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			700 lines
		
	
	
	
		
			27 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef Py_INTERNAL_OBMALLOC_H
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| #define Py_INTERNAL_OBMALLOC_H
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| #ifdef __cplusplus
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| extern "C" {
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| #endif
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| 
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| #ifndef Py_BUILD_CORE
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| #  error "this header requires Py_BUILD_CORE define"
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| #endif
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| 
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| 
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| typedef unsigned int pymem_uint;  /* assuming >= 16 bits */
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| 
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| #undef  uint
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| #define uint pymem_uint
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| 
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| 
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| /* An object allocator for Python.
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| 
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|    Here is an introduction to the layers of the Python memory architecture,
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|    showing where the object allocator is actually used (layer +2), It is
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|    called for every object allocation and deallocation (PyObject_New/Del),
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|    unless the object-specific allocators implement a proprietary allocation
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|    scheme (ex.: ints use a simple free list). This is also the place where
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|    the cyclic garbage collector operates selectively on container objects.
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| 
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| 
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|     Object-specific allocators
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|     _____   ______   ______       ________
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|    [ int ] [ dict ] [ list ] ... [ string ]       Python core         |
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| +3 | <----- Object-specific memory -----> | <-- Non-object memory --> |
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|     _______________________________       |                           |
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|    [   Python's object allocator   ]      |                           |
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| +2 | ####### Object memory ####### | <------ Internal buffers ------> |
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|     ______________________________________________________________    |
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|    [          Python's raw memory allocator (PyMem_ API)          ]   |
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| +1 | <----- Python memory (under PyMem manager's control) ------> |   |
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|     __________________________________________________________________
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|    [    Underlying general-purpose allocator (ex: C library malloc)   ]
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|  0 | <------ Virtual memory allocated for the python process -------> |
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| 
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|    =========================================================================
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|     _______________________________________________________________________
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|    [                OS-specific Virtual Memory Manager (VMM)               ]
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| -1 | <--- Kernel dynamic storage allocation & management (page-based) ---> |
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|     __________________________________   __________________________________
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|    [                                  ] [                                  ]
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| -2 | <-- Physical memory: ROM/RAM --> | | <-- Secondary storage (swap) --> |
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| 
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| */
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| /*==========================================================================*/
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| 
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| /* A fast, special-purpose memory allocator for small blocks, to be used
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|    on top of a general-purpose malloc -- heavily based on previous art. */
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| 
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| /* Vladimir Marangozov -- August 2000 */
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| 
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| /*
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|  * "Memory management is where the rubber meets the road -- if we do the wrong
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|  * thing at any level, the results will not be good. And if we don't make the
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|  * levels work well together, we are in serious trouble." (1)
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|  *
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|  * (1) Paul R. Wilson, Mark S. Johnstone, Michael Neely, and David Boles,
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|  *    "Dynamic Storage Allocation: A Survey and Critical Review",
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|  *    in Proc. 1995 Int'l. Workshop on Memory Management, September 1995.
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|  */
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| 
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| /* #undef WITH_MEMORY_LIMITS */         /* disable mem limit checks  */
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| 
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| /*==========================================================================*/
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| 
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| /*
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|  * Allocation strategy abstract:
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|  *
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|  * For small requests, the allocator sub-allocates <Big> blocks of memory.
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|  * Requests greater than SMALL_REQUEST_THRESHOLD bytes are routed to the
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|  * system's allocator.
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|  *
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|  * Small requests are grouped in size classes spaced 8 bytes apart, due
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|  * to the required valid alignment of the returned address. Requests of
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|  * a particular size are serviced from memory pools of 4K (one VMM page).
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|  * Pools are fragmented on demand and contain free lists of blocks of one
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|  * particular size class. In other words, there is a fixed-size allocator
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|  * for each size class. Free pools are shared by the different allocators
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|  * thus minimizing the space reserved for a particular size class.
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|  *
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|  * This allocation strategy is a variant of what is known as "simple
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|  * segregated storage based on array of free lists". The main drawback of
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|  * simple segregated storage is that we might end up with lot of reserved
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|  * memory for the different free lists, which degenerate in time. To avoid
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|  * this, we partition each free list in pools and we share dynamically the
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|  * reserved space between all free lists. This technique is quite efficient
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|  * for memory intensive programs which allocate mainly small-sized blocks.
