[2/3] posix: Refactor tst-waitid

The main changes are:

  - Adapt to libsupport.
  - Synchronize the signal handler using atomics.
  - Replace waitpid by waitid calls.
  - Use support_process_state_wait to wait for child state.
  - Add tests for P_PGID and P_ALL.

Checked on x86_64-linux-gnu and i686-linux-gnu.
---
 posix/tst-waitid.c | 519 +++++++++++++--------------------------------
 1 file changed, 153 insertions(+), 366 deletions(-)

-- 
2.17.1

This reminds me of the bug we have, 
<https://sourceware.org/bugzilla/show_bug.cgi?id=14666>, for intermittent 
failures of tst-waitid (I think the discussion it references starts at 
<https://sourceware.org/ml/libc-alpha/2010-09/msg00030.html>).

Was that fixed by commit a58ad3f801960fa0dc0bb1106eb0d99f7ebd77b1 in 2013, 
or is it fixed by your patch, or is it an unrelated issue?

-- 
Joseph S. Myers
joseph@codesourcery.com

On 20/11/2019 14:33, Joseph Myers wrote:
> This reminds me of the bug we have, 

> <https://sourceware.org/bugzilla/show_bug.cgi?id=14666>, for intermittent 

> failures of tst-waitid (I think the discussion it references starts at 

> <https://sourceware.org/ml/libc-alpha/2010-09/msg00030.html>).

> 

> Was that fixed by commit a58ad3f801960fa0dc0bb1106eb0d99f7ebd77b1 in 2013, 

> or is it fixed by your patch, or is it an unrelated issue?

> 


My initial idea of replacing the sleep added by a58ad3f801960f is to
loop atomically over a variable which is set by the signal handler.
However I think a better strategy would be to use sigwaitinfo instead
as Roland has suggested later in the thread.  It allows clean up the
test a little more.

And BZ#14666 does seems to be same issue mitigated by a58ad3f801960f.

My idea of using support_process_state_wait in this case is to avoid
use timeouts to sync process/threads and move towards some ideas laid
out on a recent thread on how to speed up the testsuite spent time [1]

Below I updated the patch to use sigwaitinfo instead of global variables
set by the signal handler.

[1] https://sourceware.org/ml/libc-alpha/2019-07/msg00403.html

--

[PATCH v2 2/3] posix: Refactor tst-waitid (BZ #14666)

The main changes are:

  - Adapt to libsupport.
  - Synchronize the signal handler using atomics.
  - Replace waitpid by waitid calls.
  - Use support_process_state_wait to wait for child state.
  - Add tests for P_PGID and P_ALL.
  - Use sigwaitinfo instead of global state set by the signal handler.

Checked on x86_64-linux-gnu and i686-linux-gnu.  It fixes BZ #14666.

---

diff --git a/posix/tst-waitid.c b/posix/tst-waitid.c
index c82ec2b566..808bf6a8eb 100644
--- a/posix/tst-waitid.c
+++ b/posix/tst-waitid.c
@@ -22,13 +22,20 @@
 #include <unistd.h>
 #include <sys/wait.h>
 #include <signal.h>
+#include <time.h>
+#include <stdatomic.h>
+#include <stdbool.h>
+
+#include <support/xsignal.h>
+#include <support/xunistd.h>
+#include <support/check.h>
+#include <support/process_state.h>
 
 static void
-test_child (void)
+test_child (bool setgroup)
 {
-  /* Wait a second to be sure the parent set his variables before we
-     produce a SIGCHLD.  */
-  sleep (1);
+  if (setgroup)
+    TEST_COMPARE (setpgid (0, 0), 0);
 
   /* First thing, we stop ourselves.  */
   raise (SIGSTOP);
@@ -44,475 +51,239 @@ test_child (void)
 # define WSTOPPED	WUNTRACED
 #endif
 
-static sig_atomic_t expecting_sigchld, spurious_sigchld;
-#ifdef SA_SIGINFO
-static siginfo_t sigchld_info;
+/* Set with only SIGCHLD on do_test_waitid.  */
+static sigset_t chldset;
 
+#ifdef SA_SIGINFO
 static void
 sigchld (int signo, siginfo_t *info, void *ctx)
 {
-  if (signo != SIGCHLD)
-    {
-      printf ("SIGCHLD handler got signal %d instead!\n", signo);
-      _exit (EXIT_FAILURE);
-    }
-
-  if (! expecting_sigchld)
-    {
-      spurious_sigchld = 1;
-      printf ("spurious SIGCHLD: signo %d code %d status %d pid %d\n",
-	      info->si_signo, info->si_code, info->si_status, info->si_pid);
-    }
-  else
-    {
-      sigchld_info = *info;
-      expecting_sigchld = 0;
-    }
 }
+#endif
 
 static void
-check_sigchld (const char *phase, int *ok, int code, int status, pid_t pid)
+check_sigchld (int code, int status, pid_t pid)
 {
-  if (expecting_sigchld)
-    {
-      printf ("missing SIGCHLD on %s\n", phase);
-      *ok = EXIT_FAILURE;
-      expecting_sigchld = 0;
-      return;
-    }
+#ifdef SA_SIGINFO
+  siginfo_t siginfo;
+  TEST_COMPARE (sigwaitinfo (&chldset, &siginfo), SIGCHLD);
 
-  if (sigchld_info.si_signo != SIGCHLD)
-    {
-      printf ("SIGCHLD for %s signal %d\n", phase, sigchld_info.si_signo);
-      *ok = EXIT_FAILURE;
-    }
-  if (sigchld_info.si_code != code)
-    {
-      printf ("SIGCHLD for %s code %d\n", phase, sigchld_info.si_code);
-      *ok = EXIT_FAILURE;
-    }
-  if (sigchld_info.si_status != status)
-    {
-      printf ("SIGCHLD for %s status %d\n", phase, sigchld_info.si_status);
-      *ok = EXIT_FAILURE;
-    }
-  if (sigchld_info.si_pid != pid)
-    {
-      printf ("SIGCHLD for %s pid %d\n", phase, sigchld_info.si_pid);
-      *ok = EXIT_FAILURE;
-    }
-}
-# define CHECK_SIGCHLD(phase, code_check, status_check) \
-  check_sigchld ((phase), &status, (code_check), (status_check), pid)
-#else
-# define CHECK_SIGCHLD(phase, code, status) ((void) 0)
+  TEST_COMPARE (siginfo.si_signo, SIGCHLD);
+  TEST_COMPARE (siginfo.si_code, code);
+  TEST_COMPARE (siginfo.si_status, status);
+  TEST_COMPARE (siginfo.si_pid, pid);
 #endif
+}
 
 static int
-do_test (int argc, char *argv[])
+do_test_waitd_common (idtype_t type, pid_t pid)
 {
-#ifdef SA_SIGINFO
-  struct sigaction sa;
-  sa.sa_flags = SA_SIGINFO|SA_RESTART;
-  sa.sa_sigaction = &sigchld;
-  if (sigemptyset (&sa.sa_mask) < 0 || sigaction (SIGCHLD, &sa, NULL) < 0)
-    {
-      printf ("setting SIGCHLD handler: %m\n");
-      return EXIT_FAILURE;
-    }
-#endif
+  /* Adding process_state_tracing_stop ('t') allows the test to work under
+     trace programs such as ptrace.  */
+  enum process_state_t stop_state = process_state_stopped
+				    | process_state_tracing_stop;
 
