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sleeper: handle out of order cont/term signals #37

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sleeper: handle out of order cont/term signals #37

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83 changes: 80 additions & 3 deletions sleeper.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,21 @@
#include "str.h"
#include <unistd.h>

#define SIGQLEN 64

static unsigned int sig_ptr = 0;
static int sig_queue[SIGQLEN];

static void catch_sig(int sig)
{
int ignored;
sig_queue[sig_ptr++] = sig;
if (sig_ptr < SIGQLEN) return;
ignored = write(1,"increase SIGQLEN\n",17);
_exit(2);
}

static void show_sig(int sig)
{
char buf[7+14+2] = "Caught ";
const char *name;
Expand All @@ -27,12 +41,54 @@ static void catch_sig(int sig)
i += 7;
buf[i++] = '\n';
ignored = write(1,buf,i);
if (sig != SIGCONT)
_exit(1);
}

static void show_err()
{
int ignored;
ignored = write(1,"invalid signal\n",15);
_exit(1);
}

static void show_one(int sig)
{
show_sig(sig);
_exit(1);
}

static void show_two(int sig1, int sig2)
{
show_sig(sig1);
show_sig(sig2);
_exit(1);
}

#define new_cont (new_sig == SIGCONT)
#define new_term (new_sig == SIGTERM)
#define old_cont (old_sig == SIGCONT)
#define old_term (old_sig == SIGTERM)

#define state_00 ( ! new_cont && ! new_term && ! old_cont && ! old_term)
#define state_01 ( ! new_cont && ! new_term && ! old_cont && old_term)
#define state_02 ( ! new_cont && ! new_term && old_cont && ! old_term)
#define state_03 ( ! new_cont && ! new_term && old_cont && old_term)
#define state_04 ( ! new_cont && new_term && ! old_cont && ! old_term)
#define state_05 ( ! new_cont && new_term && ! old_cont && old_term)
#define state_06 ( ! new_cont && new_term && old_cont && ! old_term)
#define state_07 ( ! new_cont && new_term && old_cont && old_term)
#define state_08 ( new_cont && ! new_term && ! old_cont && ! old_term)
#define state_09 ( new_cont && ! new_term && ! old_cont && old_term)
#define state_10 ( new_cont && ! new_term && old_cont && ! old_term)
#define state_11 ( new_cont && ! new_term && old_cont && old_term)
#define state_12 ( new_cont && new_term && ! old_cont && ! old_term)
#define state_13 ( new_cont && new_term && ! old_cont && old_term)
#define state_14 ( new_cont && new_term && old_cont && ! old_term)
#define state_15 ( new_cont && new_term && old_cont && old_term)

int main(void)
{
int i, new_sig, old_sig=0;

sig_catch(SIGALRM,catch_sig);
sig_catch(SIGCONT,catch_sig);
sig_catch(SIGHUP,catch_sig);
Expand All @@ -42,6 +98,27 @@ int main(void)
sig_catch(SIGUSR1,catch_sig);
sig_catch(SIGUSR2,catch_sig);
sig_catch(SIGWINCH,catch_sig);
sleep(9999);

for (i = 0; i < SIGQLEN; ++i) {
while (i >= sig_ptr) sleep(9999);
new_sig = sig_queue[i];
if (i) old_sig = sig_queue[i-1];
if (state_00) show_one(new_sig);
if (state_01) show_two(old_sig, new_sig);
if (state_02) show_two(old_sig, new_sig);
if (state_03) show_err();
if (state_04) continue;
if (state_05) show_one(old_sig);
if (state_06) show_two(old_sig, new_sig);
if (state_07) show_err();
if (state_08) continue;
if (state_09) show_two(new_sig, old_sig);
if (state_10) show_one(old_sig);
if (state_11) show_err();
if (state_12) show_err();
if (state_13) show_err();
if (state_14) show_err();
if (state_15) show_err();
}
return 0;
}