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|  *
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|  * For small requests we have the following table:
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|  *
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|  * Request in bytes     Size of allocated block      Size class idx
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|  * ----------------------------------------------------------------
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|  *        1-8                     8                       0
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|  *        9-16                   16                       1
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|  *       17-24                   24                       2
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|  *       25-32                   32                       3
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|  *       33-40                   40                       4
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|  *       41-48                   48                       5
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|  *       49-56                   56                       6
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|  *       57-64                   64                       7
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|  *       65-72                   72                       8
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|  *        ...                   ...                     ...
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|  *      497-504                 504                      62
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|  *      505-512                 512                      63
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|  *
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|  *      0, SMALL_REQUEST_THRESHOLD + 1 and up: routed to the underlying
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|  *      allocator.
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|  */
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| 
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| /*==========================================================================*/
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| 
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| /*
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|  * -- Main tunable settings section --
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|  */
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| 
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| /*
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|  * Alignment of addresses returned to the user. 8-bytes alignment works
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|  * on most current architectures (with 32-bit or 64-bit address buses).
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|  * The alignment value is also used for grouping small requests in size
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|  * classes spaced ALIGNMENT bytes apart.
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|  *
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|  * You shouldn't change this unless you know what you are doing.
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|  */
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| 
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| #if SIZEOF_VOID_P > 4
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| #define ALIGNMENT              16               /* must be 2^N */
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| #define ALIGNMENT_SHIFT         4
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| #else
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| #define ALIGNMENT               8               /* must be 2^N */
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| #define ALIGNMENT_SHIFT         3
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| #endif
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| 
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| /* Return the number of bytes in size class I, as a uint. */
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| #define INDEX2SIZE(I) (((pymem_uint)(I) + 1) << ALIGNMENT_SHIFT)
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| 
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| /*
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|  * Max size threshold below which malloc requests are considered to be
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|  * small enough in order to use preallocated memory pools. You can tune
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|  * this value according to your application behaviour and memory needs.
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|  *
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|  * Note: a size threshold of 512 guarantees that newly created dictionaries
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|  * will be allocated from preallocated memory pools on 64-bit.
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|  *
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|  * The following invariants must hold:
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|  *      1) ALIGNMENT <= SMALL_REQUEST_THRESHOLD <= 512
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|  *      2) SMALL_REQUEST_THRESHOLD is evenly divisible by ALIGNMENT
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|  *
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|  * Although not required, for better performance and space efficiency,
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|  * it is recommended that SMALL_REQUEST_THRESHOLD is set to a power of 2.
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|  */
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| #define SMALL_REQUEST_THRESHOLD 512
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| #define NB_SMALL_SIZE_CLASSES   (SMALL_REQUEST_THRESHOLD / ALIGNMENT)
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| 
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| /*
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|  * The system's VMM page size can be obtained on most unices with a
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|  * getpagesize() call or deduced from various header files. To make
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|  * things simpler, we assume that it is 4K, which is OK for most systems.
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|  * It is probably better if this is the native page size, but it doesn't
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|  * have to be.  In theory, if SYSTEM_PAGE_SIZE is larger than the native page
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|  * size, then `POOL_ADDR(p)->arenaindex' could rarely cause a segmentation
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|  * violation fault.  4K is apparently OK for all the platforms that python
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|  * currently targets.
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|  */
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| #define SYSTEM_PAGE_SIZE        (4 * 1024)
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| 
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| /*
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|  * Maximum amount of memory managed by the allocator for small requests.
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|  */
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| #ifdef WITH_MEMORY_LIMITS
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| #ifndef SMALL_MEMORY_LIMIT
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| #define SMALL_MEMORY_LIMIT      (64 * 1024 * 1024)      /* 64 MB -- more? */
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| #endif
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| #endif
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| 
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| #if !defined(WITH_PYMALLOC_RADIX_TREE)
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| /* Use radix-tree to track arena memory regions, for address_in_range().
