forked from 0ad/0ad
janwas
ee4c7965dd
* app_hooks: add display_error; can be used by atlas to override our dialog box * lots of small fixes (mostly pertaining to headers) * debug: clean up display_error, protect from reentrancy, fix a few edge cases (e.g. error message from dtor -> exit pressed -> suppress all subsequent errors) * delay_load: add warning: NLSO ctors are unreliable since we're compiling into static lib This was SVN commit r4009.
456 lines
13 KiB
C++
456 lines
13 KiB
C++
/**
|
|
* =========================================================================
|
|
* File : allocators.h
|
|
* Project : 0 A.D.
|
|
* Description : memory suballocators.
|
|
*
|
|
* @author Jan.Wassenberg@stud.uni-karlsruhe.de
|
|
* =========================================================================
|
|
*/
|
|
|
|
/*
|
|
* Copyright (c) 2005 Jan Wassenberg
|
|
*
|
|
* Redistribution and/or modification are also permitted under the
|
|
* terms of the GNU General Public License as published by the
|
|
* Free Software Foundation (version 2 or later, at your option).
|
|
*
|
|
* This program 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.
|
|
*/
|
|
|
|
#ifndef ALLOCATORS_H__
|
|
#define ALLOCATORS_H__
|
|
|
|
#include <map>
|
|
|
|
#include "lib/types.h"
|
|
#include "lib/sysdep/cpu.h" // CAS
|
|
#include "lib/posix.h" // PROT_* constants for da_set_prot
|
|
|
|
//
|
|
// page aligned allocator
|
|
//
|
|
|
|
// allocates memory aligned to the system page size.
|
|
//
|
|
// this is useful for file_buf_alloc, which uses this allocator to
|
|
// get sector-aligned (hopefully; see file_sector_size) IO buffers.
|
|
//
|
|
// note that this allocator is stateless and very litte error checking
|
|
// can be performed.
|
|
|
|
// returns at least unaligned_size bytes of page-aligned memory.
|
|
// it defaults to read/writable; you can mprotect it if desired.
|
|
extern void* page_aligned_alloc(size_t unaligned_size);
|
|
|
|
// free a previously allocated region. must be passed the exact values
|
|
// passed to/returned from page_aligned_malloc.
|
|
extern void page_aligned_free(void* p, size_t unaligned_size);
|
|
|
|
|
|
//
|
|
// dynamic (expandable) array
|
|
//
|
|
|
|
// provides a memory range that can be expanded but doesn't waste
|
|
// physical memory or relocate itself. building block for other allocators.
|
|
|
|
struct DynArray
|
|
{
|
|
u8* base;
|
|
size_t max_size_pa; // reserved
|
|
size_t cur_size; // committed
|
|
|
|
int prot; // applied to newly committed pages
|
|
|
|
size_t pos;
|
|
};
|
|
|
|
|
|
// ready the DynArray object for use. preallocates max_size bytes
|
|
// (rounded up to the next page size multiple) of address space for the
|
|
// array; it can never grow beyond this.
|
|
// no virtual memory is actually committed until calls to da_set_size.
|
|
extern LibError da_alloc(DynArray* da, size_t max_size);
|
|
|
|
// free all memory (address space + physical) that constitutes the
|
|
// given array. use-after-free is impossible because the memory is
|
|
// marked not-present via MMU. also zeroes the contents of <da>.
|
|
extern LibError da_free(DynArray* da);
|
|
|
|
// expand or shrink the array: changes the amount of currently committed
|
|
// (i.e. usable) memory pages. pages are added/removed until
|
|
// new_size (rounded up to the next page size multiple) is met.
|
|
extern LibError da_set_size(DynArray* da, size_t new_size);
|
|
|
|
// make sure at least <size> bytes starting at <pos> are committed and
|
|
// ready for use.
|
|
extern LibError da_reserve(DynArray* da, size_t size);
|
|
|
|
// change access rights of the array memory; used to implement
|
|
// write-protection. affects the currently committed pages as well as
|
|
// all subsequently added pages.
|
|
// prot can be a combination of the PROT_* values used with mprotect.
|
|
extern LibError da_set_prot(DynArray* da, int prot);
|
|
|
|
// "wrap" (i.e. store information about) the given buffer in a
|
|
// DynArray object, preparing it for use with da_read or da_append.
|
|
// da_free should be called when the DynArray is no longer needed,
|
|
// even though it doesn't free this memory (but does zero the DynArray).
