00d18ba917d9f361020b0fab864fb49721d0b03a
[p5sagit/p5-mst-13.2.git] / ext / threads / threads.xs
1 #define PERL_NO_GET_CONTEXT
2 #include "EXTERN.h"
3 #include "perl.h"
4 #include "XSUB.h"
5
6 #ifdef USE_ITHREADS
7
8 #ifdef WIN32
9 #include <windows.h>
10 #include <win32thread.h>
11 #define PERL_THREAD_SETSPECIFIC(k,v) TlsSetValue(k,v)
12 #define PERL_THREAD_GETSPECIFIC(k,v) v = TlsGetValue(k)
13 #define PERL_THREAD_ALLOC_SPECIFIC(k) \
14 STMT_START {\
15   if((k = TlsAlloc()) == TLS_OUT_OF_INDEXES) {\
16     PerlIO_printf(PerlIO_stderr(),"panic threads.h: TlsAlloc");\
17     exit(1);\
18   }\
19 } STMT_END
20 #else
21 #ifdef OS2
22 typedef perl_os_thread pthread_t;
23 #else
24 #include <pthread.h>
25 #endif
26 #include <thread.h>
27
28 #define PERL_THREAD_SETSPECIFIC(k,v) pthread_setspecific(k,v)
29 #ifdef OLD_PTHREADS_API
30 #define PERL_THREAD_DETACH(t) pthread_detach(&(t))
31 #define PERL_THREAD_GETSPECIFIC(k,v) pthread_getspecific(k,&v)
32 #define PERL_THREAD_ALLOC_SPECIFIC(k) STMT_START {\
33   if(pthread_keycreate(&(k),0)) {\
34     PerlIO_printf(PerlIO_stderr(), "panic threads.h: pthread_key_create");\
35     exit(1);\
36   }\
37 } STMT_END
38 #else
39 #define PERL_THREAD_DETACH(t) pthread_detach((t))
40 #define PERL_THREAD_GETSPECIFIC(k,v) v = pthread_getspecific(k)
41 #define PERL_THREAD_ALLOC_SPECIFIC(k) STMT_START {\
42   if(pthread_key_create(&(k),0)) {\
43     PerlIO_printf(PerlIO_stderr(), "panic threads.h: pthread_key_create");\
44     exit(1);\
45   }\
46 } STMT_END
47 #endif
48 #endif
49
50 /* Values for 'state' member */
51 #define PERL_ITHR_JOINABLE              0
52 #define PERL_ITHR_DETACHED              1
53 #define PERL_ITHR_FINISHED              4
54 #define PERL_ITHR_JOINED                2
55
56 typedef struct ithread_s {
57     struct ithread_s *next;     /* next thread in the list */
58     struct ithread_s *prev;     /* prev thread in the list */
59     PerlInterpreter *interp;    /* The threads interpreter */
60     I32 tid;                    /* threads module's thread id */
61     perl_mutex mutex;           /* mutex for updating things in this struct */
62     I32 count;                  /* how many SVs have a reference to us */
63     signed char state;          /* are we detached ? */
64     int gimme;                  /* Context of create */
65     SV* init_function;          /* Code to run */
66     SV* params;                 /* args to pass function */
67 #ifdef WIN32
68         DWORD   thr;            /* OS's idea if thread id */
69         HANDLE handle;          /* OS's waitable handle */
70 #else
71         pthread_t thr;          /* OS's handle for the thread */
72 #endif
73 } ithread;
74
75 ithread *threads;
76
77 /* Macros to supply the aTHX_ in an embed.h like manner */
78 #define ithread_join(thread)            Perl_ithread_join(aTHX_ thread)
79 #define ithread_DESTROY(thread)         Perl_ithread_DESTROY(aTHX_ thread)
80 #define ithread_CLONE(thread)           Perl_ithread_CLONE(aTHX_ thread)
81 #define ithread_detach(thread)          Perl_ithread_detach(aTHX_ thread)
82 #define ithread_tid(thread)             ((thread)->tid)
83 #define ithread_yield(thread)           (YIELD);
84
85 static perl_mutex create_destruct_mutex;  /* protects the creation and destruction of threads*/
86
87 I32 tid_counter = 0;
88 I32 known_threads = 0;
89 I32 active_threads = 0;
90 perl_key self_key;
91
92 /*
93  *  Clear up after thread is done with
94  */
95 void
96 Perl_ithread_destruct (pTHX_ ithread* thread, const char *why)
97 {
98         MUTEX_LOCK(&thread->mutex);
99         if (!thread->next) {
100             Perl_croak(aTHX_ "panic: destruct destroyed thread %p (%s)",thread, why);
101         }
102         if (thread->count != 0) {
103                 MUTEX_UNLOCK(&thread->mutex);
104                 return;
105         }
106         MUTEX_LOCK(&create_destruct_mutex);
107         /* Remove from circular list of threads */
108         if (thread->next == thread) {
109             /* last one should never get here ? */
110             threads = NULL;
111         }
112         else {