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|  * Enable by default since it allows larger pool sizes.  Can be disabled
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|  * using -DWITH_PYMALLOC_RADIX_TREE=0 */
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| #define WITH_PYMALLOC_RADIX_TREE 1
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| #endif
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| 
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| #if SIZEOF_VOID_P > 4
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| /* on 64-bit platforms use larger pools and arenas if we can */
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| #define USE_LARGE_ARENAS
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| #if WITH_PYMALLOC_RADIX_TREE
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| /* large pools only supported if radix-tree is enabled */
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| #define USE_LARGE_POOLS
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| #endif
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| #endif
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| 
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| /*
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|  * The allocator sub-allocates <Big> blocks of memory (called arenas) aligned
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|  * on a page boundary. This is a reserved virtual address space for the
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|  * current process (obtained through a malloc()/mmap() call). In no way this
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|  * means that the memory arenas will be used entirely. A malloc(<Big>) is
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|  * usually an address range reservation for <Big> bytes, unless all pages within
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|  * this space are referenced subsequently. So malloc'ing big blocks and not
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|  * using them does not mean "wasting memory". It's an addressable range
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|  * wastage...
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|  *
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|  * Arenas are allocated with mmap() on systems supporting anonymous memory
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|  * mappings to reduce heap fragmentation.
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|  */
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| #ifdef USE_LARGE_ARENAS
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| #define ARENA_BITS              20                    /* 1 MiB */
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| #else
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| #define ARENA_BITS              18                    /* 256 KiB */
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| #endif
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| #define ARENA_SIZE              (1 << ARENA_BITS)
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| #define ARENA_SIZE_MASK         (ARENA_SIZE - 1)
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| 
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| #ifdef WITH_MEMORY_LIMITS
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| #define MAX_ARENAS              (SMALL_MEMORY_LIMIT / ARENA_SIZE)
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| #endif
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| 
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| /*
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|  * Size of the pools used for small blocks.  Must be a power of 2.
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|  */
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| #ifdef USE_LARGE_POOLS
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| #define POOL_BITS               14                  /* 16 KiB */
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| #else
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| #define POOL_BITS               12                  /* 4 KiB */
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| #endif
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| #define POOL_SIZE               (1 << POOL_BITS)
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| #define POOL_SIZE_MASK          (POOL_SIZE - 1)
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| 
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| #if !WITH_PYMALLOC_RADIX_TREE
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| #if POOL_SIZE != SYSTEM_PAGE_SIZE
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| #   error "pool size must be equal to system page size"
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| #endif
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| #endif
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| 
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| #define MAX_POOLS_IN_ARENA  (ARENA_SIZE / POOL_SIZE)
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| #if MAX_POOLS_IN_ARENA * POOL_SIZE != ARENA_SIZE
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| #   error "arena size not an exact multiple of pool size"
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| #endif
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| 
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| /*
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|  * -- End of tunable settings section --
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|  */
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| 
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| /*==========================================================================*/
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| 
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| /* When you say memory, my mind reasons in terms of (pointers to) blocks */
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| typedef uint8_t pymem_block;
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| 
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| /* Pool for small blocks. */
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| struct pool_header {
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|     union { pymem_block *_padding;
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|             uint count; } ref;          /* number of allocated blocks    */
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|     pymem_block *freeblock;             /* pool's free list head         */
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|     struct pool_header *nextpool;       /* next pool of this size class  */
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|     struct pool_header *prevpool;       /* previous pool       ""        */
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|     uint arenaindex;                    /* index into arenas of base adr */
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|     uint szidx;                         /* block size class index        */
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|     uint nextoffset;                    /* bytes to virgin block         */
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|     uint maxnextoffset;                 /* largest valid nextoffset      */
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| };
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| 
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| typedef struct pool_header *poolp;
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| 
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| /* Record keeping for arenas. */
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| struct arena_object {
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|     /* The address of the arena, as returned by malloc.  Note that 0
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|      * will never be returned by a successful malloc, and is used
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|      * here to mark an arena_object that doesn't correspond to an
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|      * allocated arena.
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|      */
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|     uintptr_t address;
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| 
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|     /* Pool-aligned pointer to the next pool to be carved off. */
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|     pymem_block* pool_address;
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| 
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|     /* The number of available pools in the arena:  free pools + never-
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|      * allocated pools.
