gmon/gmon.c

   1 /*-
   2  * Copyright (c) 1983, 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29 #include <sys/param.h>
  30 #include <sys/time.h>
  31 #include <sys/gmon.h>
  32 #include <sys/gmon_out.h>
  33 #include <sys/uio.h>
  34
  35 #include <errno.h>
  36 #include <stdio.h>
  37 #include <fcntl.h>
  38 #include <unistd.h>
  39
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43 #include <unistd.h>
  44 #include <libc-internal.h>
  45
  46 struct __bb *__bb_head; /*  Head of basic-block list or NULL. */
  47
  48 struct gmonparam _gmonparam = { GMON_PROF_OFF };
  49
  50 /*
  51  * See profil(2) where this is described:
  52  */
  53 static int      s_scale;
  54 #define         SCALE_1_TO_1    0x10000L
  55
  56 #define ERR(s) __write(2, s, sizeof(s) - 1)
  57
  58 void moncontrol __P ((int mode));
  59 void __moncontrol __P ((int mode));
  60 static void write_hist __P ((int fd)) internal_function;
  61 static void write_call_graph __P ((int fd)) internal_function;
  62 static void write_bb_counts __P ((int fd)) internal_function;
  63
  64 /*
  65  * Control profiling
  66  *      profiling is what mcount checks to see if
  67  *      all the data structures are ready.
  68  */
  69 void
  70 __moncontrol (mode)
  71      int mode;
  72 {
  73   struct gmonparam *p = &_gmonparam;
  74
  75   /* Don't change the state if we ran into an error.  */
  76   if (p->state == GMON_PROF_ERROR)
  77     return;
  78
  79   if (mode)
  80     {
  81       /* start */
  82       __profil((void *) p->kcount, p->kcountsize, p->lowpc, s_scale);
  83       p->state = GMON_PROF_ON;
  84     }
  85   else
  86     {
  87       /* stop */
  88       __profil(NULL, 0, 0, 0);
  89       p->state = GMON_PROF_OFF;
  90     }
  91 }
  92 weak_alias (__moncontrol, moncontrol)
  93
  94
  95 void
  96 __monstartup (lowpc, highpc)
  97      u_long lowpc;
  98      u_long highpc;
  99 {
 100   register int o;
 101   char *cp;
 102   struct gmonparam *p = &_gmonparam;
 103
 104   /*
 105    * round lowpc and highpc to multiples of the density we're using
 106    * so the rest of the scaling (here and in gprof) stays in ints.
 107    */
 108   p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
 109   p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
 110   p->textsize = p->highpc - p->lowpc;
 111   p->kcountsize = p->textsize / HISTFRACTION;
 112   p->hashfraction = HASHFRACTION;
 113   p->log_hashfraction = -1;
 114   /* The following test must be kept in sync with the corresponding
 115      test in mcount.c.  */
 116   if ((HASHFRACTION & (HASHFRACTION - 1)) == 0) {
 117       /* if HASHFRACTION is a power of two, mcount can use shifting
 118          instead of integer division.  Precompute shift amount. */
 119       p->log_hashfraction = ffs(p->hashfraction * sizeof(*p->froms)) - 1;
 120   }
 121   p->fromssize = p->textsize / HASHFRACTION;
 122   p->tolimit = p->textsize * ARCDENSITY / 100;
 123   if (p->tolimit < MINARCS)
 124     p->tolimit = MINARCS;
 125   else if (p->tolimit > MAXARCS)
 126     p->tolimit = MAXARCS;
 127   p->tossize = p->tolimit * sizeof(struct tostruct);
 128
 129   cp = calloc (p->kcountsize + p->fromssize + p->tossize, 1);
 130   if (! cp)
 131     {
 132       ERR("monstartup: out of memory\n");
 133       p->tos = NULL;
 134       p->state = GMON_PROF_ERROR;
 135       return;
 136     }
 137   p->tos = (struct tostruct *)cp;
 138   cp += p->tossize;
 139   p->kcount = (u_short *)cp;
 140   cp += p->kcountsize;
 141   p->froms = (u_short *)cp;
 142
