signal.c

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#include "signal.h"

#include <cfg/debug.h>
#include <drv/timer.h>
#include <kern/proc.h>
#include <kern/proc_p.h>
 

#if CONFIG_KERN_SIGNALS

sigmask_t sig_check(sigmask_t sigs)
{
    sigmask_t result;
    cpuflags_t flags;

    IRQ_SAVE_DISABLE(flags);
    result = CurrentProcess->sig_recv & sigs;
    CurrentProcess->sig_recv &= ~sigs;
    IRQ_RESTORE(flags);

    return result;
}


sigmask_t sig_wait(sigmask_t sigs)
{
    sigmask_t result;
    cpuflags_t flags;

    IRQ_SAVE_DISABLE(flags);

    /* Loop until we get at least one of the signals */
    while (!(result = CurrentProcess->sig_recv & sigs))
    {
        /* go to sleep and proc_schedule() another process */
        CurrentProcess->sig_wait = sigs;
        proc_schedule();

        /* When we come back here, a signal must be arrived */
        ASSERT(!CurrentProcess->sig_wait);
        ASSERT(CurrentProcess->sig_recv);
    }

    /* Signals found: clear them and return */
    CurrentProcess->sig_recv &= ~sigs;

    IRQ_RESTORE(flags);
    return result;
}

sigmask_t sig_waitTimeout(sigmask_t sigs, ticks_t timeout)
{
    Timer t;
    sigmask_t res;
    cpuflags_t flags;

    ASSERT(!sig_check(SIG_TIMEOUT));
    ASSERT(!(sigs & SIG_TIMEOUT));
    /* IRQ are needed to run timer */
    ASSERT(IRQ_ENABLED());

    timer_set_event_signal(&t, proc_current(), SIG_TIMEOUT);
    timer_setDelay(&t, timeout);
    timer_add(&t);
    res = sig_wait(SIG_TIMEOUT | sigs);

    IRQ_SAVE_DISABLE(flags);
    /* Remove timer if sigs occur before timer signal */
    if (!(res & SIG_TIMEOUT) && !sig_check(SIG_TIMEOUT))
        timer_abort(&t);
    IRQ_RESTORE(flags);
    return res;
}


void sig_signal(Process *proc, sigmask_t sigs)
{
    cpuflags_t flags;
    IRQ_SAVE_DISABLE(flags);

    /* Set the signals */
    proc->sig_recv |= sigs;

    /* Check if process needs to be awoken */
    if (proc->sig_recv & proc->sig_wait)
    {
        /* Wake up process and enqueue in ready list */
        proc->sig_wait = 0;
        SCHED_ENQUEUE(proc);
    }

    IRQ_RESTORE(flags);
}

#endif /* CONFIG_KERN_SIGNALS */