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|      */
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|     uint nfreepools;
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| 
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|     /* The total number of pools in the arena, whether or not available. */
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|     uint ntotalpools;
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| 
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|     /* Singly-linked list of available pools. */
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|     struct pool_header* freepools;
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| 
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|     /* Whenever this arena_object is not associated with an allocated
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|      * arena, the nextarena member is used to link all unassociated
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|      * arena_objects in the singly-linked `unused_arena_objects` list.
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|      * The prevarena member is unused in this case.
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|      *
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|      * When this arena_object is associated with an allocated arena
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|      * with at least one available pool, both members are used in the
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|      * doubly-linked `usable_arenas` list, which is maintained in
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|      * increasing order of `nfreepools` values.
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|      *
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|      * Else this arena_object is associated with an allocated arena
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|      * all of whose pools are in use.  `nextarena` and `prevarena`
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|      * are both meaningless in this case.
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|      */
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|     struct arena_object* nextarena;
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|     struct arena_object* prevarena;
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| };
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| 
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| #define POOL_OVERHEAD   _Py_SIZE_ROUND_UP(sizeof(struct pool_header), ALIGNMENT)
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| 
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| #define DUMMY_SIZE_IDX          0xffff  /* size class of newly cached pools */
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| 
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| /* Round pointer P down to the closest pool-aligned address <= P, as a poolp */
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| #define POOL_ADDR(P) ((poolp)_Py_ALIGN_DOWN((P), POOL_SIZE))
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| 
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| /* Return total number of blocks in pool of size index I, as a uint. */
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| #define NUMBLOCKS(I) ((pymem_uint)(POOL_SIZE - POOL_OVERHEAD) / INDEX2SIZE(I))
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| 
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| /*==========================================================================*/
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| 
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| /*
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|  * Pool table -- headed, circular, doubly-linked lists of partially used pools.
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| 
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| This is involved.  For an index i, usedpools[i+i] is the header for a list of
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| all partially used pools holding small blocks with "size class idx" i. So
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| usedpools[0] corresponds to blocks of size 8, usedpools[2] to blocks of size
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| 16, and so on:  index 2*i <-> blocks of size (i+1)<<ALIGNMENT_SHIFT.
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| 
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| Pools are carved off an arena's highwater mark (an arena_object's pool_address
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| member) as needed.  Once carved off, a pool is in one of three states forever
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| after:
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| 
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| used == partially used, neither empty nor full
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|     At least one block in the pool is currently allocated, and at least one
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|     block in the pool is not currently allocated (note this implies a pool
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|     has room for at least two blocks).
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|     This is a pool's initial state, as a pool is created only when malloc
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|     needs space.
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|     The pool holds blocks of a fixed size, and is in the circular list headed
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|     at usedpools[i] (see above).  It's linked to the other used pools of the
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|     same size class via the pool_header's nextpool and prevpool members.
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|     If all but one block is currently allocated, a malloc can cause a
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|     transition to the full state.  If all but one block is not currently
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|     allocated, a free can cause a transition to the empty state.
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| 
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| full == all the pool's blocks are currently allocated
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|     On transition to full, a pool is unlinked from its usedpools[] list.
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|     It's not linked to from anything then anymore, and its nextpool and
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|     prevpool members are meaningless until it transitions back to used.
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|     A free of a block in a full pool puts the pool back in the used state.
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|     Then it's linked in at the front of the appropriate usedpools[] list, so
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|     that the next allocation for its size class will reuse the freed block.
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| 
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| empty == all the pool's blocks are currently available for allocation
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|     On transition to empty, a pool is unlinked from its usedpools[] list,
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|     and linked to the front of its arena_object's singly-linked freepools list,
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|     via its nextpool member.  The prevpool member has no meaning in this case.
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|     Empty pools have no inherent size class:  the next time a malloc finds
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|     an empty list in usedpools[], it takes the first pool off of freepools.
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|     If the size class needed happens to be the same as the size class the pool
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|     last had, some pool initialization can be skipped.
