COP 5611 Operating Systems Spring Dan C. Marinescu Office: HEC 439 B Office hours: M-Wd 2:00-3:00 PM
|
|
- Esmond Stewart
- 6 years ago
- Views:
Transcription
1 COP 5611 Operating Systems Spring 2010 Dan C. Marinescu Office: HEC 439 B Office hours: M-Wd 2:00-3:00 PM
2 Lecture 7 Last time: Thread coordination Today: Thread coordination Scheduling Multi-level memories I/O bottleneck Next Time: 2
3 Hardware support for atomic actions RSM (Read and Set Memory) instruction TST (Test and Set) instruction Two primitives: ACQUIRE (lock) RELEASE (lock) use atomic instructions to manipulate the lock.
4 Lecture 6 4
5 Processor sharing strategies The previous solution assume that each thread runs on a different processor and have the luxury of a spin lock and busy wait. Now we consider sharing a processor among several threads and need several new functions: Strategy 1: a thread voluntary releases the control of the processor Allow a thread to wait for an event; Allow several threads running on the same processor to wait for a lock. Strategy 2: force a thread to release the control of the processor What needs to be done to switch the processor from one thread to another: Save the state of the current thread Schedule another thread Start running the new thread 5
6 The kernel The role of a kernel: controls virtualization Processor sharing among threads Virtual memory management I/O operations Two modes of running: user (unprivileged) + kernel (privileged) Two types of threads: user-layer threads + processor-layer threads. Open questions How to create and terminate a thread? If multiple threads are RUNNABLE who decides which one gets control of the processor? What if no threads are ready to run? 6
7 The procedure followed when a kernel starts Procedure RUN_PROCESSORS() for each processor do allocate stack and setup processor thread /*allocation of the stack done at processor layer */ shutdown FALSE SCHEDULER() deallocate processor_thread stack /*deallocation of the stack done at processor layer */ halt processor
8 The processor_thread and the SCHEDULER Thread creation: thread_id ALLOCATE_THREAD(starting_address_of_procedure, address_space_id); What if want to create/terminate threads dynamically we have to: Allow a tread to self-destroy and clean-up -> EXIT_THREAD Allow a thread to terminate another thread of the same application DESTROY_THREAD What if no thread is able to run create a dummy thread for each processor called a processor_thread which is scheduled to run when no other thread is available the processor_thread runs in the thread layer the SCHEDULER runs in the processor layer 8
9 Switching threads with dynamic thread creation Switching from one user-thread to another requires two steps 1. Switch from the user-thread releasing the processor to the processor-thread 2. Switch from the processor thread to the new use-thread which is going to have the control of the processor. This step requires the SCHEDULER to circle through the thread_table until a thread ready to run is found The boundary between user-layer threads and processor-layer thread is crossed twice 9
10 10
11 YIELD A thread voluntarily releases the control of the processor. allow a thread to wait for an event; allow several threads running on the same processor to wait for a lock. YIELD function implemented by the kernel to Save the state of the current thread Schedule another thread. Invoke the SCHEDULER Start running the new thread dispatch the processor to the new thread Cannot be implemented in a high level language, must be implemented in the machine language. Can be called from the environment of the thread, e.g., C, C++, Java 11
12 Lecture 19 12
13 Communication with a bounded buffer using YIELD Now the producer (the thread writing to the bounded buffer) and the consumer share one processor. The SEND and RECEIVE use YIELD to allow the other thread to continue. Example: switch from thread 1 to thread 6 using YIELD ENTER_PROCESSOR_LAYER EXIT_PROCESSOR_LAYER
14 14
15 Read from the buffer location pointed by out in N-2 N-1 Write to the buffer out location pointed by out shared structure buffer message instance message[n] integer in initially 0 integer out initially 0 lock instance buffer_lock initially UNLOCKED procedure SEND (buffer reference p, message instance msg) ACQUIRE (p_buffer_lock) while p.in p.out = N do /* if buffer full wait RELEASE (p_buffer_lock) YIELD() ACQUIRE (p_buffer_lock) p.message [p.in modulo N] msg /* insert message into buffer cell p.in p.in + 1 /* increment pointer to next free cell RELEASE (p_buffer_lock) procedure RECEIVE (buffer reference p) ACQUIRE (p_buffer_lock) while p.in = p.out do /* if buffer empty wait for message RELEASE (p_buffer_lock) YIELD() ACQUIRE (p_buffer_lock) msg p.message [p.in modulo N] /* copy message from buffer cell p.out p.out + 1 /* increment pointer to next message return msg
16 Shared data structures protected by locks All threads share The bounded buffer The thread table Both resources are protected by locks. Is this sufficient? Recall that other resources shared are the pointers IN and OUT. 16
17 Two senders execute the code concurrently Processor 1 runs thread A Processor 2 runs thread B Memory contains shared data Buffer In out Processor-memory bus time Operations of Thread A Fill entry 0 at time t2 with item a Increment pointer at time t3 in=out=0 in 1 Buffer is empty 0 on=out=0 in 2 Operations of Thread B Fill entry 0 at time t1 with item b Increment pointer at time t4 Item b is overwritten, it is lost
18 Using events for thread sequence coordination YIELD requires the thread to periodically check if a condition has occurred. Basic idea use events and construct two before-or-after actions WAIT(event_name) issued by the thread which can continue only after the occurrence of the event event_name. NOTIFY(event_name) search the thread_table to find a thread waiting for the occurrence of the event event_name. 18
19 Polling and interrupts Polling periodically checking the status of a subsystem. How often should the polling be done? Interrupts Too frequently large overhead After a large time interval the system will appear non-responsive could be implemented in hardware as polling before executing the next instruction the processor checks an interrupt bit implemented as a flip-flop If the bit is ON invoke the interrupt handler instead of executing the next instruction Multiple types of interrupts multiple interrupts bits checked based upon the priority of the interrupt. Some architectures allow the interrupts to occur durin the execution of an instruction The interrupt handler should be short and very carefully written. Interrupts of lower priority could be masked.
