SlideShare a Scribd company logo

Basic Garbage Collection Techniques

•Download as PPT, PDF•
•
An Khuong
An Khuong
TechnologyEducation
1 of 39
[email_address] Basic Garbage Collection Techniques
Contents ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Tracing
1. Garbage Collection ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Explicit Storage Management Hazards ,[object Object],[object Object],[object Object],[object Object],[object Object]
Explicit Storage Management Hazards ,[object Object],[object Object],[object Object],[object Object]
GC Complexity ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Garbage Collection – The Two-Phase Abstraction ,[object Object],[object Object],[object Object],[object Object]
2. Reference Counting ,[object Object],[object Object],[object Object]
Reference Counting ,[object Object],[object Object],[object Object]
The Cycles Problem ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
The Efficiency Problem ,[object Object],[object Object],[object Object]
Deferred Reference Counting ,[object Object],[object Object],[object Object],[object Object]
Reference Counting - Recap ,[object Object],[object Object],[object Object],[object Object]
3. Mark-Sweep Collection - [McCarthy 1960] ,[object Object],[object Object],[object Object],[object Object],[object Object]
Example Mark phase Sweep phase Before Heap root root root Free_list
Example p p Live object Marked object Garbage Free list r1 Free list r1 Free list r1
Basic Algorithm New (A)= if free_list is empty mark_sweep() if free_list is empty return (“out-of-memory”) pointer = allocate(A) return (pointer) mark_sweep ()= for Ptr in Roots mark(Ptr) sweep() mark (Obj)= if mark_bit(Obj) == unmarked mark_bit(Obj)=marked for C in Children(Obj) mark(C) Sweep ()= p = Heap_bottom while (p < Heap_top) if (mark_bit(p) == unmarked) then free(p) else mark_bit(p) = unmarked; p=p+size(p)
Properties of Mark & Sweep ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Standard Engineering Techniques ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
4. Mark-Compact Collection Compact after mark ,[object Object],[object Object],[object Object]
Mark-Compact Collection ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Object Ordering ,[object Object],[object Object],[object Object],1 2 3 4 Linearizing 4 1 2 3 Arbitrary Worst 1 3 4 2 Good 1 2 3 4 Sliding Best
The Two Finger Algorithm [Edwards 1974] ,[object Object],[object Object],[object Object],[object Object]
Pass I: Compact ,[object Object],[object Object],[object Object],[object Object],[object Object]
Two finger, pass I - Example
Pass II: Fix Pointers ,[object Object],[object Object],[object Object],Compacted area free area
[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Two finger –Properties
The Lisp2 Algorithm ,[object Object],[object Object],[object Object],[object Object],Free
The Lisp2 Algorithm ,[object Object],[object Object],[object Object],Free
Lisp 2 –Properties ,[object Object],[object Object],[object Object],Slower: 3 passes. Extra space required –a pointer per object.
5. Copying Garbage Collection ,[object Object],[object Object],[object Object]
Stop-and-Copy Collector ,[object Object],[object Object],[object Object]
Cheney breath-first copying
The algorithm Init()= Tospace=Heap_bottom space_size=Heap_size/2 top_of_space=Tospace+space_size Fromspace=top_of_space+1 free=Tospace New(n)= If free+n>top_of_space Collect() if free+n>top_of_space abort“Memoryexhausted” new-object=free free=free+n return(new-object) collect()= from-space,to-space= to-space,from-space//swap scan=free=Tospace top_of_space=Tospace+space_size forRinRoots R=copy(R) whilescan<free forPinchildren(scan) *P=copy(P) scan=scan+size(scan) copy(P)= ifforwarded(P) returnforwarding_address(P) else addr=free mem-copy(P,free) free=free+size(P) forwarding_address(P)=addr return(addr) 1 2 4 3
Efficiency of Copying Collection ,[object Object],[object Object],[object Object],[object Object]
6. Non-Copying Implicit Collection ,[object Object],[object Object],[object Object],[object Object],[object Object]
7. Choosing Among Basic Tracing Techniques ,[object Object],[object Object],[object Object],[object Object],[object Object]
8. Problems with Simple Tracing Collectors
9. Conservatism in GC ,[object Object],[object Object],[object Object]

