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 /*#define DBG_SUB 1      */
   7 /*#define DBG_TIMER 1    */
   8
   9 #ifdef DBG_SUB
  10 #  define DBG_SUB_NOTIFY(A,B) warn(A, B)
  11 #else
  12 #  define DBG_SUB_NOTIFY(A,B)  /* nothing */
  13 #endif
  14
  15 #ifdef DBG_TIMER
  16 #  define DBG_TIMER_NOTIFY(A) warn(A)
  17 #else
  18 #  define DBG_TIMER_NOTIFY(A)  /* nothing */
  19 #endif
  20
  21 /* HZ == clock ticks per second */
  22 #ifdef VMS
  23 #  define HZ ((I32)CLK_TCK)
  24 #  define DPROF_HZ HZ
  25 #  include <starlet.h>  /* prototype for sys$gettim() */
  26 #  include <lib$routines.h>
  27 #  define Times(ptr) (dprof_times(aTHX_ ptr))
  28 #else
  29 #  ifndef HZ
  30 #    ifdef CLK_TCK
  31 #      define HZ ((I32)CLK_TCK)
  32 #    else
  33 #      define HZ 60
  34 #    endif
  35 #  endif
  36 #  ifdef OS2                            /* times() has significant overhead */
  37 #    define Times(ptr) (dprof_times(aTHX_ ptr))
  38 #    define INCL_DOSPROFILE
  39 #    define INCL_DOSERRORS
  40 #    include <os2.h>
  41 #    define toLongLong(arg) (*(long long*)&(arg))
  42 #    define DPROF_HZ g_dprof_ticks
  43 #  else
  44 #    define Times(ptr) (times(ptr))
  45 #    define DPROF_HZ HZ
  46 #  endif
  47 #endif
  48
  49 XS(XS_Devel__DProf_END);        /* used by prof_mark() */
  50
  51 /* Everything is built on times(2).  See its manpage for a description
  52  * of the timings.
  53  */
  54
  55 union prof_any {
  56         clock_t tms_utime;  /* cpu time spent in user space */
  57         clock_t tms_stime;  /* cpu time spent in system */
  58         clock_t realtime;   /* elapsed real time, in ticks */
  59         char *name;
  60         U32 id;
  61         opcode ptype;
  62 };
  63
  64 typedef union prof_any PROFANY;
  65
  66 typedef struct {
  67     U32         dprof_ticks;
  68     char*       out_file_name;  /* output file (defaults to tmon.out) */
  69     PerlIO*     fp;             /* pointer to tmon.out file */
  70     long        TIMES_LOCATION; /* Where in the file to store the time totals */
  71     int         SAVE_STACK;     /* How much data to buffer until end of run */
  72     int         prof_pid;       /* pid of profiled process */
  73     struct tms  prof_start;
  74     struct tms  prof_end;
  75     clock_t     rprof_start;    /* elapsed real time ticks */
  76     clock_t     rprof_end;
  77     clock_t     wprof_u;
  78     clock_t     wprof_s;
  79     clock_t     wprof_r;
  80     clock_t     otms_utime;
  81     clock_t     otms_stime;
  82     clock_t     orealtime;
  83     PROFANY*    profstack;
  84     int         profstack_max;
  85     int         profstack_ix;
  86     HV*         cv_hash;
  87     U32         total;
  88     U32         lastid;
  89     U32         default_perldb;
  90     U32         depth;
  91 #ifdef OS2
  92     ULONG       frequ;
  93     long long   start_cnt;
  94 #endif
  95 #ifdef PERL_IMPLICIT_CONTEXT
  96 #  define register
  97     pTHX;
  98 #  undef register
  99 #endif
 100 } prof_state_t;
 101
 102 prof_state_t g_prof_state;
 103
 104 #define g_dprof_ticks           g_prof_state.dprof_ticks
 105 #define g_out_file_name         g_prof_state.out_file_name
 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     STRLEN n_a;
 143
 144     if (!g_frequ) {
