ext/Devel/DProf/DProf.xs

   1 #define PERL_NO_GET_CONTEXT
   2 #include "EXTERN.h"
   3 #include "perl.h"
   4 #include "XSUB.h"
   5
   6 /* For older Perls */
   7 #ifndef dTHR
   8 #  define dTHR int dummy_thr
   9 #endif  /* dTHR */
  10
  11 /*#define DBG_SUB 1      */
  12 /*#define DBG_TIMER 1    */
  13
  14 #ifdef DBG_SUB
  15 #  define DBG_SUB_NOTIFY(A,B) warn(A, B)
  16 #else
  17 #  define DBG_SUB_NOTIFY(A,B)  /* nothing */
  18 #endif
  19
  20 #ifdef DBG_TIMER
  21 #  define DBG_TIMER_NOTIFY(A) warn(A)
  22 #else
  23 #  define DBG_TIMER_NOTIFY(A)  /* nothing */
  24 #endif
  25
  26 /* HZ == clock ticks per second */
  27 #ifdef VMS
  28 #  define HZ ((I32)CLK_TCK)
  29 #  define DPROF_HZ HZ
  30 #  include <starlet.h>  /* prototype for sys$gettim() */
  31 #  define Times(ptr) (dprof_times(aTHX_ ptr))
  32 #else
  33 #  ifndef HZ
  34 #    ifdef CLK_TCK
  35 #      define HZ ((I32)CLK_TCK)
  36 #    else
  37 #      define HZ 60
  38 #    endif
  39 #  endif
  40 #  ifdef OS2                            /* times() has significant overhead */
  41 #    define Times(ptr) (dprof_times(aTHX_ ptr))
  42 #    define INCL_DOSPROFILE
  43 #    define INCL_DOSERRORS
  44 #    include <os2.h>
  45 #    define toLongLong(arg) (*(long long*)&(arg))
  46 #    define DPROF_HZ g_dprof_ticks
  47 #  else
  48 #    define Times(ptr) (times(ptr))
  49 #    define DPROF_HZ HZ
  50 #  endif
  51 #endif
  52
  53 XS(XS_Devel__DProf_END);        /* used by prof_mark() */
  54
  55 /* Everything is built on times(2).  See its manpage for a description
  56  * of the timings.
  57  */
  58
  59 union prof_any {
  60         clock_t tms_utime;  /* cpu time spent in user space */
  61         clock_t tms_stime;  /* cpu time spent in system */
  62         clock_t realtime;   /* elapsed real time, in ticks */
  63         char *name;
  64         U32 id;
  65         opcode ptype;
  66 };
  67
  68 typedef union prof_any PROFANY;
  69
  70 typedef struct {
  71     U32         dprof_ticks;
  72     PerlIO*     fp;             /* pointer to tmon.out file */
  73     long        TIMES_LOCATION; /* Where in the file to store the time totals */
  74     int         SAVE_STACK;     /* How much data to buffer until end of run */
  75     int         prof_pid;       /* pid of profiled process */
  76     struct tms  prof_start;
  77     struct tms  prof_end;
  78     clock_t     rprof_start;    /* elapsed real time ticks */
  79     clock_t     rprof_end;
  80     clock_t     wprof_u;
  81     clock_t     wprof_s;
  82     clock_t     wprof_r;
  83     clock_t     otms_utime;
  84     clock_t     otms_stime;
  85     clock_t     orealtime;
  86     PROFANY*    profstack;
  87     int         profstack_max;
  88     int         profstack_ix;
  89     HV*         cv_hash;
  90     U32         total;
  91     U32         lastid;
  92     U32         default_perldb;
  93     U32         depth;
  94 #ifdef OS2
  95     ULONG       frequ;
  96     long long   start_cnt;
  97 #endif
  98 #ifdef PERL_IMPLICIT_CONTEXT
  99     pTHX;
 100 #endif
 101 } prof_state_t;
 102
 103 prof_state_t g_prof_state;
 104
 105 #define g_dprof_ticks           g_prof_state.dprof_ticks
 106 #define g_fp                    g_prof_state.fp
 107 #define g_TIMES_LOCATION        g_prof_state.TIMES_LOCATION
