_free_avail; /* Amount of free space possibly available in pool */ /* Locate page with enough free space */ alloc_page = mp->first; pool_free_avail = mp->free_size; while (alloc_page && pool_free_avail >= needed) { /* If we found a page with enough free space, search for large * enough free block on that page */ if (alloc_page->free_size >= needed) { size_t page_free_avail; /* Amount of free space possibly available */ /* Locate large enough block */ alloc_free = alloc_page->free_blk; page_free_avail = alloc_page->free_size; while (alloc_free && page_free_avail >= needed) { if (alloc_free->is_free) { /* If we found a large enough block, leave now */ if (alloc_free->size >= needed) goto found; /* Needed to escape double "while" loop */ /* Decrement amount of potential space left */ page_free_avail -= alloc_free->size; } /* end if */ /* Go to next block */ alloc_free = alloc_free->next; } /* end while */ } /* end if */ /* Decrement amount of potential space left */ pool_free_avail -= alloc_page->free_size; /* Go to next page */ alloc_page = alloc_page->next; } /* end while */ } /* end if */ { size_t page_size; /* Size of page needed */ /* Check if the request is too large for a standard page */ page_size = (needed > mp->max_size) ? (needed + H5MP_BLOCK_ALIGN(sizeof(H5MP_page_t))) : mp->page_size; /* Allocate new page */ if (NULL == (alloc_page = H5MP__new_page(mp, page_size))) HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for page") /* Set the block to allocate from */ alloc_free = alloc_page->free_blk; } /* end block */ /* Allocate space in page */ found: /* Sanity check */ HDassert(alloc_page); HDassert(alloc_free); /* Check if we can subdivide the free space */ if (alloc_free->size > (needed + H5MP_MIN_BLOCK)) { H5MP_page_blk_t *new_free; /* New free block created */ /* Carve out new free block after block to allocate */ new_free = (H5MP_page_blk_t *)((void *)(((unsigned char *)alloc_free) + needed)); /* Link into existing lists */ new_free->next = alloc_free->next; if (alloc_free->next) alloc_free->next->prev = new_free; new_free->prev = alloc_free; alloc_free->next = new_free; /* Set blocks' information */ new_free->size = alloc_free->size - needed; new_free->is_free = TRUE; new_free->page = alloc_free->page; alloc_free->size = needed; alloc_free->is_free = FALSE; } /* end if */ else { /* Use whole free space block for new block */ alloc_free->is_free = FALSE; } /* end else */ /* Update page & pool's free size information */ alloc_page->free_size -= alloc_free->size; if (alloc_page->free_blk == alloc_free) alloc_page->free_blk = alloc_free->next; mp->free_size -= alloc_free->size; /* Set new space pointer for the return value */ ret_value = ((unsigned char *)alloc_free) + H5MP_BLOCK_ALIGN(sizeof(H5MP_page_blk_t)); done: FUNC_LEAVE_NOAPI(ret_value) } /* end H5MP_malloc() */ /*------------------------------------------------------------------------- * Function: H5MP_free * * Purpose: Release space in a memory pool * * Return: NULL on success/NULL on failure * * Programmer: Quincey Koziol * May 3 2005 * * Note: Should we release pages that have no used blocks? * *------------------------------------------------------------------------- */ void * H5MP_free(H5MP_pool_t *mp, void *spc) { H5MP_page_blk_t *spc_blk; /* Block for space to free */ H5MP_page_t *spc_page; /* Page containing block to free */ void *ret_value = NULL; /* Return value */ FUNC_ENTER_NOAPI_NOINIT_NOERR /* Sanity check */ HDassert(mp); HDassert(spc); /* Get block header for space to free */ spc_blk = (H5MP_page_blk_t *)((void *)(((unsigned char *)spc) - H5MP_BLOCK_ALIGN(sizeof(H5MP_page_blk_t)))); /* Mark block as free */ HDassert(spc_blk->is_free == FALSE); spc_blk->is_free = TRUE; /* Add it's space to the amount of free space in the page & pool */ spc_page = spc_blk->page; spc_page->free_size += spc_blk->size; mp->free_size += spc_blk->size; /* Move page with newly freed space to front of list of pages in pool */ if (spc_page != mp->first) { /* Remove page from list */ spc_page->prev->next = spc_page->next; if (spc_page->next) spc_page->next->prev = spc_page->prev; /* Insert page at beginning of list */ spc_page->prev = NULL; spc_page->next = mp->first; mp->first->prev = spc_page; mp->first = spc_page; } /* end if */ /* Check if block can be merged with free space after it on page */ if (spc_blk->next != NULL) { H5MP_page_blk_t *next_blk; /* Block following space to free */ next_blk = spc_blk->next; HDassert(next_blk->prev == spc_blk); if (next_blk->is_free) { spc_blk->size += next_blk->size; spc_blk->next = next_blk->next; } /* end if */ } /* end if */ /* Check if block can be merged with free space before it on page */ if (spc_blk->prev != NULL) { H5MP_page_blk_t *prev_blk; /* Block before space to free */ prev_blk = spc_blk->prev; HDassert(prev_blk->next == spc_blk); if (prev_blk->is_free) { prev_blk->size += spc_blk->size; prev_blk->next = spc_blk->next; } /* end if */ } /* end if */ /* Check if the block freed becomes the first free block on the page */ if (spc_page->free_blk == NULL || spc_blk < spc_page->free_blk) spc_page->free_blk = spc_blk; FUNC_LEAVE_NOAPI(ret_value) } /* end H5MP_free() */ /*------------------------------------------------------------------------- * Function: H5MP_close * * Purpose: Release all memory for a pool and destroy pool * * Return: Non-negative on success/negative on failure * * Programmer: Quincey Koziol * May 3 2005 * *------------------------------------------------------------------------- */ herr_t H5MP_close(H5MP_pool_t *mp) { herr_t ret_value = SUCCEED; /* Return value */ FUNC_ENTER_NOAPI(FAIL) /* Release memory for pool pages */ if (mp->first != NULL) { H5MP_page_t *page, *next_page; /* Pointer to pages in pool */ /* Iterate through pages, releasing them */ page = mp->first; while (page) { next_page = page->next; /* Free the page appropriately */ if (page->fac_alloc) page = (H5MP_page_t *)H5FL_FAC_FREE(mp->page_fac, page); else page = (H5MP_page_t *)H5MM_xfree(page); page = next_page; } /* end while */ } /* end if */ /* Release page factory */ if (mp->page_fac) if (H5FL_fac_term(mp->page_fac) < 0) HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't destroy page factory") done: /* Free the memory pool itself */ mp = H5FL_FREE(H5MP_pool_t, mp); FUNC_LEAVE_NOAPI(ret_value) } /* end H5MP_close() */