/*

$ gdb qemu-e2k
(gdb) start timer_test 100000
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Temporary breakpoint 3 at 0x555555bbae5d: file ../linux-user/main.c, line 632.
Starting program: /home/andreiw/src/e2k/qemu-e2k/build/qemu-e2k timer_test 100000
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff34ff700 (LWP 1275)]

Thread 1 "qemu-e2k" hit Temporary breakpoint 3, main (argc=3, argv=0x7fffffffe4d8, envp=0x7fffffffe4f8) at ../linux-user/main.c:632
632	{
(gdb) c
Continuing.
Establishing handler for signal 14
+++++-+++--+--+---+----+-----+----+-----+----+----+----+-----+----+-----+-----+----+---+-----+-----+----+-----+----+-----+---+----+-----+-----+----+-----+----+---+-----+----+-----+----+-----+----+----+----+/home/andreiw/src/e2k/qemu-e2k/include/qemu/bswap.h:301:5: runtime error: load of null pointer of type 'unsigned int'

Thread 1 "qemu-e2k" received signal SIGSEGV, Segmentation fault.
0x0000555555b776e9 in ldl_he_p (ptr=0x0) at /home/andreiw/src/e2k/qemu-e2k/include/qemu/bswap.h:301
301	    __builtin_memcpy(&r, ptr, sizeof(r));
(gdb) bt
#0  0x0000555555b776e9 in ldl_he_p (ptr=0x0) at /home/andreiw/src/e2k/qemu-e2k/include/qemu/bswap.h:301
#1  0x0000555555b77adb in ldl_le_p (ptr=0x0) at /home/andreiw/src/e2k/qemu-e2k/include/qemu/bswap.h:334
#2  0x0000555555b78e27 in cpu_ldl_code (env=0x62e000008720, ptr=0) at ../accel/tcg/user-exec.c:453
#3  0x0000555555b76ed5 in translator_ldl_swap (env=0x62e000008720, dcbase=0x7fffffffcdd0, pc=0, do_swap=false) at ../accel/tcg/translator.c:178
#4  0x0000555555a10974 in translator_ldl (env=0x62e000008720, dcbase=0x7fffffffcdd0, pc=0) at /home/andreiw/src/e2k/qemu-e2k/include/exec/translator.h:186
#5  0x0000555555a31e4a in unpack_bundle (env=0x62e000008720, ctx=0x7fffffffcdd0) at ../target/e2k/translate.c:712
#6  0x0000555555a75800 in do_decode (ctx=0x7fffffffcdd0, cs=0x62e000000400) at ../target/e2k/translate.c:7728
#7  0x0000555555a78305 in e2k_tr_translate_insn (db=0x7fffffffcdd0, cs=0x62e000000400) at ../target/e2k/translate.c:8150
#8  0x0000555555b7619e in translator_loop (ops=0x555555ea1420 <e2k_tr_ops>, db=0x7fffffffcdd0, cpu=0x62e000000400, tb=0x7fffeae12ac0 <code_gen_buffer+1129107>, max_insns=512)
    at ../accel/tcg/translator.c:103
#9  0x0000555555a7909d in gen_intermediate_code (cs=0x62e000000400, tb=0x7fffeae12ac0 <code_gen_buffer+1129107>, max_insns=512) at ../target/e2k/translate.c:8234
#10 0x0000555555b70f27 in tb_gen_code (cpu=0x62e000000400, pc=0, cs_base=0, flags=1, cflags=0) at ../accel/tcg/translate-all.c:1447
#11 0x0000555555b5b866 in cpu_exec (cpu=0x62e000000400) at ../accel/tcg/cpu-exec.c:982
#12 0x00005555559ccbe8 in cpu_loop (env=0x62e000008720) at ../linux-user/e2k/cpu_loop.c:70
#13 0x0000555555bbc5b1 in main (argc=3, argv=0x7fffffffe4d8, envp=0x7fffffffe4f8) at ../linux-user/main.c:909
(gdb) 

*/

#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <time.h>

#define CLOCKID CLOCK_MONOTONIC
#define SIG SIGALRM

#define errExit(msg)    do { perror(msg); exit(EXIT_FAILURE);   \
  } while (0)

sigset_t sigset;
timer_t timerid;
struct itimerspec its;

static void
handler(int sig, siginfo_t *si, void *uc)
{
  write (STDIN_FILENO, "+", 1);
  fsync(STDIN_FILENO);

  if (timer_settime(timerid, 0, &its, NULL) == -1) {
    errExit("timer_settime");
  }
}

static void
loop_fn(void) {
  write (STDIN_FILENO, "-", 1);
  fsync(STDIN_FILENO);
}

int
main(int argc, char *argv[])
{
  struct sigevent sev;
  long long freq_nanosecs;
  sigset_t mask;
  struct sigaction sa;

  sigemptyset (&sigset);
  sigaddset (&sigset, SIGALRM);
  
  if (argc != 2) {
    fprintf(stderr, "Usage: %s <freq-nanosecs>\n",
            argv[0]);
    exit(EXIT_FAILURE);
  }

  /* Establish handler for timer signal. */

  printf("Establishing handler for signal %d\n", SIG);
  sa.sa_flags = SA_SIGINFO;
  sa.sa_sigaction = handler;
  sigemptyset(&sa.sa_mask);
  if (sigaction(SIG, &sa, NULL) == -1) {
    errExit("sigaction");
  }

  /* Create the timer. */

  sev.sigev_notify = SIGEV_SIGNAL;
  sev.sigev_signo = SIG;
  sev.sigev_value.sival_ptr = &timerid;
  if (timer_create(CLOCKID, &sev, &timerid) == -1) {
    errExit("timer_create");
  }
  
  /* Start the timer. */

  freq_nanosecs = atoll(argv[1]);
  its.it_value.tv_sec = freq_nanosecs / 1000000000;
  its.it_value.tv_nsec = freq_nanosecs % 1000000000;
  its.it_interval.tv_sec = 0;
  its.it_interval.tv_nsec = 0;

  if (timer_settime(timerid, 0, &its, NULL) == -1) {
    errExit("timer_settime");
  }

  while (1) {
    loop_fn();
  }

  exit(EXIT_SUCCESS);
}