 108 #define g_SAVE_STACK            g_prof_state.SAVE_STACK
 109 #define g_prof_pid              g_prof_state.prof_pid
 110 #define g_prof_start            g_prof_state.prof_start
 111 #define g_prof_end              g_prof_state.prof_end
 112 #define g_rprof_start           g_prof_state.rprof_start
 113 #define g_rprof_end             g_prof_state.rprof_end
 114 #define g_wprof_u               g_prof_state.wprof_u
 115 #define g_wprof_s               g_prof_state.wprof_s
 116 #define g_wprof_r               g_prof_state.wprof_r
 117 #define g_otms_utime            g_prof_state.otms_utime
 118 #define g_otms_stime            g_prof_state.otms_stime
 119 #define g_orealtime             g_prof_state.orealtime
 120 #define g_profstack             g_prof_state.profstack
 121 #define g_profstack_max         g_prof_state.profstack_max
 122 #define g_profstack_ix          g_prof_state.profstack_ix
 123 #define g_cv_hash               g_prof_state.cv_hash
 124 #define g_total                 g_prof_state.total
 125 #define g_lastid                g_prof_state.lastid
 126 #define g_default_perldb        g_prof_state.default_perldb
 127 #define g_depth                 g_prof_state.depth
 128 #ifdef PERL_IMPLICIT_CONTEXT
 129 #  define g_THX                 g_prof_state.aTHX
 130 #endif
 131 #ifdef OS2
 132 #  define g_frequ               g_prof_state.frequ
 133 #  define g_start_cnt           g_prof_state.start_cnt
 134 #endif
 135
 136 clock_t
 137 dprof_times(pTHX_ struct tms *t)
 138 {
 139 #ifdef OS2
 140     ULONG rc;
 141     QWORD cnt;
 142
 143     if (!g_frequ) {
 144         if (CheckOSError(DosTmrQueryFreq(&g_frequ)))
 145             croak("DosTmrQueryFreq: %s", SvPV(perl_get_sv("!",TRUE),na));
 146         else
 147             g_frequ = g_frequ/DPROF_HZ; /* count per tick */
 148         if (CheckOSError(DosTmrQueryTime(&cnt)))
 149             croak("DosTmrQueryTime: %s",
 150                   SvPV(perl_get_sv("!",TRUE),na));
 151         g_start_cnt = toLongLong(cnt);
 152     }
 153
 154     if (CheckOSError(DosTmrQueryTime(&cnt)))
 155             croak("DosTmrQueryTime: %s", SvPV(perl_get_sv("!",TRUE),na));
 156     t->tms_stime = 0;
 157     return (t->tms_utime = (toLongLong(cnt) - g_start_cnt)/g_frequ);
 158 #else           /* !OS2 */
 159 #  ifdef VMS
 160     clock_t retval;
 161     /* Get wall time and convert to 10 ms intervals to
 162      * produce the return value dprof expects */
 163 #    if defined(__DECC) && defined (__ALPHA)
 164 #      include <ints.h>
 165     uint64 vmstime;
 166     _ckvmssts(sys$gettim(&vmstime));
 167     vmstime /= 100000;
 168     retval = vmstime & 0x7fffffff;
 169 #    else
 170     /* (Older hw or ccs don't have an atomic 64-bit type, so we
 171      * juggle 32-bit ints (and a float) to produce a time_t result
 172      * with minimal loss of information.) */
 173     long int vmstime[2],remainder,divisor = 100000;
 174     _ckvmssts(sys$gettim((unsigned long int *)vmstime));
 175     vmstime[1] &= 0x7fff;  /* prevent overflow in EDIV */
 176     _ckvmssts(lib$ediv(&divisor,vmstime,(long int *)&retval,&remainder));
 177 #    endif
 178     /* Fill in the struct tms using the CRTL routine . . .*/
 179     times((tbuffer_t *)t);
 180     return (clock_t) retval;