-  expecting_sigchld = 1;
+  support_process_state_wait (pid, stop_state);
 
-  pid_t pid = fork ();
-  if (pid < 0)
-    {
-      printf ("fork: %m\n");
-      return EXIT_FAILURE;
-    }
-  else if (pid == 0)
-    {
-      test_child ();
-      _exit (127);
-    }
-
-  int status = EXIT_SUCCESS;
-#define RETURN(ok) \
-    do { if (status == EXIT_SUCCESS) status = (ok); goto out; } while (0)
-
-  /* Give the child a chance to stop.  */
-  sleep (3);
-
-  CHECK_SIGCHLD ("stopped (before waitid)", CLD_STOPPED, SIGSTOP);
+  check_sigchld (CLD_STOPPED, SIGSTOP, pid);
 
   /* Now try a wait that should not succeed.  */
   siginfo_t info;
+  int fail;
+
   info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
-  int fail = waitid (P_PID, pid, &info, WEXITED|WCONTINUED|WNOHANG);
-  switch (fail)
-    {
-    default:
-      printf ("waitid returned bogus value %d\n", fail);
-      RETURN (EXIT_FAILURE);
-    case -1:
-      printf ("waitid WNOHANG on stopped: %m\n");
-      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
-    case 0:
-      if (info.si_signo == 0)
-	break;
-      if (info.si_signo == SIGCHLD)
-	printf ("waitid WNOHANG on stopped status %d\n", info.si_status);
-      else
-	printf ("waitid WNOHANG on stopped signal %d\n", info.si_signo);
-      RETURN (EXIT_FAILURE);
-    }
+  fail = waitid (P_PID, pid, &info, WEXITED|WCONTINUED|WNOHANG);
+  if (fail == -1 && errno == ENOTSUP)
+    FAIL_RET ("waitid WNOHANG on stopped: %m");
+  TEST_COMPARE (fail, 0);
+  TEST_COMPARE (info.si_signo, 0);
 
   /* Next the wait that should succeed right away.  */
   info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
   info.si_pid = -1;
   info.si_status = -1;
   fail = waitid (P_PID, pid, &info, WSTOPPED|WNOHANG);
-  switch (fail)
-    {
-    default:
-      printf ("waitid WSTOPPED|WNOHANG returned bogus value %d\n", fail);
-      RETURN (EXIT_FAILURE);
-    case -1:
-      printf ("waitid WSTOPPED|WNOHANG on stopped: %m\n");
-      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
-    case 0:
-      if (info.si_signo != SIGCHLD)
-	{
-	  printf ("waitid WSTOPPED|WNOHANG on stopped signal %d\n",
-		  info.si_signo);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_code != CLD_STOPPED)
-	{
-	  printf ("waitid WSTOPPED|WNOHANG on stopped code %d\n",
-		  info.si_code);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_status != SIGSTOP)
-	{
-	  printf ("waitid WSTOPPED|WNOHANG on stopped status %d\n",
-		  info.si_status);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_pid != pid)
-	{
-	  printf ("waitid WSTOPPED|WNOHANG on stopped pid %d != %d\n",
-		  info.si_pid, pid);
-	  RETURN (EXIT_FAILURE);
-	}
-    }
+  if (fail == -1 && errno == ENOTSUP)
+    FAIL_RET ("waitid WNOHANG on stopped: %m");
+  TEST_COMPARE (fail, 0);
+  TEST_COMPARE (info.si_signo, SIGCHLD);
+  TEST_COMPARE (info.si_code, CLD_STOPPED);
+  TEST_COMPARE (info.si_status, SIGSTOP);
+  TEST_COMPARE (info.si_pid, pid);
 
-  expecting_sigchld = WCONTINUED != 0;
+  //expecting_sigchld = WCONTINUED != 0;
 
   if (kill (pid, SIGCONT) != 0)
-    {
-      printf ("kill (%d, SIGCONT): %m\n", pid);
-      RETURN (EXIT_FAILURE);
-    }
+    FAIL_RET ("kill (%d, SIGCONT): %m\n", pid);
 
   /* Wait for the child to have continued.  */
-  sleep (2);
+  support_process_state_wait (pid, process_state_sleeping);
 
 #if WCONTINUED != 0
-  if (expecting_sigchld)
-    {
-      printf ("no SIGCHLD seen for SIGCONT (optional)\n");
-      expecting_sigchld = 0;
-    }
-  else
-    CHECK_SIGCHLD ("continued (before waitid)", CLD_CONTINUED, SIGCONT);
+  {
+    sigset_t set;
+    sigemptyset (&set);
+    sigaddset (&set, SIGCHLD);
+    siginfo_t info;
+    TEST_COMPARE (sigwaitinfo (&set, &info), SIGCHLD);
+
+    TEST_COMPARE (info.si_signo, SIGCHLD);
+    TEST_COMPARE (info.si_code, CLD_CONTINUED);
+    TEST_COMPARE (info.si_status, SIGCONT);
+    TEST_COMPARE (info.si_pid, pid);
+  }
 
   info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
   info.si_pid = -1;
   info.si_status = -1;
   fail = waitid (P_PID, pid, &info, WCONTINUED|WNOWAIT);
-  switch (fail)
-    {
-    default:
-      printf ("waitid WCONTINUED|WNOWAIT returned bogus value %d\n", fail);
-      RETURN (EXIT_FAILURE);
-    case -1:
-      printf ("waitid WCONTINUED|WNOWAIT on continued: %m\n");
-      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
-    case 0:
-      if (info.si_signo != SIGCHLD)
-	{
-	  printf ("waitid WCONTINUED|WNOWAIT on continued signal %d\n",
-		  info.si_signo);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_code != CLD_CONTINUED)
-	{
-	  printf ("waitid WCONTINUED|WNOWAIT on continued code %d\n",
-		  info.si_code);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_status != SIGCONT)
-	{
-	  printf ("waitid WCONTINUED|WNOWAIT on continued status %d\n",
-		  info.si_status);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_pid != pid)
-	{
-	  printf ("waitid WCONTINUED|WNOWAIT on continued pid %d != %d\n",
-		  info.si_pid, pid);
-	  RETURN (EXIT_FAILURE);
-	}
-    }
+  if (fail == -1 && errno == ENOTSUP)
+    FAIL_RET ("waitid WCONTINUED|WNOWAIT on continued: %m");
+  TEST_COMPARE (fail, 0);
+  TEST_COMPARE (info.si_signo, SIGCHLD);
+  TEST_COMPARE (info.si_code, CLD_CONTINUED);
+  TEST_COMPARE (info.si_status, SIGCONT);
+  TEST_COMPARE (info.si_pid, pid);
 