20
21 This solution does not work The NOTIFY should always be sent after the WAIT. If the sender and the receiver run on two different processor there could be a race condition for the notempty event. The NOTIFY could be sent before the WAIT. Tension between modularity and locks Several possible solutions: AWAIT/ADVANCE, semaphores, etc 21
22 AWAIT - ADVANCE solution A new state, WAITING and two before-or-after actions that take a RUNNING thread into the WAITING state and back to RUNNABLE state. eventcount variables with an integer value shared between threads and the thread manager; they are like events but have a value. A thread in the WAITING state waits for a particular value of the eventcount AWAIT(eventcount,value) If eventcount >value the control is returned to the thread calling AWAIT and this thread will continue execution If eventcount value the state of the thread calling AWAIT is changed to WAITING and the thread is suspended. ADVANCE(eventcount) increments the eventcount by one then searches the thread_table for threads waiting for this eventcount if it finds a thread and the eventcount exceeds the value the thread is waiting for then the state of the thread is changed to RUNNABLE 22
23 Thread states and state transitions 23
24
25 Solution for a single sender and multiple receivers 25
26 Supporting multiple senders: the sequencer Sequencer shared variable supporting thread sequence coordination -it allows threads to be ordered and is manipulated using two before-or-after actions. TICKET(sequencer) returns a non-negative value which increases by one at each call. Two concurrent threads calling TICKET on the same sequencer will receive different values based upon the timing of the call, the one calling first will receive a smaller value. READ(sequencer) returns the current value of the sequencer 26
27 Multiple sender solution; only the SEND must be modified 27
28 structure sequencer long integer ticket procedure TICKET(sequence reference s) ACQUIRE (thread_table_lock) t s.ticket s.ticket s.ticket + 1 RELEASE(thread_table_lock) return t procedure READ(eventcount reference event) ACQUIRE (thread_table_lock) e event.count RELEASE(thread_table_lock) return
29 Thread scheduling policies Non-preemptive scheduling a running thread releases the processor at its own will. Not very likely to work in a greedy environment. Cooperative scheduling a thread calls YIEALD periodically Preemptive scheduling a thread is allowed to run for a time slot. It is enforced by the thread manager working in concert with the interrupt handler. The interrupt handler should invoke the thread exception handler. What if the interrupt handler running at the processor layer invokes directly the thread? Imagine the following sequence: Thread A acquires the thread_table_lock An interrupt occurs The YIELD call in the interrupt handler will attempt to acquire the thread_table_lock Solution: the processor is shared between two threads: The processor thread The interrupt handler thread Recall that threads have their individual address spaces so the scheduler when allocating the processor to thread must also load the page map table of the thread into the page map table register of the processor 29
30 Virtual machines First commercial product IBM VM 370 originally developed as CP-67 Advantages: One could run multiple guest operating systems on the same machine An error in one guest operating system does not bring the machine down An ideal environment for developing operating systems Word Internet Explorer Firefox X Windows User Mode Kernel Mode
31
32 Thread Layer Thread of OS1 ID.1 SP PC PMAP Thread of OSn ID.n SP PC PMAP Virtual Machine Layer Guest OS1 Guest OS2 ID ID SP SP PC PC PMAP PMAP Guest OSn ID SP PC PMAP Processor Layer Processor A ID SP PC PMAP Processor B ID SP PC PMAP
33 Performance metrics Wide range, sometimes correlated, other times with contradictory goals : Throughput, utilization, waiting time, fairness Latency (time in system) Capacity Reliability as a ultimate measure of performance Some measures of performance reflect physical limitations: capacity, bandwidth (CPU, memory, communication channel), communication latency. Often measures of performance reflect system organization and policies such as scheduling priorities. Resource sharing is an enduring problem; recall that one of the means for virtualization is multiplexing physical resources. The workload can be characterized statistically Queuing Theory can be used for analytical performance evaluation. 33
