This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
83dca9325769d9423b2209357a5d0b00677e865b
[perl5.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 WIN32
7 #include <windows.h>
8 #include <win32thread.h>
9 #define PERL_THREAD_SETSPECIFIC(k,v) TlsSetValue(k,v)
10 #define PERL_THREAD_GETSPECIFIC(k,v) v = TlsGetValue(k)
11 #define PERL_THREAD_ALLOC_SPECIFIC(k) \
12 STMT_START {\
13   if((k = TlsAlloc()) == TLS_OUT_OF_INDEXES) {\
14     PerlIO_printf(PerlIO_stderr(),"panic threads.h: TlsAlloc");\
15     exit(1);\
16   }\
17 } STMT_END
18 #else
19 #include <pthread.h>
20 #include <thread.h>
21
22 #define PERL_THREAD_SETSPECIFIC(k,v) pthread_setspecific(k,v)
23 #ifdef OLD_PTHREADS_API
24 #define PERL_THREAD_DETACH(t) pthread_detach(&(t))
25 #define PERL_THREAD_GETSPECIFIC(k,v) pthread_getspecific(k,&v)
26 #define PERL_THREAD_ALLOC_SPECIFIC(k) STMT_START {\
27   if(pthread_keycreate(&(k),0)) {\
28     PerlIO_printf(PerlIO_stderr(), "panic threads.h: pthread_key_create");\
29     exit(1);\
30   }\
31 } STMT_END
32 #else
33 #define PERL_THREAD_DETACH(t) pthread_detach((t))
34 #define PERL_THREAD_GETSPECIFIC(k,v) v = pthread_getspecific(k)
35 #define PERL_THREAD_ALLOC_SPECIFIC(k) STMT_START {\
36   if(pthread_key_create(&(k),0)) {\
37     PerlIO_printf(PerlIO_stderr(), "panic threads.h: pthread_key_create");\
38     exit(1);\
39   }\
40 } STMT_END
41 #endif
42 #endif
43
44 typedef struct ithread_s {
45     struct ithread_s *next;     /* next thread in the list */
46     struct ithread_s *prev;     /* prev thread in the list */
47     PerlInterpreter *interp;    /* The threads interpreter */
48     I32 tid;                    /* threads module's thread id */
49     perl_mutex mutex;           /* mutex for updating things in this struct */
50     I32 count;                  /* how many SVs have a reference to us */
51     signed char detached;       /* are we detached ? */
52     int gimme;                  /* Context of create */
53     SV* init_function;          /* Code to run */
54     SV* params;                 /* args to pass function */
55 #ifdef WIN32
56         DWORD   thr;            /* OS's idea if thread id */
57         HANDLE handle;          /* OS's waitable handle */
58 #else
59         pthread_t thr;          /* OS's handle for the thread */
60 #endif
61 } ithread;
62
63 ithread *threads;
64
65 /* Macros to supply the aTHX_ in an embed.h like manner */
66 #define ithread_join(thread)            Perl_ithread_join(aTHX_ thread)
67 #define ithread_DESTROY(thread)         Perl_ithread_DESTROY(aTHX_ thread)
68 #define ithread_CLONE(thread)           Perl_ithread_CLONE(aTHX_ thread)
69 #define ithread_detach(thread)          Perl_ithread_detach(aTHX_ thread)
70 #define ithread_tid(thread)             ((thread)->tid)
71
72 static perl_mutex create_mutex;  /* protects the creation of threads ??? */
73
74 I32 tid_counter = 0;
75
76 perl_key self_key;
77
78 /*
79  *  Clear up after thread is done with
80  */
81 void
82 Perl_ithread_destruct (pTHX_ ithread* thread)
83 {
84         MUTEX_LOCK(&thread->mutex);
85         if (thread->count != 0) {
86                 MUTEX_UNLOCK(&thread->mutex);
87                 return;
88         }
89         MUTEX_LOCK(&create_mutex);
90         /* Remove from circular list of threads */
91         if (thread->next == thread) {
92             /* last one should never get here ? */
93             threads = NULL;
94         }
95         else {
96             thread->next->prev = thread->prev->next;
97             thread->prev->next = thread->next->prev;
98             if (threads == thread) {
99                 threads = thread->next;
100             }
101         }
102         MUTEX_UNLOCK(&create_mutex);
103         /* Thread is now disowned */
104 #if 0
105         Perl_warn(aTHX_ "destruct %d @ %p by %p",
106                   thread->tid,thread->interp,aTHX);
107 #endif
108         if (thread->interp) {
109             dTHXa(thread->interp);
110             PERL_SET_CONTEXT(thread->interp);
111             perl_destruct(thread->interp);
112             perl_free(thread->interp);
113             thread->interp = NULL;
114         }
115         PERL_SET_CONTEXT(aTHX);
116         MUTEX_UNLOCK(&thread->mutex);
117 }
118
119
120 /* MAGIC (in mg.h sense) hooks */
121
122 int
123 ithread_mg_get(pTHX_ SV *sv, MAGIC *mg)
124 {
125     ithread *thread = (ithread *) mg->mg_ptr;
126     SvIVX(sv) = PTR2IV(thread);
127     SvIOK_on(sv);
128     return 0;
129 }
130
131 int
132 ithread_mg_free(pTHX_ SV *sv, MAGIC *mg)
133 {
134     ithread *thread = (ithread *) mg->mg_ptr;
135     MUTEX_LOCK(&thread->mutex);
