69 lines
1.8 KiB
C
69 lines
1.8 KiB
C
/*
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* SPDX-License-Identifier: MIT
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*/
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#include <sys/types.h>
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#include <time.h>
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#include <stdbool.h>
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#include <unistd.h>
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#include <pthread.h>
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#include <stdlib.h>
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#include <evl/thread.h>
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#include <evl/mutex.h>
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#include <evl/clock.h>
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#include <evl/sem.h>
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#include "helpers.h"
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#define LOW_PRIO 1
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#define HIGH_PRIO 2
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static bool check_priority(int tfd, int prio)
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{
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struct evl_thread_state statebuf;
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int ret;
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__Tcall_assert(ret, evl_get_state(tfd, &statebuf));
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return statebuf.eattrs.sched_policy == SCHED_FIFO &&
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statebuf.eattrs.sched_priority == prio;
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}
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int main(int argc, char *argv[])
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{
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struct sched_param param;
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struct evl_mutex lock;
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int tfd, gfd, ret;
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char *name;
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param.sched_priority = LOW_PRIO;
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__Texpr_assert(pthread_setschedparam(pthread_self(),
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SCHED_FIFO, ¶m) == 0);
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/* EVL inherits the inband scheduling params upon attachment. */
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__Tcall_assert(tfd, evl_attach_self("monitor-pp-tryenter:%d", getpid()));
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name = get_unique_name(EVL_MONITOR_DEV, 0);
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__Tcall_assert(gfd, evl_new_mutex_ceiling(&lock,
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EVL_CLOCK_MONOTONIC, HIGH_PRIO, name));
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/* Taking the fast locking path requires running OOB. */
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__Tcall_assert(ret, evl_switch_oob());
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__Tcall_assert(ret, evl_lock(&lock));
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__Texpr_assert(evl_trylock(&lock) == -EDEADLK);
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__Tcall_assert(ret, evl_udelay(1000)); /* Commit PP boost. */
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__Texpr_assert(check_priority(tfd, HIGH_PRIO));
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__Tcall_assert(ret, evl_unlock(&lock));
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__Texpr_assert(check_priority(tfd, LOW_PRIO));
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/* Force inband in order to skip the fast locking path. */
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__Tcall_assert(ret, evl_switch_inband());
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__Tcall_assert(ret, evl_trylock(&lock));
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/* The slow path must have enforced the ceiling. */
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__Texpr_assert(check_priority(tfd, HIGH_PRIO));
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__Tcall_assert(ret, evl_unlock(&lock));
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__Texpr_assert(check_priority(tfd, LOW_PRIO));
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evl_close_mutex(&lock);
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return 0;
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}
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