 181 #  else         /* !VMS && !OS2 */
 182     return times(t);
 183 #  endif
 184 #endif
 185 }
 186
 187 static void
 188 prof_dumpa(pTHX_ opcode ptype, U32 id)
 189 {
 190     if (ptype == OP_LEAVESUB) {
 191         PerlIO_printf(g_fp,"- %"UVxf"\n", (UV)id);
 192     }
 193     else if(ptype == OP_ENTERSUB) {
 194         PerlIO_printf(g_fp,"+ %"UVxf"\n", (UV)id);
 195     }
 196     else if(ptype == OP_GOTO) {
 197         PerlIO_printf(g_fp,"* %"UVxf"\n", (UV)id);
 198     }
 199     else if(ptype == OP_DIE) {
 200         PerlIO_printf(g_fp,"/ %"UVxf"\n", (UV)id);
 201     }
 202     else {
 203         PerlIO_printf(g_fp,"Profiler unknown prof code %d\n", ptype);
 204     }
 205 }
 206
 207 static void
 208 prof_dumps(pTHX_ U32 id, char *pname, char *gname)
 209 {
 210     PerlIO_printf(g_fp,"& %"UVxf" %s %s\n", (UV)id, pname, gname);
 211 }
 212
 213 static void
 214 prof_dumpt(pTHX_ long tms_utime, long tms_stime, long realtime)
 215 {
 216     PerlIO_printf(g_fp,"@ %ld %ld %ld\n", tms_utime, tms_stime, realtime);
 217 }
 218
 219 static void
 220 prof_dump_until(pTHX_ long ix)
 221 {
 222     long base = 0;
 223     struct tms t1, t2;
 224     clock_t realtime1, realtime2;
 225
 226     realtime1 = Times(&t1);
 227
 228     while (base < ix) {
 229         opcode ptype = g_profstack[base++].ptype;
 230         if (ptype == OP_TIME) {
 231             long tms_utime = g_profstack[base++].tms_utime;
 232             long tms_stime = g_profstack[base++].tms_stime;
 233             long realtime = g_profstack[base++].realtime;
 234
 235             prof_dumpt(aTHX_ tms_utime, tms_stime, realtime);
 236         }
 237         else if (ptype == OP_GV) {
 238             U32 id = g_profstack[base++].id;
 239             char *pname = g_profstack[base++].name;
 240             char *gname = g_profstack[base++].name;
 241
 242             prof_dumps(aTHX_ id, pname, gname);
 243         }
 244         else {
 245             U32 id = g_profstack[base++].id;
 246             prof_dumpa(aTHX_ ptype, id);
 247         }
 248     }
 249     PerlIO_flush(g_fp);
 250     realtime2 = Times(&t2);
 251     if (realtime2 != realtime1 || t1.tms_utime != t2.tms_utime
 252         || t1.tms_stime != t2.tms_stime) {
 253         g_wprof_r += realtime2 - realtime1;
 254         g_wprof_u += t2.tms_utime - t1.tms_utime;
 255         g_wprof_s += t2.tms_stime - t1.tms_stime;
 256
 257         PerlIO_printf(g_fp,"+ & Devel::DProf::write\n");
 258         PerlIO_printf(g_fp,"@ %"IVdf" %"IVdf" %"IVdf"\n",
 259                       /* The (IV) casts are one possibility:
 260                        * the Painfully Correct Way would be to
 261                        * have Clock_t_f. */
 262                       (IV)(t2.tms_utime - t1.tms_utime),
 263                       (IV)(t2.tms_stime - t1.tms_stime),
 264                       (IV)(realtime2 - realtime1));
 265         PerlIO_printf(g_fp,"- & Devel::DProf::write\n");
 266         g_otms_utime = t2.tms_utime;
 267         g_otms_stime = t2.tms_stime;
 268         g_orealtime = realtime2;
 269         PerlIO_flush(g_fp);
 270     }
 271 }
 272
 273 static void
 274 prof_mark(pTHX_ opcode ptype)
 275 {
 276     struct tms t;
 277     clock_t realtime, rdelta, udelta, sdelta;
 278     char *name, *pv;
