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Diffstat (limited to 'support/cpp/gcc/alloc-pool.h')
| -rw-r--r-- | support/cpp/gcc/alloc-pool.h | 576 |
1 files changed, 576 insertions, 0 deletions
diff --git a/support/cpp/gcc/alloc-pool.h b/support/cpp/gcc/alloc-pool.h new file mode 100644 index 000000000..3963596ea --- /dev/null +++ b/support/cpp/gcc/alloc-pool.h @@ -0,0 +1,576 @@ +/* Functions to support a pool of allocatable objects + Copyright (C) 1997-2022 Free Software Foundation, Inc. + Contributed by Daniel Berlin <dan@cgsoftware.com> + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ +#ifndef ALLOC_POOL_H +#define ALLOC_POOL_H + +#include "memory-block.h" +#include "options.h" // for flag_checking + +extern void dump_alloc_pool_statistics (void); + +/* Flag indicates whether memory statistics are gathered any longer. */ +extern bool after_memory_report; + +typedef unsigned long ALLOC_POOL_ID_TYPE; + +/* Last used ID. */ +extern ALLOC_POOL_ID_TYPE last_id; + +/* Pool allocator memory usage. */ +class pool_usage: public mem_usage +{ +public: + /* Default contructor. */ + pool_usage (): m_element_size (0), m_pool_name ("") {} + /* Constructor. */ + pool_usage (size_t allocated, size_t times, size_t peak, + size_t instances, size_t element_size, + const char *pool_name) + : mem_usage (allocated, times, peak, instances), + m_element_size (element_size), + m_pool_name (pool_name) {} + + /* Sum the usage with SECOND usage. */ + pool_usage + operator+ (const pool_usage &second) + { + return pool_usage (m_allocated + second.m_allocated, + m_times + second.m_times, + m_peak + second.m_peak, + m_instances + second.m_instances, + m_element_size, m_pool_name); + } + + /* Dump usage coupled to LOC location, where TOTAL is sum of all rows. */ + inline void + dump (mem_location *loc, const mem_usage &total) const + { + char *location_string = loc->to_string (); + + fprintf (stderr, "%-32s%-48s " PRsa(5) PRsa(9) ":%5.1f%%" + PRsa(9) PRsa(9) ":%5.1f%%%12" PRIu64 "\n", + m_pool_name, location_string, + SIZE_AMOUNT (m_instances), + SIZE_AMOUNT (m_allocated), + get_percent (m_allocated, total.m_allocated), + SIZE_AMOUNT (m_peak), + SIZE_AMOUNT (m_times), + get_percent (m_times, total.m_times), + (uint64_t)m_element_size); + + free (location_string); + } + + /* Dump header with NAME. */ + static inline void + dump_header (const char *name) + { + fprintf (stderr, "%-32s%-48s %6s%11s%16s%17s%12s\n", "Pool name", name, + "Pools", "Leak", "Peak", "Times", "Elt size"); + } + + /* Dump footer. */ + inline void + dump_footer () + { + fprintf (stderr, "%s" PRsa(82) PRsa(10) "\n", "Total", + SIZE_AMOUNT (m_instances), SIZE_AMOUNT (m_allocated)); + } + + /* Element size. */ + size_t m_element_size; + /* Pool name. */ + const char *m_pool_name; +}; + +extern mem_alloc_description<pool_usage> pool_allocator_usage; + +#if 0 +/* If a pool with custom block size is needed, one might use the following + template. An instance of this template can be used as a parameter for + instantiating base_pool_allocator template: + + typedef custom_block_allocator <128*1024> huge_block_allocator; + ... + static base_pool_allocator <huge_block_allocator> + value_pool ("value", 16384); + + Right now it's not used anywhere in the code, and is given here as an + example). */ + +template <size_t BlockSize> +class custom_block_allocator +{ +public: + static const size_t block_size = BlockSize; + + static inline void * + allocate () ATTRIBUTE_MALLOC + { + return XNEWVEC (char, BlockSize); + } + + static inline void + release (void *block) + { + XDELETEVEC (block); + } +}; +#endif + +/* Generic pool allocator. */ + +template <typename TBlockAllocator> +class base_pool_allocator +{ +public: + /* Default constructor for pool allocator called NAME. */ + base_pool_allocator (const char *name, size_t size CXX_MEM_STAT_INFO); + ~base_pool_allocator (); + void release (); + void release_if_empty (); + void *allocate () ATTRIBUTE_MALLOC; + void remove (void *object); + size_t num_elts_current (); + +private: + struct allocation_pool_list + { + allocation_pool_list *next; + }; + + /* Initialize a pool allocator. */ + void initialize (); + + struct allocation_object + { +#if CHECKING_P + /* The ID of alloc pool which the object was allocated from. */ + ALLOC_POOL_ID_TYPE id; +#endif + + union + { + /* The data of the object. */ + char data[1]; + + /* Because we want any type of data to be well aligned after the ID, + the following elements are here. They are never accessed so + the allocated object may be even smaller than this structure. + We do not care about alignment for floating-point types. */ + char *align_p; + int64_t align_i; + } u; + +#if CHECKING_P + static inline allocation_object* + get_instance (void *data_ptr) + { + return (allocation_object *)(((char *)(data_ptr)) + - offsetof (allocation_object, + u.data)); + } +#endif + + static inline void* + get_data (void *instance_ptr) + { + return (void*)(((allocation_object *) instance_ptr)->u.data); + } + }; + + /* Align X to 8. */ + static inline size_t + align_eight (size_t x) + { + return (((x+7) >> 3) << 3); + } + + const char *m_name; + ALLOC_POOL_ID_TYPE m_id; + size_t m_elts_per_block; + + /* These are the elements that have been allocated at least once + and freed. */ + allocation_pool_list *m_returned_free_list; + + /* These are the elements that have not yet been allocated out of + the last block obtained from XNEWVEC. */ + char* m_virgin_free_list; + + /* The number of elements in the virgin_free_list that can be + allocated before needing another block. */ + size_t m_virgin_elts_remaining; + /* The number of elements that are allocated. */ + size_t m_elts_allocated; + /* The number of elements that are released. */ + size_t m_elts_free; + /* The number of allocated blocks. */ + size_t m_blocks_allocated; + /* List of blocks that are used to allocate new objects. */ + allocation_pool_list *m_block_list; + /* Size of a pool elements in bytes. */ + size_t m_elt_size; + /* Size in bytes that should be allocated for each element. */ + size_t m_size; + /* Flag if a pool allocator is initialized. */ + bool m_initialized; + /* Memory allocation location. */ + mem_location m_location; +}; + +template <typename TBlockAllocator> +inline +base_pool_allocator <TBlockAllocator>::base_pool_allocator ( + const char *name, size_t size MEM_STAT_DECL): + m_name (name), m_id (0), m_elts_per_block (0), m_returned_free_list (NULL), + m_virgin_free_list (NULL), m_virgin_elts_remaining (0), m_elts_allocated (0), + m_elts_free (0), m_blocks_allocated (0), m_block_list (NULL), m_elt_size (0), + m_size (size), m_initialized (false), + m_location (ALLOC_POOL_ORIGIN, false PASS_MEM_STAT) {} + +/* Initialize a pool allocator. */ + +template <typename TBlockAllocator> +inline void +base_pool_allocator <TBlockAllocator>::initialize () +{ + gcc_checking_assert (!m_initialized); + m_initialized = true; + + size_t size = m_size; + + gcc_checking_assert (m_name); + gcc_checking_assert (m_size); + + /* Make size large enough to store the list header. */ + if (size < sizeof (allocation_pool_list*)) + size = sizeof (allocation_pool_list*); + + /* Now align the size to a multiple of 8. */ + size = align_eight (size); + + /* Add the aligned size of ID. */ + size += offsetof (allocation_object, u.data); + + m_elt_size = size; + + if (GATHER_STATISTICS) + { + pool_usage *u = pool_allocator_usage.register_descriptor + (this, new mem_location (m_location)); + + u->m_element_size = m_elt_size; + u->m_pool_name = m_name; + } + + /* List header size