136     thread->count--;
137     MUTEX_UNLOCK(&thread->mutex);
138     /* This is safe as it re-checks count */
139     Perl_ithread_destruct(aTHX_ thread);
140     return 0;
141 }
142
143 int
144 ithread_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param)
145 {
146     ithread *thread = (ithread *) mg->mg_ptr;
147     MUTEX_LOCK(&thread->mutex);
148     thread->count++;
149     MUTEX_UNLOCK(&thread->mutex);
150     return 0;
151 }
152
153 MGVTBL ithread_vtbl = {
154  ithread_mg_get,        /* get */
155  0,                     /* set */
156  0,                     /* len */
157  0,                     /* clear */
158  ithread_mg_free,       /* free */
159  0,                     /* copy */
160  ithread_mg_dup         /* dup */
161 };
162
163
164 /*
165  *      Starts executing the thread. Needs to clean up memory a tad better.
166  *      Passed as the C level function to run in the new thread
167  */
168
169 #ifdef WIN32
170 THREAD_RET_TYPE
171 Perl_ithread_run(LPVOID arg) {
172 #else
173 void*
174 Perl_ithread_run(void * arg) {
175 #endif
176         ithread* thread = (ithread*) arg;
177         dTHXa(thread->interp);
178         PERL_SET_CONTEXT(thread->interp);
179         PERL_THREAD_SETSPECIFIC(self_key,thread);
180
181 #if 0
182         /* Far from clear messing with ->thr child-side is a good idea */
183         MUTEX_LOCK(&thread->mutex);
184 #ifdef WIN32
185         thread->thr = GetCurrentThreadId();
186 #else
187         thread->thr = pthread_self();
188 #endif
189         MUTEX_UNLOCK(&thread->mutex);
190 #endif
191
192         PL_perl_destruct_level = 2;
193
194         {
195                 AV* params = (AV*) SvRV(thread->params);
196                 I32 len = av_len(params)+1;
197                 int i;
198                 dSP;
199                 ENTER;
200                 SAVETMPS;
201                 PUSHMARK(SP);
202                 for(i = 0; i < len; i++) {
203                     XPUSHs(av_shift(params));
204                 }
205                 PUTBACK;
206                 len = call_sv(thread->init_function, thread->gimme|G_EVAL);
207                 SPAGAIN;
208                 for (i=len-1; i >= 0; i--) {
209                   SV *sv = POPs;
210                   av_store(params, i, SvREFCNT_inc(sv));
211                 }
212                 PUTBACK;
213                 if (SvTRUE(ERRSV)) {
214                     Perl_warn(aTHX_ "Died:%_",ERRSV);
215                 }
216                 FREETMPS;
217                 LEAVE;
218                 SvREFCNT_dec(thread->init_function);
219         }
220
221         PerlIO_flush((PerlIO*)NULL);
222         MUTEX_LOCK(&thread->mutex);
223         if (thread->detached & 1) {
224                 MUTEX_UNLOCK(&thread->mutex);
225                 SvREFCNT_dec(thread->params);
226                 thread->params = Nullsv;
227                 Perl_ithread_destruct(aTHX_ thread);
228         } else {
229                 thread->detached |= 4;
230                 MUTEX_UNLOCK(&thread->mutex);
231         }
232 #ifdef WIN32
233         return (DWORD)0;
234 #else
235         return 0;
236 #endif
237 }
238
239 SV *
240 ithread_to_SV(pTHX_ SV *obj, ithread *thread, char *classname, bool inc)
241 {
242     SV *sv;
243     MAGIC *mg;
244     if (inc) {
245         MUTEX_LOCK(&thread->mutex);
246         thread->count++;
247         MUTEX_UNLOCK(&thread->mutex);
248     }
249     if (!obj)
250      obj = newSV(0);
251     sv = newSVrv(obj,classname);
252     sv_setiv(sv,PTR2IV(thread));
253     mg = sv_magicext(sv,Nullsv,PERL_MAGIC_shared_scalar,&ithread_vtbl,(char *)thread,0);
254     mg->mg_flags |= MGf_DUP;
255     SvREADONLY_on(sv);
256     return obj;
257 }
258
259 ithread *
260 SV_to_ithread(pTHX_ SV *sv)
261 {
262     ithread *thread;
263     if (SvROK(sv))
264      {
265       thread = INT2PTR(ithread*, SvIV(SvRV(sv)));
266      }
267     else
268      {
269       PERL_THREAD_GETSPECIFIC(self_key,thread);
270      }
271     return thread;
272 }
273
274 /*
275  * iThread->create(); ( aka iThread->new() )
276  * Called in context of parent thread
277  */
278
279 SV *
280 Perl_ithread_create(pTHX_ SV *obj, char* classname, SV* init_function, SV* params)
281 {
282         ithread*        thread;
283         CLONE_PARAMS    clone_param;
284
285         MUTEX_LOCK(&create_mutex);
286         thread = PerlMemShared_malloc(sizeof(ithread));
287         Zero(thread,1,ithread);
288         thread->next = threads;
289         thread->prev = threads->prev;
290         thread->prev->next = thread;
291         /* Set count to 1 immediately in case thread exits before
292          * we return to caller !