   /* That should leave the CLD_CONTINUED state waiting to be seen again.  */
   info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
   info.si_pid = -1;
   info.si_status = -1;
   fail = waitid (P_PID, pid, &info, WCONTINUED);
-  switch (fail)
-    {
-    default:
-      printf ("waitid WCONTINUED returned bogus value %d\n", fail);
-      RETURN (EXIT_FAILURE);
-    case -1:
-      printf ("waitid WCONTINUED on continued: %m\n");
-      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
-    case 0:
-      if (info.si_signo != SIGCHLD)
-	{
-	  printf ("waitid WCONTINUED on continued signal %d\n", info.si_signo);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_code != CLD_CONTINUED)
-	{
-	  printf ("waitid WCONTINUED on continued code %d\n", info.si_code);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_status != SIGCONT)
-	{
-	  printf ("waitid WCONTINUED on continued status %d\n",
-		  info.si_status);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_pid != pid)
-	{
-	  printf ("waitid WCONTINUED on continued pid %d != %d\n",
-		  info.si_pid, pid);
-	  RETURN (EXIT_FAILURE);
-	}
-    }
+  if (fail == -1 && errno == ENOTSUP)
+    FAIL_RET ("waitid WCONTINUED on continued: %m");
+  TEST_COMPARE (fail, 0);
+  TEST_COMPARE (info.si_signo, SIGCHLD);
+  TEST_COMPARE (info.si_code, CLD_CONTINUED);
+  TEST_COMPARE (info.si_status, SIGCONT);
+  TEST_COMPARE (info.si_pid, pid);
 
   /* Now try a wait that should not succeed.  */
   info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
   fail = waitid (P_PID, pid, &info, WCONTINUED|WNOHANG);
-  switch (fail)
-    {
-    default:
-      printf ("waitid returned bogus value %d\n", fail);
-      RETURN (EXIT_FAILURE);
-    case -1:
-      printf ("waitid WCONTINUED|WNOHANG on waited continued: %m\n");
-      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
-    case 0:
-      if (info.si_signo == 0)
-	break;
-      if (info.si_signo == SIGCHLD)
-	printf ("waitid WCONTINUED|WNOHANG on waited continued status %d\n",
-		info.si_status);
-      else
-	printf ("waitid WCONTINUED|WNOHANG on waited continued signal %d\n",
-		info.si_signo);
-      RETURN (EXIT_FAILURE);
-    }
+  if (fail == -1 && errno == ENOTSUP)
+    FAIL_RET ("waitid WCONTINUED|WNOHANG on waited continued: %m");
+  TEST_COMPARE (fail, 0);
+  TEST_COMPARE (info.si_signo, 0);
 
   /* Now stop him again and test waitpid with WCONTINUED.  */
-  expecting_sigchld = 1;
+  //expecting_sigchld = 1;
   if (kill (pid, SIGSTOP) != 0)
-    {
-      printf ("kill (%d, SIGSTOP): %m\n", pid);
-      RETURN (EXIT_FAILURE);
-    }
+    FAIL_RET ("kill (%d, SIGSTOP): %m\n", pid);
 
-  /* Give the child a chance to stop.  The waitpid call below will block
-     until it has stopped, but if we are real quick and enter the waitpid
-     system call before the SIGCHLD has been generated, then it will be
-     discarded and never delivered.  */
-  sleep (3);
+  /* Wait the child stop.  The waitid call below will block until it has
+     stopped, but if we are real quick and enter the waitid system call
+     before the SIGCHLD has been generated, then it will be discarded and
+     never delivered.  */
+  support_process_state_wait (pid, stop_state);
 
-  pid_t wpid = waitpid (pid, &fail, WUNTRACED);
-  if (wpid < 0)
-    {
-      printf ("waitpid WUNTRACED on stopped: %m\n");
-      RETURN (EXIT_FAILURE);
-    }
-  else if (wpid != pid)
-    {
-      printf ("waitpid WUNTRACED on stopped returned %d != %d (status %x)\n",
-	      wpid, pid, fail);
-      RETURN (EXIT_FAILURE);
-    }
-  else if (!WIFSTOPPED (fail) || WIFSIGNALED (fail) || WIFEXITED (fail)
-	   || WIFCONTINUED (fail) || WSTOPSIG (fail) != SIGSTOP)
-    {
-      printf ("waitpid WUNTRACED on stopped: status %x\n", fail);
-      RETURN (EXIT_FAILURE);
-    }
-  CHECK_SIGCHLD ("stopped (after waitpid)", CLD_STOPPED, SIGSTOP);
+  fail = waitid (type, pid, &info, WEXITED|WSTOPPED);
+  TEST_COMPARE (fail, 0);
+  TEST_COMPARE (info.si_signo, SIGCHLD);
+  TEST_COMPARE (info.si_code, CLD_STOPPED);
+  TEST_COMPARE (info.si_status, SIGSTOP);
+  TEST_COMPARE (info.si_pid, pid);
+
+  check_sigchld (CLD_STOPPED, SIGSTOP, pid);
 
-  expecting_sigchld = 1;
   if (kill (pid, SIGCONT) != 0)
-    {
-      printf ("kill (%d, SIGCONT): %m\n", pid);
-      RETURN (EXIT_FAILURE);
-    }
+    FAIL_RET ("kill (%d, SIGCONT): %m\n", pid);
 
   /* Wait for the child to have continued.  */
-  sleep (2);
+  support_process_state_wait (pid, process_state_sleeping);
 
-  if (expecting_sigchld)
-    {
-      printf ("no SIGCHLD seen for SIGCONT (optional)\n");
-      expecting_sigchld = 0;
-    }
-  else
-    CHECK_SIGCHLD ("continued (before waitpid)", CLD_CONTINUED, SIGCONT);
+  check_sigchld (CLD_CONTINUED, SIGCONT, pid);
 
