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/* Copyright (C) 2001-2006 Artifex Software, Inc.
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This software is provided AS-IS with no warranty, either express or
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This software is distributed under license and may not be copied, modified
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or distributed except as expressly authorized under the terms of that
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license. Refer to licensing information at http://www.artifex.com/
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or contact Artifex Software, Inc., 7 Mt. Lassen Drive - Suite A-134,
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San Rafael, CA 94903, U.S.A., +1(415)492-9861, for further information.
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/* $Id: isave.c 9043 2008-08-28 22:48:19Z giles $ */
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/* Save/restore manager for Ghostscript interpreter */
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#include "stream.h" /* for linking for forgetsave */
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#include "store.h" /* for ref_assign */
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#include "gsutil.h" /* gs_next_ids prototype */
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/* Structure descriptor */
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private_st_alloc_save();
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/* Define the maximum amount of data we are willing to scan repeatedly -- */
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/* see below for details. */
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static const long max_repeated_scan = 100000;
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/* Define the minimum space for creating an inner chunk. */
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/* Must be at least sizeof(chunk_head_t). */
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static const long min_inner_chunk_space = sizeof(chunk_head_t) + 500;
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* The logic for saving and restoring the state is complex.
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* Both the changes to individual objects, and the overall state
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* of the memory manager, must be saved and restored.
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* To save the state of the memory manager:
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* Save the state of the current chunk in which we are allocating.
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* Shrink all chunks to their inner unallocated region.
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* Save and reset the free block chains.
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* By doing this, we guarantee that no object older than the save
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* To restore the state of the memory manager:
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* Free all chunks newer than the save, and the descriptors for
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* the inner chunks created by the save.
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* Make current the chunk that was current at the time of the save.
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* Restore the state of the current chunk.
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* In addition to save ("start transaction") and restore ("abort transaction"),
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* we support forgetting a save ("commit transation"). To forget a save:
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* Reassign to the next outer save all chunks newer than the save.
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* Free the descriptors for the inners chunk, updating their outer
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* chunks to reflect additional allocations in the inner chunks.
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* Concatenate the free block chains with those of the outer save.
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* For saving changes to individual objects, we add an "attribute" bit
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* (l_new) that logically belongs to the slot where the ref is stored,
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* not to the ref itself. The bit means "the contents of this slot
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* have been changed, or the slot was allocated, since the last save."
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* To keep track of changes since the save, we associate a chain of
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* <slot, old_contents> pairs that remembers the old contents of slots.
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* When creating an object, if the save level is non-zero:
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* Set l_new in all slots.
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* When storing into a slot, if the save level is non-zero:
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* If l_new isn't set, save the address and contents of the slot
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* on the current contents chain.
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* Set l_new after storing the new value.
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* If the save level is non-zero:
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* Reset l_new in all slots on the contents chain, and in all
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* objects created since the previous save.
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* Push the head of the contents chain, and reset the chain to empty.
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* Check all the stacks to make sure they don't contain references
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* to objects created since the save.
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* Restore all the slots on the contents chain.
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* Pop the contents chain head.
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* If the save level is now non-zero:
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* Scan the newly restored contents chain, and set l_new in all
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* the slots it references.
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* Scan all objects created since the previous save, and set
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* l_new in all the slots of each object.
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* If the save level is greater than 1:
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* Set l_new as for a restore, per the next outer save.
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* Concatenate the next outer contents chain to the end of
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* If the save level is 1:
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* Reset l_new as for a save.
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* Free the contents chain.
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* A consequence of the foregoing algorithms is that the cost of a save is
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* proportional to the total amount of data allocated since the previous
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* save. If a PostScript program reads in a large amount of setup code and
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* then uses save/restore heavily, each save/restore will be expensive. To
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* mitigate this, we check to see how much data we have scanned at this save
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* level: if it is large, we do a second, invisible save. This greatly
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* reduces the cost of inner saves, at the expense of possibly saving some
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* changes twice that otherwise would only have to be saved once.
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* The presence of global and local VM complicates the situation further.
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* There is a separate save chain and contents chain for each VM space.
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* When multiple contexts are fully implemented, save and restore will have
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* the following effects, according to the privacy status of the current
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* context's global and local VM:
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* Private global, private local:
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* The outermost save saves both global and local VM;
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* otherwise, save only saves local VM.
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* Shared global, private local:
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* Save only saves local VM.
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* Shared global, shared local:
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* Save only saves local VM, and suspends all other contexts
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* sharing the same local VM until the matching restore.
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* Since we do not currently implement multiple contexts, only the first
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* Note that when saving the contents of a slot, the choice of chain
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* is determined by the VM space in which the slot is allocated,
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* not by the current allocation mode.
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/* Tracing printout */
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print_save(const char *str, uint spacen, const alloc_save_t *sav)
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if_debug5('u', "[u]%s space %u 0x%lx: cdata = 0x%lx, id = %lu\n",\
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str, spacen, (ulong)sav, (ulong)sav->client_data, (ulong)sav->id);
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/* A link to igcref.c . */
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ptr_proc_reloc(igc_reloc_ref_ptr_nocheck, ref_packed);
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* Structure for saved change chain for save/restore. Because of the
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* garbage collector, we need to distinguish the cases where the change
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* is in a static object, a dynamic ref, or a dynamic struct.