34 System design for performance When you have a clear idea of the design, simulate the system before actually implementing it. Identify the bottlenecks. Identify those bottlenecks likely to be removed naturally by the technologies expected to be embedded in your system. Keep in mind that removing one bottleneck exposes the next. Concurrency helps a lot both in hardware and in software. in hardware implies multiple execution units Pipelining multiple instructions are executed concurrently Multiple exaction units in a processor: integer, floating point, pixels Graphics Processors geometric engines. Multi-processor system Multi-core processors Paradigm: SIMD (Single instruction multiple data), MIMD (Multiple Instructions Multiple Data. 34
35 System design for performance (cont d) in software complicates writing and debugging programs. SPMD (Same Program Multiple data) paradigm Design a well balanced system: The bandwidth of individual sub-systems should be as close as possible The execution time of pipeline stages as close as possible. 35
COP 5611 Operating Systems Spring Dan C. Marinescu Office: HEC 439 B Office hours: M-Wd 2:00-3:00 PM
COP 5611 Operating Systems Spring 2010 Dan C. Marinescu Office: HEC 439 B Office hours: M-Wd 2:00-3:00 PM Lecture 6 Last time: Virtualization Today: Thread coordination Scheduling Next Time: Multi-level
More informationCOT 4600 Operating Systems Fall Dan C. Marinescu Office: HEC 439 B Office hours: Tu-Th 3:00-4:00 PM
COT 4600 Operating Systems Fall 2009 Dan C. Marinescu Office: HEC 439 B Office hours: Tu-Th 3:00-4:00 PM Lecture 23 Attention: project phase 4 due Tuesday November 24 Final exam Thursday December 10 4-6:50
More information6.033 Computer System Engineering
MIT OpenCourseWare http://ocw.mit.edu 6.033 Computer System Engineering Spring 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 6.003 Lecture 7: Threads
More informationProcesses and More. CSCI 315 Operating Systems Design Department of Computer Science
Processes and More CSCI 315 Operating Systems Design Department of Computer Science Notice: The slides for this lecture have been largely based on those accompanying the textbook Operating Systems Concepts,
More informationProcess Concepts. CSC400 - Operating Systems. 3. Process Concepts. J. Sumey
CSC400 - Operating Systems 3. Process Concepts J. Sumey Overview Concurrency Processes & Process States Process Accounting Interrupts & Interrupt Processing Interprocess Communication CSC400 - Process
More informationChapter 3: Processes. Operating System Concepts 8 th Edition,
Chapter 3: Processes, Silberschatz, Galvin and Gagne 2009 Chapter 3: Processes Process Concept Process Scheduling Operations on Processes Interprocess Communication 3.2 Silberschatz, Galvin and Gagne 2009
More informationProcess Description and Control
Process Description and Control 1 Process:the concept Process = a program in execution Example processes: OS kernel OS shell Program executing after compilation www-browser Process management by OS : Allocate
More informationToday s Topics. u Thread implementation. l Non-preemptive versus preemptive threads. l Kernel vs. user threads
Today s Topics COS 318: Operating Systems Implementing Threads u Thread implementation l Non-preemptive versus preemptive threads l Kernel vs. user threads Jaswinder Pal Singh and a Fabulous Course Staff
More informationModule 1. Introduction:
Module 1 Introduction: Operating system is the most fundamental of all the system programs. It is a layer of software on top of the hardware which constitutes the system and manages all parts of the system.
More informationAnnouncements. Reading. Project #1 due in 1 week at 5:00 pm Scheduling Chapter 6 (6 th ed) or Chapter 5 (8 th ed) CMSC 412 S14 (lect 5)
Announcements Reading Project #1 due in 1 week at 5:00 pm Scheduling Chapter 6 (6 th ed) or Chapter 5 (8 th ed) 1 Relationship between Kernel mod and User Mode User Process Kernel System Calls User Process
More informationCSE 153 Design of Operating Systems
CSE 153 Design of Operating Systems Winter 2018 Midterm Review Midterm in class on Monday Covers material through scheduling and deadlock Based upon lecture material and modules of the book indicated on
More informationProcesses Prof. James L. Frankel Harvard University. Version of 6:16 PM 10-Feb-2017 Copyright 2017, 2015 James L. Frankel. All rights reserved.
