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glibc/sysdeps/posix/sprofil.c
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/* Copyright (C) 2001, 2002, 2003, 2005 Free Software Foundation, Inc. | |
Contributed by David Mosberger-Tang <davidm@hpl.hp.com>. | |
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 <assert.h> | |
#include <signal.h> | |
#include <stdlib.h> | |
#include <string.h> | |
#include <unistd.h> | |
#include <sys/time.h> | |
#include <sys/profil.h> | |
#ifndef SIGPROF | |
# include <gmon/sprofil.c> | |
#else | |
#include <libc-internal.h> | |
struct region | |
{ | |
size_t offset; | |
size_t nsamples; | |
unsigned int scale; | |
union | |
{ | |
void *vp; | |
unsigned short *us; | |
unsigned int *ui; | |
} | |
sample; | |
size_t start; | |
size_t end; | |
}; | |
struct prof_info | |
{ | |
unsigned int num_regions; | |
struct region *region; | |
struct region *last, *overflow; | |
struct itimerval saved_timer; | |
struct sigaction saved_action; | |
}; | |
static unsigned int overflow_counter; | |
static struct region default_overflow_region = | |
{ | |
.offset = 0, | |
.nsamples = 1, | |
.scale = 2, | |
.sample = { &overflow_counter }, | |
.start = 0, | |
.end = ~(size_t) 0 | |
}; | |
static struct prof_info prof_info; | |
static unsigned long int | |
pc_to_index (size_t pc, size_t offset, unsigned int scale, int prof_uint) | |
{ | |
size_t i = (pc - offset) / (prof_uint ? sizeof (int) : sizeof (short)); | |
if (sizeof (unsigned long long int) > sizeof (size_t)) | |
return (unsigned long long int) i * scale / 65536; | |
else | |
return i / 65536 * scale + i % 65536 * scale / 65536; | |
} | |
static inline size_t | |
index_to_pc (unsigned long int n, size_t offset, unsigned int scale, | |
int prof_uint) | |
{ | |
size_t pc, bin_size = (prof_uint ? sizeof (int) : sizeof (short)); | |
if (sizeof (unsigned long long int) > sizeof (size_t)) | |
pc = offset + (unsigned long long int) n * bin_size * 65536ull / scale; | |
else | |
pc = (offset + n * bin_size / scale * 65536 | |
+ n * bin_size % scale * 65536 / scale); | |
if (pc_to_index (pc, offset, scale, prof_uint) < n) | |
/* Adjust for rounding error. */ | |
++pc; | |
assert (pc_to_index (pc - 1, offset, scale, prof_uint) < n | |
&& pc_to_index (pc, offset, scale, prof_uint) >= n); | |
return pc; | |
} | |
static void | |
profil_count (void *pcp, int prof_uint) | |
{ | |
struct region *region, *r = prof_info.last; | |
size_t lo, hi, mid, pc = (unsigned long int) pcp; | |
unsigned long int i; | |
/* Fast path: pc is in same region as before. */ | |
if (pc >= r->start && pc < r->end) | |
region = r; | |
else | |
{ | |
/* Slow path: do a binary search for the right region. */ | |
lo = 0; hi = prof_info.num_regions - 1; | |
while (lo <= hi) | |
{ | |
mid = (lo + hi) / 2; | |
r = prof_info.region + mid; | |
if (pc >= r->start && pc < r->end) | |
{ | |
prof_info.last = r; | |
region = r; | |
break; | |
} | |
if (pc < r->start) | |
hi = mid - 1; | |
else | |
lo = mid + 1; | |
} | |
/* No matching region: increment overflow count. There is no point | |
in updating the cache here, as it won't hit anyhow. */ | |
region = prof_info.overflow; | |
} | |
i = pc_to_index (pc, region->offset, region->scale, prof_uint); | |
if (i < r->nsamples) | |
{ | |
if (prof_uint) | |
{ | |
if (r->sample.ui[i] < (unsigned int) ~0) | |
++r->sample.ui[i]; | |
} | |
else | |
{ | |
if (r->sample.us[i] < (unsigned short) ~0) | |
++r->sample.us[i]; | |
} | |
} | |
else | |
{ | |
if (prof_uint) | |
++prof_info.overflow->sample.ui[0]; | |
else | |
++prof_info.overflow->sample.us[0]; | |
} | |
} | |
static inline void | |
profil_count_ushort (void *pcp) | |
{ | |
profil_count (pcp, 0); | |
} | |
static inline void | |
profil_count_uint (void *pcp) | |
{ | |
profil_count (pcp, 1); | |
} | |
/* 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. */ | |
#define profil_counter profil_counter_ushort | |
#define profil_count(pc) profil_count (pc, 0) | |
#include <profil-counter.h> | |
#undef profil_counter | |
#undef profil_count | |
#define profil_counter profil_counter_uint | |
#define profil_count(pc) profil_count (pc, 1) | |
#include <profil-counter.h> | |
static int | |
