summaryrefslogtreecommitdiff
path: root/sysdeps/mach/hurd/profil.c
blob: 43456ec628bbeeb57a7741c9c2af15f4b73fa417 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
/* 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;

  if (ss != 0)
    {
      err = update_waiter (sb, n * sizeof *sb, o, ss);
      assert_perror (err);
    }
}
text_set_element (_hurd_fork_child_hook, fork_profil);