o Don’t pertain to system o Run by users o Not typically considered part of OS o Launched by command line, mouse click, finger poke

Then it carries out the system call and returns control to the instruction following the __________.

The operating system then figures out what the calling process wants by inspecting the _________.

Aqua UI plus Cocoa programming environment. Below is kernel consisting of Mach microkernel and BSD Unix parts, plus I/O kit and dynamically loadable modules (called kernel extensions)

Provide the mechanism for creating virtual connections among processes, users, and computer systems.

Programming interface to the services provided by the OS

types of system calls

If a process is running a user program in user mode and needs a system service, such as reading data from a file, it has to execute a ____________ to transfer control to the operating system.

 Control access to resources  Get and set permissions  Allow and deny user access

Launch at boot time (Some for system startup, then terminate and some from system boot to shutdown). Provide facilities like disk checking, process scheduling, error logging, printing

_____________ methods do not limit the number or length of parameters being passed.

written to provide the most functionality in the least space. Although it has some structure, its interfaces and levels of functionality are not well separated

In a sense, making a system call is like making a special kind of ___________—only system calls enter the kernel and procedure calls do not.

_______________ can generate crash dump file containing kernel memory

Beyond crashes, ______________ can optimize system performance

Absolute loaders, relocatable loaders, linkage editors, and overlay-loaders, debugging systems for higher-level and machine language

operating system should be easy to design, implement, and maintain, as well as flexible, reliable, error-free, and efficient

• end, abort  load, execute  get process attributes, set process attributes  wait for time  wait event, signal event  allocate and free memory  Dump memory if error  Debugger for determining bugs, single step execution  Locks for managing access to shared data between processes

Developed by Open Handset Alliance (mostly Google (Open Source). Similar stack to IOS and based on Linux kernel but modified

Apple mobile OS for iPhone, iPad. Structured on Mac OS X, added functionality. Does not run OS X applications natively

 create file, delete file  open, close file  read, write, reposition  get and set file attributes

Create, delete, copy, rename, print, dump, list, and generally manipulate files and directories

 create, delete communication connection  send, receive messages if message passing model to host name or process name (From client to server)  Shared-memory model, create and gain access to memory regions  transfer status information  attach and detach remote devices

Compilers, assemblers, debuggers and interpreters sometimes provided

______________ can generate core dump file capturing memory of the process

___________ provide a convenient environment for program development and execution.

Communication takes place between user modules using ___________

Provide a convenient environment for program development and execution

 request device, release device  read, write, reposition  get device attributes, set device attributes  logically attach or detach devices

The UNIX OS consists of two separable parts:

Some ask the system for info - date, time, amount of available memory, disk space, number of users. Others provide detailed performance, logging, and debugging information

The __________ is to run the entire operating system as a single program in kernel mode. The operating system is written as a collection of procedures, linked together into a single large executable binary program.

___ generate log files containing error information

The basic idea behind the ____________ design is to achieve high reliability by splitting the operating system up into small, well-defined modules, only one of which—the microkernel—runs in kernel mode and the rest run as relatively powerless ordinary user processes.

Improve performance by removing bottlenecks

“Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.”

limited by hardware functionality, the original UNIX operating system had limited structuring.

Overall, similar to layers but with more flexible. (Linux, Solaris)

 get time or date, set time or date  get system data, set system data  get and set process, file, or device attributes

Typically, a number associated with each system call ____________, which maintains a table indexed according to these numbers

operating system should be convenient to use, easy to learn, reliable, safe, and fast

________ is finding and fixing errors, or bugs

Many modern operating systems implement ________________

- used to store and retrieve configuration information

The operating system is divided into a number of layers (levels), each built on top of lower layers. The bottom layer (layer 0), is the hardware; the highest (layer N) is the user interface.

Text editors to create and modify files. Special commands to search contents of files or perform transformations of the text