 145         if (CheckOSError(DosTmrQueryFreq(&g_frequ)))
 146             croak("DosTmrQueryFreq: %s", SvPV(perl_get_sv("!",TRUE),n_a));
 147         else
 148             g_frequ = g_frequ/DPROF_HZ; /* count per tick */
 149         if (CheckOSError(DosTmrQueryTime(&cnt)))
 150             croak("DosTmrQueryTime: %s",
 151                   SvPV(perl_get_sv("!",TRUE), n_a));
 152         g_start_cnt = toLongLong(cnt);
 153     }
 154
 155     if (CheckOSError(DosTmrQueryTime(&cnt)))
 156             croak("DosTmrQueryTime: %s", SvPV(perl_get_sv("!",TRUE), n_a));
 157     t->tms_stime = 0;
 158     return (t->tms_utime = (toLongLong(cnt) - g_start_cnt)/g_frequ);
 159 #else           /* !OS2 */
 160 #  ifdef VMS
 161     clock_t retval;
 162     /* Get wall time and convert to 10 ms intervals to
 163      * produce the return value dprof expects */
 164 #    if defined(__DECC) && defined (__ALPHA)
 165 #      include <ints.h>
 166     uint64 vmstime;
 167     _ckvmssts(sys$gettim(&vmstime));
 168     vmstime /= 100000;
 169     retval = vmstime & 0x7fffffff;
 170 #    else
 171     /* (Older hw or ccs don't have an atomic 64-bit type, so we
 172      * juggle 32-bit ints (and a float) to produce a time_t result
 173      * with minimal loss of information.) */
 174     long int vmstime[2],remainder,divisor = 100000;
 175     _ckvmssts(sys$gettim((unsigned long int *)vmstime));
 176     vmstime[1] &= 0x7fff;  /* prevent overflow in EDIV */
 177     _ckvmssts(lib$ediv(&divisor,vmstime,(long int *)&retval,&remainder));
 178 #    endif
 179     /* Fill in the struct tms using the CRTL routine . . .*/
 180     times((tbuffer_t *)t);
 181     return (clock_t) retval;
 182 #  else         /* !VMS && !OS2 */
 183     return times(t);
 184 #  endif
 185 #endif
 186 }
 187
 188 static void
 189 prof_dumpa(pTHX_ opcode ptype, U32 id)
 190 {
 191     if (ptype == OP_LEAVESUB) {
 192         PerlIO_printf(g_fp,"- %"UVxf"\n", (UV)id);
 193     }
 194     else if(ptype == OP_ENTERSUB) {
 195         PerlIO_printf(g_fp,"+ %"UVxf"\n", (UV)id);
 196     }
 197     else if(ptype == OP_GOTO) {
 198         PerlIO_printf(g_fp,"* %"UVxf"\n", (UV)id);
 199     }
 200     else if(ptype == OP_DIE) {
 201         PerlIO_printf(g_fp,"/ %"UVxf"\n", (UV)id);
 202     }
 203     else {
 204         PerlIO_printf(g_fp,"Profiler unknown prof code %d\n", ptype);
 205     }
 206 }
 207
 208 static void
 209 prof_dumps(pTHX_ U32 id, char *pname, char *gname)
 210 {
 211     PerlIO_printf(g_fp,"& %"UVxf" %s %s\n", (UV)id, pname, gname);
 212 }
 213
 214 static void
 215 prof_dumpt(pTHX_ long tms_utime, long tms_stime, long realtime)
 216 {
 217     PerlIO_printf(g_fp,"@ %ld %ld %ld\n", tms_utime, tms_stime, realtime);
 218 }
 219
 220 static void
 221 prof_dump_until(pTHX_ long ix)
 222 {
 223     long base = 0;
 224     struct tms t1, t2;
 225     clock_t realtime1, realtime2;
 226
 227     realtime1 = Times(&t1);
 228
 229     while (base < ix) {
 230         opcode ptype = g_profstack[base++].ptype;
 231         if (ptype == OP_TIME) {
 232             long tms_utime = g_profstack[base++].tms_utime;
 233             long tms_stime = g_profstack[base++].tms_stime;
 234             long realtime = g_profstack[base++].realtime;
 235
 236             prof_dumpt(aTHX_ tms_utime, tms_stime, realtime);
 237         }
 238         else if (ptype == OP_GV) {