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typedef struct alloc_change_s alloc_change_t;
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struct alloc_change_s {
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alloc_change_t *next;
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#define AC_OFFSET_STATIC (-2) /* static object */
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#define AC_OFFSET_REF (-1) /* dynamic ref */
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#define AC_OFFSET_ALLOCATED (-3) /* a newly allocated ref array */
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short offset; /* if >= 0, offset within struct */
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CLEAR_MARKS_PROC(change_clear_marks)
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alloc_change_t *const ptr = (alloc_change_t *)vptr;
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if (r_is_packed(&ptr->contents))
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r_clear_pmark((ref_packed *) & ptr->contents);
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r_clear_attrs(&ptr->contents, l_mark);
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ENUM_PTRS_WITH(change_enum_ptrs, alloc_change_t *ptr) return 0;
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ENUM_PTR(0, alloc_change_t, next);
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if (ptr->offset >= 0)
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ENUM_RETURN((byte *) ptr->where - ptr->offset);
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if (ptr->offset != AC_OFFSET_ALLOCATED)
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ENUM_RETURN_REF(ptr->where);
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/* Don't enumerate ptr->where, because it
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needs a special processing with
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alloc_save__filter_changes. */
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ENUM_RETURN_REF(&ptr->contents);
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static RELOC_PTRS_WITH(change_reloc_ptrs, alloc_change_t *ptr)
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RELOC_VAR(ptr->next);
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switch (ptr->offset) {
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case AC_OFFSET_STATIC:
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RELOC_REF_PTR_VAR(ptr->where);
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case AC_OFFSET_ALLOCATED:
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/* We know that ptr->where may point to an unmarked object
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because change_enum_ptrs skipped it,
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and we know it always points to same space
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because we took a special care when calling alloc_save_change_alloc.
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Therefore we must skip the check for the mark,
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which would happen if we call the regular relocation function
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igc_reloc_ref_ptr from RELOC_REF_PTR_VAR.
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Calling igc_reloc_ref_ptr_nocheck instead. */
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{ /* A sanity check. */
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obj_header_t *pre = (obj_header_t *)ptr->where - 1, *pre1 = 0;
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if (pre->o_type != &st_refs)
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pre1->o_type = 0; /* issue a segfault. */
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if (ptr->where != 0 && !gcst->relocating_untraced)
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ptr->where = igc_reloc_ref_ptr_nocheck(ptr->where, gcst);
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byte *obj = (byte *) ptr->where - ptr->offset;
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ptr->where = (ref_packed *) (obj + ptr->offset);
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if (r_is_packed(&ptr->contents))
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r_clear_pmark((ref_packed *) & ptr->contents);
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RELOC_REF_VAR(ptr->contents);
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r_clear_attrs(&ptr->contents, l_mark);
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gs_private_st_complex_only(st_alloc_change, alloc_change_t, "alloc_change",
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change_clear_marks, change_enum_ptrs, change_reloc_ptrs, 0);
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/* Debugging printout */
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alloc_save_print(alloc_change_t * cp, bool print_current)
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dprintf2(" 0x%lx: 0x%lx: ", (ulong) cp, (ulong) cp->where);
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if (r_is_packed(&cp->contents)) {
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dprintf2("saved=%x cur=%x\n", *(ref_packed *) & cp->contents,
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dprintf1("%x\n", *(ref_packed *) & cp->contents);
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dprintf6("saved=%x %x %lx cur=%x %x %lx\n",
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r_type_attrs(&cp->contents), r_size(&cp->contents),
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(ulong) cp->contents.value.intval,
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r_type_attrs((ref *) cp->where),
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r_size((ref *) cp->where),
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(ulong) ((ref *) cp->where)->value.intval);
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dprintf3("%x %x %lx\n",
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r_type_attrs(&cp->contents), r_size(&cp->contents),
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(ulong) cp->contents.value.intval);
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/* Forward references */
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static int restore_resources(alloc_save_t *, gs_ref_memory_t *);
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static void restore_free(gs_ref_memory_t *);
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static int save_set_new(gs_ref_memory_t * mem, bool to_new, bool set_limit, ulong *pscanned);
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static int save_set_new_changes(gs_ref_memory_t *, bool, bool);
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static bool check_l_mark(void *obj);
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/* Initialize the save/restore machinery. */
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alloc_save_init(gs_dual_memory_t * dmem)
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alloc_set_not_in_save(dmem);
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/* Record that we are in a save. */
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alloc_set_masks(gs_dual_memory_t *dmem, uint new_mask, uint test_mask)
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gs_ref_memory_t *mem;
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dmem->new_mask = new_mask;
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dmem->test_mask = test_mask;
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for (i = 0; i < countof(dmem->spaces.memories.indexed); ++i)
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if ((mem = dmem->spaces.memories.indexed[i]) != 0) {
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mem->new_mask = new_mask, mem->test_mask = test_mask;
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if (mem->stable_memory != (gs_memory_t *)mem) {
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mem = (gs_ref_memory_t *)mem->stable_memory;
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mem->new_mask = new_mask, mem->test_mask = test_mask;
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alloc_set_in_save(gs_dual_memory_t *dmem)
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alloc_set_masks(dmem, l_new, l_new);
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/* Record that we are not in a save. */
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alloc_set_not_in_save(gs_dual_memory_t *dmem)