Recommended

Garbage collection
Garbage collectionGarbage collection
Garbage collectionSomya Bagai
 
Introduction to Garbage Collection
Introduction to Garbage CollectionIntroduction to Garbage Collection
Introduction to Garbage CollectionArtur Mkrtchyan
 
Garbage collection
Garbage collectionGarbage collection
Garbage collectionMudit Gupta
 
Garbage collection algorithms
Garbage collection algorithmsGarbage collection algorithms
Garbage collection algorithmsachinth
 
Inheritance in OOPs with java
Inheritance in OOPs with javaInheritance in OOPs with java
Inheritance in OOPs with javaAAKANKSHA JAIN
 
Java Garbage Collection - How it works
Java Garbage Collection - How it worksJava Garbage Collection - How it works
Java Garbage Collection - How it worksMindfire Solutions
 
Heap Management
Heap ManagementHeap Management
Heap ManagementJenny Galino
 
Exception Handling in object oriented programming using C++
Exception Handling in object oriented programming using C++Exception Handling in object oriented programming using C++
Exception Handling in object oriented programming using C++Janki Shah
 

Recommended

Garbage collection
Garbage collectionGarbage collection
Garbage collectionSomya Bagai
 
Introduction to Garbage Collection
Introduction to Garbage CollectionIntroduction to Garbage Collection
Introduction to Garbage CollectionArtur Mkrtchyan
 
Garbage collection
Garbage collectionGarbage collection
Garbage collectionMudit Gupta
 
Garbage collection algorithms
Garbage collection algorithmsGarbage collection algorithms
Garbage collection algorithmsachinth
 
Inheritance in OOPs with java
Inheritance in OOPs with javaInheritance in OOPs with java
Inheritance in OOPs with javaAAKANKSHA JAIN
 
Java Garbage Collection - How it works
Java Garbage Collection - How it worksJava Garbage Collection - How it works
Java Garbage Collection - How it worksMindfire Solutions
 
Heap Management
Heap ManagementHeap Management
Heap ManagementJenny Galino
 
Exception Handling in object oriented programming using C++
Exception Handling in object oriented programming using C++Exception Handling in object oriented programming using C++
Exception Handling in object oriented programming using C++Janki Shah
 
Java threads
Java threadsJava threads
Java threadsPrabhakaran V M
 
contiguous memory allocation.pptx
contiguous memory allocation.pptxcontiguous memory allocation.pptx
contiguous memory allocation.pptxRajapriya82
 
Chapter 02: Classes Objects and Methods Java by Tushar B Kute
Chapter 02: Classes Objects and Methods Java by Tushar B KuteChapter 02: Classes Objects and Methods Java by Tushar B Kute
Chapter 02: Classes Objects and Methods Java by Tushar B KuteTushar B Kute
 
Cache Memory
Cache Memory Cache Memory
Cache Memory sathish sak
 
Java GC
Java GCJava GC
Java GCRay Cheng
 
C++ Memory Management
C++ Memory ManagementC++ Memory Management
C++ Memory ManagementRahul Jamwal
 
Java exception handling ppt
Java exception handling pptJava exception handling ppt
Java exception handling pptJavabynataraJ
 
Dynamic storage allocation techniques in Compiler design
Dynamic storage allocation techniques in Compiler designDynamic storage allocation techniques in Compiler design
Dynamic storage allocation techniques in Compiler designkunjan shah
 
Macro Processor
Macro ProcessorMacro Processor
Macro ProcessorSaranya1702
 
Strings in Java
Strings in JavaStrings in Java
Strings in JavaAbhilash Nair
 
Constructors & destructors
Constructors & destructorsConstructors & destructors
Constructors & destructorsForwardBlog Enewzletter
 
String handling(string class)
String handling(string class)String handling(string class)
String handling(string class)Ravi_Kant_Sahu
 
Cache memory
Cache memoryCache memory
Cache memoryShailesh Tanwar
 
Command line arguments
Command line argumentsCommand line arguments
Command line argumentsAshok Raj
 