Processes Prof. James L. Frankel Harvard University Version of 6:16 PM 10-Feb-2017 Copyright 2017, 2015 James L. Frankel. All rights reserved. Process Model Each process consists of a sequential program
More informationI/O Handling. ECE 650 Systems Programming & Engineering Duke University, Spring Based on Operating Systems Concepts, Silberschatz Chapter 13
I/O Handling ECE 650 Systems Programming & Engineering Duke University, Spring 2018 Based on Operating Systems Concepts, Silberschatz Chapter 13 Input/Output (I/O) Typical application flow consists of
More information3.1 Introduction. Computers perform operations concurrently
PROCESS CONCEPTS 1 3.1 Introduction Computers perform operations concurrently For example, compiling a program, sending a file to a printer, rendering a Web page, playing music and receiving e-mail Processes
More informationModule 6: Process Synchronization. Operating System Concepts with Java 8 th Edition
Module 6: Process Synchronization 6.1 Silberschatz, Galvin and Gagne 2009 Module 6: Process Synchronization Background The Critical-Section Problem Peterson s Solution Synchronization Hardware Semaphores
More informationMain Points of the Computer Organization and System Software Module
Main Points of the Computer Organization and System Software Module You can find below the topics we have covered during the COSS module. Reading the relevant parts of the textbooks is essential for a
More informationLast 2 Classes: Introduction to Operating Systems & C++ tutorial. Today: OS and Computer Architecture
Last 2 Classes: Introduction to Operating Systems & C++ tutorial User apps OS Virtual machine interface hardware physical machine interface An operating system is the interface between the user and the
More informationConcurrency, Mutual Exclusion and Synchronization C H A P T E R 5
Concurrency, Mutual Exclusion and Synchronization C H A P T E R 5 Multiple Processes OS design is concerned with the management of processes and threads: Multiprogramming Multiprocessing Distributed processing
More informationTHREADS AND CONCURRENCY
THREADS AND CONCURRENCY Lecture 22 CS2110 Spring 2013 Graphs summary 2 Dijkstra: given a vertex v, finds shortest path from v to x for each vertex x in the graph Key idea: maintain a 5-part invariant on
More informationSE350: Operating Systems. Lecture 3: Concurrency
SE350: Operating Systems Lecture 3: Concurrency Main Points Thread abstraction What are threads and what is the thread abstraction? Thread life cycle What states does a thread go through? Thread Implementation
More informationSubject: Operating System (BTCOC403) Class: S.Y.B.Tech. (Computer Engineering)
A. Multiple Choice Questions (60 questions) Subject: Operating System (BTCOC403) Class: S.Y.B.Tech. (Computer Engineering) Unit-I 1. What is operating system? a) collection of programs that manages hardware
More informationDistributed Systems Operation System Support
Hajussüsteemid MTAT.08.009 Distributed Systems Operation System Support slides are adopted from: lecture: Operating System(OS) support (years 2016, 2017) book: Distributed Systems: Concepts and Design,
More informationMultiprocessor System. Multiprocessor Systems. Bus Based UMA. Types of Multiprocessors (MPs) Cache Consistency. Bus Based UMA. Chapter 8, 8.
Multiprocessor System Multiprocessor Systems Chapter 8, 8.1 We will look at shared-memory multiprocessors More than one processor sharing the same memory A single CPU can only go so fast Use more than
More information6.033 Spring Lecture #6. Monolithic kernels vs. Microkernels Virtual Machines spring 2018 Katrina LaCurts
6.033 Spring 2018 Lecture #6 Monolithic kernels vs. Microkernels Virtual Machines 1 operating systems enforce modularity on a single machine using virtualization in order to enforce modularity + build
More informationLecture 15: I/O Devices & Drivers
CS 422/522 Design & Implementation of Operating Systems Lecture 15: I/O Devices & Drivers Zhong Shao Dept. of Computer Science Yale University Acknowledgement: some slides are taken from previous versions
More informationLecture 2: September 9
CMPSCI 377 Operating Systems Fall 2010 Lecture 2: September 9 Lecturer: Prashant Shenoy TA: Antony Partensky & Tim Wood 2.1 OS & Computer Architecture The operating system is the interface between a user
More informationMultiprocessor Systems. COMP s1
Multiprocessor Systems 1 Multiprocessor System We will look at shared-memory multiprocessors More than one processor sharing the same memory A single CPU can only go so fast Use more than one CPU to improve
More informationOPERATING SYSTEM OVERVIEW
OPERATING SYSTEM OVERVIEW Contents Basic hardware elements Interrupts Most I/O devices are much slower than the processor Active waiting cycle (polling) Interrupt request signal Interrupt mechanism An
More informationModule 4: Processes. Process Concept Process Scheduling Operation on Processes Cooperating Processes Interprocess Communication
Module 4: Processes Process Concept Process Scheduling Operation on Processes Cooperating Processes Interprocess Communication Operating System Concepts 4.1 Process Concept An operating system executes
More informationModule 4: Processes. Process Concept Process Scheduling Operation on Processes Cooperating Processes Interprocess Communication
Module 4: Processes Process Concept Process Scheduling Operation on Processes Cooperating Processes Interprocess Communication 4.1 Process Concept An operating system executes a variety of programs: Batch
More informationTasks. Task Implementation and management
Tasks Task Implementation and management Tasks Vocab Absolute time - real world time Relative time - time referenced to some event Interval - any slice of time characterized by start & end times Duration
More information(MCQZ-CS604 Operating Systems)
command to resume the execution of a suspended job in the foreground fg (Page 68) bg jobs kill commands in Linux is used to copy file is cp (Page 30) mv mkdir The process id returned to the child process
