godot/core/os/pool_allocator.cpp
Rémi Verschelde b5334d14f7
Update copyright statements to 2021
Happy new year to the wonderful Godot community!

2020 has been a tough year for most of us personally, but a good year for
Godot development nonetheless with a huge amount of work done towards Godot
4.0 and great improvements backported to the long-lived 3.2 branch.

We've had close to 400 contributors to engine code this year, authoring near
7,000 commit! (And that's only for the `master` branch and for the engine code,
there's a lot more when counting docs, demos and other first-party repos.)

Here's to a great year 2021 for all Godot users 🎆
2021-01-01 20:19:21 +01:00

597 lines
14 KiB
C++

/*************************************************************************/
/* pool_allocator.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* 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 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 "pool_allocator.h"
#include "core/error/error_macros.h"
#include "core/os/copymem.h"
#include "core/os/memory.h"
#include "core/os/os.h"
#include "core/string/print_string.h"
#include <assert.h>
#define COMPACT_CHUNK(m_entry, m_to_pos) \
do { \
void *_dst = &((unsigned char *)pool)[m_to_pos]; \
void *_src = &((unsigned char *)pool)[(m_entry).pos]; \
movemem(_dst, _src, aligned((m_entry).len)); \
(m_entry).pos = m_to_pos; \
} while (0);
void PoolAllocator::mt_lock() const {
}
void PoolAllocator::mt_unlock() const {
}
bool PoolAllocator::get_free_entry(EntryArrayPos *p_pos) {
if (entry_count == entry_max) {
return false;
}
for (int i = 0; i < entry_max; i++) {
if (entry_array[i].len == 0) {
*p_pos = i;
return true;
}
}
ERR_PRINT("Out of memory Chunks!");
return false; //
}
/**
* Find a hole
* @param p_pos The hole is behind the block pointed by this variable upon return. if pos==entry_count, then allocate at end
* @param p_for_size hole size
* @return false if hole found, true if no hole found
*/
bool PoolAllocator::find_hole(EntryArrayPos *p_pos, int p_for_size) {
/* position where previous entry ends. Defaults to zero (begin of pool) */
int prev_entry_end_pos = 0;
for (int i = 0; i < entry_count; i++) {
Entry &entry = entry_array[entry_indices[i]];
/* determine hole size to previous entry */
int hole_size = entry.pos - prev_entry_end_pos;
/* determine if what we want fits in that hole */
if (hole_size >= p_for_size) {
*p_pos = i;
return true;
}
/* prepare for next one */
prev_entry_end_pos = entry_end(entry);
}
/* No holes between entries, check at the end..*/
if ((pool_size - prev_entry_end_pos) >= p_for_size) {
*p_pos = entry_count;
return true;
}
return false;
}
void PoolAllocator::compact(int p_up_to) {
uint32_t prev_entry_end_pos = 0;
if (p_up_to < 0) {
p_up_to = entry_count;
}
for (int i = 0; i < p_up_to; i++) {
Entry &entry = entry_array[entry_indices[i]];
/* determine hole size to previous entry */
int hole_size = entry.pos - prev_entry_end_pos;
/* if we can compact, do it */