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| 
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| 
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| Block Management
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| 
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| Blocks within pools are again carved out as needed.  pool->freeblock points to
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| the start of a singly-linked list of free blocks within the pool.  When a
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| block is freed, it's inserted at the front of its pool's freeblock list.  Note
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| that the available blocks in a pool are *not* linked all together when a pool
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| is initialized.  Instead only "the first two" (lowest addresses) blocks are
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| set up, returning the first such block, and setting pool->freeblock to a
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| one-block list holding the second such block.  This is consistent with that
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| pymalloc strives at all levels (arena, pool, and block) never to touch a piece
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| of memory until it's actually needed.
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| 
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| So long as a pool is in the used state, we're certain there *is* a block
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| available for allocating, and pool->freeblock is not NULL.  If pool->freeblock
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| points to the end of the free list before we've carved the entire pool into
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| blocks, that means we simply haven't yet gotten to one of the higher-address
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| blocks.  The offset from the pool_header to the start of "the next" virgin
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| block is stored in the pool_header nextoffset member, and the largest value
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| of nextoffset that makes sense is stored in the maxnextoffset member when a
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| pool is initialized.  All the blocks in a pool have been passed out at least
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| once when and only when nextoffset > maxnextoffset.
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| 
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| 
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| Major obscurity:  While the usedpools vector is declared to have poolp
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| entries, it doesn't really.  It really contains two pointers per (conceptual)
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| poolp entry, the nextpool and prevpool members of a pool_header.  The
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| excruciating initialization code below fools C so that
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| 
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|     usedpool[i+i]
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| 
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| "acts like" a genuine poolp, but only so long as you only reference its
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| nextpool and prevpool members.  The "- 2*sizeof(pymem_block *)" gibberish is
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| compensating for that a pool_header's nextpool and prevpool members
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| immediately follow a pool_header's first two members:
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| 
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|     union { pymem_block *_padding;
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|             uint count; } ref;
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|     pymem_block *freeblock;
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| 
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| each of which consume sizeof(pymem_block *) bytes.  So what usedpools[i+i] really
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| contains is a fudged-up pointer p such that *if* C believes it's a poolp
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| pointer, then p->nextpool and p->prevpool are both p (meaning that the headed
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| circular list is empty).
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| 
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| It's unclear why the usedpools setup is so convoluted.  It could be to
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| minimize the amount of cache required to hold this heavily-referenced table
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| (which only *needs* the two interpool pointer members of a pool_header). OTOH,
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| referencing code has to remember to "double the index" and doing so isn't
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| free, usedpools[0] isn't a strictly legal pointer, and we're crucially relying
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| on that C doesn't insert any padding anywhere in a pool_header at or before
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| the prevpool member.
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| **************************************************************************** */
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| 
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| #define OBMALLOC_USED_POOLS_SIZE (2 * ((NB_SMALL_SIZE_CLASSES + 7) / 8) * 8)
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| 
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| struct _obmalloc_pools {
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|     poolp used[OBMALLOC_USED_POOLS_SIZE];
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| };
 | |
| 
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| 
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| /*==========================================================================
 | |
| Arena management.
 | |
| 
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| `arenas` is a vector of arena_objects.  It contains maxarenas entries, some of
 | |
| which may not be currently used (== they're arena_objects that aren't
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| currently associated with an allocated arena).  Note that arenas proper are
 | |
| separately malloc'ed.
 | |
| 
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| Prior to Python 2.5, arenas were never free()'ed.  Starting with Python 2.5,
 | |
| we do try to free() arenas, and use some mild heuristic strategies to increase
 | |
| the likelihood that arenas eventually can be freed.
 | |
| 
 | |
| unused_arena_objects
 | |
| 
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|     This is a singly-linked list of the arena_objects that are currently not
 | |
|     being used (no arena is associated with them).  Objects are taken off the
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|     head of the list in new_arena(), and are pushed on the head of the list in
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|     PyObject_Free() when the arena is empty.  Key invariant:  an arena_object
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|     is on this list if and only if its .address member is 0.
 | |
| 
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| usable_arenas
 | |
| 
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|     This is a doubly-linked list of the arena_objects associated with arenas
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|     that have pools available.  These pools are either waiting to be reused,
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|     or have not been used before.  The list is sorted to have the most-
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|     allocated arenas first (ascending order based on the nfreepools member).
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|     This means that the next allocation will come from a heavily used arena,
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|     which gives the nearly empty arenas a chance to be returned to the system.