-  wpid = waitpid (pid, &fail, WCONTINUED);
-  if (wpid < 0)
-    {
-      if (errno == EINVAL)
-	printf ("waitpid does not support WCONTINUED\n");
-      else
-	{
-	  printf ("waitpid WCONTINUED on continued: %m\n");
-	  RETURN (EXIT_FAILURE);
-	}
-    }
-  else if (wpid != pid)
-    {
-      printf ("\
-waitpid WCONTINUED on continued returned %d != %d (status %x)\n",
-	     wpid, pid, fail);
-      RETURN (EXIT_FAILURE);
-    }
-  else if (WIFSTOPPED (fail) || WIFSIGNALED (fail) || WIFEXITED (fail)
-	   || !WIFCONTINUED (fail))
-    {
-      printf ("waitpid WCONTINUED on continued: status %x\n", fail);
-      RETURN (EXIT_FAILURE);
-    }
+  fail = waitid (type, pid, &info, WCONTINUED);
+  TEST_COMPARE (fail, 0);
+  TEST_COMPARE (info.si_signo, SIGCHLD);
+  TEST_COMPARE (info.si_code, CLD_CONTINUED);
+  TEST_COMPARE (info.si_status, SIGCONT);
+  TEST_COMPARE (info.si_pid, pid);
 #endif
 
-  expecting_sigchld = 1;
-
   /* Die, child, die!  */
   if (kill (pid, SIGKILL) != 0)
-    {
-      printf ("kill (%d, SIGKILL): %m\n", pid);
-      RETURN (EXIT_FAILURE);
-    }
+    FAIL_RET ("kill (%d, SIGKILL): %m\n", pid);
 
 #ifdef WNOWAIT
   info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
   info.si_pid = -1;
   info.si_status = -1;
-  fail = waitid (P_PID, pid, &info, WEXITED|WNOWAIT);
-  switch (fail)
-    {
-    default:
-      printf ("waitid WNOWAIT returned bogus value %d\n", fail);
-      RETURN (EXIT_FAILURE);
-    case -1:
-      printf ("waitid WNOWAIT on killed: %m\n");
-      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
-    case 0:
-      if (info.si_signo != SIGCHLD)
-	{
-	  printf ("waitid WNOWAIT on killed signal %d\n", info.si_signo);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_code != CLD_KILLED)
-	{
-	  printf ("waitid WNOWAIT on killed code %d\n", info.si_code);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_status != SIGKILL)
-	{
-	  printf ("waitid WNOWAIT on killed status %d\n", info.si_status);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_pid != pid)
-	{
-	  printf ("waitid WNOWAIT on killed pid %d != %d\n", info.si_pid, pid);
-	  RETURN (EXIT_FAILURE);
-	}
-    }
+  fail = waitid (type, pid, &info, WEXITED|WNOWAIT);
+  if (fail == -1 && errno == ENOTSUP)
+    FAIL_RET ("waitid WNOHANG on killed: %m");
+  TEST_COMPARE (fail, 0);
+  TEST_COMPARE (info.si_signo, SIGCHLD);
+  TEST_COMPARE (info.si_code, CLD_KILLED);
+  TEST_COMPARE (info.si_status, SIGKILL);
+  TEST_COMPARE (info.si_pid, pid);
 #else
-  /* Allow enough time to be sure the child died; we didn't synchronize.  */
-  sleep (2);
+  support_process_state_wait (pid, process_state_zombie);
 #endif
-
-  CHECK_SIGCHLD ("killed", CLD_KILLED, SIGKILL);
+  check_sigchld (CLD_KILLED, SIGKILL, pid);
 
   info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
   info.si_pid = -1;
   info.si_status = -1;
-  fail = waitid (P_PID, pid, &info, WEXITED|WNOHANG);
-  switch (fail)
-    {
-    default:
-      printf ("waitid WNOHANG returned bogus value %d\n", fail);
-      RETURN (EXIT_FAILURE);
-    case -1:
-      printf ("waitid WNOHANG on killed: %m\n");
-      RETURN (EXIT_FAILURE);
-    case 0:
-      if (info.si_signo != SIGCHLD)
-	{
-	  printf ("waitid WNOHANG on killed signal %d\n", info.si_signo);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_code != CLD_KILLED)
-	{
-	  printf ("waitid WNOHANG on killed code %d\n", info.si_code);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_status != SIGKILL)
-	{
-	  printf ("waitid WNOHANG on killed status %d\n", info.si_status);
-	  RETURN (EXIT_FAILURE);
-	}
-      if (info.si_pid != pid)
-	{
-	  printf ("waitid WNOHANG on killed pid %d != %d\n", info.si_pid, pid);
-	  RETURN (EXIT_FAILURE);
-	}
-    }
+  fail = waitid (type, pid, &info, WEXITED | WNOHANG);
+  TEST_COMPARE (fail, 0);
+  TEST_COMPARE (info.si_signo, SIGCHLD);
+  TEST_COMPARE (info.si_code, CLD_KILLED);
+  TEST_COMPARE (info.si_status, SIGKILL);
+  TEST_COMPARE (info.si_pid, pid);
 
   fail = waitid (P_PID, pid, &info, WEXITED);
-  if (fail == -1)
-    {
-      if (errno != ECHILD)
-	{
-	  printf ("waitid WEXITED on killed: %m\n");
-	  RETURN (EXIT_FAILURE);
-	}
-    }
-  else
+  TEST_COMPARE (fail, -1);
+  TEST_COMPARE (errno, ECHILD);
+
+  return 0;
+}
+
+static int
+do_test_waitid (idtype_t type)
+{
+#ifdef SA_SIGINFO
+  {
+    struct sigaction sa;
+    sa.sa_flags = SA_SIGINFO | SA_RESTART;
+    sa.sa_sigaction = sigchld;
+    sigemptyset (&sa.sa_mask);
+    xsigaction (SIGCHLD, &sa, NULL);
+  }
+#endif
+
+  sigemptyset (&chldset);
+  sigaddset (&chldset, SIGCHLD);
+
+  /* The SIGCHLD shall has blocked at the time of the call to sigwait;
+     otherwise, the behavior is undefined.  */
+  sigprocmask (SIG_BLOCK, &chldset, NULL);
+
+  pid_t pid = xfork ();
+  if (pid == 0)
     {
-      printf ("waitid WEXITED returned bogus value %d\n", fail);
-      RETURN (EXIT_FAILURE);
+      test_child (type == P_PGID || type == P_ALL);
+      _exit (127);
     }
 
-#undef RETURN
- out:
-  if (spurious_sigchld)
-    status = EXIT_FAILURE;
-  signal (SIGCHLD, SIG_IGN);
+  int ret = do_test_waitd_common (type, pid);
+
+  xsignal (SIGCHLD, SIG_IGN);
   kill (pid, SIGKILL);		/* Make sure it's dead if we bailed early.  */
-  return status;
+  return ret;
+}
+
+static int
+do_test (void)
+{
+  int ret = 0;
+
+  ret |= do_test_waitid (P_PID);
+  ret |= do_test_waitid (P_PGID);
+  ret |= do_test_waitid (P_ALL);
+
+  return ret;
 }
 
-#include "../test-skeleton.c"
+#include <support/test-driver.c>
--

Ping.