if (hole_size > 0 && !entry.lock) {
COMPACT_CHUNK(entry, prev_entry_end_pos);
}
/* prepare for next one */
prev_entry_end_pos = entry_end(entry);
}
}
void PoolAllocator::compact_up(int p_from) {
uint32_t next_entry_end_pos = pool_size; // - static_area_size;
for (int i = entry_count - 1; i >= p_from; i--) {
Entry &entry = entry_array[entry_indices[i]];
/* determine hole size to nextious entry */
int hole_size = next_entry_end_pos - (entry.pos + aligned(entry.len));
/* if we can compact, do it */
if (hole_size > 0 && !entry.lock) {
COMPACT_CHUNK(entry, (next_entry_end_pos - aligned(entry.len)));
}
/* prepare for next one */
next_entry_end_pos = entry.pos;
}
}
bool PoolAllocator::find_entry_index(EntryIndicesPos *p_map_pos, Entry *p_entry) {
EntryArrayPos entry_pos = entry_max;
for (int i = 0; i < entry_count; i++) {
if (&entry_array[entry_indices[i]] == p_entry) {
entry_pos = i;
break;
}
}
if (entry_pos == entry_max) {
return false;
}
*p_map_pos = entry_pos;
return true;
}
PoolAllocator::ID PoolAllocator::alloc(int p_size) {
ERR_FAIL_COND_V(p_size < 1, POOL_ALLOCATOR_INVALID_ID);
#ifdef DEBUG_ENABLED
if (p_size > free_mem) {
OS::get_singleton()->debug_break();
}
#endif
ERR_FAIL_COND_V(p_size > free_mem, POOL_ALLOCATOR_INVALID_ID);
mt_lock();
if (entry_count == entry_max) {
mt_unlock();
ERR_PRINT("entry_count==entry_max");
return POOL_ALLOCATOR_INVALID_ID;
}
int size_to_alloc = aligned(p_size);
EntryIndicesPos new_entry_indices_pos;
if (!find_hole(&new_entry_indices_pos, size_to_alloc)) {
/* No hole could be found, try compacting mem */
compact();
/* Then search again */
if (!find_hole(&new_entry_indices_pos, size_to_alloc)) {
mt_unlock();
ERR_FAIL_V_MSG(POOL_ALLOCATOR_INVALID_ID, "Memory can't be compacted further.");
}
}
EntryArrayPos new_entry_array_pos;
bool found_free_entry = get_free_entry(&new_entry_array_pos);
if (!found_free_entry) {
mt_unlock();
ERR_FAIL_V_MSG(POOL_ALLOCATOR_INVALID_ID, "No free entry found in PoolAllocator.");
}
/* move all entry indices up, make room for this one */
for (int i = entry_count; i > new_entry_indices_pos; i--) {
entry_indices[i] = entry_indices[i - 1];
}
entry_indices[new_entry_indices_pos] = new_entry_array_pos;
entry_count++;
Entry &entry = entry_array[entry_indices[new_entry_indices_pos]];
entry.len = p_size;
entry.pos = (new_entry_indices_pos == 0) ? 0 : entry_end(entry_array[entry_indices[new_entry_indices_pos - 1]]); //alloc either at beginning or end of previous
entry.lock = 0;
entry.check = (check_count++) & CHECK_MASK;
free_mem -= size_to_alloc;
if (free_mem < free_mem_peak) {
free_mem_peak = free_mem;
}
ID retval = (entry_indices[new_entry_indices_pos] << CHECK_BITS) | entry.check;
mt_unlock();
//ERR_FAIL_COND_V( (uintptr_t)get(retval)%align != 0, retval );
return retval;
}
PoolAllocator::Entry *PoolAllocator::get_entry(ID p_mem) {
unsigned int check = p_mem & CHECK_MASK;
int entry = p_mem >> CHECK_BITS;
ERR_FAIL_INDEX_V(entry, entry_max, nullptr);
ERR_FAIL_COND_V(entry_array[entry].check != check, nullptr);