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|     In my unscientific tests this dramatically improved the number of arenas
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|     that could be freed.
 | |
| 
 | |
| Note that an arena_object associated with an arena all of whose pools are
 | |
| currently in use isn't on either list.
 | |
| 
 | |
| Changed in Python 3.8:  keeping usable_arenas sorted by number of free pools
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| used to be done by one-at-a-time linear search when an arena's number of
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| free pools changed.  That could, overall, consume time quadratic in the
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| number of arenas.  That didn't really matter when there were only a few
 | |
| hundred arenas (typical!), but could be a timing disaster when there were
 | |
| hundreds of thousands.  See bpo-37029.
 | |
| 
 | |
| Now we have a vector of "search fingers" to eliminate the need to search:
 | |
| nfp2lasta[nfp] returns the last ("rightmost") arena in usable_arenas
 | |
| with nfp free pools.  This is NULL if and only if there is no arena with
 | |
| nfp free pools in usable_arenas.
 | |
| */
 | |
| 
 | |
| /* How many arena_objects do we initially allocate?
 | |
|  * 16 = can allocate 16 arenas = 16 * ARENA_SIZE = 4MB before growing the
 | |
|  * `arenas` vector.
 | |
|  */
 | |
| #define INITIAL_ARENA_OBJECTS 16
 | |
| 
 | |
| struct _obmalloc_mgmt {
 | |
|     /* Array of objects used to track chunks of memory (arenas). */
 | |
|     struct arena_object* arenas;
 | |
|     /* Number of slots currently allocated in the `arenas` vector. */
 | |
|     uint maxarenas;
 | |
| 
 | |
|     /* The head of the singly-linked, NULL-terminated list of available
 | |
|      * arena_objects.
 | |
|      */
 | |
|     struct arena_object* unused_arena_objects;
 | |
| 
 | |
|     /* The head of the doubly-linked, NULL-terminated at each end, list of
 | |
|      * arena_objects associated with arenas that have pools available.
 | |
|      */
 | |
|     struct arena_object* usable_arenas;
 | |
| 
 | |
|     /* nfp2lasta[nfp] is the last arena in usable_arenas with nfp free pools */
 | |
|     struct arena_object* nfp2lasta[MAX_POOLS_IN_ARENA + 1];
 | |
| 
 | |
|     /* Number of arenas allocated that haven't been free()'d. */
 | |
|     size_t narenas_currently_allocated;
 | |
| 
 | |
|     /* Total number of times malloc() called to allocate an arena. */
 | |
|     size_t ntimes_arena_allocated;
 | |
|     /* High water mark (max value ever seen) for narenas_currently_allocated. */
 | |
|     size_t narenas_highwater;
 | |
| 
 | |
|     Py_ssize_t raw_allocated_blocks;
 | |
| };
 | |
| 
 | |
| 
 | |
| #if WITH_PYMALLOC_RADIX_TREE
 | |
| /*==========================================================================*/
 | |
| /* radix tree for tracking arena usage.  If enabled, used to implement
 | |
|    address_in_range().
 | |
| 
 | |
|    memory address bit allocation for keys
 | |
| 
 | |
|    64-bit pointers, IGNORE_BITS=0 and 2^20 arena size:
 | |
|      15 -> MAP_TOP_BITS
 | |
|      15 -> MAP_MID_BITS
 | |
|      14 -> MAP_BOT_BITS
 | |
|      20 -> ideal aligned arena
 | |
|    ----
 | |
|      64
 | |
| 
 | |
|    64-bit pointers, IGNORE_BITS=16, and 2^20 arena size:
 | |
|      16 -> IGNORE_BITS
 | |
|      10 -> MAP_TOP_BITS
 | |
|      10 -> MAP_MID_BITS
 | |
|       8 -> MAP_BOT_BITS
 | |
|      20 -> ideal aligned arena
 | |
|    ----
 | |
|      64
 | |
| 
 | |
|    32-bit pointers and 2^18 arena size:
 | |
|      14 -> MAP_BOT_BITS
 | |
|      18 -> ideal aligned arena
 | |
|    ----
 | |
|      32
 | |
| 
 | |
| */
 | |
| 
 | |
| #if SIZEOF_VOID_P == 8
 | |
| 
 | |
| /* number of bits in a pointer */
 | |
| #define POINTER_BITS 64
 | |
| 
 | |
| /* High bits of memory addresses that will be ignored when indexing into the
 | |
|  * radix tree.  Setting this to zero is the safe default.  For most 64-bit
 | |
|  * machines, setting this to 16 would be safe.  The kernel would not give
 | |
|  * user-space virtual memory addresses that have significant information in
 | |
|  * those high bits.  The main advantage to setting IGNORE_BITS > 0 is that less
 | |
|  * virtual memory will be used for the top and middle radix tree arrays.  Those
 | |
|  * arrays are allocated in the BSS segment and so will typically consume real
 | |
|  * memory only if actually accessed.
