What is an Operating System?
... System call – request to the operating system to allow user to wait for I/O completion. Device-status table contains entry for each I/O device indicating its type, address, and state. Operating system indexes into I/O device table to determine device status and to modify table entry to include ...
... System call – request to the operating system to allow user to wait for I/O completion. Device-status table contains entry for each I/O device indicating its type, address, and state. Operating system indexes into I/O device table to determine device status and to modify table entry to include ...
SCADA Systems
... All 3 lower levels may be realized by kernel, but these functions may be split on different levels. When threads are created, Thread Control Blocks are associated with them. In addition to commonly used here such data as Thread ID, starting address, context, synchronization information, for RTOS the ...
... All 3 lower levels may be realized by kernel, but these functions may be split on different levels. When threads are created, Thread Control Blocks are associated with them. In addition to commonly used here such data as Thread ID, starting address, context, synchronization information, for RTOS the ...
slides
... A sequence of instructions enclosed in a function which CPU can execute as a unit A process is a program in execution A process is composed of one or more threads Each thread is comprised of (from OS perspective) ...
... A sequence of instructions enclosed in a function which CPU can execute as a unit A process is a program in execution A process is composed of one or more threads Each thread is comprised of (from OS perspective) ...
Application Software Read/Write Standard Output Device Control
... Copyright ©: University of Illinois CS 241 Staff ...
... Copyright ©: University of Illinois CS 241 Staff ...
No Slide Title
... decisions, I/O processing, and other system activities; while the other processors just execute user code. ...
... decisions, I/O processing, and other system activities; while the other processors just execute user code. ...
The Evolution of the Unix Time
... machine had no index registers. Finally, the DMA controller was unable to access memory during an instruction. The upshot was that the disk would incur overrun errors if any indirectly-addressed instructions were executed while it was transferring. Thus control could not be returned to the user, nor ...
... machine had no index registers. Finally, the DMA controller was unable to access memory during an instruction. The upshot was that the disk would incur overrun errors if any indirectly-addressed instructions were executed while it was transferring. Thus control could not be returned to the user, nor ...
The Evolution of the Unix Time-sharing System
... the DMA controller was unable to access memory during an instruction. The upshot was that the disk would incur overrun errors if any indirectly-addressed instructions were executed while it was transferring. Thus control could not be returned to the user, nor in fact could general system code be exe ...
... the DMA controller was unable to access memory during an instruction. The upshot was that the disk would incur overrun errors if any indirectly-addressed instructions were executed while it was transferring. Thus control could not be returned to the user, nor in fact could general system code be exe ...
Document
... User mode and kernel mode Mode bit provided by hardware Provides ability to distinguish when system is running user code or kernel code Some instructions designated as privileged, only executable in kernel mode ...
... User mode and kernel mode Mode bit provided by hardware Provides ability to distinguish when system is running user code or kernel code Some instructions designated as privileged, only executable in kernel mode ...
Chapter 1 Bootstrap
... 32-bit registers that can be used directly as addresses. The Intel x86 architecture arrived at those capabilities in two stages of evolution. The 80286 introduced "protected mode" which allowed the segmentation scheme to generate physical addresses with as many bits as required. The 80386 introduced ...
... 32-bit registers that can be used directly as addresses. The Intel x86 architecture arrived at those capabilities in two stages of evolution. The 80286 introduced "protected mode" which allowed the segmentation scheme to generate physical addresses with as many bits as required. The 80386 introduced ...
Windows 2000 Dependability
... wanted to set exacting dependability goals. Unfortunately there are no industry standards for characterizing system dependability (an IFIP special interest group, of whom Microsoft is a member, is investigating the development of a dependability benchmark [1]); therefore any goal setting for a parti ...
... wanted to set exacting dependability goals. Unfortunately there are no industry standards for characterizing system dependability (an IFIP special interest group, of whom Microsoft is a member, is investigating the development of a dependability benchmark [1]); therefore any goal setting for a parti ...
Patterns for Operating Systems Access Control
... according to a set of predefined access types. Context Multiprogramming systems with a variety of users. Processes executing on behalf of these users must be able to share memory areas in a controlled way. Each process runs in its own address space. The total VAS at a given moment includes the union ...
... according to a set of predefined access types. Context Multiprogramming systems with a variety of users. Processes executing on behalf of these users must be able to share memory areas in a controlled way. Each process runs in its own address space. The total VAS at a given moment includes the union ...
A Review of Architectures - Intel Single Core, Intel Dual Core
... Each thread is assigned a subtask for which it is responsible, and the thread independently manages the execution of the subtask. Each thread can be assigned a priority reflecting the importance of the subtask it is ...
... Each thread is assigned a subtask for which it is responsible, and the thread independently manages the execution of the subtask. Each thread can be assigned a priority reflecting the importance of the subtask it is ...
w(x)
... ensure that the data in an object is seen by concurrent threads in a consistent fashion even if they are executing on different compute servers. Since several threads can simultaneously execute in an object, it is necessary to coordinate access to the object data. This is handled by Clouds object pr ...