ERR_FAIL_COND_V(entry_array[entry].len == 0, nullptr);
return &entry_array[entry];
}
const PoolAllocator::Entry *PoolAllocator::get_entry(ID p_mem) const {
unsigned int check = p_mem & CHECK_MASK;
int entry = p_mem >> CHECK_BITS;
ERR_FAIL_INDEX_V(entry, entry_max, nullptr);
ERR_FAIL_COND_V(entry_array[entry].check != check, nullptr);
ERR_FAIL_COND_V(entry_array[entry].len == 0, nullptr);
return &entry_array[entry];
}
void PoolAllocator::free(ID p_mem) {
mt_lock();
Entry *e = get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_PRINT("!e");
return;
}
if (e->lock) {
mt_unlock();
ERR_PRINT("e->lock");
return;
}
EntryIndicesPos entry_indices_pos;
bool index_found = find_entry_index(&entry_indices_pos, e);
if (!index_found) {
mt_unlock();
ERR_FAIL_COND(!index_found);
}
for (int i = entry_indices_pos; i < (entry_count - 1); i++) {
entry_indices[i] = entry_indices[i + 1];
}
entry_count--;
free_mem += aligned(e->len);
e->clear();
mt_unlock();
}
int PoolAllocator::get_size(ID p_mem) const {
int size;
mt_lock();
const Entry *e = get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_PRINT("!e");
return 0;
}
size = e->len;
mt_unlock();
return size;
}
Error PoolAllocator::resize(ID p_mem, int p_new_size) {
mt_lock();
Entry *e = get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_FAIL_COND_V(!e, ERR_INVALID_PARAMETER);
}
if (needs_locking && e->lock) {
mt_unlock();
ERR_FAIL_COND_V(e->lock, ERR_ALREADY_IN_USE);
}
uint32_t alloc_size = aligned(p_new_size);
if ((uint32_t)aligned(e->len) == alloc_size) {
e->len = p_new_size;
mt_unlock();
return OK;
} else if (e->len > (uint32_t)p_new_size) {
free_mem += aligned(e->len);
free_mem -= alloc_size;
e->len = p_new_size;
mt_unlock();
return OK;
}
//p_new_size = align(p_new_size)
int _free = free_mem; // - static_area_size;
if (uint32_t(_free + aligned(e->len)) < alloc_size) {
mt_unlock();
ERR_FAIL_V(ERR_OUT_OF_MEMORY);
}
EntryIndicesPos entry_indices_pos;
bool index_found = find_entry_index(&entry_indices_pos, e);
if (!index_found) {
mt_unlock();
ERR_FAIL_COND_V(!index_found, ERR_BUG);
}
//no need to move stuff around, it fits before the next block
uint32_t next_pos;
if (entry_indices_pos + 1 == entry_count) {
next_pos = pool_size; // - static_area_size;
} else {
next_pos = entry_array[entry_indices[entry_indices_pos + 1]].pos;
}
if ((next_pos - e->pos) > alloc_size) {
free_mem += aligned(e->len);
e->len = p_new_size;
free_mem -= alloc_size;
mt_unlock();
return OK;
}
//it doesn't fit, compact around BEFORE current index (make room behind)
compact(entry_indices_pos + 1);
if ((next_pos - e->pos) > alloc_size) {
//now fits! hooray!
free_mem += aligned(e->len);
e->len = p_new_size;
free_mem -= alloc_size;
mt_unlock();
if (free_mem < free_mem_peak) {
free_mem_peak = free_mem;
}
return OK;
}
//STILL doesn't fit, compact around AFTER current index (make room after)
compact_up(entry_indices_pos + 1);
if ((entry_array[entry_indices[entry_indices_pos + 1]].pos - e->pos) > alloc_size) {
//now fits! hooray!
