53 lines
1.9 KiB
C
53 lines
1.9 KiB
C
/**
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Allocates and deallocates regions of pages. The page before each
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region is of type BOUNDARY_TAG. All regions except the last one in
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the page file have a BOUNDARY_TAG page immediately after the end of
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the region.
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Each region is managed by an allocation manager, which manages the
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allocation of pages within a region. The contents of pages within
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a newly allocated region are undefined.
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*/
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typedef struct boundary_tag {
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pageid_t size;
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pageid_t prev_size;
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int status;
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int region_xid;
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int allocation_manager;
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} boundary_tag;
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#define REGION_BASE (123)
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#define REGION_VACANT (REGION_BASE + 0)
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#define REGION_ZONED (REGION_BASE + 1)
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#define REGION_OCCUPIED (REGION_BASE + 2)
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#define REGION_CONDEMNED (REGION_BASE + 3)
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void regionsInit();
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pageid_t TregionAlloc(int xid, pageid_t pageCount, int allocaionManager);
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void TregionDealloc(int xid, pageid_t firstPage);
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unsigned int TregionSize(int xid, pageid_t firstPage);
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/** Currently, this function is O(n) in the number of regions, so be careful! */
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void TregionFindNthActive(int xid, pageid_t n, pageid_t * firstPage, pageid_t * size);
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int TregionNextBoundaryTag(int xid, pageid_t*pid, boundary_tag *tag, int allocationManager);
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int TregionReadBoundaryTag(int xid, pageid_t pid, boundary_tag *tag);
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stasis_operation_impl stasis_op_impl_boundary_tag_alloc();
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stasis_operation_impl stasis_op_impl_region_alloc();
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stasis_operation_impl stasis_op_impl_region_alloc_inverse();
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stasis_operation_impl stasis_op_impl_region_dealloc();
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stasis_operation_impl stasis_op_impl_region_dealloc_inverse();
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/** This function checks the regions in the page file for consistency.
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It makes sure that the doublly linked list is consistent (eg
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this->next->prev == this), and it makes sure that all boundary
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tags pages (that are marked REGION_ZONED) occur somewhere in the
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linked list. */
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void fsckRegions(int xid);
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// XXX need callbacks to handle transaction commit/abort.
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