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alloc_set_masks(dmem, 0, ~0);
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/* Save the state. */
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static alloc_save_t *alloc_save_space(gs_ref_memory_t *mem,
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gs_dual_memory_t *dmem,
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alloc_free_save(gs_ref_memory_t *mem, alloc_save_t *save, const char *scn)
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gs_free_object((gs_memory_t *)mem, save, scn);
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/* Free any inner chunk structures. This is the easiest way to do it. */
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alloc_save_state(gs_dual_memory_t * dmem, void *cdata, ulong *psid)
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gs_ref_memory_t *lmem = dmem->space_local;
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gs_ref_memory_t *gmem = dmem->space_global;
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ulong sid = gs_next_ids((const gs_memory_t *)lmem->stable_memory, 2);
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lmem->save_level == 0 && gmem != lmem &&
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gmem->num_contexts == 1;
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alloc_save_t *gsave =
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(global ? alloc_save_space(gmem, dmem, sid + 1) : (alloc_save_t *) 0);
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alloc_save_t *lsave = alloc_save_space(lmem, dmem, sid);
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if (lsave == 0 || (global && gsave == 0)) {
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alloc_free_save(lmem, lsave, "alloc_save_state(local save)");
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alloc_free_save(gmem, gsave, "alloc_save_state(global save)");
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gsave->client_data = 0;
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print_save("save", gmem->space, gsave);
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/* Restore names when we do the local restore. */
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lsave->restore_names = gsave->restore_names;
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gsave->restore_names = false;
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lsave->client_data = cdata;
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print_save("save", lmem->space, lsave);
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/* Reset the l_new attribute in all slots. The only slots that */
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/* can have the attribute set are the ones on the changes chain, */
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/* and ones in objects allocated since the last save. */
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if (lmem->save_level > 1) {
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int code = save_set_new(&lsave->state, false, true, &scanned);
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#if 0 /* Disable invisible save levels. */
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if ((lsave->state.total_scanned += scanned) > max_repeated_scan) {
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/* Do a second, invisible save. */
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rsave = alloc_save_space(lmem, dmem, 0L);
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rsave->client_data = cdata;
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#if 0 /* Bug 688153 */
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rsave->id = lsave->id;
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print_save("save", lmem->space, rsave);
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lsave->id = 0; /* mark as invisible */
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rsave->state.save_level--; /* ditto */
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lsave->client_data = 0;
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rsave->id = 0; /* mark as invisible */
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print_save("save", lmem->space, rsave);
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rsave->state.save_level--; /* ditto */
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rsave->client_data = 0;
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/* Inherit the allocated space count -- */
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/* we need this for triggering a GC. */
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print_save("save", lmem->space, lsave);
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alloc_set_in_save(dmem);
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/* Save the state of one space (global or local). */
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static alloc_save_t *
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alloc_save_space(gs_ref_memory_t * mem, gs_dual_memory_t * dmem, ulong sid)
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gs_ref_memory_t save_mem;
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chunk_t *new_pcc = 0;
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alloc_close_chunk(mem);
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gs_memory_status((gs_memory_t *) mem, &mem->previous_status);
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/* Create inner chunks wherever it's worthwhile. */
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for (cp = save_mem.cfirst; cp != 0; cp = cp->cnext) {
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if (cp->ctop - cp->cbot > min_inner_chunk_space) {
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/* Create an inner chunk to cover only the unallocated part. */
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gs_raw_alloc_struct_immovable(mem->non_gc_memory, &st_chunk,
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"alloc_save_space(inner)");
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break; /* maybe should fail */
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alloc_init_chunk(inner, cp->cbot, cp->ctop, cp->sreloc != 0, cp);
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alloc_link_chunk(inner, mem);
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if_debug2('u', "[u]inner chunk: cbot=0x%lx ctop=0x%lx\n",
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(ulong) inner->cbot, (ulong) inner->ctop);
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if (cp == save_mem.pcc)
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alloc_open_chunk(mem);
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save = gs_alloc_struct((gs_memory_t *) mem, alloc_save_t,
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&st_alloc_save, "alloc_save_space(save)");
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if_debug2('u', "[u]save space %u at 0x%lx\n",
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mem->space, (ulong) save);
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/* Free the inner chunk structures. This is the easiest way. */
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save->state = save_mem;
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save->spaces = dmem->spaces;
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save->restore_names = (name_memory(mem) == (gs_memory_t *) mem);
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save->is_current = (dmem->current == mem);
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if_debug2('u', "[u%u]file_save 0x%lx\n",
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mem->space, (ulong) mem->streams);
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mem->total_scanned = 0;
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mem->total_scanned_after_compacting = 0;
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/* Record a state change that must be undone for restore, */
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/* and mark it as having been saved. */
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alloc_save_change_in(gs_ref_memory_t *mem, const ref * pcont,
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ref_packed * where, client_name_t cname)
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register alloc_change_t *cp;
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if (mem->new_mask == 0)