free_mem += aligned(e->len);
e->len = p_new_size;
free_mem -= alloc_size;
mt_unlock();
if (free_mem < free_mem_peak) {
free_mem_peak = free_mem;
}
return OK;
}
mt_unlock();
ERR_FAIL_V(ERR_OUT_OF_MEMORY);
}
Error PoolAllocator::lock(ID p_mem) {
if (!needs_locking) {
return OK;
}
mt_lock();
Entry *e = get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_PRINT("!e");
return ERR_INVALID_PARAMETER;
}
e->lock++;
mt_unlock();
return OK;
}
bool PoolAllocator::is_locked(ID p_mem) const {
if (!needs_locking) {
return false;
}
mt_lock();
const Entry *e = ((PoolAllocator *)(this))->get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_PRINT("!e");
return false;
}
bool locked = e->lock;
mt_unlock();
return locked;
}
const void *PoolAllocator::get(ID p_mem) const {
if (!needs_locking) {
const Entry *e = get_entry(p_mem);
ERR_FAIL_COND_V(!e, nullptr);
return &pool[e->pos];
}
mt_lock();
const Entry *e = get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_FAIL_COND_V(!e, nullptr);
}
if (e->lock == 0) {
mt_unlock();
ERR_PRINT("e->lock == 0");
return nullptr;
}
if ((int)e->pos >= pool_size) {
mt_unlock();
ERR_PRINT("e->pos<0 || e->pos>=pool_size");
return nullptr;
}
const void *ptr = &pool[e->pos];
mt_unlock();
return ptr;
}
void *PoolAllocator::get(ID p_mem) {
if (!needs_locking) {
Entry *e = get_entry(p_mem);
ERR_FAIL_COND_V(!e, nullptr);
return &pool[e->pos];
}
mt_lock();
Entry *e = get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_FAIL_COND_V(!e, nullptr);
}
if (e->lock == 0) {
//assert(0);
mt_unlock();
ERR_PRINT("e->lock == 0");
return nullptr;
}
if ((int)e->pos >= pool_size) {
mt_unlock();
ERR_PRINT("e->pos<0 || e->pos>=pool_size");
return nullptr;
}
void *ptr = &pool[e->pos];
mt_unlock();
return ptr;
}
void PoolAllocator::unlock(ID p_mem) {
if (!needs_locking) {
return;
}
mt_lock();
Entry *e = get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_FAIL_COND(!e);
}
if (e->lock == 0) {
mt_unlock();
ERR_PRINT("e->lock == 0");
return;
}
e->lock--;
mt_unlock();
}
int PoolAllocator::get_used_mem() const {
return pool_size - free_mem;
}
int PoolAllocator::get_free_peak() {
return free_mem_peak;
}
int PoolAllocator::get_free_mem() {
return free_mem;
}
void PoolAllocator::create_pool(void *p_mem, int p_size, int p_max_entries) {
pool = (uint8_t *)p_mem;
pool_size = p_size;
entry_array = memnew_arr(Entry, p_max_entries);
entry_indices = memnew_arr(int, p_max_entries);
entry_max = p_max_entries;
entry_count = 0;
free_mem = p_size;
free_mem_peak = p_size;
check_count = 0;
}
PoolAllocator::PoolAllocator(int p_size, bool p_needs_locking, int p_max_entries) {
mem_ptr = memalloc(p_size);
ERR_FAIL_COND(!mem_ptr);
align = 1;
create_pool(mem_ptr, p_size, p_max_entries);
needs_locking = p_needs_locking;
}
PoolAllocator::PoolAllocator(void *p_mem, int p_size, int p_align, bool p_needs_locking, int p_max_entries) {
if (p_align > 1) {
uint8_t *mem8 = (uint8_t *)p_mem;
uint64_t ofs = (uint64_t)mem8;
if (ofs % p_align) {
int dif = p_align - (ofs % p_align);
mem8 += p_align - (ofs % p_align);
p_size -= dif;
p_mem = (void *)mem8;
}
}
create_pool(p_mem, p_size, p_max_entries);
needs_locking = p_needs_locking;
align = p_align;
mem_ptr = nullptr;
}
PoolAllocator::PoolAllocator(int p_align, int p_size, bool p_needs_locking, int p_max_entries) {
ERR_FAIL_COND(p_align < 1);
mem_ptr = Memory::alloc_static(p_size + p_align, true);
uint8_t *mem8 = (uint8_t *)mem_ptr;
uint64_t ofs = (uint64_t)mem8;
if (ofs % p_align) {
mem8 += p_align - (ofs % p_align);
}
create_pool(mem8, p_size, p_max_entries);
needs_locking = p_needs_locking;
align = p_align;
}
PoolAllocator::~PoolAllocator() {
if (mem_ptr) {
memfree(mem_ptr);
}
memdelete_arr(entry_array);
memdelete_arr(entry_indices);
}