godot/core/pool_allocator.cpp
Rémi Verschelde 1426cd3b3a
One Copyright Update to rule them all
As many open source projects have started doing it, we're removing the
current year from the copyright notice, so that we don't need to bump
it every year.

It seems like only the first year of publication is technically
relevant for copyright notices, and even that seems to be something
that many companies stopped listing altogether (in a version controlled
codebase, the commits are a much better source of date of publication
than a hardcoded copyright statement).

We also now list Godot Engine contributors first as we're collectively
the current maintainers of the project, and we clarify that the
"exclusive" copyright of the co-founders covers the timespan before
opensourcing (their further contributions are included as part of Godot
Engine contributors).

Also fixed "cf." Frenchism - it's meant as "refer to / see".

Backported from #70885.
2023-01-10 15:26:54 +01:00

587 lines
14 KiB
C++

/**************************************************************************/
/* pool_allocator.cpp */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* 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_macros.h"
#include "core/os/memory.h"
#include "core/os/os.h"
#include "core/print_string.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]; \
memmove(_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);
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) {
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);
}