 279     char *hvname;
 280     STRLEN len;
 281     SV *sv;
 282     U32 id;
 283     SV *Sub = GvSV(PL_DBsub);   /* name of current sub */
 284
 285     if (g_SAVE_STACK) {
 286         if (g_profstack_ix + 5 > g_profstack_max) {
 287                 g_profstack_max = g_profstack_max * 3 / 2;
 288                 Renew(g_profstack, g_profstack_max, PROFANY);
 289         }
 290     }
 291
 292     realtime = Times(&t);
 293     rdelta = realtime - g_orealtime;
 294     udelta = t.tms_utime - g_otms_utime;
 295     sdelta = t.tms_stime - g_otms_stime;
 296     if (rdelta || udelta || sdelta) {
 297         if (g_SAVE_STACK) {
 298             g_profstack[g_profstack_ix++].ptype = OP_TIME;
 299             g_profstack[g_profstack_ix++].tms_utime = udelta;
 300             g_profstack[g_profstack_ix++].tms_stime = sdelta;
 301             g_profstack[g_profstack_ix++].realtime = rdelta;
 302         }
 303         else { /* Write it to disk now so's not to eat up core */
 304             if (g_prof_pid == (int)getpid()) {
 305                 prof_dumpt(aTHX_ udelta, sdelta, rdelta);
 306                 PerlIO_flush(g_fp);
 307             }
 308         }
 309         g_orealtime = realtime;
 310         g_otms_stime = t.tms_stime;
 311         g_otms_utime = t.tms_utime;
 312     }
 313
 314     {
 315         SV **svp;
 316         char *gname, *pname;
 317         CV *cv;
 318
 319         cv = INT2PTR(CV*,SvIVX(Sub));
 320         svp = hv_fetch(g_cv_hash, (char*)&cv, sizeof(CV*), TRUE);
 321         if (!SvOK(*svp)) {
 322             GV *gv = CvGV(cv);
 323
 324             sv_setiv(*svp, id = ++g_lastid);
 325             pname = ((GvSTASH(gv) && HvNAME(GvSTASH(gv)))
 326                      ? HvNAME(GvSTASH(gv))
 327                      : "(null)");
 328             gname = GvNAME(gv);
 329             if (CvXSUB(cv) == XS_Devel__DProf_END)
 330                 return;
 331             if (g_SAVE_STACK) { /* Store it for later recording  -JH */
 332                 g_profstack[g_profstack_ix++].ptype = OP_GV;
 333                 g_profstack[g_profstack_ix++].id = id;
 334                 g_profstack[g_profstack_ix++].name = pname;
 335                 g_profstack[g_profstack_ix++].name = gname;
 336             }
 337             else { /* Write it to disk now so's not to eat up core */
 338                 /* Only record the parent's info */
 339                 if (g_prof_pid == (int)getpid()) {
 340                     prof_dumps(aTHX_ id, pname, gname);
 341                     PerlIO_flush(g_fp);
 342                 }
 343                 else
 344                     PL_perldb = 0;              /* Do not debug the kid. */
 345             }
 346         }
 347         else {
 348             id = SvIV(*svp);
 349         }
 350     }
 351
 352     g_total++;
 353     if (g_SAVE_STACK) { /* Store it for later recording  -JH */
 354         g_profstack[g_profstack_ix++].ptype = ptype;
 355         g_profstack[g_profstack_ix++].id = id;
 356
 357         /* Only record the parent's info */
 358         if (g_SAVE_STACK < g_profstack_ix) {
 359             if (g_prof_pid == (int)getpid())
 360                 prof_dump_until(aTHX_ g_profstack_ix);
 361             else
 362                 PL_perldb = 0;          /* Do not debug the kid. */