On 20/11/2019 16:42, Adhemerval Zanella wrote:
> 

> 

> On 20/11/2019 14:33, Joseph Myers wrote:

>> This reminds me of the bug we have, 

>> <https://sourceware.org/bugzilla/show_bug.cgi?id=14666>, for intermittent 

>> failures of tst-waitid (I think the discussion it references starts at 

>> <https://sourceware.org/ml/libc-alpha/2010-09/msg00030.html>).

>>

>> Was that fixed by commit a58ad3f801960fa0dc0bb1106eb0d99f7ebd77b1 in 2013, 

>> or is it fixed by your patch, or is it an unrelated issue?

>>

> 

> My initial idea of replacing the sleep added by a58ad3f801960f is to

> loop atomically over a variable which is set by the signal handler.

> However I think a better strategy would be to use sigwaitinfo instead

> as Roland has suggested later in the thread.  It allows clean up the

> test a little more.

> 

> And BZ#14666 does seems to be same issue mitigated by a58ad3f801960f.

> 

> My idea of using support_process_state_wait in this case is to avoid

> use timeouts to sync process/threads and move towards some ideas laid

> out on a recent thread on how to speed up the testsuite spent time [1]

> 

> Below I updated the patch to use sigwaitinfo instead of global variables

> set by the signal handler.

> 

> [1] https://sourceware.org/ml/libc-alpha/2019-07/msg00403.html

> 

> --

> 

> [PATCH v2 2/3] posix: Refactor tst-waitid (BZ #14666)

> 

> The main changes are:

> 

>   - Adapt to libsupport.

>   - Synchronize the signal handler using atomics.

>   - Replace waitpid by waitid calls.

>   - Use support_process_state_wait to wait for child state.

>   - Add tests for P_PGID and P_ALL.

>   - Use sigwaitinfo instead of global state set by the signal handler.

> 

> Checked on x86_64-linux-gnu and i686-linux-gnu.  It fixes BZ #14666.

> 

> ---

> 

> diff --git a/posix/tst-waitid.c b/posix/tst-waitid.c

> index c82ec2b566..808bf6a8eb 100644

> --- a/posix/tst-waitid.c

> +++ b/posix/tst-waitid.c

> @@ -22,13 +22,20 @@

>  #include <unistd.h>

>  #include <sys/wait.h>

>  #include <signal.h>

> +#include <time.h>

> +#include <stdatomic.h>

> +#include <stdbool.h>

> +

> +#include <support/xsignal.h>

> +#include <support/xunistd.h>

> +#include <support/check.h>

> +#include <support/process_state.h>

>  

>  static void

> -test_child (void)

> +test_child (bool setgroup)

>  {

> -  /* Wait a second to be sure the parent set his variables before we

> -     produce a SIGCHLD.  */

> -  sleep (1);

> +  if (setgroup)

> +    TEST_COMPARE (setpgid (0, 0), 0);

>  

>    /* First thing, we stop ourselves.  */

>    raise (SIGSTOP);

> @@ -44,475 +51,239 @@ test_child (void)

>  # define WSTOPPED	WUNTRACED

>  #endif

>  

> -static sig_atomic_t expecting_sigchld, spurious_sigchld;

> -#ifdef SA_SIGINFO

> -static siginfo_t sigchld_info;

> +/* Set with only SIGCHLD on do_test_waitid.  */

> +static sigset_t chldset;

>  

> +#ifdef SA_SIGINFO

>  static void

>  sigchld (int signo, siginfo_t *info, void *ctx)

>  {

> -  if (signo != SIGCHLD)

> -    {

> -      printf ("SIGCHLD handler got signal %d instead!\n", signo);

> -      _exit (EXIT_FAILURE);

> -    }

> -

> -  if (! expecting_sigchld)

> -    {

> -      spurious_sigchld = 1;

> -      printf ("spurious SIGCHLD: signo %d code %d status %d pid %d\n",

> -	      info->si_signo, info->si_code, info->si_status, info->si_pid);

> -    }

> -  else

> -    {

> -      sigchld_info = *info;

> -      expecting_sigchld = 0;

> -    }

>  }

> +#endif

>  

>  static void

> -check_sigchld (const char *phase, int *ok, int code, int status, pid_t pid)

> +check_sigchld (int code, int status, pid_t pid)

>  {

> -  if (expecting_sigchld)

> -    {

> -      printf ("missing SIGCHLD on %s\n", phase);

> -      *ok = EXIT_FAILURE;

> -      expecting_sigchld = 0;

> -      return;

> -    }

> +#ifdef SA_SIGINFO

> +  siginfo_t siginfo;

> +  TEST_COMPARE (sigwaitinfo (&chldset, &siginfo), SIGCHLD);

>  

> -  if (sigchld_info.si_signo != SIGCHLD)

> -    {

> -      printf ("SIGCHLD for %s signal %d\n", phase, sigchld_info.si_signo);

> -      *ok = EXIT_FAILURE;

> -    }

> -  if (sigchld_info.si_code != code)

> -    {

> -      printf ("SIGCHLD for %s code %d\n", phase, sigchld_info.si_code);

> -      *ok = EXIT_FAILURE;

> -    }

> -  if (sigchld_info.si_status != status)

> -    {

> -      printf ("SIGCHLD for %s status %d\n", phase, sigchld_info.si_status);

> -      *ok = EXIT_FAILURE;

> -    }

> -  if (sigchld_info.si_pid != pid)

> -    {

> -      printf ("SIGCHLD for %s pid %d\n", phase, sigchld_info.si_pid);

> -      *ok = EXIT_FAILURE;

> -    }

> -}

> -# define CHECK_SIGCHLD(phase, code_check, status_check) \

> -  check_sigchld ((phase), &status, (code_check), (status_check), pid)

> -#else

> -# define CHECK_SIGCHLD(phase, code, status) ((void) 0)

> +  TEST_COMPARE (siginfo.si_signo, SIGCHLD);

> +  TEST_COMPARE (siginfo.si_code, code);

> +  TEST_COMPARE (siginfo.si_status, status);

> +  TEST_COMPARE (siginfo.si_pid, pid);

>  #endif

> +}

>  

>  static int

> -do_test (int argc, char *argv[])

> +do_test_waitd_common (idtype_t type, pid_t pid)

>  {

> -#ifdef SA_SIGINFO

> -  struct sigaction sa;

> -  sa.sa_flags = SA_SIGINFO|SA_RESTART;

> -  sa.sa_sigaction = &sigchld;

> -  if (sigemptyset (&sa.sa_mask) < 0 || sigaction (SIGCHLD, &sa, NULL) < 0)

> -    {

> -      printf ("setting SIGCHLD handler: %m\n");

> -      return EXIT_FAILURE;

> -    }

> -#endif

> +  /* Adding process_state_tracing_stop ('t') allows the test to work under

> +     trace programs such as ptrace.  */

> +  enum process_state_t stop_state = process_state_stopped

> +				    | process_state_tracing_stop;

>  

> -  expecting_sigchld = 1;

> +  support_process_state_wait (pid, stop_state);