More information6.033 Spring 2018 Lecture #5
6.033 Spring 2018 Lecture #5 Threads Condition Variables Preemption operating systems enforce modularity on a single machine using virtualization in order to enforce modularity + build an effective operating
More informationEECS 482 Introduction to Operating Systems
EECS 482 Introduction to Operating Systems Winter 2018 Baris Kasikci Slides by: Harsha V. Madhyastha Use of CVs in Project 1 Incorrect use of condition variables: while (cond) { } cv.signal() cv.wait()
More informationLecture 5: Process Description and Control Multithreading Basics in Interprocess communication Introduction to multiprocessors
Lecture 5: Process Description and Control Multithreading Basics in Interprocess communication Introduction to multiprocessors 1 Process:the concept Process = a program in execution Example processes:
More informationChapter 4: Threads. Overview Multithreading Models Thread Libraries Threading Issues Operating System Examples Windows XP Threads Linux Threads
Chapter 4: Threads Overview Multithreading Models Thread Libraries Threading Issues Operating System Examples Windows XP Threads Linux Threads Chapter 4: Threads Objectives To introduce the notion of a
More informationChapter 2 Processes and Threads
MODERN OPERATING SYSTEMS Third Edition ANDREW S. TANENBAUM Chapter 2 Processes and Threads The Process Model Figure 2-1. (a) Multiprogramming of four programs. (b) Conceptual model of four independent,
More informationSynchronization I. Jo, Heeseung
Synchronization I Jo, Heeseung Today's Topics Synchronization problem Locks 2 Synchronization Threads cooperate in multithreaded programs To share resources, access shared data structures Also, to coordinate
More informationMASSACHUSETTS INSTITUTE OF TECHNOLOGY Computer Systems Engineering: Spring Quiz I Solutions
Department of Electrical Engineering and Computer Science MASSACHUSETTS INSTITUTE OF TECHNOLOGY 6.033 Computer Systems Engineering: Spring 2011 Quiz I Solutions There are 10 questions and 12 pages in this
More informationProcess- Concept &Process Scheduling OPERATING SYSTEMS
OPERATING SYSTEMS Prescribed Text Book Operating System Principles, Seventh Edition By Abraham Silberschatz, Peter Baer Galvin and Greg Gagne PROCESS MANAGEMENT Current day computer systems allow multiple
More informationSMD149 - Operating Systems
SMD149 - Operating Systems Roland Parviainen November 3, 2005 1 / 45 Outline Overview 2 / 45 Process (tasks) are necessary for concurrency Instance of a program in execution Next invocation of the program
More informationDiagram of Process State Process Control Block (PCB)
The Big Picture So Far Chapter 4: Processes HW Abstraction Processor Memory IO devices File system Distributed systems Example OS Services Process management, protection, synchronization Memory Protection,
More informationMulti-core Architecture and Programming
Multi-core Architecture and Programming Yang Quansheng( 杨全胜 ) http://www.njyangqs.com School of Computer Science & Engineering 1 http://www.njyangqs.com Process, threads and Parallel Programming Content
More informationSemaphore. Originally called P() and V() wait (S) { while S <= 0 ; // no-op S--; } signal (S) { S++; }
Semaphore Semaphore S integer variable Two standard operations modify S: wait() and signal() Originally called P() and V() Can only be accessed via two indivisible (atomic) operations wait (S) { while
More informationThreads. Raju Pandey Department of Computer Sciences University of California, Davis Spring 2011
Threads Raju Pandey Department of Computer Sciences University of California, Davis Spring 2011 Threads Effectiveness of parallel computing depends on the performance of the primitives used to express
More informationProcesses, PCB, Context Switch
THE HONG KONG POLYTECHNIC UNIVERSITY Department of Electronic and Information Engineering EIE 272 CAOS Operating Systems Part II Processes, PCB, Context Switch Instructor Dr. M. Sakalli enmsaka@eie.polyu.edu.hk
More informationToday s Topics. u Thread implementation. l Non-preemptive versus preemptive threads. l Kernel vs. user threads
Today s Topics COS 318: Operating Systems Implementing Threads u Thread implementation l Non-preemptive versus preemptive threads l Kernel vs. user threads Jaswinder Pal Singh Computer Science Department
More informationREAL-TIME MULTITASKING KERNEL FOR IBM-BASED MICROCOMPUTERS
Malaysian Journal of Computer Science, Vol. 9 No. 1, June 1996, pp. 12-17 REAL-TIME MULTITASKING KERNEL FOR IBM-BASED MICROCOMPUTERS Mohammed Samaka School of Computer Science Universiti Sains Malaysia
More informationCSL373: Lecture 5 Deadlocks (no process runnable) + Scheduling (> 1 process runnable)
CSL373: Lecture 5 Deadlocks (no process runnable) + Scheduling (> 1 process runnable) Past & Present Have looked at two constraints: Mutual exclusion constraint between two events is a requirement that
More informationApplications, services. Middleware. OS2 Processes, threads, Processes, threads, communication,... communication,... Platform
Operating System Support Introduction Distributed systems act as resource managers for the underlying hardware, allowing users access to memory, storage, CPUs, peripheral devices, and the network Much
More informationCS 318 Principles of Operating Systems
CS 318 Principles of Operating Systems Fall 2017 Midterm Review Ryan Huang 10/12/17 CS 318 Midterm Review 2 Midterm October 17 th Tuesday 9:00-10:20 am at classroom Covers material before virtual memory
More informationOperating Systems Design Fall 2010 Exam 1 Review. Paul Krzyzanowski
Operating Systems Design Fall 2010 Exam 1 Review Paul Krzyzanowski pxk@cs.rutgers.edu 1 Question 1 To a programmer, a system call looks just like a function call. Explain the difference in the underlying
More informationChapter 3 Processes. Process Concept. Process Concept. Process Concept (Cont.) Process Concept (Cont.) Process Concept (Cont.)
