interrupt | 易学教程

Boost Thread - How to acknowledge interrupt

阅读更多关于 Boost Thread - How to acknowledge interrupt

问题 I have blocking task which will be performed by find_the_question() function. However, I do not want thread executing this function take more than 10 seconds. So in case it takes more than 10 seconds, I want to close that thread with cleaning all the resources. I tried to write a code for that, but somehow I am not able to get a interrupt in find_the_question() function if thread takes more than 10 seconds. Could you please tell me what am I doing wrong? void find_the_question(std::string

do system calls execute inside a software interrupt handler in entirety?

阅读更多关于 do system calls execute inside a software interrupt handler in entirety?

Do system calls execute in the context of a software interrupt handler in entirety? I mean, some system calls like read() could take a long time to return, against the policy that ISR should be very short in execution time. Are system calls offloaded to other threads? How does that work? [A reference to any kernel is fine] Benoit The syscalls run on most kernels inside an ISR . Take a quick glance at a former release of Linux and you will notice the int $Ox80 to invoke the kernel. This solution which is probably the simplest from a kernel development point of view, has a strong drawback: as

Why can't I call BIOS interrupts from protected mode?

阅读更多关于 Why can't I call BIOS interrupts from protected mode?

问题 Right. I've spent over three hours today trying to understand why you can't call a bios ISR when in protected mode. I get that once you set and IDT it wont necessarily be in the usual address for the IVT plus segments dont have a fixed size in Protected mode, etc.. But I still don't get why can't you jsut create a single 4GB segment, map your IDT segments to the BIOS IVT, set everything in ring 0 and call them. Shouldn't that work? Most articles either say: "Remember you cant use BIOS

how to print RTC use Assembly interrupt vector 1ah

阅读更多关于 how to print RTC use Assembly interrupt vector 1ah

问题 I need to output an Interrupt 1h. (RTC). But I don't know how to print RTC in console. Should I use interrupt 10h, or is there another way? I already tried to find some in google, and I applied the interrupt 10 directly as below. mov ah 0x02 int 0x1a But it's not working. I know that the code is poor. Please give me some help. If you can make example for me, I'd really appreciate it. 回答1: Looking at docs for int 0x10 , we see a number of functions. You didn't specify which you tried to use,

How do system calls work?

阅读更多关于 How do system calls work?

问题 I understand that a user can own a process and each process has an address space (which contains valid memory locations, this process can reference). I know that a process can call a system call and pass parameters to it, just like any other library function. This seems to suggest that all system calls are in a process address space by sharing memory, etc. But perhaps, this is only an illusion created by the fact that in high level programming language, system calls look like any other

Do I have to pop the error code pushed to stack by certain exceptions before returning from the interrupt handler?

阅读更多关于 Do I have to pop the error code pushed to stack by certain exceptions before returning from the interrupt handler?

I have loaded an idt table with 256 entries, all pointing to similar handlers: for exceptions 8 and 10-14, push the exception number (these exceptions push an error code automatically) for the others, push a "dummy" error code and the exception number; then jump to a common handler So when the common handler enters, the stack is properly aligned and contains the exception/interrupt number, error code (which may just be a dummy), eflags, cs and eip. My question regards returning from the interrupt handler. I use iret to return after taking out the exception number and the error code from the

how quick can the processor handle the interrupts

阅读更多关于 how quick can the processor handle the interrupts

问题 I was studying about interrupts. So most architecture are interrupt driven, if everything is interrupt driven, how fast the processor can handle all of those. For example, while pressing a key board keys, it creates an interrupt asking the kernel to look for the buffer for new characters, in that case, how fast the processor can serve, also when an interrupt is put, the processor needs to switch to kernel space and that costs a lot in terms of context switch. So I assume, even after all these

Temporarily disable interrupts on ARM

阅读更多关于 Temporarily disable interrupts on ARM

I am starting working with the ARM platform (specifically the TI TMS570 family). I have some code with critical regions where I don't want an exception to occur. So I want to save the IRQ and FIR enabled flags on entering the regions and restore them on exiting. How do I do that? To temporarily mask IRQs and FIQs at the CPU, the nicest option for ARMv7 is to use cps : // assembly code assuming interrupts unmasked on entry cpsid if // mask IRQ and FIQ ... // do critical stuff cpsie if // unmask Some compilers provide a set of __disable_irq() etc. intrinsics usable from C code, but for others

Can the R console support background tasks or interrupts (event-handling)?

阅读更多关于 Can the R console support background tasks or interrupts (event-handling)?

While working in an R console, I'd like to set up a background task that monitors a particular connection and when an event occurs, another function (an alert) is executed. Alternatively, I can set things up so that an external function simply sends an alert to R, but this seems to be the same problem: it is necessary to set up a listener. I can do this in a dedicated process of R, but I don't know if this is feasible from within a console. Also, I'm not interested in interrupting R if it is calculating a function, but alerting or interrupting if the console is merely waiting on input. Here

SQL: Interrupting a query

阅读更多关于 SQL: Interrupting a query

I've worked on a project using a proprietary non-SQL DB where queries could be interrupted and in the codebase there were quite some spots where that functionnality was used and made perfect sense (for example to stop a long running query that gets cancelled by the user, or when a more recent query takes place and renders the previous query obsolete, etc.) and I realized I never really saw that kind of "interrupted queries" previously and thought it could make a good SO question (several questions, but they're all related to exactly the same thing): can SQL queries be interrupted? is this part