Data Structure and Algorithms.pptx
Data Structure and Algorithms.pptxData Structure and Algorithms.pptx
Data Structure and Algorithms.pptxSyed Zaid Irshad
 
Memory Management In C++
Memory Management In C++Memory Management In C++
Memory Management In C++ShriKant Vashishtha
 
Cache memory ppt
Cache memory ppt Cache memory ppt
Cache memory ppt Arpita Naik
 
sets and maps
sets and maps sets and maps
sets and mapsRajkattamuri
 
MULTI THREADING IN JAVA
MULTI THREADING IN JAVAMULTI THREADING IN JAVA
MULTI THREADING IN JAVAVINOTH R
 
classes and objects in C++
classes and objects in C++classes and objects in C++
classes and objects in C++HalaiHansaika
 
Garbage Collection in Hotspot JVM
Garbage Collection in Hotspot JVMGarbage Collection in Hotspot JVM
Garbage Collection in Hotspot JVMjaganmohanreddyk
 
I phone arc
I phone arcI phone arc
I phone arcPragati Singh
 

More Related Content

What's hot

contiguous memory allocation.pptx
contiguous memory allocation.pptxcontiguous memory allocation.pptx
contiguous memory allocation.pptxRajapriya82
 
Chapter 02: Classes Objects and Methods Java by Tushar B Kute
Chapter 02: Classes Objects and Methods Java by Tushar B KuteChapter 02: Classes Objects and Methods Java by Tushar B Kute
Chapter 02: Classes Objects and Methods Java by Tushar B KuteTushar B Kute
 
C++ Memory Management
C++ Memory ManagementC++ Memory Management
C++ Memory ManagementRahul Jamwal
 
Java exception handling ppt
Java exception handling pptJava exception handling ppt
Java exception handling pptJavabynataraJ
 
Dynamic storage allocation techniques in Compiler design
Dynamic storage allocation techniques in Compiler designDynamic storage allocation techniques in Compiler design
Dynamic storage allocation techniques in Compiler designkunjan shah
 
String handling(string class)
String handling(string class)String handling(string class)
String handling(string class)Ravi_Kant_Sahu
 
Command line arguments
Command line argumentsCommand line arguments
Command line argumentsAshok Raj
 
Data Structure and Algorithms.pptx
Data Structure and Algorithms.pptxData Structure and Algorithms.pptx
Data Structure and Algorithms.pptxSyed Zaid Irshad
 
Cache memory ppt
Cache memory ppt Cache memory ppt
Cache memory ppt Arpita Naik
 
MULTI THREADING IN JAVA
MULTI THREADING IN JAVAMULTI THREADING IN JAVA
MULTI THREADING IN JAVAVINOTH R
 
classes and objects in C++
classes and objects in C++classes and objects in C++
classes and objects in C++HalaiHansaika
 

What's hot (20)

Java threads
Java threadsJava threads
Java threads
 
contiguous memory allocation.pptx
contiguous memory allocation.pptxcontiguous memory allocation.pptx
contiguous memory allocation.pptx
 
Chapter 02: Classes Objects and Methods Java by Tushar B Kute
Chapter 02: Classes Objects and Methods Java by Tushar B KuteChapter 02: Classes Objects and Methods Java by Tushar B Kute
Chapter 02: Classes Objects and Methods Java by Tushar B Kute
 
Cache Memory
Cache Memory Cache Memory
Cache Memory
 
Java GC
Java GCJava GC
Java GC
 
C++ Memory Management
C++ Memory ManagementC++ Memory Management
C++ Memory Management
 
Java exception handling ppt
Java exception handling pptJava exception handling ppt
Java exception handling ppt
 
Dynamic storage allocation techniques in Compiler design
Dynamic storage allocation techniques in Compiler designDynamic storage allocation techniques in Compiler design
Dynamic storage allocation techniques in Compiler design
 
Macro Processor
Macro ProcessorMacro Processor
Macro Processor
 
Strings in Java
Strings in JavaStrings in Java
Strings in Java
 
Constructors & destructors
Constructors & destructorsConstructors & destructors
Constructors & destructors
 
