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Pertemuan 3 Konsep Sistem Operasi. Matakuliah : T0316/sistem Operasi Tahun : 2005 Versi/Revisi : 5. Learning Outcomes. Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : menjelaskan istilah dan konsep sistem operasi (C2). Outline Materi. Konsep Processes Deadlock
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Pertemuan 3Konsep Sistem Operasi Matakuliah : T0316/sistem Operasi Tahun : 2005 Versi/Revisi : 5
Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : • menjelaskan istilah dan konsep sistem operasi (C2)
Outline Materi Konsep • Processes • Deadlock • Memory management • I/O • File • Shell • System call • Struktur • Monolithic • Layered • Virtual machine • Exokernels • Client-Server
²OPERATING SYSTEM CONCEPT Process -Program in execution -Consist of: oExecutable program, data, stack oProgram counter, stack pointer, registers -Process table array or linked list of structure of the process in execution -Process has: oAddress space (core image) oAttribute/information in the process table
Deadlock -Condition in which interacting process cannot be continued and there is no process that can get out of that condition. (a) A potential deadlock. (b) an actual deadlock.
Memory Management -Multiple program dalam memory needs: oProtection oAddress space management Input/Output -Independent I/O software -Device dependent, eg. device drivers
·Files -Directory -Pathname -Protection mode rwx bits -File descriptor
Before mounting After mounting -Mounted file system -Special file oBlock oCharacter -Pipe
·Security -Protection, eg. rwx bits -Intruders, from human or non-human (eg. virus) ·Shell -Unix command interpreter -Prompt Example: date date > file sort < file1 > file2 cat file1 file2 file3 | sort > /dev/lp cat file1 file2 file3 | sort > /dev/lp & -Background job
SYSTEM CALLS Interface between user program and operating system Steps in Making a System Call
-Example of system calls: oProcess Management
oFile Management oDirectory and file system management
²OPERATING SYSTEM STRUCTURE Monolithic system -The big mess -No structure Simple structuring model
Layered System -Hierarchical layer, each layer is built on top of the layer below it. -Eg: THE system Generalisation of layering concept at MULTICS concentric ring
Virtual Machine -Virtual machine monitor not an extended machine, but an exact copy of the bare hardware -CMS (Conversational Monitor System) -JVM (Java Virtual Machine) Structure of VM/370 with CMS
Exokernels -Designed for a system that gives each user clone of the actual computer, but with a subset of resources -Program run on the bottom layer to allocate resources to virtual machine
Client-server model -Mikrokernel -Client process -Server process -Mechanism vs policy The client-server model
The client-server model in a distributed system Advantages of distributed system model: -Smaller parts are easier to maintain -No direct access toward hardware -Adaptability