Panda3D
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An implementation of a very simple block allocator. More...
#include "simpleAllocator.h"
Public Member Functions | |
SimpleAllocator (size_t max_size, Mutex &lock) | |
SimpleAllocatorBlock * | alloc (size_t size) |
Allocates a new block. | |
size_t | get_contiguous () const |
Returns an upper-bound estimate of the size of the largest contiguous block that may be allocated. | |
SimpleAllocatorBlock * | get_first_block () const |
Returns a pointer to the first allocated block, or NULL if there are no allocated blocks. | |
size_t | get_max_size () const |
Returns the available space for allocated objects. | |
size_t | get_total_size () const |
Returns the total size of allocated objects. | |
bool | is_empty () const |
Returns true if there are no blocks allocated on this page, or false if there is at least one. | |
void | output (ostream &out) const |
void | set_max_size (size_t max_size) |
Changes the available space for allocated objects. | |
void | write (ostream &out) const |
Protected Member Functions | |
virtual void | changed_contiguous () |
This callback function is made whenever the estimate of contiguous available space changes, either through an alloc or free. | |
SimpleAllocatorBlock * | do_alloc (size_t size) |
Allocates a new block. | |
bool | do_is_empty () const |
Returns true if there are no blocks allocated on this page, or false if there is at least one. | |
void | insert_after (LinkedListNode *node) |
Adds a LinkedListNode record after the indicated node in the doubly-linked list. | |
void | insert_before (LinkedListNode *node) |
Adds a LinkedListNode record before the indicated node in the doubly-linked list. | |
bool | is_on_list () const |
Returns true if the node is member of any list, false if it has been removed or never added. | |
virtual SimpleAllocatorBlock * | make_block (size_t start, size_t size) |
Creates a new SimpleAllocatorBlock object. | |
void | mark_contiguous (const LinkedListNode *block) |
Some space has been made available following the indicated block. | |
void | remove_from_list () |
Removes a LinkedListNode record from the doubly-linked list. | |
void | take_list_from (LinkedListNode *other_root) |
Given that this LinkedListNode represents the root of a list, and the other pointer represents the root of a different list, move all of the nodes (except the root itself) from other_root onto this list. | |
Protected Attributes | |
size_t | _contiguous |
Mutex & | _lock |
size_t | _max_size |
LinkedListNode * | _next |
LinkedListNode * | _prev |
size_t | _total_size |
Friends | |
class | SimpleAllocatorBlock |
An implementation of a very simple block allocator.
This class can allocate ranges of nonnegative integers within a specified upper limit; it uses a simple first-fit algorithm to find the next available space.
Definition at line 33 of file simpleAllocator.h.
SimpleAllocatorBlock * SimpleAllocator::alloc | ( | size_t | size | ) | [inline] |
Allocates a new block.
Returns NULL if a block of the requested size cannot be allocated.
To free the allocated block, call block->free(), or simply delete the block pointer.
Reimplemented in VertexDataPage.
Definition at line 41 of file simpleAllocator.I.
References do_alloc().
void SimpleAllocator::changed_contiguous | ( | ) | [protected, virtual] |
This callback function is made whenever the estimate of contiguous available space changes, either through an alloc or free.
The lock will be held.
Reimplemented in VertexDataPage.
Definition at line 177 of file simpleAllocator.cxx.
Referenced by do_alloc(), and mark_contiguous().
SimpleAllocatorBlock * SimpleAllocator::do_alloc | ( | size_t | size | ) | [protected] |
Allocates a new block.
Returns NULL if a block of the requested size cannot be allocated.
To free the allocated block, call block->free(), or simply delete the block pointer.
Assumes the lock is already held.
Definition at line 78 of file simpleAllocator.cxx.
References changed_contiguous(), SimpleAllocatorBlock::get_allocator(), LinkedListNode::insert_before(), and make_block().
Referenced by alloc().
bool SimpleAllocator::do_is_empty | ( | ) | const [inline, protected] |
Returns true if there are no blocks allocated on this page, or false if there is at least one.
Assumes the lock is already held.