 363             g_profstack_ix = 0;
 364         }
 365     }
 366     else { /* Write it to disk now so's not to eat up core */
 367
 368         /* Only record the parent's info */
 369         if (g_prof_pid == (int)getpid()) {
 370             prof_dumpa(aTHX_ ptype, id);
 371             PerlIO_flush(g_fp);
 372         }
 373         else
 374             PL_perldb = 0;              /* Do not debug the kid. */
 375     }
 376 }
 377
 378 #ifdef PL_NEEDED
 379 #  define defstash PL_defstash
 380 #endif
 381
 382 /* Counts overhead of prof_mark and extra XS call. */
 383 static void
 384 test_time(pTHX_ clock_t *r, clock_t *u, clock_t *s)
 385 {
 386     dTHR;
 387     CV *cv = perl_get_cv("Devel::DProf::NONESUCH_noxs", FALSE);
 388     int i, j, k = 0;
 389     HV *oldstash = PL_curstash;
 390     struct tms t1, t2;
 391     clock_t realtime1, realtime2;
 392     U32 ototal = g_total;
 393     U32 ostack = g_SAVE_STACK;
 394     U32 operldb = PL_perldb;
 395
 396     g_SAVE_STACK = 1000000;
 397     realtime1 = Times(&t1);
 398
 399     while (k < 2) {
 400         i = 0;
 401             /* Disable debugging of perl_call_sv on second pass: */
 402         PL_curstash = (k == 0 ? PL_defstash : PL_debstash);
 403         PL_perldb = g_default_perldb;
 404         while (++i <= 100) {
 405             j = 0;
 406             g_profstack_ix = 0;         /* Do not let the stack grow */
 407             while (++j <= 100) {
 408 /*              prof_mark(aTHX_ OP_ENTERSUB); */
 409
 410                 PUSHMARK(PL_stack_sp);
 411                 perl_call_sv((SV*)cv, G_SCALAR);
 412                 PL_stack_sp--;
 413 /*              prof_mark(aTHX_ OP_LEAVESUB); */
 414             }
 415         }
 416         PL_curstash = oldstash;
 417         if (k == 0) {                   /* Put time with debugging */
 418             realtime2 = Times(&t2);
 419             *r = realtime2 - realtime1;
 420             *u = t2.tms_utime - t1.tms_utime;
 421             *s = t2.tms_stime - t1.tms_stime;
 422         }
 423         else {                          /* Subtract time without debug */
 424             realtime1 = Times(&t1);
 425             *r -= realtime1 - realtime2;
 426             *u -= t1.tms_utime - t2.tms_utime;
 427             *s -= t1.tms_stime - t2.tms_stime;
 428         }
 429         k++;
 430     }
 431     g_total = ototal;
 432     g_SAVE_STACK = ostack;
 433     PL_perldb = operldb;
 434 }
 435
 436 static void
 437 prof_recordheader(pTHX)
 438 {
 439     clock_t r, u, s;
 440
 441     /* g_fp is opened in the BOOT section */
 442     PerlIO_printf(g_fp, "#fOrTyTwO\n");
 443     PerlIO_printf(g_fp, "$hz=%"IVdf";\n", (IV)DPROF_HZ);
 444     PerlIO_printf(g_fp, "$XS_VERSION='DProf %s';\n", XS_VERSION);
 445     PerlIO_printf(g_fp, "# All values are given in HZ\n");
 446     test_time(aTHX_ &r, &u, &s);
 447     PerlIO_printf(g_fp,
 448                   "$over_utime=%"IVdf"; $over_stime=%"IVdf"; $over_rtime=%"IVdf";\n",
 449                   /* The (IV) casts are one possibility:
 450                    * the Painfully Correct Way would be to
 451                    * have Clock_t_f. */
 452                   (IV)u, (IV)s, (IV)r);
 453     PerlIO_printf(g_fp, "$over_tests=10000;\n");