should be a multiple of 8. */ + size_t header_size = align_eight (sizeof (allocation_pool_list)); + + m_elts_per_block = (TBlockAllocator::block_size - header_size) / size; + gcc_checking_assert (m_elts_per_block != 0); + + /* Increase the last used ID and use it for this pool. + ID == 0 is used for free elements of pool so skip it. */ + last_id++; + if (last_id == 0) + last_id++; + + m_id = last_id; +} + +/* Free all memory allocated for the given memory pool. */ +template <typename TBlockAllocator> +inline void +base_pool_allocator <TBlockAllocator>::release () +{ + if (!m_initialized) + return; + + allocation_pool_list *block, *next_block; + + /* Free each block allocated to the pool. */ + for (block = m_block_list; block != NULL; block = next_block) + { + next_block = block->next; + TBlockAllocator::release (block); + } + + if (GATHER_STATISTICS && !after_memory_report) + { + pool_allocator_usage.release_instance_overhead + (this, (m_elts_allocated - m_elts_free) * m_elt_size); + } + + m_returned_free_list = NULL; + m_virgin_free_list = NULL; + m_virgin_elts_remaining = 0; + m_elts_allocated = 0; + m_elts_free = 0; + m_blocks_allocated = 0; + m_block_list = NULL; +} + +template <typename TBlockAllocator> +inline void +base_pool_allocator <TBlockAllocator>::release_if_empty () +{ + if (m_elts_free == m_elts_allocated) + release (); +} + +template <typename TBlockAllocator> +inline base_pool_allocator <TBlockAllocator>::~base_pool_allocator () +{ + release (); +} + +/* Allocates one element from the pool specified. */ +template <typename TBlockAllocator> +inline void* +base_pool_allocator <TBlockAllocator>::allocate () +{ + if (!m_initialized) + initialize (); + + allocation_pool_list *header; +#ifdef ENABLE_VALGRIND_ANNOTATIONS + int size; +#endif + + if (GATHER_STATISTICS) + { + pool_allocator_usage.register_instance_overhead (m_elt_size, this); + } + +#ifdef ENABLE_VALGRIND_ANNOTATIONS + size = m_elt_size - offsetof (allocation_object, u.data); +#endif + + /* If there are no more free elements, make some more!. */ + if (!m_returned_free_list) + { + char *block; + if (!m_virgin_elts_remaining) + { + allocation_pool_list *block_header; + + /* Make the block. */ + block = reinterpret_cast<char *> (TBlockAllocator::allocate ()); + block_header = new (block) allocation_pool_list; + block += align_eight (sizeof (allocation_pool_list)); + + /* Throw it on the block list. */ + block_header->next = m_block_list; + m_block_list = block_header; + + /* Make the block available for allocation. */ + m_virgin_free_list = block; + m_virgin_elts_remaining = m_elts_per_block; + + /* Also update the number of elements we have free/allocated, and + increment the allocated block count. */ + m_elts_allocated += m_elts_per_block; + m_elts_free += m_elts_per_block; + m_blocks_allocated += 1; + } + + /* We now know that we can take the first elt off the virgin list and + put it on the returned list. */ + block = m_virgin_free_list; + header = (allocation_pool_list*) allocation_object::get_data (block); + header->next = NULL; + + /* Mark the element to be free. */ +#if CHECKING_P + ((allocation_object*) block)->id = 0; +#endif + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (header,size)); + m_returned_free_list = header; + m_virgin_free_list += m_elt_size; + m_virgin_elts_remaining--; + + } + + /* Pull the first free element from the free list, and return it. */ + header = m_returned_free_list; + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (header, sizeof (*header))); + m_returned_free_list = header->next; + m_elts_free--; + + /* Set the ID for element. */ +#if CHECKING_P + allocation_object::get_instance (header)->id = m_id; +#endif + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (header, size)); + + return (void *)(header); +} + +/* Puts PTR back on POOL's free list. */ +template <typename TBlockAllocator> +inline void +base_pool_allocator <TBlockAllocator>::remove (void *object) +{ + int size = m_elt_size - offsetof (allocation_object, u.data); + + if (flag_checking) + { + gcc_assert (m_initialized); + gcc_assert (object + /* Check if we free more than we allocated. */ + && m_elts_free < m_elts_allocated); +#if CHECKING_P + /* Check whether the PTR was allocated from POOL. */ + gcc_assert (m_id == allocation_object::get_instance (object)->id); +#endif + + memset (object, 0xaf, size); + } + +#if CHECKING_P + /* Mark the element to be free. */ + allocation_object::get_instance (object)->id = 0; +#endif + + allocation_pool_list *header = new (object) allocation_pool_list; + header->next = m_returned_free_list; + m_returned_free_list = header; + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (object, size)); + m_elts_free++; + + if (GATHER_STATISTICS) + { + pool_allocator_usage.release_instance_overhead (this, m_elt_size); + } +} + +/* Number of elements currently active (not returned to pool). Used for cheap + consistency checks. */ +template <typename TBlockAllocator> +inline size_t +base_pool_allocator <TBlockAllocator>::num_elts_current () +{ + return m_elts_allocated - m_elts_free; +} + +/* Specialization of base_pool_allocator which should be used in most cases. + Another specialization may be needed, if object size is greater than + memory_block_pool::block_size (64 KB). */ +typedef base_pool_allocator <memory_block_pool> pool_allocator; + +/* Type based memory pool allocator. */ +template <typename T> +class object_allocator +{ +public: + /* Default constructor for pool allocator called NAME. */ + object_allocator (const char *name CXX_MEM_STAT_INFO): + m_allocator (name, sizeof (T) PASS_MEM_STAT) {} + + inline void + release () + { + m_allocator.release (); + } + + inline void release_if_empty () + { + m_allocator.release_if_empty (); + } + + + /* Allocate memory for instance of type T and call a default constructor. */ + + inline T * + allocate () ATTRIBUTE_MALLOC + { + return ::new (m_allocator.allocate ()) T; + } + + /* Allocate memory for instance of type T and return void * that + could be used in situations where a default constructor is not provided + by the class T. */ + + inline void * + allocate_raw () ATTRIBUTE_MALLOC + { + return m_allocator.allocate (); + } + + inline void + remove (T *object) + { + /* Call destructor. */ + object->~T (); + + m_allocator.remove (object); + } + + inline void + remove_raw (void *object) + { + m_allocator.remove (object); + } + + inline size_t + num_elts_current () + { + return m_allocator.num_elts_current (); + } + +private: + pool_allocator m_allocator; +}; + +/* Store information about each particular alloc_pool. Note that this + will underestimate the amount the amount of storage used by a small amount: + 1) The overhead in a pool is not accounted for. + 2) The unallocated elements in a block are not accounted for. Note + that this can at worst case be one element smaller that the block + size for that pool. */ +struct alloc_pool_descriptor +{ + /* Number of pools allocated. */ + unsigned long created; + /* Gross allocated storage. */ + unsigned long allocated; + /* Amount of currently active storage. */ + unsigned long current; + /* Peak amount of storage used. */ + unsigned long peak; + /* Size of element in the pool. */ + int elt_size; +}; + +/* Helper for classes that do not provide default ctor. */ + +template <typename T> +inline void * +operator new (size_t, object_allocator<T> &a) +{ + return a.allocate_raw (); +} + +/* Hashtable mapping alloc_pool names to descriptors. */ +extern hash_map<const char *, alloc_pool_descriptor> *alloc_pool_hash; + + +#endif |