String handling(string class)
String handling(string class)String handling(string class)
String handling(string class)
 
Cache memory
Cache memoryCache memory
Cache memory
 
Command line arguments
Command line argumentsCommand line arguments
Command line arguments
 
Data Structure and Algorithms.pptx
Data Structure and Algorithms.pptxData Structure and Algorithms.pptx
Data Structure and Algorithms.pptx
 
Memory Management In C++
Memory Management In C++Memory Management In C++
Memory Management In C++
 
Cache memory ppt
Cache memory ppt Cache memory ppt
Cache memory ppt
 
sets and maps
sets and maps sets and maps
sets and maps
 
MULTI THREADING IN JAVA
MULTI THREADING IN JAVAMULTI THREADING IN JAVA
MULTI THREADING IN JAVA
 
classes and objects in C++
classes and objects in C++classes and objects in C++
classes and objects in C++
 

Similar to Basic Garbage Collection Techniques

Garbage Collection in Hotspot JVM
Garbage Collection in Hotspot JVMGarbage Collection in Hotspot JVM
Garbage Collection in Hotspot JVMjaganmohanreddyk
 
.NET Core, ASP.NET Core Course, Session 4
.NET Core, ASP.NET Core Course, Session 4.NET Core, ASP.NET Core Course, Session 4
.NET Core, ASP.NET Core Course, Session 4aminmesbahi
 
Garbage collector complete information
Garbage collector complete informationGarbage collector complete information
Garbage collector complete informationMubarak Hussain
 
Memory Management in the Java Virtual Machine(Garbage collection)
Memory Management in the Java Virtual Machine(Garbage collection)Memory Management in the Java Virtual Machine(Garbage collection)
Memory Management in the Java Virtual Machine(Garbage collection)Prashanth Kumar
 
Java Garbage Collection, Monitoring, and Tuning
Java Garbage Collection, Monitoring, and TuningJava Garbage Collection, Monitoring, and Tuning
Java Garbage Collection, Monitoring, and TuningCarol McDonald
 
Garbage Collection in Java.pdf
Garbage Collection in Java.pdfGarbage Collection in Java.pdf
Garbage Collection in Java.pdfSudhanshiBakre1
 
.NET UY Meetup 7 - CLR Memory by Fabian Alves
.NET UY Meetup 7 - CLR Memory by Fabian Alves.NET UY Meetup 7 - CLR Memory by Fabian Alves
.NET UY Meetup 7 - CLR Memory by Fabian Alves.NET UY Meetup
 
Stacks
StacksStacks
StacksAcad
 
Let's talk about Garbage Collection
Let's talk about Garbage CollectionLet's talk about Garbage Collection
Let's talk about Garbage CollectionHaim Yadid
 
How to empower community by using GIS lecture 2
How to empower community by using GIS lecture 2How to empower community by using GIS lecture 2
How to empower community by using GIS lecture 2wang yaohui
 
Memory Management in Go: Stack, Heap & Garbage Collector
Memory Management in Go: Stack, Heap & Garbage CollectorMemory Management in Go: Stack, Heap & Garbage Collector
Memory Management in Go: Stack, Heap & Garbage CollectorWednesday Solutions
 
Chronicles Of Garbage Collection (GC)
Chronicles Of Garbage Collection (GC)Chronicles Of Garbage Collection (GC)
Chronicles Of Garbage Collection (GC)Techizzaa
 
Is2215 lecture5 lecturer_g_cand_classlibraries
Is2215 lecture5 lecturer_g_cand_classlibrariesIs2215 lecture5 lecturer_g_cand_classlibraries
Is2215 lecture5 lecturer_g_cand_classlibrariesdannygriff1
 

Similar to Basic Garbage Collection Techniques (20)

Garbage Collection in Hotspot JVM
Garbage Collection in Hotspot JVMGarbage Collection in Hotspot JVM
Garbage Collection in Hotspot JVM
 
