Finish move of clock_* functions to libc. [BZ #24959]

In glibc 2.17, the functions clock_getcpuclockid, clock_getres,
clock_gettime, clock_nanosleep, and clock_settime were moved from
librt.so to libc.so, leaving compatibility stubs behind.  Now that the
dynamic linker no longer insists on finding versioned symbols in the
same library that originally defined them, we do not need the stubs
anymore, and this means we don't need GLIBC_PRIVATE __-prefix aliases
for most of the functions anymore either.  (clock_gettime still needs
one.)  For ports added before 2.17, libc.so needs to provide two
symbol versions for each, the default at GLIBC_2.17 plus a compat
version matching what librt had.

While I'm at it, move the clock_*.c files and their tests from rt/ to
time/.

1 files changed, 320 insertions, 0 deletions

diff --git a/time/tst-cpuclock1.c b/time/tst-cpuclock1.c
new file mode 100644
index 0000000000..e3f23aa307
--- /dev/null
+++ b/time/tst-cpuclock1.c
@@ -0,0 +1,320 @@
+/* Test program for process CPU clocks.
+   Copyright (C) 2004-2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdint.h>
+#include <sys/wait.h>
+
+/* This function is intended to rack up both user and system time.  */
+static void
+chew_cpu (void)
+{
+  while (1)
+    {
+      static volatile char buf[4096];
+      for (int i = 0; i < 100; ++i)
+	for (size_t j = 0; j < sizeof buf; ++j)
+	  buf[j] = 0xaa;
+      int nullfd = open ("/dev/null", O_WRONLY);
+      for (int i = 0; i < 100; ++i)
+	for (size_t j = 0; j < sizeof buf; ++j)
+	  buf[j] = 0xbb;
+      write (nullfd, (char *) buf, sizeof buf);
+      close (nullfd);
+      if (getppid () == 1)
+	_exit (2);
+    }
+}
+
+static int
+do_test (void)
+{
+  int result = 0;
+  clockid_t cl;
+  int e;
+  pid_t dead_child, child;
+
+  /* Fork a child and let it die, to give us a PID known not be valid
+     (assuming PIDs don't wrap around during the test).  */
+  {
+    dead_child = fork ();
+    if (dead_child == 0)
+      _exit (0);
+    if (dead_child < 0)
+      {
+	perror ("fork");
+	return 1;
+      }
+    int x;
+    if (wait (&x) != dead_child)
+      {
+	perror ("wait");
+	return 2;
+      }
+  }
+
+  /* POSIX says we should get ESRCH for this.  */
+  e = clock_getcpuclockid (dead_child, &cl);
+  if (e != ENOSYS && e != ESRCH && e != EPERM)
+    {
+      printf ("clock_getcpuclockid on dead PID %d => %s\n",
+	      dead_child, strerror (e));
+      result = 1;
+    }
+
+  /* Now give us a live child eating up CPU time.  */
+  child = fork ();
+  if (child == 0)
+    {
+      chew_cpu ();
+      _exit (1);
+    }
+  if (child < 0)
+    {
+      perror ("fork");
+      return 1;
+    }
+
+  e = clock_getcpuclockid (child, &cl);
+  if (e == EPERM)
+    {
+      puts ("clock_getcpuclockid does not support other processes");
+      goto done;
+    }
+  if (e != 0)
+    {
+      printf ("clock_getcpuclockid on live PID %d => %s\n",
+	      child, strerror (e));
+      result = 1;
+      goto done;
+    }
+
+  const clockid_t child_clock = cl;
+  struct timespec res;
+  if (clock_getres (child_clock, &res) < 0)
+    {
+      printf ("clock_getres on live PID %d clock %lx => %s\n",
+	      child, (unsigned long int) child_clock, strerror (errno));
+      result = 1;
+      goto done;
+    }
+  printf ("live PID %d clock %lx resolution %ju.%.9ju\n",
+	  child, (unsigned long int) child_clock,
+	  (uintmax_t) res.tv_sec, (uintmax_t) res.tv_nsec);
+
+  struct timespec before, after;
+  if (clock_gettime (child_clock, &before) < 0)
+    {
+      printf ("clock_gettime on live PID %d clock %lx => %s\n",
+	      child, (unsigned long int) child_clock, strerror (errno));
+      result = 1;
+      goto done;
+    }
+  /* Should be close to 0.0.  */
+  printf ("live PID %d before sleep => %ju.%.9ju\n",
+	  child, (uintmax_t) before.tv_sec, (uintmax_t) before.tv_nsec);
+
+  struct timespec sleeptime = { .tv_nsec = 500000000 };
+  if (nanosleep (&sleeptime, NULL) != 0)
+    {
+      perror ("nanosleep");
+      result = 1;
+      goto done;
+    }
+
+  if (clock_gettime (child_clock, &after) < 0)
+    {
+      printf ("clock_gettime on live PID %d clock %lx => %s\n",
+	      child, (unsigned long int) child_clock, strerror (errno));
+      result = 1;
+      goto done;
+    }
+  /* Should be close to 0.5.  */