 | |
|  */
 | |
| #define IGNORE_BITS 0
 | |
| 
 | |
| /* use the top and mid layers of the radix tree */
 | |
| #define USE_INTERIOR_NODES
 | |
| 
 | |
| #elif SIZEOF_VOID_P == 4
 | |
| 
 | |
| #define POINTER_BITS 32
 | |
| #define IGNORE_BITS 0
 | |
| 
 | |
| #else
 | |
| 
 | |
|  /* Currently this code works for 64-bit or 32-bit pointers only.  */
 | |
| #error "obmalloc radix tree requires 64-bit or 32-bit pointers."
 | |
| 
 | |
| #endif /* SIZEOF_VOID_P */
 | |
| 
 | |
| /* arena_coverage_t members require this to be true  */
 | |
| #if ARENA_BITS >= 32
 | |
| #   error "arena size must be < 2^32"
 | |
| #endif
 | |
| 
 | |
| /* the lower bits of the address that are not ignored */
 | |
| #define ADDRESS_BITS (POINTER_BITS - IGNORE_BITS)
 | |
| 
 | |
| #ifdef USE_INTERIOR_NODES
 | |
| /* number of bits used for MAP_TOP and MAP_MID nodes */
 | |
| #define INTERIOR_BITS ((ADDRESS_BITS - ARENA_BITS + 2) / 3)
 | |
| #else
 | |
| #define INTERIOR_BITS 0
 | |
| #endif
 | |
| 
 | |
| #define MAP_TOP_BITS INTERIOR_BITS
 | |
| #define MAP_TOP_LENGTH (1 << MAP_TOP_BITS)
 | |
| #define MAP_TOP_MASK (MAP_TOP_LENGTH - 1)
 | |
| 
 | |
| #define MAP_MID_BITS INTERIOR_BITS
 | |
| #define MAP_MID_LENGTH (1 << MAP_MID_BITS)
 | |
| #define MAP_MID_MASK (MAP_MID_LENGTH - 1)
 | |
| 
 | |
| #define MAP_BOT_BITS (ADDRESS_BITS - ARENA_BITS - 2*INTERIOR_BITS)
 | |
| #define MAP_BOT_LENGTH (1 << MAP_BOT_BITS)
 | |
| #define MAP_BOT_MASK (MAP_BOT_LENGTH - 1)
 | |
| 
 | |
| #define MAP_BOT_SHIFT ARENA_BITS
 | |
| #define MAP_MID_SHIFT (MAP_BOT_BITS + MAP_BOT_SHIFT)
 | |
| #define MAP_TOP_SHIFT (MAP_MID_BITS + MAP_MID_SHIFT)
 | |
| 
 | |
| #define AS_UINT(p) ((uintptr_t)(p))
 | |
| #define MAP_BOT_INDEX(p) ((AS_UINT(p) >> MAP_BOT_SHIFT) & MAP_BOT_MASK)
 | |
| #define MAP_MID_INDEX(p) ((AS_UINT(p) >> MAP_MID_SHIFT) & MAP_MID_MASK)
 | |
| #define MAP_TOP_INDEX(p) ((AS_UINT(p) >> MAP_TOP_SHIFT) & MAP_TOP_MASK)
 | |
| 
 | |
| #if IGNORE_BITS > 0
 | |
| /* Return the ignored part of the pointer address.  Those bits should be same
 | |
|  * for all valid pointers if IGNORE_BITS is set correctly.