|
|
extern LibError da_wrap_fixed(DynArray* da, u8* p, size_t size);
|
|
|
|
// "read" from array, i.e. copy into the given buffer.
|
|
// starts at offset DynArray.pos and advances this.
|
|
extern LibError da_read(DynArray* da, void* data_dst, size_t size);
|
|
|
|
// "write" to array, i.e. copy from the given buffer.
|
|
// starts at offset DynArray.pos and advances this.
|
|
extern LibError da_append(DynArray* da, const void* data_src, size_t size);
|
|
|
|
|
|
|
|
//
|
|
// pool allocator
|
|
//
|
|
|
|
// design parameters:
|
|
// - O(1) alloc and free;
|
|
// - fixed- XOR variable-sized blocks;
|
|
// - doesn't preallocate the entire pool;
|
|
// - returns sequential addresses.
|
|
|
|
// opaque! do not read/write any fields!
|
|
struct Pool
|
|
{
|
|
DynArray da;
|
|
|
|
// size of elements. = 0 if pool set up for variable-sized
|
|
// elements, otherwise rounded up to pool alignment.
|
|
size_t el_size;
|
|
|
|
// pointer to freelist (opaque); see freelist_*.
|
|
// never used (remains 0) if elements are of variable size.
|
|
void* freelist;
|
|
};
|
|
|
|
// pass as pool_create's <el_size> param to indicate variable-sized allocs
|
|
// are required (see below).
|
|
const size_t POOL_VARIABLE_ALLOCS = ~0u;
|
|
|
|
// ready <p> for use. <max_size> is the upper limit [bytes] on
|
|
// pool size (this is how much address space is reserved).
|
|
//
|
|
// <el_size> can be 0 to allow variable-sized allocations
|
|
// (which cannot be freed individually);
|
|
// otherwise, it specifies the number of bytes that will be
|
|
// returned by pool_alloc (whose size parameter is then ignored).
|
|
extern LibError pool_create(Pool* p, size_t max_size, size_t el_size);
|
|
|
|
// free all memory that ensued from <p>. all elements are made unusable
|
|
// (it doesn't matter if they were "allocated" or in freelist or unused);
|
|
// future alloc and free calls on this pool will fail.
|
|
extern LibError pool_destroy(Pool* p);
|
|
|
|
// indicate whether <el> was allocated from the given pool.
|
|
// this is useful for callers that use several types of allocators.
|
|
extern bool pool_contains(Pool* p, void* el);
|
|
|
|
// return an entry from the pool, or 0 if it would have to be expanded and
|
|
// there isn't enough memory to do so.
|
|
// exhausts the freelist before returning new entries to improve locality.
|
|
//
|
|
// if the pool was set up with fixed-size elements, <size> is ignored;
|
|
// otherwise, <size> bytes are allocated.
|
|
extern void* pool_alloc(Pool* p, size_t size);
|
|
|
|
// make <el> available for reuse in the given Pool.
|
|
//
|
|
// this is not allowed if created for variable-size elements.
|
|
// rationale: avoids having to pass el_size here and compare with size when
|
|
// allocating; also prevents fragmentation and leaking memory.
|
|
extern void pool_free(Pool* p, void* el);
|
|
|
|
// "free" all allocations that ensued from the given Pool.
|
|
// this resets it as if freshly pool_create-d, but doesn't release the
|
|
// underlying memory.
|
|
extern void pool_free_all(Pool* p);
|
|
|
|
|
|
//
|
|
// bucket allocator
|
|
//
|
|
|
|
// design goals:
|
|
// - fixed- XOR variable-sized blocks;
|
|
// - allow freeing individual blocks if they are all fixed-size;
|
|
// - never relocates;
|
|
// - no fixed limit.
|
|
|
|
// note: this type of allocator is called "region-based" in the literature.
|
|
// see "Reconsidering Custom Memory Allocation" (Berger, Zorn, McKinley).
|
|
// if individual variable-size elements must be freeable, consider "reaps":
|
|
// basically a combination of region and heap, where frees go to the heap and
|
|
// allocs exhaust that memory first and otherwise use the region.
|
|
|
|
// opaque! do not read/write any fields!
|
|
struct Bucket
|
|
{
|
|
// currently open bucket.
|
|
u8* bucket;
|
|
|
|
// offset of free space at end of current bucket (i.e. # bytes in use).
