summary refs log tree commit diff
path: root/sysdeps
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/posix/profil.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/sysdeps/posix/profil.c b/sysdeps/posix/profil.c
new file mode 100644
index 0000000000..8e34b3564f
--- /dev/null
+++ b/sysdeps/posix/profil.c
@@ -0,0 +1,92 @@
+/* Low-level statistical profiling support function.  Mostly POSIX.1 version.
+Copyright (C) 1996 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 Library General Public License as
+published by the Free Software Foundation; either version 2 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <sys/time.h>
+
+#ifndef SIGPROF
+
+#include_next <profil.c>
+
+#else
+
+static u_short *samples;
+static size_t nsamples;
+static size_t pc_offset;
+static u_int pc_scale;
+
+static inline void
+profil_count (void *pc)
+{
+  size_t i = ((pc - pc_offset - (void *) 0) / 2) * pc_scale / 65536;
+  if (i < nsamples)
+    ++samples[i];
+}
+
+/* Get the machine-dependent definition of `profil_counter', the signal
+   handler for SIGPROF.  It calls `profil_count' (above) with the PC of the
+   interrupted code.  */
+#include "profil-counter.h"
+
+/* Enable statistical profiling, writing samples of the PC into at most
+   SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
+   is enabled, the system examines the user PC and increments
+   SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
+   disable profiling.  Returns zero on success, -1 on error.  */
+
+int
+profil (u_short *sample_buffer, size_t size, size_t offset, u_int scale)
+{
+  static struct sigaction act, oact;
+  static struct itimerval timer, otimer;
+
+  if (sample_buffer == NULL)
+    {
+      /* Disable profiling.  */
+      if (samples == NULL)
+	/* Wasn't turned on.  */
+	return 0;
+      samples = NULL;
+
+      if (sigaction (SIGPROF, &oact, NULL) < 0)
+	return -1;
+      return setitimer (ITIMER_PROF, &otimer, NULL);
+    }
+
+  samples = sample_buffer;
+  nsamples = size / sizeof *samples;
+  pc_offset = offset;
+  pc_scale = scale;
+
+  act.sa_handler = (sighandler_t) &profil_counter;
+  act.sa_flags = SA_RESTART;
+  sigfillset (&act.sa_mask);
+  if (sigaction (SIGPROF, &act, &oact) < 0)
+    return -1;
+
+  timer.it_value.tv_sec = 0;
+  timer.it_value.tv_usec = 1;
+  timer.it_interval = timer.it_value;
+  return setitimer (ITIMER_PROF, &timer, &otimer);
+}
+
+#endif