godot/core/pool_allocator.cpp
Thaer Razeq f50488a361 Various fixes detected using PVS-Studio static analyzer.
- Add FIXME tags comments to some unfixed potential bugs
- Remove some checks (always false: unsigned never < 0)
- Fix some if statements based on reviews.
- Bunch of missing `else` statements
2017-02-28 07:52:02 -06:00

661 lines
14 KiB
C++

/*************************************************************************/
/* pool_allocator.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 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 "error_macros.h"
#include "core/os/os.h"
#include "os/memory.h"
#include "os/copymem.h"
#include "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;
/* detemine 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 entrys, 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_PRINT("memory can't be compacted further");
return POOL_ALLOCATOR_INVALID_ID;
}
}
EntryArrayPos new_entry_array_pos;
bool found_free_entry=get_free_entry(&new_entry_array_pos);
if (!found_free_entry) {
mt_unlock();
ERR_FAIL_COND_V( !found_free_entry , POOL_ALLOCATOR_INVALID_ID );
}
/* 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 begining 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,NULL);
ERR_FAIL_COND_V(entry_array[entry].check!=check,NULL);
ERR_FAIL_COND_V(entry_array[entry].len==0,NULL);
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,NULL);
ERR_FAIL_COND_V(entry_array[entry].check!=check,NULL);
ERR_FAIL_COND_V(entry_array[entry].len==0,NULL);
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);
}
int alloc_size = aligned(p_new_size);
if (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 ((_free + aligned(e->len)) - alloc_size < 0) {
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
int 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,NULL);
return &pool[e->pos];
}
mt_lock();
const Entry *e=get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_FAIL_COND_V(!e,NULL);
}
if (e->lock==0) {
mt_unlock();
ERR_PRINT( "e->lock == 0" );
return NULL;
}
if ((int)e->pos>=pool_size) {
mt_unlock();
ERR_PRINT("e->pos<0 || e->pos>=pool_size");
return NULL;
}
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);
if (!e) {
ERR_FAIL_COND_V(!e,NULL);
};
return &pool[e->pos];
}
mt_lock();
Entry *e=get_entry(p_mem);
if (!e) {
mt_unlock();
ERR_FAIL_COND_V(!e,NULL);
}
if (e->lock==0) {
//assert(0);
mt_unlock();
ERR_PRINT( "e->lock == 0" );
return NULL;
}
if ((int)e->pos>=pool_size) {
mt_unlock();
ERR_PRINT("e->pos<0 || e->pos>=pool_size");
return NULL;
}
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->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=NULL;
}
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,"PoolAllocator()");
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 );
}