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return 0; /* no saving */
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cp = gs_alloc_struct((gs_memory_t *)mem, alloc_change_t,
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&st_alloc_change, "alloc_save_change");
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cp->next = mem->changes;
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cp->offset = AC_OFFSET_STATIC;
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else if (r_is_array(pcont) || r_has_type(pcont, t_dictionary))
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cp->offset = AC_OFFSET_REF;
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else if (r_is_struct(pcont))
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cp->offset = (byte *) where - (byte *) pcont->value.pstruct;
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lprintf3("Bad type %u for save! pcont = 0x%lx, where = 0x%lx\n",
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r_type(pcont), (ulong) pcont, (ulong) where);
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gs_abort((const gs_memory_t *)mem);
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if (r_is_packed(where))
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*(ref_packed *)&cp->contents = *where;
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ref_assign_inline(&cp->contents, (ref *) where);
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r_set_attrs((ref *) where, l_new);
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if (gs_debug_c('U')) {
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dlprintf1("[U]save(%s)", client_name_string(cname));
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alloc_save_print(cp, false);
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alloc_save_change(gs_dual_memory_t * dmem, const ref * pcont,
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ref_packed * where, client_name_t cname)
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gs_ref_memory_t *mem =
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(pcont == NULL ? dmem->space_local :
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dmem->spaces_indexed[r_space(pcont) >> r_space_shift]);
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return alloc_save_change_in(mem, pcont, where, cname);
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/* Allocate a structure for recording an allocation event. */
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alloc_save_change_alloc(gs_ref_memory_t *mem, client_name_t cname, ref_packed ***ppr)
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register alloc_change_t *cp;
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if (mem->new_mask == 0)
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return 0; /* no saving */
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cp = gs_alloc_struct((gs_memory_t *)mem, alloc_change_t,
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&st_alloc_change, "alloc_save_change");
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return_error(e_VMerror);
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cp->next = mem->changes;
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cp->offset = AC_OFFSET_ALLOCATED;
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make_null(&cp->contents);
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/* Remove an AC_OFFSET_ALLOCATED element. */
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alloc_save_remove(gs_ref_memory_t *mem, ref_packed *obj, client_name_t cname)
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alloc_change_t **cpp = &mem->changes;
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for (; *cpp != NULL;) {
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alloc_change_t *cp = *cpp;
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if (cp->offset == AC_OFFSET_ALLOCATED && cp->where == obj) {
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if (mem->scan_limit == cp)
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mem->scan_limit = cp->next;
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gs_free_object((gs_memory_t *)mem, cp, "alloc_save_remove");
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/* Filter save change lists. */
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alloc_save__filter_changes_in_space(gs_ref_memory_t *mem)
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/* This is a special function, which is called
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from the garbager after setting marks and before collecting
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unused space. Therefore it just resets marks for
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elements being released instead releasing them really. */
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alloc_change_t **cpp = &mem->changes;
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for (; *cpp != NULL; ) {
571
alloc_change_t *cp = *cpp;
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if (cp->offset == AC_OFFSET_ALLOCATED && !check_l_mark(cp->where)) {
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obj_header_t *pre = (obj_header_t *)cp - 1;
578
if (mem->scan_limit == cp)
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mem->scan_limit = cp->next;
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/* Filter save change lists. */
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alloc_save__filter_changes(gs_ref_memory_t *memory)
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gs_ref_memory_t *mem = memory;
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for (; mem; mem = &mem->saved->state)
593
alloc_save__filter_changes_in_space(mem);
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/* Return (the id of) the innermost externally visible save object, */
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/* i.e., the innermost save with a non-zero ID. */
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alloc_save_current_id(const gs_dual_memory_t * dmem)
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const alloc_save_t *save = dmem->space_local->saved;
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while (save != 0 && save->id == 0)
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save = save->state.saved;
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alloc_save_current(const gs_dual_memory_t * dmem)
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return alloc_find_save(dmem, alloc_save_current_id(dmem));
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/* Test whether a reference would be invalidated by a restore. */
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alloc_is_since_save(const void *vptr, const alloc_save_t * save)
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/* A reference postdates a save iff it is in a chunk allocated */
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/* since the save (including any carried-over inner chunks). */
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const char *const ptr = (const char *)vptr;
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register const gs_ref_memory_t *mem = save->space_local;
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if_debug2('U', "[U]is_since_save 0x%lx, 0x%lx:\n",
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(ulong) ptr, (ulong) save);
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if (mem->saved == 0) { /* This is a special case, the final 'restore' from */
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/* alloc_restore_all. */
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/* Check against chunks allocated since the save. */
630
/* (There may have been intermediate saves as well.) */
631
for (;; mem = &mem->saved->state) {
634
if_debug1('U', "[U]checking mem=0x%lx\n", (ulong) mem);
635
for (cp = mem->cfirst; cp != 0; cp = cp->cnext) {
636
if (ptr_is_within_chunk(ptr, cp)) {
637
if_debug3('U', "[U+]in new chunk 0x%lx: 0x%lx, 0x%lx\n",
639
(ulong) cp->cbase, (ulong) cp->cend);
642
if_debug1('U', "[U-]not in 0x%lx\n", (ulong) cp);
644
if (mem->saved == save) { /* We've checked all the more recent saves, */
651
* If we're about to do a global restore (a restore to the level 0),
652
* and there is only one context using this global VM
653
* (the normal case, in which global VM is saved by the
654
* outermost save), we also have to check the global save.