>  

> -  pid_t pid = fork ();

> -  if (pid < 0)

> -    {

> -      printf ("fork: %m\n");

> -      return EXIT_FAILURE;

> -    }

> -  else if (pid == 0)

> -    {

> -      test_child ();

> -      _exit (127);

> -    }

> -

> -  int status = EXIT_SUCCESS;

> -#define RETURN(ok) \

> -    do { if (status == EXIT_SUCCESS) status = (ok); goto out; } while (0)

> -

> -  /* Give the child a chance to stop.  */

> -  sleep (3);

> -

> -  CHECK_SIGCHLD ("stopped (before waitid)", CLD_STOPPED, SIGSTOP);

> +  check_sigchld (CLD_STOPPED, SIGSTOP, pid);

>  

>    /* Now try a wait that should not succeed.  */

>    siginfo_t info;

> +  int fail;

> +

>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */

> -  int fail = waitid (P_PID, pid, &info, WEXITED|WCONTINUED|WNOHANG);

> -  switch (fail)

> -    {

> -    default:

> -      printf ("waitid returned bogus value %d\n", fail);

> -      RETURN (EXIT_FAILURE);

> -    case -1:

> -      printf ("waitid WNOHANG on stopped: %m\n");

> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);

> -    case 0:

> -      if (info.si_signo == 0)

> -	break;

> -      if (info.si_signo == SIGCHLD)

> -	printf ("waitid WNOHANG on stopped status %d\n", info.si_status);

> -      else

> -	printf ("waitid WNOHANG on stopped signal %d\n", info.si_signo);

> -      RETURN (EXIT_FAILURE);

> -    }

> +  fail = waitid (P_PID, pid, &info, WEXITED|WCONTINUED|WNOHANG);

> +  if (fail == -1 && errno == ENOTSUP)

> +    FAIL_RET ("waitid WNOHANG on stopped: %m");

> +  TEST_COMPARE (fail, 0);

> +  TEST_COMPARE (info.si_signo, 0);

>  

>    /* Next the wait that should succeed right away.  */

>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */

>    info.si_pid = -1;

>    info.si_status = -1;

>    fail = waitid (P_PID, pid, &info, WSTOPPED|WNOHANG);

> -  switch (fail)

> -    {

> -    default:

> -      printf ("waitid WSTOPPED|WNOHANG returned bogus value %d\n", fail);

> -      RETURN (EXIT_FAILURE);

> -    case -1:

> -      printf ("waitid WSTOPPED|WNOHANG on stopped: %m\n");

> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);

> -    case 0:

> -      if (info.si_signo != SIGCHLD)

> -	{

> -	  printf ("waitid WSTOPPED|WNOHANG on stopped signal %d\n",

> -		  info.si_signo);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_code != CLD_STOPPED)

> -	{

> -	  printf ("waitid WSTOPPED|WNOHANG on stopped code %d\n",

> -		  info.si_code);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_status != SIGSTOP)

> -	{

> -	  printf ("waitid WSTOPPED|WNOHANG on stopped status %d\n",

> -		  info.si_status);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_pid != pid)

> -	{

> -	  printf ("waitid WSTOPPED|WNOHANG on stopped pid %d != %d\n",

> -		  info.si_pid, pid);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -    }

> +  if (fail == -1 && errno == ENOTSUP)

> +    FAIL_RET ("waitid WNOHANG on stopped: %m");

> +  TEST_COMPARE (fail, 0);

> +  TEST_COMPARE (info.si_signo, SIGCHLD);

> +  TEST_COMPARE (info.si_code, CLD_STOPPED);

> +  TEST_COMPARE (info.si_status, SIGSTOP);

> +  TEST_COMPARE (info.si_pid, pid);

>  

> -  expecting_sigchld = WCONTINUED != 0;

> +  //expecting_sigchld = WCONTINUED != 0;

>  

>    if (kill (pid, SIGCONT) != 0)

> -    {

> -      printf ("kill (%d, SIGCONT): %m\n", pid);

> -      RETURN (EXIT_FAILURE);

> -    }

> +    FAIL_RET ("kill (%d, SIGCONT): %m\n", pid);

>  

>    /* Wait for the child to have continued.  */

> -  sleep (2);

> +  support_process_state_wait (pid, process_state_sleeping);

>  

>  #if WCONTINUED != 0

> -  if (expecting_sigchld)

> -    {

> -      printf ("no SIGCHLD seen for SIGCONT (optional)\n");

> -      expecting_sigchld = 0;

> -    }

> -  else

> -    CHECK_SIGCHLD ("continued (before waitid)", CLD_CONTINUED, SIGCONT);

> +  {

> +    sigset_t set;

> +    sigemptyset (&set);

> +    sigaddset (&set, SIGCHLD);

> +    siginfo_t info;

> +    TEST_COMPARE (sigwaitinfo (&set, &info), SIGCHLD);

> +

> +    TEST_COMPARE (info.si_signo, SIGCHLD);

> +    TEST_COMPARE (info.si_code, CLD_CONTINUED);

> +    TEST_COMPARE (info.si_status, SIGCONT);

> +    TEST_COMPARE (info.si_pid, pid);

> +  }

>  

>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */

>    info.si_pid = -1;

>    info.si_status = -1;

>    fail = waitid (P_PID, pid, &info, WCONTINUED|WNOWAIT);

> -  switch (fail)

> -    {

> -    default:

> -      printf ("waitid WCONTINUED|WNOWAIT returned bogus value %d\n", fail);

> -      RETURN (EXIT_FAILURE);

> -    case -1:

> -      printf ("waitid WCONTINUED|WNOWAIT on continued: %m\n");

> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);

> -    case 0:

> -      if (info.si_signo != SIGCHLD)

> -	{

> -	  printf ("waitid WCONTINUED|WNOWAIT on continued signal %d\n",

> -		  info.si_signo);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_code != CLD_CONTINUED)

> -	{

> -	  printf ("waitid WCONTINUED|WNOWAIT on continued code %d\n",

> -		  info.si_code);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_status != SIGCONT)

> -	{

> -	  printf ("waitid WCONTINUED|WNOWAIT on continued status %d\n",

> -		  info.si_status);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_pid != pid)

> -	{

> -	  printf ("waitid WCONTINUED|WNOWAIT on continued pid %d != %d\n",

> -		  info.si_pid, pid);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -    }

> +  if (fail == -1 && errno == ENOTSUP)

> +    FAIL_RET ("waitid WCONTINUED|WNOWAIT on continued: %m");

> +  TEST_COMPARE (fail, 0);

> +  TEST_COMPARE (info.si_signo, SIGCHLD);

> +  TEST_COMPARE (info.si_code, CLD_CONTINUED);

> +  TEST_COMPARE (info.si_status, SIGCONT);

> +  TEST_COMPARE (info.si_pid, pid);