113             thread->next->prev = thread->prev;
114             thread->prev->next = thread->next;
115             if (threads == thread) {
116                 threads = thread->next;
117             }
118             thread->next = NULL;
119             thread->prev = NULL;
120         }
121         known_threads--;
122         assert( known_threads >= 0 );
123 #if 0
124         Perl_warn(aTHX_ "destruct %d @ %p by %p now %d",
125                   thread->tid,thread->interp,aTHX, known_threads);
126 #endif
127         MUTEX_UNLOCK(&create_destruct_mutex);
128         /* Thread is now disowned */
129
130         if(thread->interp) {
131             dTHXa(thread->interp);
132             ithread*        current_thread;
133             PERL_SET_CONTEXT(thread->interp);
134             PERL_THREAD_GETSPECIFIC(self_key,current_thread);
135             PERL_THREAD_SETSPECIFIC(self_key,thread);
136
137
138             
139             SvREFCNT_dec(thread->params);
140
141
142
143             thread->params = Nullsv;
144             perl_destruct(thread->interp);
145             perl_free(thread->interp);
146             thread->interp = NULL;
147             PERL_THREAD_SETSPECIFIC(self_key,current_thread);
148
149         }
150         MUTEX_UNLOCK(&thread->mutex);
151         MUTEX_DESTROY(&thread->mutex);
152         PerlMemShared_free(thread);
153
154         PERL_SET_CONTEXT(aTHX);
155 }
156
157 int
158 Perl_ithread_hook(pTHX)
159 {
160     int veto_cleanup = 0;
161     MUTEX_LOCK(&create_destruct_mutex);
162     if (aTHX == PL_curinterp && active_threads != 1) {
163         Perl_warn(aTHX_ "A thread exited while %" IVdf " other threads were still running",
164                                                 (IV)active_threads);
165         veto_cleanup = 1;
166     }
167     MUTEX_UNLOCK(&create_destruct_mutex);
168     return veto_cleanup;
169 }
170
171 void
172 Perl_ithread_detach(pTHX_ ithread *thread)
173 {
174     MUTEX_LOCK(&thread->mutex);
175     if (!(thread->state & (PERL_ITHR_DETACHED|PERL_ITHR_JOINED))) {
176         thread->state |= PERL_ITHR_DETACHED;
177 #ifdef WIN32
178         CloseHandle(thread->handle);
179         thread->handle = 0;
180 #else
181         PERL_THREAD_DETACH(thread->thr);
182 #endif
183     }
184     if ((thread->state & PERL_ITHR_FINISHED) &&
185         (thread->state & PERL_ITHR_DETACHED)) {
186         MUTEX_UNLOCK(&thread->mutex);
187         Perl_ithread_destruct(aTHX_ thread, "detach");
188     }
189     else {
190         MUTEX_UNLOCK(&thread->mutex);
191     }
192 }
193
194 /* MAGIC (in mg.h sense) hooks */
195
196 int
197 ithread_mg_get(pTHX_ SV *sv, MAGIC *mg)
198 {
199     ithread *thread = (ithread *) mg->mg_ptr;
200     SvIVX(sv) = PTR2IV(thread);
201     SvIOK_on(sv);
202     return 0;
203 }
204
205 int
206 ithread_mg_free(pTHX_ SV *sv, MAGIC *mg)
207 {
208     ithread *thread = (ithread *) mg->mg_ptr;
209     MUTEX_LOCK(&thread->mutex);
210     thread->count--;
211     if (thread->count == 0) {
212        if(thread->state & PERL_ITHR_FINISHED &&
213           (thread->state & PERL_ITHR_DETACHED ||
214            thread->state & PERL_ITHR_JOINED))
215        {
216             MUTEX_UNLOCK(&thread->mutex);
217             Perl_ithread_destruct(aTHX_ thread, "no reference");
218        }
219        else {
220             MUTEX_UNLOCK(&thread->mutex);
221        }    
222     }
223     else {
224         MUTEX_UNLOCK(&thread->mutex);
225     }
226     return 0;
227 }
228
229 int
230 ithread_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
231 {
232     ithread *thread = (ithread *) mg->mg_ptr;
233     MUTEX_LOCK(&thread->mutex);
234     thread->count++;
235     MUTEX_UNLOCK(&thread->mutex);
236     return 0;
237 }
238
239 MGVTBL ithread_vtbl = {
240  ithread_mg_get,        /* get */
241  0,                     /* set */
242  0,                     /* len */
243  0,                     /* clear */
244  ithread_mg_free,       /* free */
245  0,                     /* copy */
246  ithread_mg_dup         /* dup */
247 };
248
249
250 /*
251  *      Starts executing the thread. Needs to clean up memory a tad better.