I phone arc
I phone arcI phone arc
I phone arc
 
Gc in android
Gc in androidGc in android
Gc in android
 
.NET Core, ASP.NET Core Course, Session 4
.NET Core, ASP.NET Core Course, Session 4.NET Core, ASP.NET Core Course, Session 4
.NET Core, ASP.NET Core Course, Session 4
 
Garbage collector complete information
Garbage collector complete informationGarbage collector complete information
Garbage collector complete information
 
Memory Management in the Java Virtual Machine(Garbage collection)
Memory Management in the Java Virtual Machine(Garbage collection)Memory Management in the Java Virtual Machine(Garbage collection)
Memory Management in the Java Virtual Machine(Garbage collection)
 
Java Garbage Collection, Monitoring, and Tuning
Java Garbage Collection, Monitoring, and TuningJava Garbage Collection, Monitoring, and Tuning
Java Garbage Collection, Monitoring, and Tuning
 
Unit 5
Unit 5Unit 5
Unit 5
 
Garbage Collection in Java.pdf
Garbage Collection in Java.pdfGarbage Collection in Java.pdf
Garbage Collection in Java.pdf
 
Chapter 7 Run Time Environment
Chapter 7 Run Time EnvironmentChapter 7 Run Time Environment
Chapter 7 Run Time Environment
 
.NET UY Meetup 7 - CLR Memory by Fabian Alves
.NET UY Meetup 7 - CLR Memory by Fabian Alves.NET UY Meetup 7 - CLR Memory by Fabian Alves
.NET UY Meetup 7 - CLR Memory by Fabian Alves
 
Hashing.pptx
Hashing.pptxHashing.pptx
Hashing.pptx
 
Stacks
StacksStacks
Stacks
 
Ruby memory tips and tricks
Ruby memory tips and tricksRuby memory tips and tricks
Ruby memory tips and tricks
 
Memory management
Memory managementMemory management
Memory management
 
Let's talk about Garbage Collection
Let's talk about Garbage CollectionLet's talk about Garbage Collection
Let's talk about Garbage Collection
 
How to empower community by using GIS lecture 2
How to empower community by using GIS lecture 2How to empower community by using GIS lecture 2
How to empower community by using GIS lecture 2
 
Memory Management in Go: Stack, Heap & Garbage Collector
Memory Management in Go: Stack, Heap & Garbage CollectorMemory Management in Go: Stack, Heap & Garbage Collector
Memory Management in Go: Stack, Heap & Garbage Collector
 
Chronicles Of Garbage Collection (GC)
Chronicles Of Garbage Collection (GC)Chronicles Of Garbage Collection (GC)
Chronicles Of Garbage Collection (GC)
 
Is2215 lecture5 lecturer_g_cand_classlibraries
Is2215 lecture5 lecturer_g_cand_classlibrariesIs2215 lecture5 lecturer_g_cand_classlibraries
Is2215 lecture5 lecturer_g_cand_classlibraries
 

Recently uploaded

How to convert PDF to text with Nanonets
How to convert PDF to text with NanonetsHow to convert PDF to text with Nanonets
How to convert PDF to text with Nanonetsnaman860154
 
WhatsApp 9892124323 ✓Call Girls In Kalyan ( Mumbai ) secure service
WhatsApp 9892124323 ✓Call Girls In Kalyan ( Mumbai ) secure serviceWhatsApp 9892124323 ✓Call Girls In Kalyan ( Mumbai ) secure service
WhatsApp 9892124323 ✓Call Girls In Kalyan ( Mumbai ) secure servicePooja Nehwal
 
Making_way_through_DLL_hollowing_inspite_of_CFG_by_Debjeet Banerjee.pptx
Making_way_through_DLL_hollowing_inspite_of_CFG_by_Debjeet Banerjee.pptxMaking_way_through_DLL_hollowing_inspite_of_CFG_by_Debjeet Banerjee.pptx
Making_way_through_DLL_hollowing_inspite_of_CFG_by_Debjeet Banerjee.pptxnull - The Open Security Community
 
Injustice - Developers Among Us (SciFiDevCon 2024)
Injustice - Developers Among Us (SciFiDevCon 2024)Injustice - Developers Among Us (SciFiDevCon 2024)
Injustice - Developers Among Us (SciFiDevCon 2024)Allon Mureinik
 