 454
 455     g_TIMES_LOCATION = PerlIO_tell(g_fp);
 456
 457     /* Pad with whitespace. */
 458     /* This should be enough even for very large numbers. */
 459     PerlIO_printf(g_fp, "%*s\n", 240 , "");
 460
 461     PerlIO_printf(g_fp, "\n");
 462     PerlIO_printf(g_fp, "PART2\n");
 463
 464     PerlIO_flush(g_fp);
 465 }
 466
 467 static void
 468 prof_record(pTHX)
 469 {
 470     /* g_fp is opened in the BOOT section */
 471
 472     /* Now that we know the runtimes, fill them in at the recorded
 473        location -JH */
 474
 475     clock_t r, u, s;
 476
 477     if (g_SAVE_STACK) {
 478         prof_dump_until(aTHX_ g_profstack_ix);
 479     }
 480     PerlIO_seek(g_fp, g_TIMES_LOCATION, SEEK_SET);
 481     /* Write into reserved 240 bytes: */
 482     PerlIO_printf(g_fp,
 483                   "$rrun_utime=%"IVdf"; $rrun_stime=%"IVdf"; $rrun_rtime=%"IVdf";",
 484                   /* The (IV) casts are one possibility:
 485                    * the Painfully Correct Way would be to
 486                    * have Clock_t_f. */
 487                   (IV)(g_prof_end.tms_utime-g_prof_start.tms_utime-g_wprof_u),
 488                   (IV)(g_prof_end.tms_stime-g_prof_start.tms_stime-g_wprof_s),
 489                   (IV)(g_rprof_end-g_rprof_start-g_wprof_r));
 490     PerlIO_printf(g_fp, "\n$total_marks=%"IVdf, (IV)g_total);
 491
 492     PerlIO_close(g_fp);
 493 }
 494
 495 #define NONESUCH()
 496
 497 static void
 498 check_depth(pTHX_ void *foo)
 499 {
 500     U32 need_depth = (U32)foo;
 501     if (need_depth != g_depth) {
 502         if (need_depth > g_depth) {
 503             warn("garbled call depth when profiling");
 504         }
 505         else {
 506             I32 marks = g_depth - need_depth;
 507
 508 /*          warn("Check_depth: got %d, expected %d\n", g_depth, need_depth); */
 509             while (marks--) {
 510                 prof_mark(aTHX_ OP_DIE);
 511             }
 512             g_depth = need_depth;
 513         }
 514     }
 515 }
 516
 517 #define for_real
 518 #ifdef for_real
 519
 520 XS(XS_DB_sub)
 521 {
 522     dXSARGS;
 523     dORIGMARK;
 524     SV *Sub = GvSV(PL_DBsub);           /* name of current sub */
 525
 526 #ifdef PERL_IMPLICIT_CONTEXT
 527     /* profile only the interpreter that loaded us */
 528     if (g_THX != aTHX) {
 529         PUSHMARK(ORIGMARK);
 530         perl_call_sv(INT2PTR(SV*,SvIV(Sub)), GIMME | G_NODEBUG);
 531     }
 532     else
 533 #endif
 534     {
 535         HV *oldstash = PL_curstash;
 536
 537         DBG_SUB_NOTIFY("XS DBsub(%s)\n", SvPV(Sub, na));
 538
 539         SAVEDESTRUCTOR_X(check_depth, (void*)g_depth);
 540         g_depth++;
 541
 542         prof_mark(aTHX_ OP_ENTERSUB);
 543         PUSHMARK(ORIGMARK);
 544         perl_call_sv(INT2PTR(SV*,SvIV(Sub)), GIMME | G_NODEBUG);
 545         prof_mark(aTHX_ OP_LEAVESUB);
 546         g_depth--;
 547     }
 548     return;
 549 }
 550
 551 XS(XS_DB_goto)
 552 {
 553 #ifdef PERL_IMPLICIT_CONTEXT
 554     if (g_THX == aTHX)
 555 #endif
 556     {
 557         prof_mark(aTHX_ OP_GOTO);
 558         return;
 559     }
 560 }
 561
 562 #endif /* for_real */
 563
 564 #ifdef testing
 565
 566         MODULE = Devel::DProf           PACKAGE = DB
 567
 568         void
 569         sub(...)