 239             U32 id = g_profstack[base++].id;
 240             char *pname = g_profstack[base++].name;
 241             char *gname = g_profstack[base++].name;
 242
 243             prof_dumps(aTHX_ id, pname, gname);
 244         }
 245         else {
 246             U32 id = g_profstack[base++].id;
 247             prof_dumpa(aTHX_ ptype, id);
 248         }
 249     }
 250     PerlIO_flush(g_fp);
 251     realtime2 = Times(&t2);
 252     if (realtime2 != realtime1 || t1.tms_utime != t2.tms_utime
 253         || t1.tms_stime != t2.tms_stime) {
 254         g_wprof_r += realtime2 - realtime1;
 255         g_wprof_u += t2.tms_utime - t1.tms_utime;
 256         g_wprof_s += t2.tms_stime - t1.tms_stime;
 257
 258         PerlIO_printf(g_fp,"+ & Devel::DProf::write\n");
 259         PerlIO_printf(g_fp,"@ %"IVdf" %"IVdf" %"IVdf"\n",
 260                       /* The (IV) casts are one possibility:
 261                        * the Painfully Correct Way would be to
 262                        * have Clock_t_f. */
 263                       (IV)(t2.tms_utime - t1.tms_utime),
 264                       (IV)(t2.tms_stime - t1.tms_stime),
 265                       (IV)(realtime2 - realtime1));
 266         PerlIO_printf(g_fp,"- & Devel::DProf::write\n");
 267         g_otms_utime = t2.tms_utime;
 268         g_otms_stime = t2.tms_stime;
 269         g_orealtime = realtime2;
 270         PerlIO_flush(g_fp);
 271     }
 272 }
 273
 274 static void
 275 prof_mark(pTHX_ opcode ptype)
 276 {
 277     struct tms t;
 278     clock_t realtime, rdelta, udelta, sdelta;
 279     char *name, *pv;
 280     char *hvname;
 281     STRLEN len;
 282     SV *sv;
 283     U32 id;
 284     SV *Sub = GvSV(PL_DBsub);   /* name of current sub */
 285
 286     if (g_SAVE_STACK) {
 287         if (g_profstack_ix + 5 > g_profstack_max) {
 288                 g_profstack_max = g_profstack_max * 3 / 2;
 289                 Renew(g_profstack, g_profstack_max, PROFANY);
 290         }
 291     }
 292
 293     realtime = Times(&t);
 294     rdelta = realtime - g_orealtime;
 295     udelta = t.tms_utime - g_otms_utime;
 296     sdelta = t.tms_stime - g_otms_stime;
 297     if (rdelta || udelta || sdelta) {
 298         if (g_SAVE_STACK) {
 299             g_profstack[g_profstack_ix++].ptype = OP_TIME;
 300             g_profstack[g_profstack_ix++].tms_utime = udelta;
 301             g_profstack[g_profstack_ix++].tms_stime = sdelta;
 302             g_profstack[g_profstack_ix++].realtime = rdelta;
 303         }
 304         else { /* Write it to disk now so's not to eat up core */
 305             if (g_prof_pid == (int)getpid()) {
 306                 prof_dumpt(aTHX_ udelta, sdelta, rdelta);
 307                 PerlIO_flush(g_fp);
 308             }
 309         }
 310         g_orealtime = realtime;
 311         g_otms_stime = t.tms_stime;
 312         g_otms_utime = t.tms_utime;
 313     }
 314
 315     {
 316         SV **svp;
 317         char *gname, *pname;
 318         CV *cv;
 319
 320         cv = INT2PTR(CV*,SvIVX(Sub));
 321         svp = hv_fetch(g_cv_hash, (char*)&cv, sizeof(CV*), TRUE);
 322         if (!SvOK(*svp)) {
 323             GV *gv = CvGV(cv);
 324
 325             sv_setiv(*svp, id = ++g_lastid);
 326             pname = ((GvSTASH(gv) && HvNAME(GvSTASH(gv)))
 327                      ? HvNAME(GvSTASH(gv))