293          */
294         thread->count = 1;
295         MUTEX_INIT(&thread->mutex);
296         thread->tid = tid_counter++;
297         thread->gimme = GIMME_V;
298         thread->detached = (thread->gimme == G_VOID) ? 1 : 0;
299
300         /* "Clone" our interpreter into the thread's interpreter
301          * This gives thread access to "static data" and code.
302          */
303
304         PerlIO_flush((PerlIO*)NULL);
305
306 #ifdef WIN32
307         thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE | CLONEf_CLONE_HOST);
308 #else
309         thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE);
310 #endif
311         /* perl_clone leaves us in new interpreter's context.
312            As it is tricky to spot implcit aTHX create a new scope
313            with aTHX matching the context for the duration of
314            our work for new interpreter.
315          */
316         {
317             dTHXa(thread->interp);
318
319             clone_param.flags = 0;
320             thread->init_function = sv_dup(init_function, &clone_param);
321             if (SvREFCNT(thread->init_function) == 0) {
322                 SvREFCNT_inc(thread->init_function);
323             }
324
325             thread->params = sv_dup(params, &clone_param);
326             SvREFCNT_inc(thread->params);
327             SvTEMP_off(thread->init_function);
328             ptr_table_free(PL_ptr_table);
329             PL_ptr_table = NULL;
330         }
331
332         PERL_SET_CONTEXT(aTHX);
333
334         /* Start the thread */
335
336 #ifdef WIN32
337
338         thread->handle = CreateThread(NULL, 0, Perl_ithread_run,
339                         (LPVOID)thread, 0, &thread->thr);
340
341 #else
342         {
343           static pthread_attr_t attr;
344           static int attr_inited = 0;
345           sigset_t fullmask, oldmask;
346           static int attr_joinable = PTHREAD_CREATE_JOINABLE;
347           if (!attr_inited) {
348             attr_inited = 1;
349             pthread_attr_init(&attr);
350           }
351 #  ifdef PTHREAD_ATTR_SETDETACHSTATE
352             PTHREAD_ATTR_SETDETACHSTATE(&attr, attr_joinable);
353 #  endif
354 #  ifdef THREAD_CREATE_NEEDS_STACK
355             if(pthread_attr_setstacksize(&attr, THREAD_CREATE_NEEDS_STACK))
356               croak("panic: pthread_attr_setstacksize failed");
357 #  endif
358
359 #ifdef OLD_PTHREADS_API
360           pthread_create( &thread->thr, attr, Perl_ithread_run, (void *)thread);
361 #else
362           pthread_create( &thread->thr, &attr, Perl_ithread_run, (void *)thread);
363 #endif
364         }
365 #endif
366         MUTEX_UNLOCK(&create_mutex);
367         return ithread_to_SV(aTHX_ obj, thread, classname, FALSE);
368 }
369
370 SV*
371 Perl_ithread_self (pTHX_ SV *obj, char* Class)
372 {
373     ithread *thread;
374     PERL_THREAD_GETSPECIFIC(self_key,thread);
375     return ithread_to_SV(aTHX_ obj, thread, Class, TRUE);
376 }
377
378 /*
379  * Joins the thread this code needs to take the returnvalue from the
380  * call_sv and send it back
381  */
382
383 void
384 Perl_ithread_CLONE(pTHX_ SV *obj)
385 {
386  if (SvROK(obj))
387   {
388    ithread *thread = SV_to_ithread(aTHX_ obj);
389   }
390  else
391   {
392    Perl_warn(aTHX_ "CLONE %_",obj);
393   }
394 }
395
396 AV* 
397 Perl_ithread_join(pTHX_ SV *obj)
398 {
399     ithread *thread = SV_to_ithread(aTHX_ obj);
400     MUTEX_LOCK(&thread->mutex);
401     if (thread->detached & 1) {
402         MUTEX_UNLOCK(&thread->mutex);
403         Perl_croak(aTHX_ "Cannot join a detached thread");
404     }
405     else if (thread->detached & 2) {
406         MUTEX_UNLOCK(&thread->mutex);
407         Perl_croak(aTHX_ "Thread already joined");
408     }
409     else {