 143   p->tos[0].link = 0;
 144
 145   o = p->highpc - p->lowpc;
 146   if (p->kcountsize < (u_long) o)
 147     {
 148 #ifndef hp300
 149       s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
 150 #else
 151       /* avoid floating point operations */
 152       int quot = o / p->kcountsize;
 153
 154       if (quot >= 0x10000)
 155         s_scale = 1;
 156       else if (quot >= 0x100)
 157         s_scale = 0x10000 / quot;
 158       else if (o >= 0x800000)
 159         s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
 160       else
 161         s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
 162 #endif
 163     } else
 164       s_scale = SCALE_1_TO_1;
 165
 166   __moncontrol(1);
 167 }
 168 weak_alias(__monstartup, monstartup)
 169
 170
 171 static void
 172 internal_function
 173 write_hist (fd)
 174      int fd;
 175 {
 176   u_char tag = GMON_TAG_TIME_HIST;
 177   struct gmon_hist_hdr thdr __attribute__ ((aligned (__alignof__ (char *))));
 178
 179   if (_gmonparam.kcountsize > 0)
 180     {
 181       struct iovec iov[3] =
 182         {
 183           { &tag, sizeof (tag) },
 184           { &thdr, sizeof (struct gmon_hist_hdr) },
 185           { _gmonparam.kcount, _gmonparam.kcountsize }
 186         };
 187
 188       *(char **) thdr.low_pc = (char *) _gmonparam.lowpc;
 189       *(char **) thdr.high_pc = (char *) _gmonparam.highpc;
 190       *(int32_t *) thdr.hist_size = (_gmonparam.kcountsize
 191                                      / sizeof (HISTCOUNTER));
 192       *(int32_t *) thdr.prof_rate = __profile_frequency ();
 193       strncpy (thdr.dimen, "seconds", sizeof (thdr.dimen));
 194       thdr.dimen_abbrev = 's';
 195
 196       __writev (fd, iov, 3);
 197     }
 198 }
 199
 200
 201 static void
 202 internal_function
 203 write_call_graph (fd)
 204      int fd;
 205 {
 206 #define NARCS_PER_WRITEV        32
 207   u_char tag = GMON_TAG_CG_ARC;
 208   struct gmon_cg_arc_record raw_arc[NARCS_PER_WRITEV]
 209     __attribute__ ((aligned (__alignof__ (char*))));
 210   int from_index, to_index, from_len;
 211   u_long frompc;
 212   struct iovec iov[2 * NARCS_PER_WRITEV];
 213   int nfilled;
 214
 215   for (nfilled = 0; nfilled < NARCS_PER_WRITEV; ++nfilled)
 216     {
 217       iov[2 * nfilled].iov_base = &tag;
 218       iov[2 * nfilled].iov_len = sizeof (tag);
 219
 220       iov[2 * nfilled + 1].iov_base = &raw_arc[nfilled];
 221       iov[2 * nfilled + 1].iov_len = sizeof (struct gmon_cg_arc_record);
 222     }
 223
 224   nfilled = 0;
 225   from_len = _gmonparam.fromssize / sizeof (*_gmonparam.froms);
 226   for (from_index = 0; from_index < from_len; ++from_index)
 227     {
 228       if (_gmonparam.froms[from_index] == 0)
 229         continue;
 230
 231       frompc = _gmonparam.lowpc;
 232       frompc += (from_index * _gmonparam.hashfraction
 233                  * sizeof (*_gmonparam.froms));
 234       for (to_index = _gmonparam.froms[from_index];
 235            to_index != 0;
 236            to_index = _gmonparam.tos[to_index].link)
 237         {
 238           struct arc
 239             {
 240               char *frompc;
 241               char *selfpc;
 242               int32_t count;
 243             }
 244           arc;
 245
 246           arc.frompc = (char *) frompc;
 247           arc.selfpc = (char *) _gmonparam.tos[to_index].selfpc;
 248           arc.count  = _gmonparam.tos[to_index].count;
 249           memcpy (raw_arc + nfilled, &arc, sizeof (raw_arc [0]));
 250
 251           if (++nfilled == NARCS_PER_WRITEV)
 252             {