252  *      Passed as the C level function to run in the new thread
253  */
254
255 #ifdef WIN32
256 THREAD_RET_TYPE
257 Perl_ithread_run(LPVOID arg) {
258 #else
259 void*
260 Perl_ithread_run(void * arg) {
261 #endif
262         ithread* thread = (ithread*) arg;
263         dTHXa(thread->interp);
264         PERL_SET_CONTEXT(thread->interp);
265         PERL_THREAD_SETSPECIFIC(self_key,thread);
266
267 #if 0
268         /* Far from clear messing with ->thr child-side is a good idea */
269         MUTEX_LOCK(&thread->mutex);
270 #ifdef WIN32
271         thread->thr = GetCurrentThreadId();
272 #else
273         thread->thr = pthread_self();
274 #endif
275         MUTEX_UNLOCK(&thread->mutex);
276 #endif
277
278         PL_perl_destruct_level = 2;
279
280         {
281                 AV* params = (AV*) SvRV(thread->params);
282                 I32 len = av_len(params)+1;
283                 int i;
284                 dSP;
285                 ENTER;
286                 SAVETMPS;
287                 PUSHMARK(SP);
288                 for(i = 0; i < len; i++) {
289                     XPUSHs(av_shift(params));
290                 }
291                 PUTBACK;
292                 len = call_sv(thread->init_function, thread->gimme|G_EVAL);
293
294                 SPAGAIN;
295                 for (i=len-1; i >= 0; i--) {
296                   SV *sv = POPs;
297                   av_store(params, i, SvREFCNT_inc(sv));
298                 }
299                 if (SvTRUE(ERRSV)) {
300                     Perl_warn(aTHX_ "thread failed to start: %" SVf, ERRSV);
301                 }
302                 FREETMPS;
303                 LEAVE;
304                 SvREFCNT_dec(thread->init_function);
305         }
306
307         PerlIO_flush((PerlIO*)NULL);
308         MUTEX_LOCK(&thread->mutex);
309         thread->state |= PERL_ITHR_FINISHED;
310
311         if (thread->state & PERL_ITHR_DETACHED) {
312                 MUTEX_UNLOCK(&thread->mutex);
313                 Perl_ithread_destruct(aTHX_ thread, "detached finish");
314         } else {
315                 MUTEX_UNLOCK(&thread->mutex);
316         }
317         MUTEX_LOCK(&create_destruct_mutex);
318         active_threads--;
319         assert( active_threads >= 0 );
320         MUTEX_UNLOCK(&create_destruct_mutex);
321
322 #ifdef WIN32
323         return (DWORD)0;
324 #else
325         return 0;
326 #endif
327 }
328
329 SV *
330 ithread_to_SV(pTHX_ SV *obj, ithread *thread, char *classname, bool inc)
331 {
332     SV *sv;
333     MAGIC *mg;
334     if (inc) {
335         MUTEX_LOCK(&thread->mutex);
336         thread->count++;
337         MUTEX_UNLOCK(&thread->mutex);
338     }
339     if (!obj)
340      obj = newSV(0);
341     sv = newSVrv(obj,classname);
342     sv_setiv(sv,PTR2IV(thread));
343     mg = sv_magicext(sv,Nullsv,PERL_MAGIC_shared_scalar,&ithread_vtbl,(char *)thread,0);
344     mg->mg_flags |= MGf_DUP;
345     SvREADONLY_on(sv);
346     return obj;
347 }
348
349 ithread *
350 SV_to_ithread(pTHX_ SV *sv)
351 {
352     ithread *thread;
353     if (SvROK(sv))
354      {
355       thread = INT2PTR(ithread*, SvIV(SvRV(sv)));
356      }
357     else