 570         PPCODE:
 571             {
 572                 dORIGMARK;
 573                 HV *oldstash = PL_curstash;
 574                 SV *Sub = GvSV(PL_DBsub);       /* name of current sub */
 575                 /* SP -= items;  added by xsubpp */
 576                 DBG_SUB_NOTIFY("XS DBsub(%s)\n", SvPV(Sub, na));
 577
 578                 sv_setiv(PL_DBsingle, 0);       /* disable DB single-stepping */
 579
 580                 prof_mark(aTHX_ OP_ENTERSUB);
 581                 PUSHMARK(ORIGMARK);
 582
 583                 PL_curstash = PL_debstash;      /* To disable debugging of perl_call_sv */
 584                 perl_call_sv(Sub, GIMME);
 585                 PL_curstash = oldstash;
 586
 587                 prof_mark(aTHX_ OP_LEAVESUB);
 588                 SPAGAIN;
 589                 /* PUTBACK;  added by xsubpp */
 590             }
 591
 592 #endif /* testing */
 593
 594 MODULE = Devel::DProf           PACKAGE = Devel::DProf
 595
 596 void
 597 END()
 598 PPCODE:
 599     {
 600         if (PL_DBsub) {
 601             /* maybe the process forked--we want only
 602              * the parent's profile.
 603              */
 604             if (
 605 #ifdef PERL_IMPLICIT_CONTEXT
 606                 g_THX == aTHX &&
 607 #endif
 608                 g_prof_pid == (int)getpid())
 609             {
 610                 g_rprof_end = Times(&g_prof_end);
 611                 DBG_TIMER_NOTIFY("Profiler timer is off.\n");
 612                 prof_record(aTHX);
 613             }
 614         }
 615     }
 616
 617 void
 618 NONESUCH()
 619
 620 BOOT:
 621     {
 622         g_TIMES_LOCATION = 42;
 623         g_SAVE_STACK = 1<<14;
 624         g_profstack_max = 128;
 625 #ifdef PERL_IMPLICIT_CONTEXT
 626         g_THX = aTHX;
 627 #endif
 628
 629         /* Before we go anywhere make sure we were invoked
 630          * properly, else we'll dump core.
 631          */
 632         if (!PL_DBsub)
 633             croak("DProf: run perl with -d to use DProf.\n");
 634
 635         /* When we hook up the XS DB::sub we'll be redefining
 636          * the DB::sub from the PM file.  Turn off warnings
 637          * while we do this.
 638          */
 639         {
 640             I32 warn_tmp = PL_dowarn;
 641             PL_dowarn = 0;
 642             newXS("DB::sub", XS_DB_sub, file);
 643             newXS("DB::goto", XS_DB_goto, file);
 644             PL_dowarn = warn_tmp;
 645         }
 646
 647         sv_setiv(PL_DBsingle, 0);       /* disable DB single-stepping */
 648
 649         {
 650             char *buffer = getenv("PERL_DPROF_BUFFER");
 651
 652             if (buffer) {
 653                 g_SAVE_STACK = atoi(buffer);
 654             }
 655
 656             buffer = getenv("PERL_DPROF_TICKS");
 657
 658             if (buffer) {
 659                 g_dprof_ticks = atoi(buffer); /* Used under OS/2 only */
 660             }
 661             else {
 662                 g_dprof_ticks = HZ;
 663             }
 664         }
 665
 666         if ((g_fp = PerlIO_open("tmon.out", "w")) == NULL)
 667             croak("DProf: unable to write tmon.out, errno = %d\n", errno);
 668
 669         g_default_perldb = PERLDBf_NONAME | PERLDBf_SUB | PERLDBf_GOTO;
 670         g_cv_hash = newHV();
 671         g_prof_pid = (int)getpid();
 672
 673         New(0, g_profstack, g_profstack_max, PROFANY);
 674         prof_recordheader(aTHX);
 675         DBG_TIMER_NOTIFY("Profiler timer is on.\n");
 676         g_orealtime = g_rprof_start = Times(&g_prof_start);
 677         g_otms_utime = g_prof_start.tms_utime;
 678         g_otms_stime = g_prof_start.tms_stime;
 679         PL_perldb = g_default_perldb;
 680     }