1 files changed, 103 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/clock_getcpuclockid.c b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c
new file mode 100644
index 0000000000..04bf49e45f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c
@@ -0,0 +1,103 @@
+/* clock_getcpuclockid -- Get a clockid_t for process CPU time.  Linux version.
+   Copyright (C) 2004, 2005, 2006 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <time.h>
+#include <unistd.h>
+#include <kernel-features.h>
+#include "kernel-posix-cpu-timers.h"
+
+#ifndef HAS_CPUCLOCK
+# define HAS_CPUCLOCK 1
+#endif
+
+int
+clock_getcpuclockid (pid_t pid, clockid_t *clock_id)
+{
+#ifdef __NR_clock_getres
+  /* The clockid_t value is a simple computation from the PID.
+     But we do a clock_getres call to validate it.  */
+
+  const clockid_t pidclock = MAKE_PROCESS_CPUCLOCK (pid, CPUCLOCK_SCHED);
+
+# if !(__ASSUME_POSIX_CPU_TIMERS > 0)
+  extern int __libc_missing_posix_cpu_timers attribute_hidden;
+#  if !(__ASSUME_POSIX_TIMERS > 0)
+  extern int __libc_missing_posix_timers attribute_hidden;
+  if (__libc_missing_posix_timers && !__libc_missing_posix_cpu_timers)
+    __libc_missing_posix_cpu_timers = 1;
+#  endif
+  if (!__libc_missing_posix_cpu_timers)
+# endif
+    {
+      INTERNAL_SYSCALL_DECL (err);
+      int r = INTERNAL_SYSCALL (clock_getres, err, 2, pidclock, NULL);
+      if (!INTERNAL_SYSCALL_ERROR_P (r, err))
+	{
+	  *clock_id = pidclock;
+	  return 0;
+	}
+
+# if !(__ASSUME_POSIX_TIMERS > 0)
+      if (INTERNAL_SYSCALL_ERRNO (r, err) == ENOSYS)
+	{
+	  /* The kernel doesn't support these calls at all.  */
+	  __libc_missing_posix_timers = 1;
+	  __libc_missing_posix_cpu_timers = 1;
+	}
+      else
+# endif
+	if (INTERNAL_SYSCALL_ERRNO (r, err) == EINVAL)
+	  {
+# if !(__ASSUME_POSIX_CPU_TIMERS > 0)
+	    if (pidclock == MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED)
+		|| INTERNAL_SYSCALL_ERROR_P (INTERNAL_SYSCALL
+					     (clock_getres, err, 2,
+					      MAKE_PROCESS_CPUCLOCK
+					      (0, CPUCLOCK_SCHED), NULL),
+					     err))
+	      /* The kernel doesn't support these clocks at all.  */
+	      __libc_missing_posix_cpu_timers = 1;
+	    else
+# endif
+	      /* The clock_getres system call checked the PID for us.  */
+	      return ESRCH;
+	  }
+	else
+	  return INTERNAL_SYSCALL_ERRNO (r, err);
+    }
+#endif
+
+  /* We don't allow any process ID but our own.  */
+  if (pid != 0 && pid != getpid ())
+    return EPERM;
+
+#ifdef CLOCK_PROCESS_CPUTIME_ID
+  if (HAS_CPUCLOCK)
+    {
+      /* Store the number.  */
+      *clock_id = CLOCK_PROCESS_CPUTIME_ID;
+
+      return 0;
+    }
+#endif
+
+  /* We don't have a timer for that.  */
+  return ENOENT;
+}