IAC 2024 - IA Fast Track to Search Focused AI Solutions
IAC 2024 - IA Fast Track to Search Focused AI SolutionsIAC 2024 - IA Fast Track to Search Focused AI Solutions
IAC 2024 - IA Fast Track to Search Focused AI SolutionsEnterprise Knowledge
 
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 3652toLead Limited
 
08448380779 Call Girls In Diplomatic Enclave Women Seeking Men
08448380779 Call Girls In Diplomatic Enclave Women Seeking Men08448380779 Call Girls In Diplomatic Enclave Women Seeking Men
08448380779 Call Girls In Diplomatic Enclave Women Seeking MenDelhi Call girls
 
Azure Monitor & Application Insight to monitor Infrastructure & Application
Azure Monitor & Application Insight to monitor Infrastructure & ApplicationAzure Monitor & Application Insight to monitor Infrastructure & Application
Azure Monitor & Application Insight to monitor Infrastructure & ApplicationAndikSusilo4
 
FULL ENJOY 🔝 8264348440 🔝 Call Girls in Diplomatic Enclave | Delhi
FULL ENJOY 🔝 8264348440 🔝 Call Girls in Diplomatic Enclave | DelhiFULL ENJOY 🔝 8264348440 🔝 Call Girls in Diplomatic Enclave | Delhi
FULL ENJOY 🔝 8264348440 🔝 Call Girls in Diplomatic Enclave | Delhisoniya singh
 
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024BookNet Canada
 
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmaticsKotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmaticscarlostorres15106
 
Pigging Solutions in Pet Food Manufacturing
Pigging Solutions in Pet Food ManufacturingPigging Solutions in Pet Food Manufacturing
Pigging Solutions in Pet Food ManufacturingPigging Solutions
 
Maximizing Board Effectiveness 2024 Webinar.pptx
Maximizing Board Effectiveness 2024 Webinar.pptxMaximizing Board Effectiveness 2024 Webinar.pptx
Maximizing Board Effectiveness 2024 Webinar.pptxOnBoard
 
Hyderabad Call Girls Khairatabad ✨ 7001305949 ✨ Cheap Price Your Budget
Hyderabad Call Girls Khairatabad ✨ 7001305949 ✨ Cheap Price Your BudgetHyderabad Call Girls Khairatabad ✨ 7001305949 ✨ Cheap Price Your Budget
Hyderabad Call Girls Khairatabad ✨ 7001305949 ✨ Cheap Price Your BudgetEnjoy Anytime
 
Neo4j - How KGs are shaping the future of Generative AI at AWS Summit London ...
Neo4j - How KGs are shaping the future of Generative AI at AWS Summit London ...Neo4j - How KGs are shaping the future of Generative AI at AWS Summit London ...
Neo4j - How KGs are shaping the future of Generative AI at AWS Summit London ...Neo4j
 
Transforming Data Streams with Kafka Connect: An Introduction to Single Messa...
Transforming Data Streams with Kafka Connect: An Introduction to Single Messa...Transforming Data Streams with Kafka Connect: An Introduction to Single Messa...
Transforming Data Streams with Kafka Connect: An Introduction to Single Messa...HostedbyConfluent
 
Artificial intelligence in the post-deep learning era
Artificial intelligence in the post-deep learning eraArtificial intelligence in the post-deep learning era
Artificial intelligence in the post-deep learning eraDeakin University
 
Install Stable Diffusion in windows machine
Install Stable Diffusion in windows machineInstall Stable Diffusion in windows machine
Install Stable Diffusion in windows machinePadma Pradeep
 

Recently uploaded (20)

The transition to renewables in India.pdf
The transition to renewables in India.pdfThe transition to renewables in India.pdf
The transition to renewables in India.pdf
 
How to convert PDF to text with Nanonets
How to convert PDF to text with NanonetsHow to convert PDF to text with Nanonets
How to convert PDF to text with Nanonets
 