>  

>    /* That should leave the CLD_CONTINUED state waiting to be seen again.  */

>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */

>    info.si_pid = -1;

>    info.si_status = -1;

>    fail = waitid (P_PID, pid, &info, WCONTINUED);

> -  switch (fail)

> -    {

> -    default:

> -      printf ("waitid WCONTINUED returned bogus value %d\n", fail);

> -      RETURN (EXIT_FAILURE);

> -    case -1:

> -      printf ("waitid WCONTINUED on continued: %m\n");

> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);

> -    case 0:

> -      if (info.si_signo != SIGCHLD)

> -	{

> -	  printf ("waitid WCONTINUED on continued signal %d\n", info.si_signo);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_code != CLD_CONTINUED)

> -	{

> -	  printf ("waitid WCONTINUED on continued code %d\n", info.si_code);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_status != SIGCONT)

> -	{

> -	  printf ("waitid WCONTINUED on continued status %d\n",

> -		  info.si_status);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_pid != pid)

> -	{

> -	  printf ("waitid WCONTINUED on continued pid %d != %d\n",

> -		  info.si_pid, pid);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -    }

> +  if (fail == -1 && errno == ENOTSUP)

> +    FAIL_RET ("waitid WCONTINUED on continued: %m");

> +  TEST_COMPARE (fail, 0);

> +  TEST_COMPARE (info.si_signo, SIGCHLD);

> +  TEST_COMPARE (info.si_code, CLD_CONTINUED);

> +  TEST_COMPARE (info.si_status, SIGCONT);

> +  TEST_COMPARE (info.si_pid, pid);

>  

>    /* Now try a wait that should not succeed.  */

>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */

>    fail = waitid (P_PID, pid, &info, WCONTINUED|WNOHANG);

> -  switch (fail)

> -    {

> -    default:

> -      printf ("waitid returned bogus value %d\n", fail);

> -      RETURN (EXIT_FAILURE);

> -    case -1:

> -      printf ("waitid WCONTINUED|WNOHANG on waited continued: %m\n");

> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);

> -    case 0:

> -      if (info.si_signo == 0)

> -	break;

> -      if (info.si_signo == SIGCHLD)

> -	printf ("waitid WCONTINUED|WNOHANG on waited continued status %d\n",

> -		info.si_status);

> -      else

> -	printf ("waitid WCONTINUED|WNOHANG on waited continued signal %d\n",

> -		info.si_signo);

> -      RETURN (EXIT_FAILURE);

> -    }

> +  if (fail == -1 && errno == ENOTSUP)

> +    FAIL_RET ("waitid WCONTINUED|WNOHANG on waited continued: %m");

> +  TEST_COMPARE (fail, 0);

> +  TEST_COMPARE (info.si_signo, 0);

>  

>    /* Now stop him again and test waitpid with WCONTINUED.  */

> -  expecting_sigchld = 1;

> +  //expecting_sigchld = 1;

>    if (kill (pid, SIGSTOP) != 0)

> -    {

> -      printf ("kill (%d, SIGSTOP): %m\n", pid);

> -      RETURN (EXIT_FAILURE);

> -    }

> +    FAIL_RET ("kill (%d, SIGSTOP): %m\n", pid);

>  

> -  /* Give the child a chance to stop.  The waitpid call below will block

> -     until it has stopped, but if we are real quick and enter the waitpid

> -     system call before the SIGCHLD has been generated, then it will be

> -     discarded and never delivered.  */

> -  sleep (3);

> +  /* Wait the child stop.  The waitid call below will block until it has

> +     stopped, but if we are real quick and enter the waitid system call

> +     before the SIGCHLD has been generated, then it will be discarded and

> +     never delivered.  */

> +  support_process_state_wait (pid, stop_state);

>  

> -  pid_t wpid = waitpid (pid, &fail, WUNTRACED);

> -  if (wpid < 0)

> -    {

> -      printf ("waitpid WUNTRACED on stopped: %m\n");

> -      RETURN (EXIT_FAILURE);

> -    }

> -  else if (wpid != pid)

> -    {

> -      printf ("waitpid WUNTRACED on stopped returned %d != %d (status %x)\n",

> -	      wpid, pid, fail);

> -      RETURN (EXIT_FAILURE);

> -    }

> -  else if (!WIFSTOPPED (fail) || WIFSIGNALED (fail) || WIFEXITED (fail)

> -	   || WIFCONTINUED (fail) || WSTOPSIG (fail) != SIGSTOP)

> -    {

> -      printf ("waitpid WUNTRACED on stopped: status %x\n", fail);

> -      RETURN (EXIT_FAILURE);

> -    }

> -  CHECK_SIGCHLD ("stopped (after waitpid)", CLD_STOPPED, SIGSTOP);

> +  fail = waitid (type, pid, &info, WEXITED|WSTOPPED);

> +  TEST_COMPARE (fail, 0);

> +  TEST_COMPARE (info.si_signo, SIGCHLD);

> +  TEST_COMPARE (info.si_code, CLD_STOPPED);

> +  TEST_COMPARE (info.si_status, SIGSTOP);

> +  TEST_COMPARE (info.si_pid, pid);

> +

> +  check_sigchld (CLD_STOPPED, SIGSTOP, pid);

>  

> -  expecting_sigchld = 1;

>    if (kill (pid, SIGCONT) != 0)

> -    {

> -      printf ("kill (%d, SIGCONT): %m\n", pid);

> -      RETURN (EXIT_FAILURE);

> -    }

> +    FAIL_RET ("kill (%d, SIGCONT): %m\n", pid);

>  

>    /* Wait for the child to have continued.  */

> -  sleep (2);

> +  support_process_state_wait (pid, process_state_sleeping);

>  

> -  if (expecting_sigchld)

> -    {

> -      printf ("no SIGCHLD seen for SIGCONT (optional)\n");

> -      expecting_sigchld = 0;

> -    }

> -  else

> -    CHECK_SIGCHLD ("continued (before waitpid)", CLD_CONTINUED, SIGCONT);

> +  check_sigchld (CLD_CONTINUED, SIGCONT, pid);

>  

> -  wpid = waitpid (pid, &fail, WCONTINUED);

> -  if (wpid < 0)

> -    {

> -      if (errno == EINVAL)

> -	printf ("waitpid does not support WCONTINUED\n");

> -      else

> -	{

> -	  printf ("waitpid WCONTINUED on continued: %m\n");

> -	  RETURN (EXIT_FAILURE);

> -	}

> -    }

> -  else if (wpid != pid)

> -    {

> -      printf ("\

> -waitpid WCONTINUED on continued returned %d != %d (status %x)\n",

> -	     wpid, pid, fail);

> -      RETURN (EXIT_FAILURE);

> -    }

> -  else if (WIFSTOPPED (fail) || WIFSIGNALED (fail) || WIFEXITED (fail)

