Sunday, April 7, 2019

Interrupt and a Trap in an Operating System Essay Example for Free

Interrupt and a Trap in an Operating System EssayWhat are the differences between an frustrate and a old salt? What are their importance? According to Stallings (2012) an interrupt is a suspension of a process, such as the act of a computer program, caused by an event external to that process and performed in such a means that the process can be resumed (p. 716). Stallings (2012) goes on to say that interrupts are provided primarily as a bureau to improve processor utilization. For example, most I/O devices are much slower than the processor (p. 14). A trap is an unprogrammed conditional jump to a specified address that is automatically activated by hardware the location from which the jump was made is recorded (Stallings, 2012, p. 721). A trap is actually a software generated interrupt caused either by an error (for example division by zero, invalid memory access etc.), or by a specific request by an operating agreement service generated by a user program.Trap is sometim es called Exception. The hardware or software can generate these interrupts. When the interrupt or trap occurs, the hardware transfers control to the operating system which first preserves the current state of the system by saving the current CPU registers content and program counters value. Then the focus shifts to the determination of which geek of interrupt has occurred. For each type of interrupt, separate segments of code in the operating system determine what body process should be taken and thus the system keeps on functioning by executing computational instruction, I/O instruction, storage instruction etc. Provide an example of each.Example of an Interrupt retrieved from http//www.scriptoriumdesigns.com/embedded/show_codefile.php?fname=interrupts/AVR_ISR_1.c// AVR_ISR_1 acknowledge avr/io.hinclude avr/interrupt.htypedef uint8_t u8 // convenient unsigned variable designationstypedef uint16_t u16define INPORT PINDdefine OUTPORT PORTCdefine OUTDDR DDRCvolatile u8 Int_flag = 0 ISR( INT0_vect )OUTPORT = 0x01 // render LEDvoid int0_init( void )MCUCR = (1ISC01) // enable negative edge on INT0GICR = (1INT0) // enable INT0int main( void )OUTDDR = 0x01 // unbending bit 0 to outputOUTPORT = 0x01 // set LED off (active low)int0_init() // configure INT0sei() // enable global interrupts musical composition (1) // loop forever, all work happens in ISRreturn(0)Example of a trap retrieved from http//www.ibm.com/developerworks/aix/library/au-usingtraps/index.html / store/bashproj_dir=/ favour/pcake/bin check file is presentif -f $proj_dir/run_pj thenecho $proj_dir/run_pj not present pallingexit 1fi make a supporting copycp -p $proj_dir/run_pj $proj_dir/run_pj.24042011if $? = 0 thenecho $proj_dir/run_pj no backup madeexitingexit 1fi copy over updated fileif -f /opt/dump/rollout/run_pj thenecho /opt/dump/rollout/run_pj not presentexitingexit 1ficp -p /opt/dump/rollout/run_pj $proj_dir/run_pjif $? = 0 thenecho $proj_dir/run_pj was not copied..exitingexit 1fiRef erencesStallings, W. (2012). Operating systems Internals and design principles (7th ed.). Boston, MA Prentice Hall.

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