|
|
size_t pos;
|
|
|
|
void* freelist;
|
|
|
|
size_t el_size : 16;
|
|
|
|
// records # buckets allocated; verifies the list of buckets is correct.
|
|
uint num_buckets : 16;
|
|
};
|
|
|
|
|
|
// ready <b> for use.
|
|
//
|
|
// <el_size> can be 0 to allow variable-sized allocations
|
|
// (which cannot be freed individually);
|
|
// otherwise, it specifies the number of bytes that will be
|
|
// returned by bucket_alloc (whose size parameter is then ignored).
|
|
extern LibError bucket_create(Bucket* b, size_t el_size);
|
|
|
|
// free all memory that ensued from <b>.
|
|
// future alloc and free calls on this Bucket will fail.
|
|
extern void bucket_destroy(Bucket* b);
|
|
|
|
// return an entry from the bucket, or 0 if another would have to be
|
|
// allocated and there isn't enough memory to do so.
|
|
// exhausts the freelist before returning new entries to improve locality.
|
|
//
|
|
// if the bucket was set up with fixed-size elements, <size> is ignored;
|
|
// otherwise, <size> bytes are allocated.
|
|
extern void* bucket_alloc(Bucket* b, size_t size);
|
|
|
|
// make <el> available for reuse in <b>.
|
|
//
|
|
// this is not allowed if created for variable-size elements.
|
|
// rationale: avoids having to pass el_size here and compare with size when
|
|
// allocating; also prevents fragmentation and leaking memory.
|
|
extern void bucket_free(Bucket* b, void* el);
|
|
|
|
|
|
//
|
|
// matrix allocator
|
|
//
|
|
|
|
// takes care of the dirty work of allocating 2D matrices:
|
|
// - aligns data
|
|
// - only allocates one memory block, which is more efficient than
|
|
// malloc/new for each row.
|
|
|
|
// allocate a 2D cols x rows matrix of <el_size> byte cells.
|
|
// this must be freed via matrix_free. returns 0 if out of memory.
|
|
//
|
|
// the returned pointer should be cast to the target type (e.g. int**) and
|
|
// can then be accessed by matrix[col][row].
|
|
//
|
|
extern void** matrix_alloc(uint cols, uint rows, size_t el_size);
|
|
|
|
// free the given matrix (allocated by matrix_alloc). no-op if matrix == 0.
|
|
// callers will likely want to pass variables of a different type
|
|
// (e.g. int**); they must be cast to void**.
|
|
extern void matrix_free(void** matrix);
|
|
|
|
|
|
//
|
|
// allocator optimized for single instances
|
|
//
|
|
|
|
// intended for applications that frequently alloc/free a single
|
|
// fixed-size object. caller provides static storage and an in-use flag;
|
|
// we use that memory if available and otherwise fall back to the heap.
|
|
// if the application only has one object in use at a time, malloc is
|
|
// avoided; this is faster and avoids heap fragmentation.
|
|
//
|
|
// thread-safe.
|
|
|
|
extern void* single_calloc(void* storage, volatile uintptr_t* in_use_flag, size_t size);
|
|
|
|
extern void single_free(void* storage, volatile uintptr_t* in_use_flag, void* p);
|
|
|
|
// C++ wrapper
|
|
#ifdef __cplusplus
|
|
|
|
// T must be POD (Plain Old Data) because it is memset to 0!
|
|
template<class T> class SingleAllocator
|
|
{
|
|
T storage;
|
|
volatile uintptr_t is_in_use;
|
|
|
|
public:
|
|
SingleAllocator()
|
|
{
|
|
is_in_use = 0;
|
|
}
|
|
|
|
T* alloc()
|
|
{
|
|
return (T*)single_calloc(&storage, &is_in_use, sizeof(storage));
|
|
}
|
|
|
|
void release(T* p)
|
|
{
|
|
single_free(&storage, &is_in_use, p);
|
|
}
|
|
};
|
|
|
|
#endif // #ifdef __cplusplus
|
|
|
|
|
|
//
|
|
// overrun protection
|
|
//
|
|
|
|
/*
|
|
OverrunProtector wraps an arbitrary object in DynArray memory and can detect
|
|
inadvertent writes to it. this is useful for tracking down memory overruns.
|
|
|
|
the basic idea is to require users to request access to the object and
|
|
notify us when done; memory access permission is temporarily granted.
|
|
(similar in principle to Software Transaction Memory).