Process Concept Chapter 3 Processes Computers can do several activities at a time Executing user programs, reading from disks writing to a printer, etc. In multiprogramming: CPU switches from program to
More informationOperating Systems Comprehensive Exam. Spring Student ID # 3/16/2006
Operating Systems Comprehensive Exam Spring 2006 Student ID # 3/16/2006 You must complete all of part I (60%) You must complete two of the three sections in part II (20% each) In Part I, circle or select
More informationFrequently asked questions from the previous class survey
CS 370: OPERATING SYSTEMS [CPU SCHEDULING] Shrideep Pallickara Computer Science Colorado State University L14.1 Frequently asked questions from the previous class survey Turnstiles: Queue for threads blocked
More informationReminder from last time
Concurrent systems Lecture 2: More mutual exclusion, semaphores, and producer-consumer relationships DrRobert N. M. Watson 1 Reminder from last time Definition of a concurrent system Origins of concurrency
More informationMultiprocessor Systems. Chapter 8, 8.1
Multiprocessor Systems Chapter 8, 8.1 1 Learning Outcomes An understanding of the structure and limits of multiprocessor hardware. An appreciation of approaches to operating system support for multiprocessor
More information[537] Locks. Tyler Harter
[537] Locks Tyler Harter Review: Threads+Locks CPU 1 CPU 2 running thread 1 running thread 2 RAM PageDir A PageDir B CPU 1 CPU 2 running thread 1 running thread 2 RAM PageDir A PageDir B Virt Mem (PageDir
More informationOPERATING SYSTEMS. UNIT II Sections A, B & D. An operating system executes a variety of programs:
OPERATING SYSTEMS UNIT II Sections A, B & D PREPARED BY ANIL KUMAR PRATHIPATI, ASST. PROF., DEPARTMENT OF CSE. PROCESS CONCEPT An operating system executes a variety of programs: Batch system jobs Time-shared
More informationOperating Systems. Lecture 4 - Concurrency and Synchronization. Master of Computer Science PUF - Hồ Chí Minh 2016/2017
Operating Systems Lecture 4 - Concurrency and Synchronization Adrien Krähenbühl Master of Computer Science PUF - Hồ Chí Minh 2016/2017 Mutual exclusion Hardware solutions Semaphores IPC: Message passing
More information6.033 Spring Lecture #5. Threads Condition Variables Preemption spring 2018 Katrina LaCurts
6.033 Spring 2018 Lecture #5 Threads Condition Variables Preemption 1 operating systems enforce modularity on a single machine using virtualization in order to enforce modularity + build an effective operating
More informationChapter 5: Process Synchronization. Operating System Concepts 9 th Edition
Chapter 5: Process Synchronization Silberschatz, Galvin and Gagne 2013 Chapter 5: Process Synchronization Background The Critical-Section Problem Peterson s Solution Synchronization Hardware Mutex Locks
More informationDealing with Issues for Interprocess Communication
Dealing with Issues for Interprocess Communication Ref Section 2.3 Tanenbaum 7.1 Overview Processes frequently need to communicate with other processes. In a shell pipe the o/p of one process is passed
More informationCS 333 Introduction to Operating Systems. Class 3 Threads & Concurrency. Jonathan Walpole Computer Science Portland State University
CS 333 Introduction to Operating Systems Class 3 Threads & Concurrency Jonathan Walpole Computer Science Portland State University 1 Process creation in UNIX All processes have a unique process id getpid(),
More informationPerformance Throughput Utilization of system resources
Concurrency 1. Why concurrent programming?... 2 2. Evolution... 2 3. Definitions... 3 4. Concurrent languages... 5 5. Problems with concurrency... 6 6. Process Interactions... 7 7. Low-level Concurrency
More informationLecture 2 Process Management
Lecture 2 Process Management Process Concept An operating system executes a variety of programs: Batch system jobs Time-shared systems user programs or tasks The terms job and process may be interchangeable
More informationOperating Systems CMPSCI 377 Spring Mark Corner University of Massachusetts Amherst
Operating Systems CMPSCI 377 Spring 2017 Mark Corner University of Massachusetts Amherst Last Class: Intro to OS An operating system is the interface between the user and the architecture. User-level Applications
More informationWhat s An OS? Cyclic Executive. Interrupts. Advantages Simple implementation Low overhead Very predictable