358      {
359       PERL_THREAD_GETSPECIFIC(self_key,thread);
360      }
361     return thread;
362 }
363
364 /*
365  * iThread->create(); ( aka iThread->new() )
366  * Called in context of parent thread
367  */
368
369 SV *
370 Perl_ithread_create(pTHX_ SV *obj, char* classname, SV* init_function, SV* params)
371 {
372         ithread*        thread;
373         CLONE_PARAMS    clone_param;
374         ithread*        current_thread;
375
376         SV**            tmps_tmp = PL_tmps_stack;
377         I32             tmps_ix  = PL_tmps_ix;
378
379         PERL_THREAD_GETSPECIFIC(self_key,current_thread);
380         MUTEX_LOCK(&create_destruct_mutex);
381         thread = PerlMemShared_malloc(sizeof(ithread));
382         Zero(thread,1,ithread);
383         thread->next = threads;
384         thread->prev = threads->prev;
385         threads->prev = thread;
386         thread->prev->next = thread;
387         /* Set count to 1 immediately in case thread exits before
388          * we return to caller !
389          */
390         thread->count = 1;
391         MUTEX_INIT(&thread->mutex);
392         thread->tid = tid_counter++;
393         thread->gimme = GIMME_V;
394
395         /* "Clone" our interpreter into the thread's interpreter
396          * This gives thread access to "static data" and code.
397          */
398
399         PerlIO_flush((PerlIO*)NULL);
400         PERL_THREAD_SETSPECIFIC(self_key,thread);
401
402
403
404 #ifdef WIN32
405         thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE | CLONEf_CLONE_HOST);
406 #else
407         thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE);
408 #endif
409         /* perl_clone leaves us in new interpreter's context.
410            As it is tricky to spot an implicit aTHX, create a new scope
411            with aTHX matching the context for the duration of
412            our work for new interpreter.
413          */
414         {
415             dTHXa(thread->interp);
416             /* Here we remove END blocks since they should only run
417                in the thread they are created
418             */
419             SvREFCNT_dec(PL_endav);
420             PL_endav = newAV();
421             clone_param.flags = 0;
422             thread->init_function = sv_dup(init_function, &clone_param);
423             if (SvREFCNT(thread->init_function) == 0) {
424                 SvREFCNT_inc(thread->init_function);
425             }
426             
427
428
429             thread->params = sv_dup(params, &clone_param);
430             SvREFCNT_inc(thread->params);
431
432
433             /* The code below checks that anything living on
434                the tmps stack and has been cloned (so it lives in the
435                ptr_table) has a refcount higher than 0
436
437                If the refcount is 0 it means that a something on the
438                stack/context was holding a reference to it and
439                since we init_stacks() in perl_clone that won't get
440                cleaned and we will get a leaked scalar.
441                The reason it was cloned was that it lived on the
442                @_ stack.
