about summary refs log tree commit diff
path: root/sysdeps/mach/hurd/profil.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/mach/hurd/profil.c')
-rw-r--r--sysdeps/mach/hurd/profil.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/profil.c b/sysdeps/mach/hurd/profil.c
new file mode 100644
index 0000000000..4032219a9e
--- /dev/null
+++ b/sysdeps/mach/hurd/profil.c
@@ -0,0 +1,164 @@
+/* Low-level statistical profiling support function.  Mach/Hurd version.
+Copyright (C) 1995 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 <hurd.h>
+#include <mach/mach4.h>
+#include <mach/pc_sample.h>
+#include <cthreads.h>
+#include <assert.h>
+
+static thread_t profile_thread = MACH_PORT_NULL;
+static u_short *samples;
+static size_t maxsamples;
+static size_t pc_offset;
+static size_t sample_scale;
+static sampled_pc_seqno_t seqno;
+static struct mutex lock = MUTEX_INITIALIZER;
+
+/* 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.  */
+
+static error_t
+update_waiter (u_short *sample_buffer, size_t size, size_t offset, u_int scale)
+{
+  error_t err;
+
+  if (profile_thread == MACH_PORT_NULL)
+    {
+      /* Set up the profiling collector thread.  */
+      static void profile_waiter (void);
+      err = __thread_create (__mach_task_self (), &profile_thread);
+      if (! err)
+	err = __mach_setup_thread (__mach_task_self (), profile_thread,
+				   &profile_waiter, NULL, NULL);
+    }
+  else
+    err = 0;
+
+  if (! err)
+    {
+      if (sample_scale == 0)
+	err = __thread_resume (profile_thread);
+      if (! err)
+	{
+	  samples = sample_buffer;
+	  maxsamples = size / sizeof *sample_buffer;
+	  pc_offset = offset;
+	  sample_scale = scale;
+	}
+    }
+
+  return err;
+}
+
+int
+profil (u_short *sample_buffer, size_t size, size_t offset, u_int scale)
+{
+  error_t err;
+
+  __mutex_lock (&lock);
+
+  if (scale == 0)
+    {
+      /* Disable profiling.  */
+      int count;
+      __thread_suspend (profile_thread);
+      err = __task_disable_pc_sampling (__mach_task_self (), &count);
+      sample_scale = 0;
+      seqno = 0;
+    }
+  else
+    err = update_waiter (sample_buffer, size, offset, scale);
+
+  __mutex_unlock (&lock);
+
+  return err ? __hurd_fail (err) : 0;
+}
+
+static void
+profile_waiter (void)
+{
+  sampled_pc_t pc_samples[512];
+  mach_msg_type_number_t nsamples = 512, i;
+  mach_port_t rcv = __mach_reply_port ();
+  mach_msg_header_t msg;
+  const mach_msg_timeout_t timeout = 17; /* ??? XXX */
+  error_t err;
+
+  while (1)
+    {
+      __mutex_lock (&lock);
+
+      err = __task_get_sampled_pcs (__mach_task_self (), &seqno,
+				    pc_samples, &nsamples);
+      assert_perror (err);
+
+      for (i = 0; i < nsamples; ++i)
+	{
+	  size_t idx = (((pc_samples[i].pc - pc_offset) / 2) *
+			sample_scale / 65536);
+	  if (idx < maxsamples)
+	    ++samples[idx];
+	}
+
+      __vm_deallocate (__mach_task_self (),
+		       (vm_address_t) pc_samples,
+		       nsamples * sizeof *pc_samples);
+
+      __mutex_unlock (&lock);
+
+      __mach_msg (&msg, MACH_RCV_MSG|MACH_RCV_TIMEOUT, 0, sizeof msg,
+		  rcv, timeout, MACH_PORT_NULL);
+    }
+}
+
+data_set_element (_hurd_fork_locks, lock);
+
+static void
+fork_profil (void)
+{
+  u_short *sb;
+  size_t n, o, ss;
+  error_t err;
+
+  if (profile_thread != MACH_PORT_NULL)
+    {
+      __mach_port_deallocate (__mach_task_self (), profile_thread);
+      profile_thread = MACH_PORT_NULL;
+    }
+
+  sb = samples;
+  samples = NULL;
+  n = maxsamples;
+  maxsamples = 0;
+  o = pc_offset;
+  pc_offset = 0;
+  ss = sample_scale;
+  sample_scale = 0;
+
+  err = update_waiter (sb, n * sizeof *sb, o, ss);
+  assert_perror (err);
+}
+text_set_element (_hurd_fork_child_hook, fork_profil);