What s An OS? Provides environment for executing programs Process abstraction for multitasking/concurrency scheduling Hardware abstraction layer (device drivers) File systems Communication Do we need an
More informationPart V. Process Management. Sadeghi, Cubaleska RUB Course Operating System Security Memory Management and Protection
Part V Process Management Sadeghi, Cubaleska RUB 2008-09 Course Operating System Security Memory Management and Protection Roadmap of Chapter 5 Notion of Process and Thread Data Structures Used to Manage
More informationCS370 Operating Systems
CS370 Operating Systems Colorado State University Yashwant K Malaiya Fall 2016 Lecture 2 Slides based on Text by Silberschatz, Galvin, Gagne Various sources 1 1 2 System I/O System I/O (Chap 13) Central
More informationDevice-Functionality Progression
Chapter 12: I/O Systems I/O Hardware I/O Hardware Application I/O Interface Kernel I/O Subsystem Transforming I/O Requests to Hardware Operations Incredible variety of I/O devices Common concepts Port
More informationChapter 12: I/O Systems. I/O Hardware
Chapter 12: I/O Systems I/O Hardware Application I/O Interface Kernel I/O Subsystem Transforming I/O Requests to Hardware Operations I/O Hardware Incredible variety of I/O devices Common concepts Port
More informationThreading and Synchronization. Fahd Albinali
Threading and Synchronization Fahd Albinali Parallelism Parallelism and Pseudoparallelism Why parallelize? Finding parallelism Advantages: better load balancing, better scalability Disadvantages: process/thread
More informationLast Class: OS and Computer Architecture. Last Class: OS and Computer Architecture
Last Class: OS and Computer Architecture System bus Network card CPU, memory, I/O devices, network card, system bus Lecture 4, page 1 Last Class: OS and Computer Architecture OS Service Protection Interrupts
More informationCS 326: Operating Systems. CPU Scheduling. Lecture 6
CS 326: Operating Systems CPU Scheduling Lecture 6 Today s Schedule Agenda? Context Switches and Interrupts Basic Scheduling Algorithms Scheduling with I/O Symmetric multiprocessing 2/7/18 CS 326: Operating
More informationChapter 13: I/O Systems
Chapter 13: I/O Systems DM510-14 Chapter 13: I/O Systems I/O Hardware Application I/O Interface Kernel I/O Subsystem Transforming I/O Requests to Hardware Operations STREAMS Performance 13.2 Objectives
More informationCS370 Operating Systems
CS370 Operating Systems Colorado State University Yashwant K Malaiya Spring 1018 L10 Synchronization Slides based on Text by Silberschatz, Galvin, Gagne Various sources 1 1 FAQ Development project: You
More informationConcurrent programming: Introduction I
Computer Architecture course Real-Time Operating Systems Concurrent programming: Introduction I Anna Lina Ruscelli - Scuola Superiore Sant Anna Contact info Email a.ruscelli@sssup.it Computer Architecture
More informationCSE 4/521 Introduction to Operating Systems
CSE 4/521 Introduction to Operating Systems Lecture 7 Process Synchronization II (Classic Problems of Synchronization, Synchronization Examples) Summer 2018 Overview Objective: 1. To examine several classical
More informationCourse Syllabus. Operating Systems
Course Syllabus. Introduction - History; Views; Concepts; Structure 2. Process Management - Processes; State + Resources; Threads; Unix implementation of Processes 3. Scheduling Paradigms; Unix; Modeling
More informationTHREADS & CONCURRENCY
27/04/2018 Sorry for the delay in getting slides for today 2 Another reason for the delay: Yesterday: 63 posts on the course Piazza yesterday. A7: If you received 100 for correctness (perhaps minus a late
More informationCS370 Operating Systems
CS370 Operating Systems Colorado State University Yashwant K Malaiya Spring 2018 Lecture 2 Slides based on Text by Silberschatz, Galvin, Gagne Various sources 1 1 2 What is an Operating System? What is
More informationReview: Program Execution. Memory program code program data program stack containing procedure activation records
Threads and Concurrency 1 Review: Program Execution Registers program counter, stack pointer,... Memory program code program data program stack containing procedure activation records CPU fetches and executes
More informationUniversity of Waterloo Midterm Examination Model Solution CS350 Operating Systems
University of Waterloo Midterm Examination Model Solution CS350 Operating Systems Fall, 2003 1. (10 total marks) Suppose that two processes, a and b, are running in a uniprocessor system. a has three threads.