 328                      : "(null)");
 329             gname = GvNAME(gv);
 330             if (CvXSUB(cv) == XS_Devel__DProf_END)
 331                 return;
 332             if (g_SAVE_STACK) { /* Store it for later recording  -JH */
 333                 g_profstack[g_profstack_ix++].ptype = OP_GV;
 334                 g_profstack[g_profstack_ix++].id = id;
 335                 g_profstack[g_profstack_ix++].name = pname;
 336                 g_profstack[g_profstack_ix++].name = gname;
 337             }
 338             else { /* Write it to disk now so's not to eat up core */
 339                 /* Only record the parent's info */
 340                 if (g_prof_pid == (int)getpid()) {
 341                     prof_dumps(aTHX_ id, pname, gname);
 342                     PerlIO_flush(g_fp);
 343                 }
 344                 else
 345                     PL_perldb = 0;              /* Do not debug the kid. */
 346             }
 347         }
 348         else {
 349             id = SvIV(*svp);
 350         }
 351     }
 352
 353     g_total++;
 354     if (g_SAVE_STACK) { /* Store it for later recording  -JH */
 355         g_profstack[g_profstack_ix++].ptype = ptype;
 356         g_profstack[g_profstack_ix++].id = id;
 357
 358         /* Only record the parent's info */
 359         if (g_SAVE_STACK < g_profstack_ix) {
 360             if (g_prof_pid == (int)getpid())
 361                 prof_dump_until(aTHX_ g_profstack_ix);
 362             else
 363                 PL_perldb = 0;          /* Do not debug the kid. */
 364             g_profstack_ix = 0;
 365         }
 366     }
 367     else { /* Write it to disk now so's not to eat up core */
 368
 369         /* Only record the parent's info */
 370         if (g_prof_pid == (int)getpid()) {
 371             prof_dumpa(aTHX_ ptype, id);
 372             PerlIO_flush(g_fp);
 373         }
 374         else
 375             PL_perldb = 0;              /* Do not debug the kid. */
 376     }
 377 }
 378
 379 #ifdef PL_NEEDED
 380 #  define defstash PL_defstash
 381 #endif
 382
 383 /* Counts overhead of prof_mark and extra XS call. */
 384 static void
 385 test_time(pTHX_ clock_t *r, clock_t *u, clock_t *s)
 386 {
 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 = PTR2UV(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_nolen(Sub));
 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_nolen(Sub));
 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             buffer = getenv("PERL_DPROF_OUT_FILE_NAME");
 666             g_out_file_name = savepv(buffer ? buffer : "tmon.out");
 667         }
 668
 669         if ((g_fp = PerlIO_open(g_out_file_name, "w")) == NULL)
 670             croak("DProf: unable to write '%s', errno = %d\n",
 671                   g_out_file_name, errno);
 672
 673         g_default_perldb = PERLDBf_NONAME | PERLDBf_SUB | PERLDBf_GOTO;
 674         g_cv_hash = newHV();
 675         g_prof_pid = (int)getpid();
 676
 677         New(0, g_profstack, g_profstack_max, PROFANY);
 678         prof_recordheader(aTHX);
 679         DBG_TIMER_NOTIFY("Profiler timer is on.\n");
 680         g_orealtime = g_rprof_start = Times(&g_prof_start);
 681         g_otms_utime = g_prof_start.tms_utime;
 682         g_otms_stime = g_prof_start.tms_stime;
 683         PL_perldb = g_default_perldb;
 684     }