655
* Global saves can't be nested, which makes things easy.
657
if (save->state.save_level == 0 /* Restoring to save level 0 - see bug 688157, 688161 */ &&
658
(mem = save->space_global) != save->space_local &&
659
save->space_global->num_contexts == 1
663
if_debug1('U', "[U]checking global mem=0x%lx\n", (ulong) mem);
664
for (cp = mem->cfirst; cp != 0; cp = cp->cnext)
665
if (ptr_is_within_chunk(ptr, cp)) {
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if_debug3('U', "[U+] new chunk 0x%lx: 0x%lx, 0x%lx\n",
667
(ulong) cp, (ulong) cp->cbase, (ulong) cp->cend);
676
/* Test whether a name would be invalidated by a restore. */
678
alloc_name_is_since_save(const gs_memory_t *mem,
679
const ref * pnref, const alloc_save_t * save)
681
const name_string_t *pnstr;
683
if (!save->restore_names)
685
pnstr = names_string_inline(mem->gs_lib_ctx->gs_name_table, pnref);
686
if (pnstr->foreign_string)
688
return alloc_is_since_save(pnstr->string_bytes, save);
691
alloc_name_index_is_since_save(const gs_memory_t *mem,
692
uint nidx, const alloc_save_t *save)
694
const name_string_t *pnstr;
696
if (!save->restore_names)
698
pnstr = names_index_string_inline(mem->gs_lib_ctx->gs_name_table, nidx);
699
if (pnstr->foreign_string)
701
return alloc_is_since_save(pnstr->string_bytes, save);
704
/* Check whether any names have been created since a given save */
705
/* that might be released by the restore. */
707
alloc_any_names_since_save(const alloc_save_t * save)
709
return save->restore_names;
712
/* Get the saved state with a given ID. */
714
alloc_find_save(const gs_dual_memory_t * dmem, ulong sid)
716
alloc_save_t *sprev = dmem->space_local->saved;
719
return 0; /* invalid id */
721
if (sprev->id == sid)
723
sprev = sprev->state.saved;
728
/* Get the client data from a saved state. */
730
alloc_save_client_data(const alloc_save_t * save)
732
return save->client_data;
736
* Do one step of restoring the state. The client is responsible for
737
* calling alloc_find_save to get the save object, and for ensuring that
738
* there are no surviving pointers for which alloc_is_since_save is true.
739
* Return true if the argument was the innermost save, in which case
740
* this is the last (or only) step.
741
* Note that "one step" may involve multiple internal steps,
742
* if this is the outermost restore (which requires restoring both local
743
* and global VM) or if we created extra save levels to reduce scanning.
745
static void restore_finalize(gs_ref_memory_t *);
746
static void restore_space(gs_ref_memory_t *, gs_dual_memory_t *);
749
alloc_restore_step_in(gs_dual_memory_t *dmem, alloc_save_t * save)
751
/* Get save->space_* now, because the save object will be freed. */
752
gs_ref_memory_t *lmem = save->space_local;
753
gs_ref_memory_t *gmem = save->space_global;
754
gs_ref_memory_t *mem = lmem;
758
/* Finalize all objects before releasing resources or undoing changes. */
764
restore_finalize(mem); /* finalize objects */
769
while (sprev != save);
770
if (mem->save_level == 0) {
771
/* This is the outermost save, which might also */
772
/* need to restore global VM. */
774
if (mem != lmem && mem->saved != 0)
775
restore_finalize(mem);
778
/* Do one (externally visible) step of restoring the state. */
785
code = restore_resources(sprev, mem); /* release other resources */
788
restore_space(mem, dmem); /* release memory */
792
while (sprev != save);
794
if (mem->save_level == 0) {
795
/* This is the outermost save, which might also */
796
/* need to restore global VM. */
798
if (mem != lmem && mem->saved != 0) {
799
code = restore_resources(mem->saved, mem);
802
restore_space(mem, dmem);
804
alloc_set_not_in_save(dmem);
805
} else { /* Set the l_new attribute in all slots that are now new. */
808
code = save_set_new(mem, true, false, &scanned);
813
return sprev == save;
815
/* Restore the memory of one space, by undoing changes and freeing */
816
/* memory allocated since the save. */
818
restore_space(gs_ref_memory_t * mem, gs_dual_memory_t *dmem)
820
alloc_save_t *save = mem->saved;
823
print_save("restore", mem->space, save);
825
/* Undo changes since the save. */
827
register alloc_change_t *cp = mem->changes;
831
if (gs_debug_c('U')) {
832
dlputs("[U]restore");
833
alloc_save_print(cp, true);
836
if (cp->offset == AC_OFFSET_ALLOCATED)