More informationLecture 5: Synchronization w/locks
Lecture 5: Synchronization w/locks CSE 120: Principles of Operating Systems Alex C. Snoeren Lab 1 Due 10/19 Threads Are Made to Share Global variables and static objects are shared Stored in the static
More informationOperating System Design Issues. I/O Management
I/O Management Chapter 5 Operating System Design Issues Efficiency Most I/O devices slow compared to main memory (and the CPU) Use of multiprogramming allows for some processes to be waiting on I/O while
More informationò Paper reading assigned for next Tuesday ò Understand low-level building blocks of a scheduler User Kernel ò Understand competing policy goals
Housekeeping Paper reading assigned for next Tuesday Scheduling Don Porter CSE 506 Memory Management Logical Diagram Binary Memory Formats Allocators Threads Today s Lecture Switching System to CPU Calls
More informationCS 326: Operating Systems. Process Execution. Lecture 5
CS 326: Operating Systems Process Execution Lecture 5 Today s Schedule Process Creation Threads Limited Direct Execution Basic Scheduling 2/5/18 CS 326: Operating Systems 2 Today s Schedule Process Creation
More informationDr. Rafiq Zakaria Campus. Maulana Azad College of Arts, Science & Commerce, Aurangabad. Department of Computer Science. Academic Year
Dr. Rafiq Zakaria Campus Maulana Azad College of Arts, Science & Commerce, Aurangabad Department of Computer Science Academic Year 2015-16 MCQs on Operating System Sem.-II 1.What is operating system? a)
More informationAnnouncements. Program #1. Reading. Due 2/15 at 5:00 pm. Finish scheduling Process Synchronization: Chapter 6 (8 th Ed) or Chapter 7 (6 th Ed)
Announcements Program #1 Due 2/15 at 5:00 pm Reading Finish scheduling Process Synchronization: Chapter 6 (8 th Ed) or Chapter 7 (6 th Ed) 1 Scheduling criteria Per processor, or system oriented CPU utilization
More informationLecture 2: Architectural Support for OSes
Lecture 2: Architectural Support for OSes CSE 120: Principles of Operating Systems Alex C. Snoeren HW 1 Due Tuesday 10/03 Why Architecture? Operating systems mediate between applications and the physical
More informationTHREADS & CONCURRENCY
4/26/16 Announcements BRING YOUR CORNELL ID TO THE PRELIM. 2 You need it to get in THREADS & CONCURRENCY Prelim 2 is next Tonight BRING YOUR CORNELL ID! A7 is due Thursday. Our Heap.java: on Piazza (A7
More informationPROCESSES & THREADS. Charles Abzug, Ph.D. Department of Computer Science James Madison University Harrisonburg, VA Charles Abzug
PROCESSES & THREADS Charles Abzug, Ph.D. Department of Computer Science James Madison University Harrisonburg, VA 22807 Voice Phone: 540-568-8746; Cell Phone: 443-956-9424 E-mail: abzugcx@jmu.edu OR CharlesAbzug@ACM.org
More informationLecture Topics. Announcements. Today: Advanced Scheduling (Stallings, chapter ) Next: Deadlock (Stallings, chapter
Lecture Topics Today: Advanced Scheduling (Stallings, chapter 10.1-10.4) Next: Deadlock (Stallings, chapter 6.1-6.6) 1 Announcements Exam #2 returned today Self-Study Exercise #10 Project #8 (due 11/16)
More informationProcesses and Threads. Processes: Review
Processes and Threads Processes and their scheduling Threads and scheduling Multiprocessor scheduling Distributed Scheduling/migration Lecture 3, page 1 Processes: Review Multiprogramming versus multiprocessing
More informationLecture notes Lectures 1 through 5 (up through lecture 5 slide 63) Book Chapters 1-4
EE445M Midterm Study Guide (Spring 2017) (updated February 25, 2017): Instructions: Open book and open notes. No calculators or any electronic devices (turn cell phones off). Please be sure that your answers
More informationReview: Program Execution. Memory program code program data program stack containing procedure activation records
Threads and Concurrency 1 Review: Program Execution Registers program counter, stack pointer,... Memory program code program data program stack containing procedure activation records CPU fetches and executes
More informationCOT 4600 Operating Systems Fall 2009
COT 4600 Operating Systems Fall 2009 Dan C. Marinescu Office: HEC 439 B Office hours: Tu-Th 3:00-4:00 PM Lecture 5 1 Lecture 5 Last time: Project. Today: Names and the basic abstractions Storage Next Time
More informationCS 162 Operating Systems and Systems Programming Professor: Anthony D. Joseph Spring 2004
CS 162 Operating Systems and Systems Programming Professor: Anthony D. Joseph Spring 2004 Lecture 9: Readers-Writers and Language Support for Synchronization 9.1.2 Constraints 1. Readers can access database
More informationMid Term from Feb-2005 to Nov 2012 CS604- Operating System
Mid Term from Feb-2005 to Nov 2012 CS604- Operating System Latest Solved from Mid term Papers Resource Person Hina 1-The problem with priority scheduling algorithm is. Deadlock Starvation (Page# 84) Aging
More information