interrupt | 易学教程

How can I add a user interrupt to an infinite loop?

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问题 I have a ruby script below which infinitely prints numbers from 1 onward. How can I make the script stop its infinite execution through an interrupt in the terminal like 'Ctrl+C' or key 'q'? a = 0 while( a ) puts a a += 1 # the code should quit if an interrupt of a character is given end Through every iteration, no user input should be asked. 回答1: I think you will have to check the exit condition in a separate thread: # check for exit condition Thread.new do loop do exit if gets.chomp == 'q'

How do interrupts work on the Intel 8080?

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问题 How do interrupts work on the Intel 8080? I have searched Google and in Intel's official documentation (197X), and I've found only a little description about this. I need a detailed explanation about it, to emulate this CPU. 回答1: The 8080 has an Interrupt line (pin 14). All peripherals are wired to this pin, usually in a "wire-OR" configuration (meaning interrupt request outputs are open-collector and the interrupt pin is pulled high with a resistor). Internally, the processor has an

How does threads sleep with interrupt disabled?

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I am trying to understand how the code below works. This is straight out of my profs lecture slides. This P() and V() function is the part of semaphore implementation in the OS that we use in class (OS161). I think you might need understanding of the OS161 to answer my question, since its widely used, hopefully some one can answer this questions. My understanding of this code with lecture notes: X:Flow of the P() function 1. When a thread call P(), we disable interrupt 2. check if we have any resources available on sem->count 3.a) if count is 0 then we go to sleep 3.b) if count != 0 then we

What happens when a mov instruction causes a page fault with interrupts disabled on x86?

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问题 I recently encountered an issue in a custom Linux kernel (2.6.31.5, x86) driver where copy_to_user would periodically not copy any bytes to user space. It would return the count of bytes passed to it, indicating that it had not copied anything. After code inspection we found that the code was disabling interrupts while calling copy_to_user which violates it's contract. After correcting this, the issue stopped occurring. Because the issue happened so infrequently, I need to prove that

How can I interrupt MATLAB when it gets really really busy?

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问题 I'm running a long simulation in MATLAB that I've realized I need to stop and rerun. However, MATLAB is really into this calculation, and it's stopped responding. How can I interrupt this run without killing MATLAB? (I realize this is a problem with many Windows programs, but it's really acute with MATLAB.) 回答1: Go to the command window, and hit Ctrl-C a lot. From my experience, on a single-core machine you do not have a chance, unless you do lots of output. On a multi-core or multi-processor

Do interrupts interrupt other interrupts on Arduino?

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问题 I have an Arduino Uno (awesome little device!). It has two interrupts; let's call them 0 and 1 . I attach a handler to interrupt 0 and a different one to interrupt 1, using attachInterrupt() : http://www.arduino.cc/en/Reference/AttachInterrupt. Interrupt 0 is triggered and it calls its handler, which does some number crunching. If interrupt 0 's handler is still executing when interrupt 1 is triggered, what will happen? Will interrupt 1 interrupt interrupt 0 , or will interrupt 1 wait until

What are Linux Local timer interrupts?

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问题 All is in the title. Any links to good documentations are welcome. 回答1: The local timer interrupt is a timer implemented on the APIC that interrupts only a particular CPU instead of raising an interrupt that can be handled by any CPU. It's discussed in Bovet & Cesati's "Understanding the Linux Kernel". A snippet: The local APIC present in recent 80x86 microprocessors (see the section “Interrupts and Exceptions” in Chapter 4) provides yet another time-measuring device: the CPU local timer. The

Should my interrupt handler disable interrupts or does the ARM processor do it automatically?

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Our group is using a custom driver to interface four MAX3107 UARTs on a shared I2C bus. The interrupts of the four MAX3107's are connected (i.e. shared interrupt via logic or'ing)) to a GPIO pin on the ARM9 processor (LPC3180 module). When one or more of these devices interrupt, they pull the GPIO line, which is configured as a level-sensitive interrupt, low. My question concerns the need, or not, to disable the specific interrupt line in the handler code. (I should add that we are running Linux 2.6.10). Based on my reading of several ARM-specific app notes on interrupts, it seems that when

What happens when you disable interrupts, and what do you do with interrupts you don't know how to handle?

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问题 When you disable interrupts (with the cli instruction in x86), what exactly happens? Does the PIC wait for you to turn on interrupts, and fire the interrupt when that happens? (If so, how long does it wait, and what happens if the time 'expires'?) Does the interrupt -- from the device's perspective -- get sent into a "black hole", with no response? Does the PIC somehow tell the device that "the CPU is busy" or something? Or does something else happen? Also, how do you deal with an interrupt

Java Hardware Interrupt Handling

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I would like to know if it is possible to automatically invoke a Java method when a hardware interrupt is raised. There may be an alternative. I'm doing something similar: In an application I monitor 4 mice for clicks. Those clicks generate interrupts but I'm happy enough not to deal with them directly from Java. Under Linux, it turns out there are device files ( /dev/input/mouse# ) that spew a bunch of characters when something happens with the mouse. I have a Thread for each one with a FileReader blocking on a read. Once characters arrive, the appertaining thread unblocks and I can do