Definition at line 130 of file simpleAllocator.I.
Referenced by VertexDataPage::changed_contiguous(), and is_empty().
size_t SimpleAllocator::get_contiguous | ( | ) | const [inline] |
Returns an upper-bound estimate of the size of the largest contiguous block that may be allocated.
It is guaranteed that an attempt to allocate a block larger than this will fail, though it is not guaranteed that an attempt to allocate a block this size or smaller will succeed.
Definition at line 104 of file simpleAllocator.I.
SimpleAllocatorBlock * SimpleAllocator::get_first_block | ( | ) | const [inline] |
Returns a pointer to the first allocated block, or NULL if there are no allocated blocks.
Reimplemented in VertexDataPage.
Definition at line 116 of file simpleAllocator.I.
size_t SimpleAllocator::get_max_size | ( | ) | const [inline] |
Returns the available space for allocated objects.
Definition at line 75 of file simpleAllocator.I.
size_t SimpleAllocator::get_total_size | ( | ) | const [inline] |
Returns the total size of allocated objects.
Definition at line 64 of file simpleAllocator.I.
Referenced by VertexDataSaveFile::get_used_file_size().
void LinkedListNode::insert_after | ( | LinkedListNode * | node | ) | [inline, protected, inherited] |
Adds a LinkedListNode record after the indicated node in the doubly-linked list.
Definition at line 108 of file linkedListNode.I.
void LinkedListNode::insert_before | ( | LinkedListNode * | node | ) | [inline, protected, inherited] |
Adds a LinkedListNode record before the indicated node in the doubly-linked list.
Definition at line 91 of file linkedListNode.I.
Referenced by do_alloc(), AdaptiveLru::do_partial_lru_update(), and SimpleLruPage::enqueue_lru().
bool SimpleAllocator::is_empty | ( | ) | const [inline] |
Returns true if there are no blocks allocated on this page, or false if there is at least one.
Definition at line 53 of file simpleAllocator.I.
References do_is_empty().
bool LinkedListNode::is_on_list | ( | ) | const [inline, protected, inherited] |
Returns true if the node is member of any list, false if it has been removed or never added.
The head of a list generally appears to to always be a member of itself.
Definition at line 62 of file linkedListNode.I.
SimpleAllocatorBlock * SimpleAllocator::make_block | ( | size_t | start, |
size_t | size | ||
) | [protected, virtual] |
Creates a new SimpleAllocatorBlock object.
Override this function to specialize the block type returned.
Reimplemented in VertexDataPage, and VertexDataSaveFile.
Definition at line 165 of file simpleAllocator.cxx.
Referenced by do_alloc().
void SimpleAllocator::mark_contiguous | ( | const LinkedListNode * | block | ) | [inline, protected] |
Some space has been made available following the indicated block.
Increase the contiguous space accordingly.
Assumes the lock is already held.
Definition at line 144 of file simpleAllocator.I.
References changed_contiguous().
Referenced by SimpleAllocatorBlock::do_free(), and SimpleAllocatorBlock::do_realloc().
void LinkedListNode::remove_from_list | ( | ) | [inline, protected, inherited] |
Removes a LinkedListNode record from the doubly-linked list.
Definition at line 73 of file linkedListNode.I.
Referenced by SimpleLruPage::dequeue_lru(), SimpleAllocatorBlock::do_free(), AdaptiveLru::do_partial_lru_update(), and SimpleLruPage::enqueue_lru().
void SimpleAllocator::set_max_size | ( | size_t | max_size | ) | [inline] |
Changes the available space for allocated objects.
This will not affect any already-allocated objects, but will have an effect on future calls to alloc().
Definition at line 88 of file simpleAllocator.I.
void LinkedListNode::take_list_from | ( | LinkedListNode * | other_root | ) | [inline, protected, inherited] |
Given that this LinkedListNode represents the root of a list, and the other pointer represents the root of a different list, move all of the nodes (except the root itself) from other_root onto this list.
Definition at line 127 of file linkedListNode.I.
Referenced by BufferContextChain::take_from().