443
444                Example of this can be found in bugreport 15837
445                where calls in the parameter list end up as a temp
446
447                One could argue that this fix should be in perl_clone
448             */
449                
450
451             while (tmps_ix > 0) { 
452               SV* sv = (SV*)ptr_table_fetch(PL_ptr_table, tmps_tmp[tmps_ix]);
453               tmps_ix--;
454               if (sv && SvREFCNT(sv) == 0) {
455                 SvREFCNT_inc(sv);
456                 SvREFCNT_dec(sv);
457               }
458             }
459             
460
461
462             SvTEMP_off(thread->init_function);
463             ptr_table_free(PL_ptr_table);
464             PL_ptr_table = NULL;
465             PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
466         }
467         PERL_THREAD_SETSPECIFIC(self_key,current_thread);
468         PERL_SET_CONTEXT(aTHX);
469
470         /* Start the thread */
471
472 #ifdef WIN32
473
474         thread->handle = CreateThread(NULL, 0, Perl_ithread_run,
475                         (LPVOID)thread, 0, &thread->thr);
476
477 #else
478         {
479           static pthread_attr_t attr;
480           static int attr_inited = 0;
481           static int attr_joinable = PTHREAD_CREATE_JOINABLE;
482           if (!attr_inited) {
483             attr_inited = 1;
484             pthread_attr_init(&attr);
485           }
486 #  ifdef PTHREAD_ATTR_SETDETACHSTATE
487             PTHREAD_ATTR_SETDETACHSTATE(&attr, attr_joinable);
488 #  endif
489 #  ifdef THREAD_CREATE_NEEDS_STACK
490             if(pthread_attr_setstacksize(&attr, THREAD_CREATE_NEEDS_STACK))
491               croak("panic: pthread_attr_setstacksize failed");
492 #  endif
493
494 #ifdef OLD_PTHREADS_API
495           pthread_create( &thread->thr, attr, Perl_ithread_run, (void *)thread);
496 #else
497           pthread_create( &thread->thr, &attr, Perl_ithread_run, (void *)thread);
498 #endif
499         }
500 #endif
501         known_threads++;
502         active_threads++;
503         MUTEX_UNLOCK(&create_destruct_mutex);
504         sv_2mortal(params);
505
506         return ithread_to_SV(aTHX_ obj, thread, classname, FALSE);
507 }
508
509 SV*
510 Perl_ithread_self (pTHX_ SV *obj, char* Class)
511 {
512     ithread *thread;
513     PERL_THREAD_GETSPECIFIC(self_key,thread);
514     return ithread_to_SV(aTHX_ obj, thread, Class, TRUE);
515 }
516
517 /*
518  * Joins the thread this code needs to take the returnvalue from the
519  * call_sv and send it back
520  */
521
522 void
523 Perl_ithread_CLONE(pTHX_ SV *obj)
524 {
525  if (SvROK(obj))
526   {
527    ithread *thread = SV_to_ithread(aTHX_ obj);
528   }
529  else
530   {
531    Perl_warn(aTHX_ "CLONE %" SVf,obj);
532   }
533 }
534
535 AV*
536 Perl_ithread_join(pTHX_ SV *obj)
537 {
538     ithread *thread = SV_to_ithread(aTHX_ obj);
539     MUTEX_LOCK(&thread->mutex);
540     if (thread->state & PERL_ITHR_DETACHED) {
541         MUTEX_UNLOCK(&thread->mutex);
542         Perl_croak(aTHX_ "Cannot join a detached thread");
543     }
544     else if (thread->state & PERL_ITHR_JOINED) {
545         MUTEX_UNLOCK(&thread->mutex);
546         Perl_croak(aTHX_ "Thread already joined");
547     }
548     else {
549         AV* retparam;
550 #ifdef WIN32
551         DWORD waitcode;
552 #else
553         void *retval;
554 #endif
555         MUTEX_UNLOCK(&thread->mutex);
556 #ifdef WIN32
557         waitcode = WaitForSingleObject(thread->handle, INFINITE);
558 #else
559         pthread_join(thread->thr,&retval);
560 #endif
561         MUTEX_LOCK(&thread->mutex);
562         
563         /* sv_dup over the args */
564         {
565           ithread*        current_thread;
566           AV* params = (AV*) SvRV(thread->params);      
567           CLONE_PARAMS clone_params;
568           clone_params.stashes = newAV();
569           clone_params.flags |= CLONEf_JOIN_IN;
570           PL_ptr_table = ptr_table_new();
571           PERL_THREAD_GETSPECIFIC(self_key,current_thread);
572           PERL_THREAD_SETSPECIFIC(self_key,thread);
573
574 #if 0
575           {
576             I32 len = av_len(params)+1;
577             I32 i;
578             for(i = 0; i < len; i++) {
579               sv_dump(SvRV(AvARRAY(params)[i]));
580             }
581           }
582 #endif
583           retparam = (AV*) sv_dup((SV*)params, &clone_params);
584 #if 0
585           {
586             I32 len = av_len(retparam)+1;
587             I32 i;
588             for(i = 0; i < len; i++) {
589                 sv_dump(SvRV(AvARRAY(retparam)[i]));
590             }
591           }
592 #endif
593           PERL_THREAD_SETSPECIFIC(self_key,current_thread);
594           SvREFCNT_dec(clone_params.stashes);
595           SvREFCNT_inc(retparam);
596           ptr_table_free(PL_ptr_table);
597           PL_ptr_table = NULL;
598
599         }
600         /* We have finished with it */
601         thread->state |= PERL_ITHR_JOINED;
602         MUTEX_UNLOCK(&thread->mutex);
603         sv_unmagic(SvRV(obj),PERL_MAGIC_shared_scalar);
604         return retparam;
605     }
606     return (AV*)NULL;
607 }
608
609 void
610 Perl_ithread_DESTROY(pTHX_ SV *sv)
611 {
612     ithread *thread = SV_to_ithread(aTHX_ sv);
613     sv_unmagic(SvRV(sv),PERL_MAGIC_shared_scalar);
614 }
615
616 #endif /* USE_ITHREADS */
617
618 MODULE = threads                PACKAGE = threads       PREFIX = ithread_
619 PROTOTYPES: DISABLE
620
621 #ifdef USE_ITHREADS
622
623 void
624 ithread_new (classname, function_to_call, ...)
