Purify: Fast Detection of Memory Leaks and Access Errors

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• Purify Fast Detection of Memory Leaks and Access
  Errors

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???? ?????? ????? ?????? ?????? ? Memory Access
Errors ????? ??????? ????? ?????? ??? ?????
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????? ?? Run-Time Debugging
Source Code
Instrumentation
Executable
Run-Time debugger
BUG
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• Purify
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• Object Code Insertion
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• ??????

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Error Warning Information
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???? ?? ????? ?????? ?-Object Code??? ??? ?????
(Third Party Code)
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Code Instrumentation
1) Including Files
Source Code
2) Source Code Insertion
Object Code
3) Object Code Insertion
Executable
4) Executable Code Insertion
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Object Code Insertion
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????? ?????? ????? ?? Purify
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?????? ??????????? ??
???????? ????? ????????????? ?? ?????? (???, ???)
?????? ????????(unresolved references)
?????? ????????(unresolved references)
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Old Object Code Table
New Object Code Table
Forward Index Table
Forward Index Control Table
Inter-Item Offset Table
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Memory Status Array Memory
Monitoring Memory Access - byte-level detection -
stack access efficiency
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Detecting Array Bounds Violations
????? ?-red-zones ?????? ??? ?????? (watch points)
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Detecting Memory Leaks
??? ????? MARK ????? ?? ??????? ??? ??
???????? ????????????. ??? ??? SWEEP ????? ??
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????? ?????. ) ?-Heap ????? ?????? ????? -
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?????? ??? ??? ????????? (??? ??????? ???????) -
?????? ????? ??? (?? ??????? ???????)
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??????? OCI
1) ???? ?????? 2) Instrumentation ???? ????? ???
????? ????????? 3) ??? ????? ??????, ??? ????
???? ?????. ???? ????? ??? ?? ???? ???? ???
?-assembly ??????? ????????. 4) ????? ????
????? ????? ????? ???? ???? ???? ?-object
code ???? ?????? ??????? ?????? ?? ?? ????.
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??????? ???????
1) ???? ???? ???? ?????? ??????????, ???? ?????
?????? ?????? (????? ????? ?? ??????). 2)
????? ?????? ???? ???? ????. 3) ??????? ??????
?????????? ????? ???????? - ?????? ????? -
?????? ??????? ?????? - dangling pointers -
?-Purify ?? ?????? ???? ????? ??????? (Sub-Allocat
ors)
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Working at Source Level
Memdebug (Schmit Rene) ????? ????????? ???????
malloc, calloc, realloc ?-free. ????? ??
????? ?-PreProcessor
?? ????? ?-header ???? memdebug.h, define
MEMDEBUG ????? ???? ????? ??????.???? ?????
?????? ?????? ????? ?-stdout.
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??????? ??????
?????? ??????? - ?? sentinels memorization
?-BlockDescriptor ???? ?????
????? ?-CallSequence record ???? ?????? ?????
(?????????)
????? ?-malloc
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????? ?-free
??? ????? ???? ?????? ???? ?? ??????? ???????
????? ???.
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Insure / ParaSoft Source Code Insertion
????? ???? ???? ??????? ???? (printf(d,
1.0 . ???? ?????? ??? ??????? - ??? ????
?????? ?? ????? ??????, ????? ????? ???.
???? ?????? ??? ???????? - ????? ???? ????? ????
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?????? ?? reference counting ???? ??????.
????? ?????? ?????? ???????. ????? ?????? ?????
?-object code (??? Sentinel). Interfaces.
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Mutation Testing
Subsumption of the coverage criteria
Statement coverage Decision
coverage Condition coverage The coupling
effect Effective test case killed mutant
Adequate test sets
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Creating the Test Set
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The Mothra system mutation operators