 253               __writev (fd, iov, 2 * nfilled);
 254               nfilled = 0;
 255             }
 256         }
 257     }
 258   if (nfilled > 0)
 259     __writev (fd, iov, 2 * nfilled);
 260 }
 261
 262
 263 static void
 264 internal_function
 265 write_bb_counts (fd)
 266      int fd;
 267 {
 268   struct __bb *grp;
 269   u_char tag = GMON_TAG_BB_COUNT;
 270   size_t ncounts;
 271   size_t i;
 272
 273   struct iovec bbhead[2] =
 274     {
 275       { &tag, sizeof (tag) },
 276       { &ncounts, sizeof (ncounts) }
 277     };
 278   struct iovec bbbody[8];
 279   size_t nfilled;
 280
 281   for (i = 0; i < (sizeof (bbbody) / sizeof (bbbody[0])); i += 2)
 282     {
 283       bbbody[i].iov_len = sizeof (grp->addresses[0]);
 284       bbbody[i + 1].iov_len = sizeof (grp->counts[0]);
 285     }
 286
 287   /* Write each group of basic-block info (all basic-blocks in a
 288      compilation unit form a single group). */
 289
 290   for (grp = __bb_head; grp; grp = grp->next)
 291     {
 292       ncounts = grp->ncounts;
 293       __writev (fd, bbhead, 2);
 294       for (nfilled = i = 0; i < ncounts; ++i)
 295         {
 296           if (nfilled > (sizeof (bbbody) / sizeof (bbbody[0])) - 2)
 297             {
 298               __writev (fd, bbbody, nfilled);
 299               nfilled = 0;
 300             }
 301
 302           bbbody[nfilled++].iov_base = (char *) &grp->addresses[i];
 303           bbbody[nfilled++].iov_base = &grp->counts[i];
 304         }
 305       if (nfilled > 0)
 306         __writev (fd, bbbody, nfilled);
 307     }
 308 }
 309
 310
 311 static void
 312 write_gmon (void)
 313 {
 314     struct gmon_hdr ghdr __attribute__ ((aligned (__alignof__ (int))));
 315     int fd = -1;
 316     char *env;
 317
 318     env = getenv ("GMON_OUT_PREFIX");
 319     if (env != NULL && !__libc_enable_secure)
 320       {
 321         size_t len = strlen (env);
 322         char buf[len + 20];
 323         sprintf (buf, "%s.%u", env, __getpid ());
 324         fd = __open (buf, O_CREAT|O_TRUNC|O_WRONLY, 0666);
 325       }
 326
 327     if (fd == -1)
 328       {
 329         fd = __open ("gmon.out", O_CREAT|O_TRUNC|O_WRONLY, 0666);
 330         if (fd < 0)
 331           {
 332             char buf[300];
 333             int errnum = errno;
 334             fprintf (stderr, "_mcleanup: gmon.out: %s\n",
 335                      __strerror_r (errnum, buf, sizeof buf));
 336             return;
 337           }
 338       }
 339
 340     /* write gmon.out header: */
 341     memset (&ghdr, '\0', sizeof (struct gmon_hdr));
 342     memcpy (&ghdr.cookie[0], GMON_MAGIC, sizeof (ghdr.cookie));
 343     *(int32_t *) ghdr.version = GMON_VERSION;
 344     __write (fd, &ghdr, sizeof (struct gmon_hdr));
 345
 346     /* write PC histogram: */
 347     write_hist (fd);
 348
 349     /* write call-graph: */
 350     write_call_graph (fd);
 351
 352     /* write basic-block execution counts: */
 353     write_bb_counts (fd);
 354
 355     __close (fd);
 356 }
 357
 358
 359 void
 360 __write_profiling (void)
 361 {
 362   int save = _gmonparam.state;
 363   _gmonparam.state = GMON_PROF_OFF;
 364   if (save == GMON_PROF_ON)
 365     write_gmon ();
 366   _gmonparam.state = save;
 367 }
 368 weak_alias (__write_profiling, write_profiling)
 369
 370
 371 void
 372 _mcleanup (void)
 373 {
 374   __moncontrol (0);
 375
 376   if (_gmonparam.state != GMON_PROF_ERROR)
 377     write_gmon ();
 378
 379   /* free the memory. */
 380   if (_gmonparam.tos != NULL)
 381     free (_gmonparam.tos);
 382 }