/* Copyright (C) 2001-2006 Artifex Software, Inc.
All Rights Reserved.
This software is provided AS-IS with no warranty, either express or
This software is distributed under license and may not be copied, modified
or distributed except as expressly authorized under the terms of that
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or contact Artifex Software, Inc., 7 Mt. Lassen Drive - Suite A-134,
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/* $Id: isave.h 9043 2008-08-28 22:48:19Z giles $ */
/* Procedures for save/restore */
/* Requires imemory.h */
# define isave_INCLUDED
* In PLRM2, save objects are simple, not composite. Consequently, we
* cannot use their natural representation, namely a t_struct pointing to an
* alloc_save_t, since we aren't willing to allocate them all in global VM
* and rely on garbage collection to clean them up. Instead, we assign each
* one a unique "save ID", and store this in the alloc_save_t object.
* Mapping the number to the object requires at most searching the local
* save chain for the current gs_dual_memory_t, and this approach means we
* don't have to do anything to invalidate save objects when we do a
* In PLRM3, Adobe did the reasonable thing and changed save objects to
* composite. However, this means that 'restore' must treat save objects on
* the stack differently in LL2 vs. LL3 (yes, the Genoa LL2 and LL3 tests
* require this!). See zvmem.c:restore_check_stack.
#ifndef alloc_save_t_DEFINED /* also in inamedef.h */
typedef struct alloc_save_s alloc_save_t;
# define alloc_save_t_DEFINED
/* Initialize the save machinery. */
extern void alloc_save_init(gs_dual_memory_t *);
/* Map a save ID to its save object. Return 0 if the ID is invalid. */
alloc_save_t *alloc_find_save(const gs_dual_memory_t *, ulong);
* Save the state. Return 0 if we can't allocate the save object,
* otherwise return the save ID. The second argument is a client data
* pointer, assumed to point to an object.
int alloc_save_state(gs_dual_memory_t * dmem, void *cdata, ulong *psid);
/* Get the client pointer passed to alloc_saved_state. */
void *alloc_save_client_data(const alloc_save_t *);
/* Return (the id of) the innermost externally visible save object. */
ulong alloc_save_current_id(const gs_dual_memory_t *);
alloc_save_t *alloc_save_current(const gs_dual_memory_t *);
/* Check whether a pointer refers to an object allocated since a given save. */
bool alloc_is_since_save(const void *, const alloc_save_t *);
/* Check whether a name was created since a given save. */
bool alloc_name_is_since_save(const gs_memory_t *mem, const ref *, const alloc_save_t *);
bool alloc_name_index_is_since_save(const gs_memory_t *mem, uint, const alloc_save_t *);
* Check whether any names have been created since a given save
* that might be released by the restore.
bool alloc_any_names_since_save(const alloc_save_t *);
* Do one step of restoring the state. Return true if the argument
* was the innermost save, in which case this is the last (or only) step.
* Assume the caller obtained the argument by calling alloc_find_save;
* if this is the case, the operation cannot fail.
int alloc_restore_step_in(gs_dual_memory_t *, alloc_save_t *);
* Forget a save -- like committing a transaction (restore is like
* aborting a transaction). Assume the caller obtained the argument
* by calling alloc_find_save. Note that forgetting a save does not
* require checking pointers for recency.
int alloc_forget_save_in(gs_dual_memory_t *, alloc_save_t *);
/* Release all memory -- like doing a restore "past the bottom". */
int alloc_restore_all(gs_dual_memory_t *);
/* Filter save change lists. */
void alloc_save__filter_changes(gs_ref_memory_t *mem);
/* ------ Internals ------ */
* If we are in a save, we want to save the old contents if l_new is
* not set; if we are not in a save, we never want to save old contents.
* We can test this quickly with a single mask that is l_new if we are
* in a save, and -1 if we are not, since type_attrs of a valid ref
* cannot be 0; this is the test_mask in a gs_dual_memory_t. Similarly,
* we want to set the l_new bit in newly allocated objects iff we are in
* a save; this is the new_mask in a gs_dual_memory_t.
/* Record that we are in a save. */
void alloc_set_in_save(gs_dual_memory_t *);
/* Record that we are not in a save. */
void alloc_set_not_in_save(gs_dual_memory_t *);
/* Remove entries from font and character caches. */
int font_restore(const alloc_save_t * save);
#endif /* isave_INCLUDED */