WhatsApp 9892124323 ✓Call Girls In Kalyan ( Mumbai ) secure service
WhatsApp 9892124323 ✓Call Girls In Kalyan ( Mumbai ) secure serviceWhatsApp 9892124323 ✓Call Girls In Kalyan ( Mumbai ) secure service
WhatsApp 9892124323 ✓Call Girls In Kalyan ( Mumbai ) secure service
 
E-Vehicle_Hacking_by_Parul Sharma_null_owasp.pptx
E-Vehicle_Hacking_by_Parul Sharma_null_owasp.pptxE-Vehicle_Hacking_by_Parul Sharma_null_owasp.pptx
E-Vehicle_Hacking_by_Parul Sharma_null_owasp.pptx
 
Making_way_through_DLL_hollowing_inspite_of_CFG_by_Debjeet Banerjee.pptx
Making_way_through_DLL_hollowing_inspite_of_CFG_by_Debjeet Banerjee.pptxMaking_way_through_DLL_hollowing_inspite_of_CFG_by_Debjeet Banerjee.pptx
Making_way_through_DLL_hollowing_inspite_of_CFG_by_Debjeet Banerjee.pptx
 
Injustice - Developers Among Us (SciFiDevCon 2024)
Injustice - Developers Among Us (SciFiDevCon 2024)Injustice - Developers Among Us (SciFiDevCon 2024)
Injustice - Developers Among Us (SciFiDevCon 2024)
 
IAC 2024 - IA Fast Track to Search Focused AI Solutions
IAC 2024 - IA Fast Track to Search Focused AI SolutionsIAC 2024 - IA Fast Track to Search Focused AI Solutions
IAC 2024 - IA Fast Track to Search Focused AI Solutions
 
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
Tech-Forward - Achieving Business Readiness For Copilot in Microsoft 365
 
08448380779 Call Girls In Diplomatic Enclave Women Seeking Men
08448380779 Call Girls In Diplomatic Enclave Women Seeking Men08448380779 Call Girls In Diplomatic Enclave Women Seeking Men
08448380779 Call Girls In Diplomatic Enclave Women Seeking Men
 
Azure Monitor & Application Insight to monitor Infrastructure & Application
Azure Monitor & Application Insight to monitor Infrastructure & ApplicationAzure Monitor & Application Insight to monitor Infrastructure & Application
Azure Monitor & Application Insight to monitor Infrastructure & Application
 
FULL ENJOY 🔝 8264348440 🔝 Call Girls in Diplomatic Enclave | Delhi
FULL ENJOY 🔝 8264348440 🔝 Call Girls in Diplomatic Enclave | DelhiFULL ENJOY 🔝 8264348440 🔝 Call Girls in Diplomatic Enclave | Delhi
FULL ENJOY 🔝 8264348440 🔝 Call Girls in Diplomatic Enclave | Delhi
 
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
Transcript: #StandardsGoals for 2024: What’s new for BISAC - Tech Forum 2024
 
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmaticsKotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
Kotlin Multiplatform & Compose Multiplatform - Starter kit for pragmatics
 
Pigging Solutions in Pet Food Manufacturing
Pigging Solutions in Pet Food ManufacturingPigging Solutions in Pet Food Manufacturing
Pigging Solutions in Pet Food Manufacturing
 
Maximizing Board Effectiveness 2024 Webinar.pptx
Maximizing Board Effectiveness 2024 Webinar.pptxMaximizing Board Effectiveness 2024 Webinar.pptx
Maximizing Board Effectiveness 2024 Webinar.pptx
 
Hyderabad Call Girls Khairatabad ✨ 7001305949 ✨ Cheap Price Your Budget
Hyderabad Call Girls Khairatabad ✨ 7001305949 ✨ Cheap Price Your BudgetHyderabad Call Girls Khairatabad ✨ 7001305949 ✨ Cheap Price Your Budget
Hyderabad Call Girls Khairatabad ✨ 7001305949 ✨ Cheap Price Your Budget
 
Neo4j - How KGs are shaping the future of Generative AI at AWS Summit London ...
Neo4j - How KGs are shaping the future of Generative AI at AWS Summit London ...Neo4j - How KGs are shaping the future of Generative AI at AWS Summit London ...
Neo4j - How KGs are shaping the future of Generative AI at AWS Summit London ...
 