insert (int i, unsigned long int start, unsigned long int end, struct prof *p, | |
int prof_uint) | |
{ | |
struct region *r; | |
size_t to_copy; | |
if (start >= end) | |
return 0; /* don't bother with empty regions */ | |
if (prof_info.num_regions == 0) | |
r = malloc (sizeof (*r)); | |
else | |
r = realloc (prof_info.region, (prof_info.num_regions + 1) * sizeof (*r)); | |
if (r == NULL) | |
return -1; | |
to_copy = prof_info.num_regions - i; | |
if (to_copy > 0) | |
memmove (r + i + 1, r + i, to_copy * sizeof (*r)); | |
r[i].offset = p->pr_off; | |
r[i].nsamples = p->pr_size / (prof_uint ? sizeof (int) : sizeof (short)); | |
r[i].scale = p->pr_scale; | |
r[i].sample.vp = p->pr_base; | |
r[i].start = start; | |
r[i].end = end; | |
prof_info.region = r; | |
++prof_info.num_regions; | |
if (p->pr_off == 0 && p->pr_scale == 2) | |
prof_info.overflow = r; | |
return 0; | |
} | |
/* Add a new profiling region. If the new region overlaps with | |
existing ones, this may add multiple subregions so that the final | |
data structure is free of overlaps. The absence of overlaps makes | |
it possible to use a binary search in profil_count(). Note that | |
this function depends on new regions being presented in DECREASING | |
ORDER of starting address. */ | |
static int | |
add_region (struct prof *p, int prof_uint) | |
{ | |
unsigned long int nsamples; | |
size_t start, end; | |
unsigned int i; | |
if (p->pr_scale < 2) | |
return 0; | |
nsamples = p->pr_size / (prof_uint ? sizeof (int) : sizeof (short)); | |
start = p->pr_off; | |
end = index_to_pc (nsamples, p->pr_off, p->pr_scale, prof_uint); | |
/* Merge with existing regions. */ | |
for (i = 0; i < prof_info.num_regions; ++i) | |
{ | |
if (start < prof_info.region[i].start) | |
{ | |
if (end < prof_info.region[i].start) | |
break; | |
else if (insert (i, start, prof_info.region[i].start, p, prof_uint) | |
< 0) | |
return -1; | |
} | |
start = prof_info.region[i].end; | |
} | |
return insert (i, start, end, p, prof_uint); | |
} | |
static int | |
pcmp (const void *left, const void *right) | |
{ | |
struct prof *l = *(struct prof **) left; | |
struct prof *r = *(struct prof **) right; | |
if (l->pr_off < r->pr_off) | |
return 1; | |
else if (l->pr_off > r->pr_off) | |
return -1; | |
return 0; | |
} | |
int | |
__sprofil (struct prof *profp, int profcnt, struct timeval *tvp, | |
unsigned int flags) | |
{ | |
struct prof *p[profcnt]; | |
struct itimerval timer; | |
struct sigaction act; | |
int i; | |
if (tvp != NULL) | |
{ | |
/* Return profiling period. */ | |
unsigned long int t = 1000000 / __profile_frequency (); | |
tvp->tv_sec = t / 1000000; | |
tvp->tv_usec = t % 1000000; | |
} | |
if (prof_info.num_regions > 0) | |
{ | |
/* Disable profiling. */ | |
if (__setitimer (ITIMER_PROF, &prof_info.saved_timer, NULL) < 0) | |
return -1; | |
if (__sigaction (SIGPROF, &prof_info.saved_action, NULL) < 0) | |
return -1; | |
free (prof_info.region); | |
return 0; | |
} | |
prof_info.num_regions = 0; | |
prof_info.region = NULL; | |
prof_info.overflow = &default_overflow_region; | |
for (i = 0; i < profcnt; ++i) | |
p[i] = profp + i; | |
/* Sort in order of decreasing starting address: */ | |
qsort (p, profcnt, sizeof (p[0]), pcmp); | |
/* Add regions in order of decreasing starting address: */ | |
for (i = 0; i < profcnt; ++i) | |
if (add_region (p[i], (flags & PROF_UINT) != 0) < 0) | |
{ | |
if (prof_info.region) | |
free (prof_info.region); | |
prof_info.num_regions = 0; | |
prof_info.region = NULL; | |
return -1; | |
} | |
if (prof_info.num_regions == 0) | |
return 0; | |
prof_info.last = prof_info.region; | |
/* Install SIGPROF handler. */ | |
if (flags & PROF_UINT) | |
act.sa_handler = (sighandler_t) &profil_counter_uint; | |
else | |
act.sa_handler = (sighandler_t) &profil_counter_ushort; | |
act.sa_flags = SA_RESTART; | |
__sigfillset (&act.sa_mask); | |
if (__sigaction (SIGPROF, &act, &prof_info.saved_action) < 0) | |
return -1; | |
/* Setup profiling timer. */ | |
timer.it_value.tv_sec = 0; | |
timer.it_value.tv_usec = 1; | |
timer.it_interval = timer.it_value; | |
return __setitimer (ITIMER_PROF, &timer, &prof_info.saved_timer); | |
} | |
weak_alias (__sprofil, sprofil) | |
#endif /* SIGPROF */ |