> -	   || !WIFCONTINUED (fail))

> -    {

> -      printf ("waitpid WCONTINUED on continued: status %x\n", fail);

> -      RETURN (EXIT_FAILURE);

> -    }

> +  fail = waitid (type, pid, &info, WCONTINUED);

> +  TEST_COMPARE (fail, 0);

> +  TEST_COMPARE (info.si_signo, SIGCHLD);

> +  TEST_COMPARE (info.si_code, CLD_CONTINUED);

> +  TEST_COMPARE (info.si_status, SIGCONT);

> +  TEST_COMPARE (info.si_pid, pid);

>  #endif

>  

> -  expecting_sigchld = 1;

> -

>    /* Die, child, die!  */

>    if (kill (pid, SIGKILL) != 0)

> -    {

> -      printf ("kill (%d, SIGKILL): %m\n", pid);

> -      RETURN (EXIT_FAILURE);

> -    }

> +    FAIL_RET ("kill (%d, SIGKILL): %m\n", pid);

>  

>  #ifdef WNOWAIT

>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */

>    info.si_pid = -1;

>    info.si_status = -1;

> -  fail = waitid (P_PID, pid, &info, WEXITED|WNOWAIT);

> -  switch (fail)

> -    {

> -    default:

> -      printf ("waitid WNOWAIT returned bogus value %d\n", fail);

> -      RETURN (EXIT_FAILURE);

> -    case -1:

> -      printf ("waitid WNOWAIT on killed: %m\n");

> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);

> -    case 0:

> -      if (info.si_signo != SIGCHLD)

> -	{

> -	  printf ("waitid WNOWAIT on killed signal %d\n", info.si_signo);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_code != CLD_KILLED)

> -	{

> -	  printf ("waitid WNOWAIT on killed code %d\n", info.si_code);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_status != SIGKILL)

> -	{

> -	  printf ("waitid WNOWAIT on killed status %d\n", info.si_status);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_pid != pid)

> -	{

> -	  printf ("waitid WNOWAIT on killed pid %d != %d\n", info.si_pid, pid);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -    }

> +  fail = waitid (type, pid, &info, WEXITED|WNOWAIT);

> +  if (fail == -1 && errno == ENOTSUP)

> +    FAIL_RET ("waitid WNOHANG on killed: %m");

> +  TEST_COMPARE (fail, 0);

> +  TEST_COMPARE (info.si_signo, SIGCHLD);

> +  TEST_COMPARE (info.si_code, CLD_KILLED);

> +  TEST_COMPARE (info.si_status, SIGKILL);

> +  TEST_COMPARE (info.si_pid, pid);

>  #else

> -  /* Allow enough time to be sure the child died; we didn't synchronize.  */

> -  sleep (2);

> +  support_process_state_wait (pid, process_state_zombie);

>  #endif

> -

> -  CHECK_SIGCHLD ("killed", CLD_KILLED, SIGKILL);

> +  check_sigchld (CLD_KILLED, SIGKILL, pid);

>  

>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */

>    info.si_pid = -1;

>    info.si_status = -1;

> -  fail = waitid (P_PID, pid, &info, WEXITED|WNOHANG);

> -  switch (fail)

> -    {

> -    default:

> -      printf ("waitid WNOHANG returned bogus value %d\n", fail);

> -      RETURN (EXIT_FAILURE);

> -    case -1:

> -      printf ("waitid WNOHANG on killed: %m\n");

> -      RETURN (EXIT_FAILURE);

> -    case 0:

> -      if (info.si_signo != SIGCHLD)

> -	{

> -	  printf ("waitid WNOHANG on killed signal %d\n", info.si_signo);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_code != CLD_KILLED)

> -	{

> -	  printf ("waitid WNOHANG on killed code %d\n", info.si_code);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_status != SIGKILL)

> -	{

> -	  printf ("waitid WNOHANG on killed status %d\n", info.si_status);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -      if (info.si_pid != pid)

> -	{

> -	  printf ("waitid WNOHANG on killed pid %d != %d\n", info.si_pid, pid);

> -	  RETURN (EXIT_FAILURE);

> -	}

> -    }

> +  fail = waitid (type, pid, &info, WEXITED | WNOHANG);

> +  TEST_COMPARE (fail, 0);

> +  TEST_COMPARE (info.si_signo, SIGCHLD);

> +  TEST_COMPARE (info.si_code, CLD_KILLED);

> +  TEST_COMPARE (info.si_status, SIGKILL);

> +  TEST_COMPARE (info.si_pid, pid);

>  

>    fail = waitid (P_PID, pid, &info, WEXITED);

> -  if (fail == -1)

> -    {

> -      if (errno != ECHILD)

> -	{

> -	  printf ("waitid WEXITED on killed: %m\n");

> -	  RETURN (EXIT_FAILURE);

> -	}

> -    }

> -  else

> +  TEST_COMPARE (fail, -1);

> +  TEST_COMPARE (errno, ECHILD);

> +

> +  return 0;

> +}

> +

> +static int

> +do_test_waitid (idtype_t type)

> +{

> +#ifdef SA_SIGINFO

> +  {

> +    struct sigaction sa;

> +    sa.sa_flags = SA_SIGINFO | SA_RESTART;

> +    sa.sa_sigaction = sigchld;

> +    sigemptyset (&sa.sa_mask);

> +    xsigaction (SIGCHLD, &sa, NULL);

> +  }

> +#endif

> +

> +  sigemptyset (&chldset);

> +  sigaddset (&chldset, SIGCHLD);

> +

> +  /* The SIGCHLD shall has blocked at the time of the call to sigwait;

> +     otherwise, the behavior is undefined.  */

> +  sigprocmask (SIG_BLOCK, &chldset, NULL);

> +

> +  pid_t pid = xfork ();

> +  if (pid == 0)

>      {

> -      printf ("waitid WEXITED returned bogus value %d\n", fail);

> -      RETURN (EXIT_FAILURE);

> +      test_child (type == P_PGID || type == P_ALL);

> +      _exit (127);

>      }

>  

> -#undef RETURN

> - out:

> -  if (spurious_sigchld)

> -    status = EXIT_FAILURE;

> -  signal (SIGCHLD, SIG_IGN);

> +  int ret = do_test_waitd_common (type, pid);

> +

> +  xsignal (SIGCHLD, SIG_IGN);

>    kill (pid, SIGKILL);		/* Make sure it's dead if we bailed early.  */

> -  return status;

> +  return ret;

> +}

> +

> +static int

> +do_test (void)

> +{

> +  int ret = 0;

> +

> +  ret |= do_test_waitid (P_PID);

> +  ret |= do_test_waitid (P_PGID);

> +  ret |= do_test_waitid (P_ALL);

> +

> +  return ret;

>  }

>  

> -#include "../test-skeleton.c"

> +#include <support/test-driver.c>

> --

>