839
if (r_is_packed(&cp->contents))
840
*cp->where = *(ref_packed *) & cp->contents;
842
ref_assign_inline((ref *) cp->where, &cp->contents);
847
/* Free memory allocated since the save. */
848
/* Note that this frees all chunks except the inner ones */
849
/* belonging to this level. */
853
/* Restore the allocator state. */
855
int num_contexts = mem->num_contexts; /* don't restore */
858
mem->num_contexts = num_contexts;
860
alloc_open_chunk(mem);
862
/* Make the allocator current if it was current before the save. */
863
if (saved.is_current) {
865
dmem->current_space = mem->space;
869
/* Restore to the initial state, releasing all resources. */
870
/* The allocator is no longer usable after calling this routine! */
872
alloc_restore_all(gs_dual_memory_t * dmem)
875
* Save the memory pointers, since freeing space_local will also
878
gs_ref_memory_t *lmem = dmem->space_local;
879
gs_ref_memory_t *gmem = dmem->space_global;
880
gs_ref_memory_t *smem = dmem->space_system;
881
gs_ref_memory_t *mem;
884
/* Restore to a state outside any saves. */
885
while (lmem->save_level != 0) {
886
code = alloc_restore_step_in(dmem, lmem->saved);
891
/* Finalize memory. */
892
restore_finalize(lmem);
893
if ((mem = (gs_ref_memory_t *)lmem->stable_memory) != lmem)
894
restore_finalize(mem);
895
if (gmem != lmem && gmem->num_contexts == 1) {
896
restore_finalize(gmem);
897
if ((mem = (gs_ref_memory_t *)gmem->stable_memory) != gmem)
898
restore_finalize(mem);
900
restore_finalize(smem);
902
/* Release resources other than memory, using fake */
903
/* save and memory objects. */
905
alloc_save_t empty_save;
907
empty_save.spaces = dmem->spaces;
908
empty_save.restore_names = false; /* don't bother to release */
909
code = restore_resources(&empty_save, NULL);
914
/* Finally, release memory. */
916
if ((mem = (gs_ref_memory_t *)lmem->stable_memory) != lmem)
919
if (!--(gmem->num_contexts)) {
921
if ((mem = (gs_ref_memory_t *)gmem->stable_memory) != gmem)
930
* Finalize objects that will be freed by a restore.
931
* Note that we must temporarily disable the freeing operations
932
* of the allocator while doing this.
935
restore_finalize(gs_ref_memory_t * mem)
939
alloc_close_chunk(mem);
940
gs_enable_free((gs_memory_t *) mem, false);
941
for (cp = mem->clast; cp != 0; cp = cp->cprev) {
942
SCAN_CHUNK_OBJECTS(cp)
944
struct_proc_finalize((*finalize)) =
945
pre->o_type->finalize;
947
if_debug2('u', "[u]restore finalizing %s 0x%lx\n",
948
struct_type_name_string(pre->o_type),
950
(*finalize) (pre + 1);
954
gs_enable_free((gs_memory_t *) mem, true);
957
/* Release resources for a restore */
959
restore_resources(alloc_save_t * sprev, gs_ref_memory_t * mem)
964
/* Note restoring of the file list. */
965
if_debug4('u', "[u%u]file_restore 0x%lx => 0x%lx for 0x%lx\n",
966
mem->space, (ulong)mem->streams,
967
(ulong)sprev->state.streams, (ulong) sprev);
971
/* Remove entries from font and character caches. */
972
code = font_restore(sprev);
976
/* Adjust the name table. */
977
if (sprev->restore_names)
978
names_restore(mem->gs_lib_ctx->gs_name_table, sprev);
982
/* Release memory for a restore. */
984
restore_free(gs_ref_memory_t * mem)
986
/* Free chunks allocated since the save. */
987
gs_free_all((gs_memory_t *) mem);
990
/* Forget a save, by merging this level with the next outer one. */
991
static void file_forget_save(gs_ref_memory_t *);
992
static void combine_space(gs_ref_memory_t *);
993
static void forget_changes(gs_ref_memory_t *);
995
alloc_forget_save_in(gs_dual_memory_t *dmem, alloc_save_t * save)
997
gs_ref_memory_t *mem = save->space_local;
1002
print_save("forget_save", mem->space, save);
1004
/* Iteratively combine the current level with the previous one. */
1009
if (mem->save_level != 0) {
1010
alloc_change_t *chp = mem->changes;
1012
code = save_set_new(&sprev->state, true, false, &scanned);
1015
/* Concatenate the changes chains. */
1017
mem->changes = sprev->state.changes;
1019
while (chp->next != 0)
1021
chp->next = sprev->state.changes;
1023
file_forget_save(mem);
1024
combine_space(mem); /* combine memory */
1026
forget_changes(mem);
1027
code = save_set_new(mem, false, false, &scanned);
1030
file_forget_save(mem);
1031
combine_space(mem); /* combine memory */
1032
/* This is the outermost save, which might also */
