Concurrent vsparallel
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The document presents an overview of concurrency and parallelism in programming, highlighting the differences and relationship between the two concepts. It discusses various programming languages that support these techniques, including C, C++, and Go, and outlines the advantages and challenges associated with their implementation. Additionally, it emphasizes the importance of understanding complex algorithms, debugging issues, and performance considerations.
Concurrent vsparallel
- 1. GlusterFS1 Concurrent is NOT Parallel Joseph Fernandes Senior Software Engineer, Red Hat Storage
- 2. GlusterFS2 Who am I ? ● Joseph Fernandes (Senior Software Engineer, Red Hat Storage) ● Gluster Data Tiering ● YADL (Deduplication) ● Gluster Archival/Compliance – WORM/Retention
- 3. GlusterFS3 Agenda ● What is Concurrency ? ● What is Parallelism ? ● Concurrency with Parallelism ● Just Concurrent Not Parallel ● Advantages vs Disadvantages ● Programming Language support ● C ● C++ ● GO
- 4. GlusterFS4 What is Concurrency? Concurrency is about dealing with lots of things at once.
- 5. GlusterFS5 What is Concurrency? Masala Dosa & Coffee…. Hmmm EAT DRINK LEAVE Place order Place order Order Ready Order Ready
- 7. GlusterFS7 What is Parallelism? Parallelism is about doing lots of things at once.
- 8. GlusterFS8 What is Parallelism? Masala Dosa & Coffee…. Hmmm EAT DRINK LEAVE Place order Place order Order Ready Order Ready Waiting or Doing something CLONE1 CLONE2
- 10. GlusterFS10 Concurrency with Parallelism Food Order Queue Prepared Food Queue Concurrent Order Receiver Concurrent Dosa Master Concurrent Customer Context Switch
- 11. GlusterFS11 Concurrency with Parallelism Concurrent Customers Food Order Queue Prepared Food Queue Concurrent + Parallel Order Receivers Concurrent + Parallel Dosa Masters
- 12. GlusterFS12 Similarity with IO systems Application IO API Blocking IO Calls Concurrent IO Thread Concurrent IO Thread Concurrent IO Thread IO Device Interface Thread 1 Thread 2 Thread 3 Context Memory Context Memory
- 13. GlusterFS13 More Simplified .. Thread1 { Block1() { Yield() } Continue } Thread2 { Block2() { Yield () } Continue } Thread3 { Block3() { Yield () } Continue } Context Memory (Will be waked when unblocked error or success) Concurrent IO Thread
- 14. GlusterFS14 More Simplified Context memory Wakeup1() Concurrent IO Thread Thread1 Wakeup2() Thread2 Wakeup3() Thread3 Sleep() until Something comes In the context memory
- 15. GlusterFS15 Just Concurrent Not Parallel consume () { char a = ''; while (a == getchar()) { //do somehing with a } } producer () { { char a = '' while (doing something) { a = somecompute to produce; putchar (a); } } Interesting problem : How do I communicate memory without having multiple threads/processes?
- 16. GlusterFS16 Just Concurrent Not Parallel Producer () produces 'a' consumer () consumes 'a' Producer () produces 'b' consumer () consumes 'b' Producer () produces 'EOF' And returns consumer () consumes 'EOF' And returns Thread 1
- 17. GlusterFS17 Co-routines Coroutines are computer program components that generalize subroutines for nonpreemptive multitasking, by allowing multiple entry points for suspending and resuming execution at certain locations.
- 18. GlusterFS18 Advantages ● Improved performance and responsiveness ● More real-life approach of solving problems ● Code is more modular and hence less duplication ● Efficient use of Multi-Core CPUs
- 19. GlusterFS19 Things to remember ● Increase memory footprints ● Complex Algorithms for implementation ● Dangerous concurrency and synchronization bugs ● Complex Debugging : Bugs, Memory Leaks, Deadlocks etc ● Performance Backfire : Sloppy design ● Code Portability
- 20. GlusterFS20 Programming Language Support : C ● Pthread ● Mutex locks ● Condition Variables ● Atomic Variables ● setjmp, sigsetjmp, longjmp, siglongjmp - performing a nonlocal goto
- 21. GlusterFS21 Programming Language Support : C++ ● Support as C ● Coroutines ● Boost Library ● C++17
- 22. GlusterFS22 Programming Language Support : GO ● Goroutines ● Go Channels
- 23. GlusterFS23 References ● http://tutorials.jenkov.com/java-concurrency/concurrency-vs ● https://en.wikipedia.org/wiki/Concurrent_computing ● http://blog.golang.org/concurrency-is-not-parallelism ● http://stackoverflow.com/questions/1050222/concurrency-v