410         AV* retparam;
411 #ifdef WIN32
412         DWORD waitcode;
413 #else
414         void *retval;
415 #endif
416         MUTEX_UNLOCK(&thread->mutex);
417 #ifdef WIN32
418         waitcode = WaitForSingleObject(thread->handle, INFINITE);
419 #else
420         pthread_join(thread->thr,&retval);
421 #endif
422         MUTEX_LOCK(&thread->mutex);
423         
424         {
425           AV* params = (AV*) SvRV(thread->params);        
426           CLONE_PARAMS clone_params;
427           clone_params.stashes = newAV();
428           PL_ptr_table = ptr_table_new();
429           retparam = (AV*) sv_dup((SV*)params, &clone_params);
430           SvREFCNT_dec(clone_params.stashes);
431           SvREFCNT_inc(retparam);
432           ptr_table_free(PL_ptr_table);
433           PL_ptr_table = NULL;
434
435         }
436         /* sv_dup over the args */
437         /* We have finished with it */
438         thread->detached |= 2;
439         MUTEX_UNLOCK(&thread->mutex);
440         sv_unmagic(SvRV(obj),PERL_MAGIC_shared_scalar);
441         Perl_ithread_destruct(aTHX_ thread);
442         return retparam;
443     }
444     return (AV*)NULL;
445 }
446
447 void
448 Perl_ithread_detach(pTHX_ ithread *thread)
449 {
450     MUTEX_LOCK(&thread->mutex);
451     if (!thread->detached) {
452         thread->detached = 1;
453 #ifdef WIN32
454         CloseHandle(thread->handle);
455         thread->handle = 0;
456 #else
457         PERL_THREAD_DETACH(thread->thr);
458 #endif
459     }
460     MUTEX_UNLOCK(&thread->mutex);
461 }
462
463
464 void
465 Perl_ithread_DESTROY(pTHX_ SV *sv)
466 {
467     ithread *thread = SV_to_ithread(aTHX_ sv);
468     sv_unmagic(SvRV(sv),PERL_MAGIC_shared_scalar);
469 }
470
471
472
473 MODULE = threads                PACKAGE = threads       PREFIX = ithread_
474 PROTOTYPES: DISABLE
475
476 void
477 ithread_new (classname, function_to_call, ...)
478 char *  classname
479 SV *    function_to_call
480 CODE:
481 {
482     AV* params = newAV();
483     if (items > 2) {
484         int i;
485         for(i = 2; i < items ; i++) {
486             av_push(params, ST(i));
487         }
488     }
489     ST(0) = sv_2mortal(Perl_ithread_create(aTHX_ Nullsv, classname, function_to_call, newRV_noinc((SV*) params)));
490     XSRETURN(1);
491 }
492
493 void
494 ithread_self(char *classname)
495 CODE:
496 {
497         ST(0) = sv_2mortal(Perl_ithread_self(aTHX_ Nullsv,classname));
498         XSRETURN(1);
499 }
500
501 int
502 ithread_tid(ithread *thread)
503
504 void
505 ithread_join(SV *obj)
506 PPCODE:
507 {
508   AV* params = Perl_ithread_join(aTHX_ obj);
509   int i;
510   I32 len = AvFILL(params);
511   for (i = 0; i <= len; i++) {
512     XPUSHs(av_shift(params));
513   }
514   SvREFCNT_dec(params);
515 }
516
517
518 void
519 ithread_detach(ithread *thread)
520
521 void
522 ithread_DESTROY(SV *thread)
523
524 BOOT:
525 {
526         ithread* thread;
527         PL_perl_destruct_level = 2;
528         PERL_THREAD_ALLOC_SPECIFIC(self_key);
529         MUTEX_INIT(&create_mutex);
530         MUTEX_LOCK(&create_mutex);
531         thread  = PerlMemShared_malloc(sizeof(ithread));
532         Zero(thread,1,ithread);
533         PL_perl_destruct_level = 2;
534         MUTEX_INIT(&thread->mutex);
535         threads = thread;
536         thread->next = thread;
537         thread->prev = thread;
538         thread->interp = aTHX;
539         thread->count  = 1;  /* imortal */
540         thread->tid = tid_counter++;
541         thread->detached = 1;
542 #ifdef WIN32
543         thread->thr = GetCurrentThreadId();
544 #else
545         thread->thr = pthread_self();
546 #endif
547         PERL_THREAD_SETSPECIFIC(self_key,thread);
548         MUTEX_UNLOCK(&create_mutex);
549 }
550