... ensure that the data in an object is seen by concurrent threads in a consistent fashion even if they are executing on different compute servers. Since several threads can simultaneously execute in an object, it is necessary to coordinate access to the object data. This is handled by Clouds object pr ...
slide
... A saved context when not running – a separate program counter An execution stack Some static storage for local variables for this thread Access to memory and resources of its process, shared with all other threads in that process (global variables) ...
... A saved context when not running – a separate program counter An execution stack Some static storage for local variables for this thread Access to memory and resources of its process, shared with all other threads in that process (global variables) ...
Processes, Threads and Synchronization
... disable interrupt checking check whether current thread has run “long enough” if yes, post asynchronous software trap (AST) enable interrupt checking exit interrupt handler enter “return-to-user” code check whether AST was posted if not, restore user thread state and return to executin ...
... disable interrupt checking check whether current thread has run “long enough” if yes, post asynchronous software trap (AST) enable interrupt checking exit interrupt handler enter “return-to-user” code check whether AST was posted if not, restore user thread state and return to executin ...
CS 519 -- Operating Systems -
... disable interrupt checking check whether current thread has run “long enough” if yes, post asynchronous software trap (AST) enable interrupt checking exit interrupt handler enter “return-to-user” code check whether AST was posted if not, restore user thread state and return to executin ...
... disable interrupt checking check whether current thread has run “long enough” if yes, post asynchronous software trap (AST) enable interrupt checking exit interrupt handler enter “return-to-user” code check whether AST was posted if not, restore user thread state and return to executin ...
Memory Management
... Memory Management with Buddies • The memory manager maintains a list of free blocks of size 1,2,4,8,16 bytes up to the size of the memory. (1M memory = 21 lists). • Initially all of memory is free and the 1M list has a single entry containing a single 1M hole. • As memory requests are coming in, li ...
... Memory Management with Buddies • The memory manager maintains a list of free blocks of size 1,2,4,8,16 bytes up to the size of the memory. (1M memory = 21 lists). • Initially all of memory is free and the 1M list has a single entry containing a single 1M hole. • As memory requests are coming in, li ...
ch3-v2
... Producer writes to one end (the write-end of the pipe) Consumer reads from the other end (the read-end of the pipe) Ordinary pipes are therefore unidirectional Require parent-child relationship between communicating processes ...
... Producer writes to one end (the write-end of the pipe) Consumer reads from the other end (the read-end of the pipe) Ordinary pipes are therefore unidirectional Require parent-child relationship between communicating processes ...
第二章
... Given the I/O instructions are privileged, how does the user program perform I/O? I/O指令是要特权的，用户程序如何完成I/O？ ...
... Given the I/O instructions are privileged, how does the user program perform I/O? I/O指令是要特权的，用户程序如何完成I/O？ ...
Monday, 26 November, 2007.
... A subset of total jobs in system is kept in memory One job selected and run via job scheduling (aka long-term scheduling) When it has to wait (for I/O for example), OS switches to another job What are the main differences with the “single-user” setting? Benefits vs. problems? ...
... A subset of total jobs in system is kept in memory One job selected and run via job scheduling (aka long-term scheduling) When it has to wait (for I/O for example), OS switches to another job What are the main differences with the “single-user” setting? Benefits vs. problems? ...
History of Unix OS - Seneca
... than one person to directly communicate with the computer. Although the OS can only work on one task at a time, a small piece of time (time slice) is dedicated to each task or user - this is referred to as “time-sharing”. Time sharing gives the illusion that the CPU is giving all the users its full ...
... than one person to directly communicate with the computer. Although the OS can only work on one task at a time, a small piece of time (time slice) is dedicated to each task or user - this is referred to as “time-sharing”. Time sharing gives the illusion that the CPU is giving all the users its full ...
HistoryAndHardware
... of one command, it seeks the next “control statement” from the user’s keyboard. On-line file system must be available for users to access data and code Jobs may be swapped in and out of memory to the disk. ...
... of one command, it seeks the next “control statement” from the user’s keyboard. On-line file system must be available for users to access data and code Jobs may be swapped in and out of memory to the disk. ...
CPU Scheduling
... to maximize CPU utilization. For a uniprocessor system, there will never be more than one running process. If there are more processes, the rest will have to wait until the CPU is free and can be rescheduled. The idea of multiprogramming is relatively simple. A process is executed until it must wait ...
... to maximize CPU utilization. For a uniprocessor system, there will never be more than one running process. If there are more processes, the rest will have to wait until the CPU is free and can be rescheduled. The idea of multiprogramming is relatively simple. A process is executed until it must wait ...
Computer System Architecture
... perform I/O on its behalf. The operating system, executing in monitor mode, checks that the request is valid, and (if the request is valid) does the I/O requested. The operating system then returns to the user. ...
... perform I/O on its behalf. The operating system, executing in monitor mode, checks that the request is valid, and (if the request is valid) does the I/O requested. The operating system then returns to the user. ...
EECC722 - Shaaban
... kernel activity (the kernel executing on behalf of this user thread, some other user thread, a kernel thread, or an interrupt). ...
... kernel activity (the kernel executing on behalf of this user thread, some other user thread, a kernel thread, or an interrupt). ...