Transforming Data Streams with Kafka Connect: An Introduction to Single Messa...
Transforming Data Streams with Kafka Connect: An Introduction to Single Messa...Transforming Data Streams with Kafka Connect: An Introduction to Single Messa...
Transforming Data Streams with Kafka Connect: An Introduction to Single Messa...
 
Artificial intelligence in the post-deep learning era
Artificial intelligence in the post-deep learning eraArtificial intelligence in the post-deep learning era
Artificial intelligence in the post-deep learning era
 
Install Stable Diffusion in windows machine
Install Stable Diffusion in windows machineInstall Stable Diffusion in windows machine
Install Stable Diffusion in windows machine
 

Basic Garbage Collection Techniques

  • 1. [email_address] Basic Garbage Collection Techniques
  • 2.
  • 3.
  • 4.
  • 5.
  • 6.
  • 7.
  • 8.
  • 9.
  • 10.
  • 11.
  • 12.
  • 13.
  • 14.
  • 15. Example Mark phase Sweep phase Before Heap root root root Free_list
  • 16. Example p p Live object Marked object Garbage Free list r1 Free list r1 Free list r1
  • 17. Basic Algorithm New (A)= if free_list is empty mark_sweep() if free_list is empty return (“out-of-memory”) pointer = allocate(A) return (pointer) mark_sweep ()= for Ptr in Roots mark(Ptr) sweep() mark (Obj)= if mark_bit(Obj) == unmarked mark_bit(Obj)=marked for C in Children(Obj) mark(C) Sweep ()= p = Heap_bottom while (p < Heap_top) if (mark_bit(p) == unmarked) then free(p) else mark_bit(p) = unmarked; p=p+size(p)
  • 18.
  • 19.
  • 20.
  • 21.
  • 22.
  • 23.
  • 24.
  • 25. Two finger, pass I - Example
  • 26.
  • 27.
  • 28.
  • 29.
  • 30.
  • 31.
  • 32.
  • 34. The algorithm Init()= Tospace=Heap_bottom space_size=Heap_size/2 top_of_space=Tospace+space_size Fromspace=top_of_space+1 free=Tospace New(n)= If free+n>top_of_space Collect() if free+n>top_of_space abort“Memoryexhausted” new-object=free free=free+n return(new-object) collect()= from-space,to-space= to-space,from-space//swap scan=free=Tospace top_of_space=Tospace+space_size forRinRoots R=copy(R) whilescan<free forPinchildren(scan) *P=copy(P) scan=scan+size(scan) copy(P)= ifforwarded(P) returnforwarding_address(P) else addr=free mem-copy(P,free) free=free+size(P) forwarding_address(P)=addr return(addr) 1 2 4 3
  • 35.
  • 36.
  • 37.
  • 38. 8. Problems with Simple Tracing Collectors
  • 39.

Editor's Notes

  1. Ưu điểm: Ko cần cấp thêm vùng nhớ để lưu trữ trường count field Các object ko cần di chuyển trong quá trình GC Loại bỏ được rác trong trường hợp có tham chiếu vòng (cyclic structures) Nhược điểm: Giới hạn giá trị lớn nhất có thể của ô nhớ (integer) Tăng khả năng làm phân mảnh vùng nhớ Chương trình phải tạm dừng khi GC thực thi Giai đoạn sweep tốn chi phí cao(thời gian)
  2. Ưu điểm: Giảm khả năng phân mảnh vùng nhớ heap. Thời gian thực hiện công việc thì tỉ lệ với các live object Có thể xử lý được rác chứa các tham chiếu vòng Không tốn bộ nhớ để lưu trường count field Nhược điểm: Vùng nhớ dùng cho chương trình bị chia đôi(fromspace – tospace) Các object phải di chuyển trong vùng nhớ trong suốt quá trình thu gom rác, do vậy các tham chiếu đến các đối tượng cũng phải cập nhật. Chương trình phải tạm dừng khi bộ thu gom rác thực thi.