diff options
Diffstat (limited to 'sysdeps/posix')
| -rw-r--r-- | sysdeps/posix/sprofil.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/sysdeps/posix/sprofil.c b/sysdeps/posix/sprofil.c new file mode 100644 index 0000000000..c653253ed6 --- /dev/null +++ b/sysdeps/posix/sprofil.c @@ -0,0 +1,357 @@ +/* Copyright (C) 2001 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 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., 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 <sysdeps/generic/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 inline 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 inline 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; + 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 */ |