|
|
|
|
since this is quite slow, the protection is disabled unless
|
|
CONFIG_OVERRUN_PROTECTION == 1; this avoids having to remove the
|
|
wrapper code in release builds and re-write when looking for overruns.
|
|
|
|
example usage:
|
|
OverrunProtector<your_class> your_class_wrapper;
|
|
..
|
|
your_class* yc = your_class_wrapper.get(); // unlock, make ready for use
|
|
if(!yc) // your_class_wrapper's one-time alloc of a your_class-
|
|
abort(); // instance had failed - can't continue.
|
|
doSomethingWith(yc); // read/write access
|
|
your_class_wrapper.lock(); // disallow further access until next .get()
|
|
..
|
|
*/
|
|
|
|
template<class T> class OverrunProtector
|
|
{
|
|
DynArray da;
|
|
T* cached_ptr;
|
|
uintptr_t initialized;
|
|
|
|
public:
|
|
OverrunProtector()
|
|
{
|
|
memset(&da, 0, sizeof(da));
|
|
cached_ptr = 0;
|
|
initialized = 0;
|
|
}
|
|
|
|
~OverrunProtector()
|
|
{
|
|
shutdown();
|
|
}
|
|
|
|
void lock()
|
|
{
|
|
#if CONFIG_OVERRUN_PROTECTION
|
|
da_set_prot(&da, PROT_NONE);
|
|
#endif
|
|
}
|
|
|
|
private:
|
|
void unlock()
|
|
{
|
|
#if CONFIG_OVERRUN_PROTECTION
|
|
da_set_prot(&da, PROT_READ|PROT_WRITE);
|
|
#endif
|
|
}
|
|
|
|
void init()
|
|
{
|
|
if(da_alloc(&da, sizeof(T)) < 0)
|
|
{
|
|
fail:
|
|
WARN_ERR(ERR_NO_MEM);
|
|
return;
|
|
}
|
|
if(da_set_size(&da, sizeof(T)) < 0)
|
|
goto fail;
|
|
|
|
#include "nommgr.h"
|
|
cached_ptr = new(da.base) T();
|
|
#include "mmgr.h"
|
|
lock();
|
|
}
|
|
|
|
void shutdown()
|
|
{
|
|
if(!CAS(&initialized, 1, 2))
|
|
return; // never initialized or already shut down - abort
|
|
unlock();
|
|
cached_ptr->~T(); // call dtor (since we used placement new)
|
|
cached_ptr = 0;
|
|
(void)da_free(&da);
|
|
}
|
|
|
|
public:
|
|
T* get()
|
|
{
|
|
// this could theoretically be done in the ctor, but we try to
|
|
// minimize non-trivial code at NLSO ctor time
|
|
// (avoids init order problems).
|
|
if(CAS(&initialized, 0, 1))
|
|
init();
|
|
debug_assert(initialized != 2 && "OverrunProtector: used after dtor called:");
|
|
unlock();
|
|
return cached_ptr;
|
|
}
|
|
};
|
|
|
|
|
|
//
|
|
// allocator test rig
|
|
//
|
|
|
|
// call for each allocator operation to sanity-check them.
|
|
// should only be used during debug mode due to serious overhead.
|
|
class AllocatorChecker
|
|
{
|
|
public:
|
|
void notify_alloc(void* p, size_t size)
|
|
{
|
|
const Allocs::value_type item = std::make_pair(p, size);
|
|
std::pair<Allocs::iterator, bool> ret = allocs.insert(item);
|
|
debug_assert(ret.second == true); // wasn't already in map
|
|
}
|
|
|
|
void notify_free(void* p, size_t size)
|
|
{
|
|
Allocs::iterator it = allocs.find(p);
|
|
if(it == allocs.end())
|
|
debug_warn("AllocatorChecker: freeing invalid pointer");
|
|
else
|
|
{
|
|
// size must match what was passed to notify_alloc
|
|
const size_t allocated_size = it->second;
|
|
debug_assert(size == allocated_size);
|
|
|
|
allocs.erase(it);
|
|
}
|
|
}
|
|
|
|
void notify_clear()
|
|
{
|
|
allocs.clear();
|
|
}
|
|
|
|
private:
|
|
typedef std::map<void*, size_t> Allocs;
|
|
Allocs allocs;
|
|
};
|
|
|
|
#endif // #ifndef ALLOCATORS_H__
|