+  printf ("live PID %d after sleep => %ju.%.9ju\n",
+	  child, (uintmax_t) after.tv_sec, (uintmax_t) after.tv_nsec);
+
+  struct timespec diff = { .tv_sec = after.tv_sec - before.tv_sec,
+			   .tv_nsec = after.tv_nsec - before.tv_nsec };
+  if (diff.tv_nsec < 0)
+    {
+      --diff.tv_sec;
+      diff.tv_nsec += 1000000000;
+    }
+  if (diff.tv_sec != 0
+      || diff.tv_nsec > 600000000
+      || diff.tv_nsec < 100000000)
+    {
+      printf ("before - after %ju.%.9ju outside reasonable range\n",
+	      (uintmax_t) diff.tv_sec, (uintmax_t) diff.tv_nsec);
+      result = 1;
+    }
+
+  sleeptime.tv_nsec = 100000000;
+  e = clock_nanosleep (child_clock, 0, &sleeptime, NULL);
+  if (e == EINVAL || e == ENOTSUP || e == ENOSYS)
+    {
+      printf ("clock_nanosleep not supported for other process clock: %s\n",
+	      strerror (e));
+    }
+  else if (e != 0)
+    {
+      printf ("clock_nanosleep on other process clock: %s\n", strerror (e));
+      result = 1;
+    }
+  else
+    {
+      struct timespec afterns;
+      if (clock_gettime (child_clock, &afterns) < 0)
+	{
+	  printf ("clock_gettime on live PID %d clock %lx => %s\n",
+		  child, (unsigned long int) child_clock, strerror (errno));
+	  result = 1;
+	}
+      else
+	{
+	  struct timespec d = { .tv_sec = afterns.tv_sec - after.tv_sec,
+				.tv_nsec = afterns.tv_nsec - after.tv_nsec };
+	  if (d.tv_nsec < 0)
+	    {
+	      --d.tv_sec;
+	      d.tv_nsec += 1000000000;
+	    }
+	  if (d.tv_sec > 0
+	      || d.tv_nsec < sleeptime.tv_nsec
+	      || d.tv_nsec > sleeptime.tv_nsec * 2)
+	    {
+	      printf ("nanosleep time %ju.%.9ju outside reasonable range\n",
+		      (uintmax_t) d.tv_sec, (uintmax_t) d.tv_nsec);
+	      result = 1;
+	    }
+	}
+    }
+
+  if (kill (child, SIGKILL) != 0)
+    {
+      perror ("kill");
+      result = 2;
+      goto done;
+    }
+
+  /* Wait long enough to let the child finish dying.  */
+
+  sleeptime.tv_nsec = 200000000;
+  if (nanosleep (&sleeptime, NULL) != 0)
+    {
+      perror ("nanosleep");
+      result = 1;
+      goto done;
+    }
+
+  struct timespec dead;
+  if (clock_gettime (child_clock, &dead) < 0)
+    {
+      printf ("clock_gettime on dead PID %d clock %lx => %s\n",
+	      child, (unsigned long int) child_clock, strerror (errno));
+      result = 1;
+      goto done;
+    }
+  /* Should be close to 0.6.  */
+  printf ("dead PID %d => %ju.%.9ju\n",
+	  child, (uintmax_t) dead.tv_sec, (uintmax_t) dead.tv_nsec);
+
+  diff.tv_sec = dead.tv_sec - after.tv_sec;
+  diff.tv_nsec = dead.tv_nsec - after.tv_nsec;
+  if (diff.tv_nsec < 0)
+    {
+      --diff.tv_sec;
+      diff.tv_nsec += 1000000000;
+    }
+  if (diff.tv_sec != 0 || diff.tv_nsec > 200000000)
+    {
+      printf ("dead - after %ju.%.9ju outside reasonable range\n",
+	      (uintmax_t) diff.tv_sec, (uintmax_t) diff.tv_nsec);
+      result = 1;
+    }
+
+  /* Now reap the child and verify that its clock is no longer valid.  */
+  {
+    int x;
+    if (waitpid (child, &x, 0) != child)
+      {
+	perror ("waitpid");
+	result = 1;
+      }
+  }
+
+  if (clock_gettime (child_clock, &dead) == 0)
+    {
+      printf ("clock_gettime on reaped PID %d clock %lx => %ju%.9ju\n",
+	      child, (unsigned long int) child_clock,
+	      (uintmax_t) dead.tv_sec, (uintmax_t) dead.tv_nsec);
+      result = 1;
+    }
+  else
+    {
+      if (errno != EINVAL)
+	result = 1;
+      printf ("clock_gettime on reaped PID %d clock %lx => %s\n",
+	      child, (unsigned long int) child_clock, strerror (errno));
+    }
+
+  if (clock_getres (child_clock, &dead) == 0)
+    {
+      printf ("clock_getres on reaped PID %d clock %lx => %ju%.9ju\n",
+	      child, (unsigned long int) child_clock,
+	      (uintmax_t) dead.tv_sec, (uintmax_t) dead.tv_nsec);
+      result = 1;
+    }
+  else
+    {
+      if (errno != EINVAL)
+	result = 1;
+      printf ("clock_getres on reaped PID %d clock %lx => %s\n",
+	      child, (unsigned long int) child_clock, strerror (errno));
+    }
+
+  return result;
+
+ done:
+  {
+    if (kill (child, SIGKILL) != 0 && errno != ESRCH)
+      {
+	perror ("kill");
+	return 2;
+      }
+    int x;
+    if (waitpid (child, &x, 0) != child && errno != ECHILD)
+      {
+	perror ("waitpid");
+	return 2;
+      }
+  }
+
+  return result;
+}
+
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"