625 char *  classname
626 SV *    function_to_call
627 CODE:
628 {
629     AV* params = newAV();
630     if (items > 2) {
631         int i;
632         for(i = 2; i < items ; i++) {
633             av_push(params, SvREFCNT_inc(ST(i)));
634         }
635     }
636     ST(0) = sv_2mortal(Perl_ithread_create(aTHX_ Nullsv, classname, function_to_call, newRV_noinc((SV*) params)));
637     XSRETURN(1);
638 }
639
640 void
641 ithread_list(char *classname)
642 PPCODE:
643 {
644   ithread *curr_thread;
645   MUTEX_LOCK(&create_destruct_mutex);
646   curr_thread = threads;
647   if(curr_thread->tid != 0)     
648     PUSHs( sv_2mortal(ithread_to_SV(aTHX_ NULL, curr_thread, classname, TRUE)));
649   while(curr_thread) {
650     curr_thread = curr_thread->next;
651     if(curr_thread == threads)
652       break;
653     if(curr_thread->state & PERL_ITHR_DETACHED ||
654        curr_thread->state & PERL_ITHR_JOINED)
655          continue;
656      PUSHs( sv_2mortal(ithread_to_SV(aTHX_ NULL, curr_thread, classname, TRUE)));
657   }     
658   MUTEX_UNLOCK(&create_destruct_mutex);
659 }
660
661
662 void
663 ithread_self(char *classname)
664 CODE:
665 {
666         ST(0) = sv_2mortal(Perl_ithread_self(aTHX_ Nullsv,classname));
667         XSRETURN(1);
668 }
669
670 int
671 ithread_tid(ithread *thread)
672
673 void
674 ithread_join(SV *obj)
675 PPCODE:
676 {
677   AV* params = Perl_ithread_join(aTHX_ obj);
678   int i;
679   I32 len = AvFILL(params);
680   for (i = 0; i <= len; i++) {
681     SV* tmp = av_shift(params);
682     XPUSHs(tmp);
683     sv_2mortal(tmp);
684   }
685   SvREFCNT_dec(params);
686 }
687
688 void
689 yield(...)
690 CODE:
691 {
692     YIELD;
693 }
694         
695
696 void
697 ithread_detach(ithread *thread)
698
699 void
700 ithread_DESTROY(SV *thread)
701
702 #endif /* USE_ITHREADS */
703
704 BOOT:
705 {
706 #ifdef USE_ITHREADS
707         ithread* thread;
708         PL_perl_destruct_level = 2;
709         PERL_THREAD_ALLOC_SPECIFIC(self_key);
710         MUTEX_INIT(&create_destruct_mutex);
711         MUTEX_LOCK(&create_destruct_mutex);
712         PL_threadhook = &Perl_ithread_hook;
713         thread  = PerlMemShared_malloc(sizeof(ithread));
714         Zero(thread,1,ithread);
715         PL_perl_destruct_level = 2;
716         MUTEX_INIT(&thread->mutex);
717         threads = thread;
718         thread->next = thread;
719         thread->prev = thread;
720         thread->interp = aTHX;
721         thread->count  = 1;  /* imortal */
722         thread->tid = tid_counter++;
723         known_threads++;
724         active_threads++;
725         thread->state = 1;
726 #ifdef WIN32
727         thread->thr = GetCurrentThreadId();
728 #else
729         thread->thr = pthread_self();
730 #endif
731
732         PERL_THREAD_SETSPECIFIC(self_key,thread);
733         MUTEX_UNLOCK(&create_destruct_mutex);
734 #endif /* USE_ITHREADS */
735 }
736