1033
/* need to combine global VM. */
1034
mem = save->space_global;
1035
if (mem != save->space_local && mem->saved != 0) {
1036
forget_changes(mem);
1037
code = save_set_new(mem, false, false, &scanned);
1040
file_forget_save(mem);
1043
alloc_set_not_in_save(dmem);
1044
break; /* must be outermost */
1047
while (sprev != save);
1050
/* Combine the chunks of the next outer level with those of the current one, */
1051
/* and free the bookkeeping structures. */
1053
combine_space(gs_ref_memory_t * mem)
1055
alloc_save_t *saved = mem->saved;
1056
gs_ref_memory_t *omem = &saved->state;
1060
alloc_close_chunk(mem);
1061
for (cp = mem->cfirst; cp != 0; cp = csucc) {
1062
csucc = cp->cnext; /* save before relinking */
1064
alloc_link_chunk(cp, omem);
1066
chunk_t *outer = cp->outer;
1068
outer->inner_count--;
1071
if (mem->cfreed.cp == cp)
1072
mem->cfreed.cp = outer;
1073
/* "Free" the header of the inner chunk, */
1074
/* and any immediately preceding gap left by */
1075
/* the GC having compacted the outer chunk. */
1077
obj_header_t *hp = (obj_header_t *) outer->cbot;
1080
hp->o_size = (char *)(cp->chead + 1)
1082
hp->o_type = &st_bytes;
1083
/* The following call is probably not safe. */
1084
#if 0 /* **************** */
1085
gs_free_object((gs_memory_t *) mem,
1086
hp + 1, "combine_space(header)");
1087
#endif /* **************** */
1089
/* Update the outer chunk's allocation pointers. */
1090
outer->cbot = cp->cbot;
1091
outer->rcur = cp->rcur;
1092
outer->rtop = cp->rtop;
1093
outer->ctop = cp->ctop;
1094
outer->has_refs |= cp->has_refs;
1095
gs_free_object(mem->non_gc_memory, cp,
1096
"combine_space(inner)");
1099
/* Update relevant parts of allocator state. */
1100
mem->cfirst = omem->cfirst;
1101
mem->clast = omem->clast;
1102
mem->allocated += omem->allocated;
1103
mem->gc_allocated += omem->allocated;
1104
mem->lost.objects += omem->lost.objects;
1105
mem->lost.refs += omem->lost.refs;
1106
mem->lost.strings += omem->lost.strings;
1107
mem->saved = omem->saved;
1108
mem->previous_status = omem->previous_status;
1109
{ /* Concatenate free lists. */
1112
for (i = 0; i < num_freelists; i++) {
1113
obj_header_t *olist = omem->freelists[i];
1114
obj_header_t *list = mem->freelists[i];
1118
mem->freelists[i] = olist;
1120
while (*(obj_header_t **) list != 0)
1121
list = *(obj_header_t **) list;
1122
*(obj_header_t **) list = olist;
1125
if (omem->largest_free_size > mem->largest_free_size)
1126
mem->largest_free_size = omem->largest_free_size;
1128
gs_free_object((gs_memory_t *) mem, saved, "combine_space(saved)");
1129
alloc_open_chunk(mem);
1131
/* Free the changes chain for a level 0 .forgetsave, */
1132
/* resetting the l_new flag in the changed refs. */
1134
forget_changes(gs_ref_memory_t * mem)
1136
register alloc_change_t *chp = mem->changes;
1137
alloc_change_t *next;
1139
for (; chp; chp = next) {
1140
ref_packed *prp = chp->where;
1142
if_debug1('U', "[U]forgetting change 0x%lx\n", (ulong) chp);
1143
if (chp->offset == AC_OFFSET_ALLOCATED)
1146
if (!r_is_packed(prp))
1147
r_clear_attrs((ref *) prp, l_new);
1149
gs_free_object((gs_memory_t *) mem, chp, "forget_changes");
1153
/* Update the streams list when forgetting a save. */
1155
file_forget_save(gs_ref_memory_t * mem)
1157
const alloc_save_t *save = mem->saved;
1158
stream *streams = mem->streams;
1159
stream *saved_streams = save->state.streams;
1161
if_debug4('u', "[u%d]file_forget_save 0x%lx + 0x%lx for 0x%lx\n",
1162
mem->space, (ulong) streams, (ulong) saved_streams,
1165
mem->streams = saved_streams;
1166
else if (saved_streams != 0) {
1167
while (streams->next != 0)
1168
streams = streams->next;
1169
streams->next = saved_streams;
1170
saved_streams->prev = streams;
1175
mark_allocated(void *obj, bool to_new, uint *psize)
1177
obj_header_t *pre = (obj_header_t *)obj - 1;
1178
uint size = pre_obj_contents_size(pre);
1179
ref_packed *prp = (ref_packed *) (pre + 1);
1180
ref_packed *next = (ref_packed *) ((char *)prp + size);
1181
#ifdef ALIGNMENT_ALIASING_BUG
1183
# define RP_REF(rp) (rpref = (ref *)rp, rpref)
1185
# define RP_REF(rp) ((ref *)rp)
1188
if (pre->o_type != &st_refs) {
1189
/* Must not happen. */
1190
if_debug0('u', "Wrong object type when expected a ref.\n");
1191
return_error(e_Fatal);
1193
/* We know that every block of refs ends with */
