src/functional/pthread_cancel-points.c

   1 // testing cancellation points
   2 #include <errno.h>
   3 #include <pthread.h>
   4 #include <semaphore.h>
   5 #include <string.h>
   6 #include <sys/mman.h>
   7 #include <fcntl.h>
   8 #include <unistd.h>
   9 #include "test.h"
  10
  11 #define TESTC(c, m) ( (c) || (t_error(#c " failed (%s, " m ")\n", cdescr), 0) )
  12 #define TESTR(f, m) do {int r; \
  13         if ((r = (f))) t_error(#f " failed: %s (%s, " m ")\n", strerror(r), cdescr); } while (0)
  14 #define TESTE(f, m) do { \
  15         if ((f)==-1) t_error(#f " failed: %s (%s, " m ")\n", strerror(errno), cdescr); } while (0)
  16
  17 static sem_t sem_seq, sem_test;
  18
  19 static int seqno;
  20
  21 static const char *cdescr = "global initialization";
  22
  23 static void prepare_sem(void *arg)
  24 {
  25         TESTR(sem_init(&sem_test, 0, (long)arg), "creating semaphore");
  26 }
  27
  28 static void cleanup_sem(void *arg)
  29 {
  30         TESTR(sem_destroy(&sem_test), "destroying semaphore");
  31 }
  32
  33 static void execute_sem_wait(void *arg)
  34 {
  35         TESTR(sem_wait(&sem_test), "waiting on semaphore in the canceled thread");
  36 }
  37
  38 static void execute_sem_timedwait(void *arg)
  39 {
  40         struct timespec ts;
  41         clock_gettime(CLOCK_REALTIME, &ts);
  42         ts.tv_sec += 1;
  43         TESTR(sem_timedwait(&sem_test, &ts), "timed-waiting on semaphore in the canceled thread");
  44 }
  45
  46 static pthread_t td_test;
  47
  48 static void *run_test(void *arg)
  49 {
  50         while (sem_wait(&sem_test));
  51         return 0;
  52 }
  53
  54 static void prepare_thread(void *arg)
  55 {
  56         prepare_sem(arg);
  57         TESTR(pthread_create(&td_test, 0, run_test, 0), "creating auxiliary thread");
  58 }
  59
  60 static void cleanup_thread(void *arg)
  61 {
  62         void *res;
  63         if (td_test) {
  64                 TESTR(sem_post(&sem_test), "posting semaphore");
  65                 TESTR(pthread_join(td_test, &res), "joining auxiliary thread");
  66                 TESTC(res == 0, "auxiliary thread exit status");
  67         }
  68         cleanup_sem(arg);
  69 }
  70
  71 static void execute_thread_join(void *arg)
  72 {
  73         TESTR(pthread_join(td_test, 0), "joining in the canceled thread");
  74         td_test = 0;
  75 }
  76
  77 static void prepare_dummy(void *arg)
  78 {
  79 }
  80
  81 static void execute_shm_open(void *arg)
  82 {
  83         int *fd = arg;
  84         TESTE(*fd = shm_open("/testshm", O_RDWR|O_CREAT, 0666), "");
  85 }
  86
  87 static void cleanup_shm(void *arg)
  88 {
  89         int *fd = arg;
  90         if (*fd > 0) {
  91                 TESTE(close(*fd), "shm fd");
  92                 TESTE(shm_unlink("/testshm"), "");
  93         }
  94 }
  95
  96 static struct {
  97         int want_cancel;
  98         void (*prepare)(void *);
  99         void (*execute)(void *);
 100         void (*cleanup)(void *);
 101         void *arg;
 102         const char *descr;
 103 } scenarios[] = {
 104         {1, prepare_sem, execute_sem_wait, cleanup_sem, 0, "blocking sem_wait"},
 105         {1, prepare_sem, execute_sem_wait, cleanup_sem, (void*)1, "non-blocking sem_wait"},
 106         {1, prepare_sem, execute_sem_timedwait, cleanup_sem, 0, "blocking sem_timedwait"},
 107         {1, prepare_sem, execute_sem_timedwait, cleanup_sem, (void*)1, "non-blocking sem_timedwait"},
 108         {1, prepare_thread, execute_thread_join, cleanup_thread, 0, "blocking pthread_join"},
 109         {1, prepare_thread, execute_thread_join, cleanup_thread, (void*)1, "non-blocking pthread_join"},
 110         {0, prepare_dummy, execute_shm_open, cleanup_shm, &(int){0}, "shm_open"},
 111         { 0 }
 112 }, *cur_sc = scenarios;
 113
 114 static void *run_execute(void *arg)
 115 {
 116         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0);
 117         while (sem_wait(&sem_seq));
 118         pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, 0);
 119         seqno = 1;
 120         cur_sc->execute(cur_sc->arg);
 121         seqno = 2;
 122         return 0;
 123 }
 124
 125 int main(void)
 126 {
 127         TESTR(sem_init(&sem_seq, 0, 0), "creating semaphore");
 128
 129         for (; cur_sc->prepare; cur_sc++) {
 130                 pthread_t td;
 131                 void *res;
 132
 133                 cdescr = cur_sc->descr;
 134                 cur_sc->prepare(cur_sc->arg);
 135                 seqno = 0;
 136                 TESTR(pthread_create(&td, 0, run_execute, 0), "creating thread to be canceled");
 137                 TESTR(pthread_cancel(td), "canceling");
 138                 TESTR(sem_post(&sem_seq), "unblocking canceled thread");
 139                 TESTR(pthread_join(td, &res), "joining canceled thread");
 140                 if (cur_sc->want_cancel) {
 141                         TESTC(res == PTHREAD_CANCELED, "canceled thread exit status")
 142                         && TESTC(seqno == 1, "seqno");
 143                 } else {
 144                         TESTC(res != PTHREAD_CANCELED, "canceled thread exit status")
 145                         && TESTC(seqno == 2, "seqno");
 146                 }
 147                 cur_sc->cleanup(cur_sc->arg);
 148         }
 149
 150         return t_status;
 151 }