 | |
|  */
 | |
| #define HIGH_BITS(p) (AS_UINT(p) >> ADDRESS_BITS)
 | |
| #else
 | |
| #define HIGH_BITS(p) 0
 | |
| #endif
 | |
| 
 | |
| 
 | |
| /* This is the leaf of the radix tree.  See arena_map_mark_used() for the
 | |
|  * meaning of these members. */
 | |
| typedef struct {
 | |
|     int32_t tail_hi;
 | |
|     int32_t tail_lo;
 | |
| } arena_coverage_t;
 | |
| 
 | |
| typedef struct arena_map_bot {
 | |
|     /* The members tail_hi and tail_lo are accessed together.  So, it
 | |
|      * better to have them as an array of structs, rather than two
 | |
|      * arrays.
 | |
|      */
 | |
|     arena_coverage_t arenas[MAP_BOT_LENGTH];
 | |
| } arena_map_bot_t;
 | |
| 
 | |
| #ifdef USE_INTERIOR_NODES
 | |
| typedef struct arena_map_mid {
 | |
|     struct arena_map_bot *ptrs[MAP_MID_LENGTH];
 | |
| } arena_map_mid_t;
 | |
| 
 | |
| typedef struct arena_map_top {
 | |
|     struct arena_map_mid *ptrs[MAP_TOP_LENGTH];
 | |
| } arena_map_top_t;
 | |
| #endif
 | |
| 
 | |
| struct _obmalloc_usage {
 | |
|     /* The root of radix tree.  Note that by initializing like this, the memory
 | |
|      * should be in the BSS.  The OS will only memory map pages as the MAP_MID
 | |
|      * nodes get used (OS pages are demand loaded as needed).
 | |
|      */
 | |
| #ifdef USE_INTERIOR_NODES
 | |
|     arena_map_top_t arena_map_root;
 | |
|     /* accounting for number of used interior nodes */
 | |
|     int arena_map_mid_count;
 | |
|     int arena_map_bot_count;
 | |
| #else
 | |
|     arena_map_bot_t arena_map_root;
 | |
| #endif
 | |
| };
 | |
| 
 | |
| #endif /* WITH_PYMALLOC_RADIX_TREE */
 | |
| 
 | |
| 
 | |
| struct _obmalloc_global_state {
 | |
|     int dump_debug_stats;
 | |
|     Py_ssize_t interpreter_leaks;
 | |
| };
 | |
| 
 | |
| struct _obmalloc_state {
 | |
|     struct _obmalloc_pools pools;
 | |
|     struct _obmalloc_mgmt mgmt;
 | |
| #if WITH_PYMALLOC_RADIX_TREE
 | |
|     struct _obmalloc_usage usage;
 | |
| #endif
 | |
| };
 | |
| 
 | |
| 
 | |
| #undef  uint
 | |
| 
 | |
| 
 | |
| /* Allocate memory directly from the O/S virtual memory system,
 | |
|  * where supported. Otherwise fallback on malloc */
 | |
| void *_PyObject_VirtualAlloc(size_t size);
 | |
| void _PyObject_VirtualFree(void *, size_t size);
 | |
| 
 | |
| 
 | |
| /* This function returns the number of allocated memory blocks, regardless of size */
 | |
| extern Py_ssize_t _Py_GetGlobalAllocatedBlocks(void);
 | |
| #define _Py_GetAllocatedBlocks() \
 | |
|     _Py_GetGlobalAllocatedBlocks()
 | |
| extern Py_ssize_t _PyInterpreterState_GetAllocatedBlocks(PyInterpreterState *);
 | |
| extern void _PyInterpreterState_FinalizeAllocatedBlocks(PyInterpreterState *);
 | |
| 
 | |
| 
 | |
| #ifdef WITH_PYMALLOC
 | |
| // Export the symbol for the 3rd party 'guppy3' project
 | |
| PyAPI_FUNC(int) _PyObject_DebugMallocStats(FILE *out);
 | |
| #endif
 | |
| 
 | |
| 
 | |
| #ifdef __cplusplus
 | |
| }
 | |
| #endif
 | |
| #endif  // !Py_INTERNAL_OBMALLOC_H
 | 