1194
/* a full-size ref, so we only need the end check */
1195
/* when we encounter one of those. */
1198
if (r_is_packed(prp))
1201
RP_REF(prp)->tas.type_attrs |= l_new;
1202
prp += packed_per_ref;
1208
if (r_is_packed(prp))
1211
RP_REF(prp)->tas.type_attrs &= ~l_new;
1212
prp += packed_per_ref;
1222
/* Check if a block contains refs marked by garbager. */
1224
check_l_mark(void *obj)
1226
obj_header_t *pre = (obj_header_t *)obj - 1;
1227
uint size = pre_obj_contents_size(pre);
1228
ref_packed *prp = (ref_packed *) (pre + 1);
1229
ref_packed *next = (ref_packed *) ((char *)prp + size);
1230
#ifdef ALIGNMENT_ALIASING_BUG
1232
# define RP_REF(rp) (rpref = (ref *)rp, rpref)
1234
# define RP_REF(rp) ((ref *)rp)
1237
/* We know that every block of refs ends with */
1238
/* a full-size ref, so we only need the end check */
1239
/* when we encounter one of those. */
1241
if (r_is_packed(prp)) {
1242
if (r_has_pmark(prp))
1246
if (r_has_attr(RP_REF(prp), l_mark))
1248
prp += packed_per_ref;
1256
/* Set or reset the l_new attribute in every relevant slot. */
1257
/* This includes every slot on the current change chain, */
1258
/* and every (ref) slot allocated at this save level. */
1259
/* Return the number of bytes of data scanned. */
1261
save_set_new(gs_ref_memory_t * mem, bool to_new, bool set_limit, ulong *pscanned)
1266
/* Handle the change chain. */
1267
code = save_set_new_changes(mem, to_new, set_limit);
1271
/* Handle newly allocated ref objects. */
1272
SCAN_MEM_CHUNKS(mem, cp) {
1274
bool has_refs = false;
1276
SCAN_CHUNK_OBJECTS(cp)
1278
if_debug3('U', "[U]set_new scan(0x%lx(%u), %d)\n",
1279
(ulong) pre, size, to_new);
1280
if (pre->o_type == &st_refs) {
1281
/* These are refs, scan them. */
1282
ref_packed *prp = (ref_packed *) (pre + 1);
1285
code = mark_allocated(prp, to_new, &size);
1290
scanned += sizeof(obj_header_t);
1292
cp->has_refs = has_refs;
1296
if_debug2('u', "[u]set_new (%s) scanned %ld\n",
1297
(to_new ? "restore" : "save"), scanned);
1298
*pscanned = scanned;
1302
/* Drop redundant elements from the changes list and set l_new. */
1304
drop_redundant_changes(gs_ref_memory_t * mem)
1306
register alloc_change_t *chp = mem->changes, *chp_back = NULL, *chp_forth;
1308
/* First reverse the list and set all. */
1309
for (; chp; chp = chp_forth) {
1310
chp_forth = chp->next;
1311
if (chp->offset != AC_OFFSET_ALLOCATED) {
1312
ref_packed *prp = chp->where;
1314
if (!r_is_packed(prp)) {
1315
ref *const rp = (ref *)prp;
1317
rp->tas.type_attrs |= l_new;
1320
chp->next = chp_back;
1323
mem->changes = chp_back;
1325
/* Then filter, reset and reverse again. */
1326
for (chp = mem->changes; chp; chp = chp_forth) {
1327
chp_forth = chp->next;
1328
if (chp->offset != AC_OFFSET_ALLOCATED) {
1329
ref_packed *prp = chp->where;
1331
if (!r_is_packed(prp)) {
1332
ref *const rp = (ref *)prp;
1334
if ((rp->tas.type_attrs & l_new) == 0) {
1335
if (mem->scan_limit == chp)
1336
mem->scan_limit = chp_back;
1337
if (mem->changes == chp)
1338
mem->changes = chp_back;
1339
gs_free_object((gs_memory_t *)mem, chp, "alloc_save_remove");
1342
rp->tas.type_attrs &= ~l_new;
1345
chp->next = chp_back;
1348
mem->changes = chp_back;
1352
/* Set or reset the l_new attribute on the changes chain. */
1354
save_set_new_changes(gs_ref_memory_t * mem, bool to_new, bool set_limit)
1356
register alloc_change_t *chp;
1357
register uint new = (to_new ? l_new : 0);
1360
if (!to_new && mem->total_scanned_after_compacting > max_repeated_scan * 16) {
1361
mem->total_scanned_after_compacting = 0;
1362
drop_redundant_changes(mem);
1364
for (chp = mem->changes; chp; chp = chp->next) {
1365
if (chp->offset == AC_OFFSET_ALLOCATED) {
1366
if (chp->where != 0) {
1368
int code = mark_allocated((void *)chp->where, to_new, &size);
1375
ref_packed *prp = chp->where;
1377
if_debug3('U', "[U]set_new 0x%lx: (0x%lx, %d)\n",
1378
(ulong)chp, (ulong)prp, new);
1379
if (!r_is_packed(prp)) {
1380
ref *const rp = (ref *) prp;
1382
rp->tas.type_attrs =
1383
(rp->tas.type_attrs & ~l_new) + new;
1386
if (mem->scan_limit == chp)
1390
mem->total_scanned_after_compacting += scanned;
1391
if (scanned + mem->total_scanned >= max_repeated_scan) {
1392
mem->scan_limit = mem->changes;
1393
mem->total_scanned = 0;
1395
mem->total_scanned += scanned;
added
removed
psi/isave.c
