This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
make threads use MY_CXT API rather than using PL_modglobal
[perl5.git] / ext / threads / threads.xs
index 0e19923..d19e425 100755 (executable)
@@ -5,44 +5,28 @@
 
 #ifdef USE_ITHREADS
 
+
 #ifdef WIN32
 #include <windows.h>
 #include <win32thread.h>
-#define PERL_THREAD_SETSPECIFIC(k,v) TlsSetValue(k,v)
-#define PERL_THREAD_GETSPECIFIC(k,v) v = TlsGetValue(k)
-#define PERL_THREAD_ALLOC_SPECIFIC(k) \
-STMT_START {\
-  if((k = TlsAlloc()) == TLS_OUT_OF_INDEXES) {\
-    PerlIO_printf(PerlIO_stderr(),"panic threads.h: TlsAlloc");\
-    exit(1);\
-  }\
-} STMT_END
+#else
+#ifdef OS2
+typedef perl_os_thread pthread_t;
 #else
 #include <pthread.h>
+#endif
 #include <thread.h>
-
 #define PERL_THREAD_SETSPECIFIC(k,v) pthread_setspecific(k,v)
 #ifdef OLD_PTHREADS_API
 #define PERL_THREAD_DETACH(t) pthread_detach(&(t))
-#define PERL_THREAD_GETSPECIFIC(k,v) pthread_getspecific(k,&v)
-#define PERL_THREAD_ALLOC_SPECIFIC(k) STMT_START {\
-  if(pthread_keycreate(&(k),0)) {\
-    PerlIO_printf(PerlIO_stderr(), "panic threads.h: pthread_key_create");\
-    exit(1);\
-  }\
-} STMT_END
 #else
 #define PERL_THREAD_DETACH(t) pthread_detach((t))
-#define PERL_THREAD_GETSPECIFIC(k,v) v = pthread_getspecific(k)
-#define PERL_THREAD_ALLOC_SPECIFIC(k) STMT_START {\
-  if(pthread_key_create(&(k),0)) {\
-    PerlIO_printf(PerlIO_stderr(), "panic threads.h: pthread_key_create");\
-    exit(1);\
-  }\
-} STMT_END
-#endif
+#endif  /* OLD_PTHREADS_API */
 #endif
 
+
+
+
 /* Values for 'state' member */
 #define PERL_ITHR_JOINABLE             0
 #define PERL_ITHR_DETACHED             1
@@ -50,16 +34,16 @@ STMT_START {\
 #define PERL_ITHR_JOINED               2
 
 typedef struct ithread_s {
-    struct ithread_s *next;    /* next thread in the list */
-    struct ithread_s *prev;    /* prev thread in the list */
+    struct ithread_s *next;    /* Next thread in the list */
+    struct ithread_s *prev;    /* Prev thread in the list */
     PerlInterpreter *interp;   /* The threads interpreter */
-    I32 tid;                   /* threads module's thread id */
-    perl_mutex mutex;          /* mutex for updating things in this struct */
-    I32 count;                 /* how many SVs have a reference to us */
-    signed char state;         /* are we detached ? */
+    I32 tid;                   /* Threads module's thread id */
+    perl_mutex mutex;          /* Mutex for updating things in this struct */
+    I32 count;                 /* How many SVs have a reference to us */
+    signed char state;         /* Are we detached ? */
     int gimme;                 /* Context of create */
     SV* init_function;          /* Code to run */
-    SV* params;                 /* args to pass function */
+    SV* params;                 /* Args to pass function */
 #ifdef WIN32
        DWORD   thr;            /* OS's idea if thread id */
        HANDLE handle;          /* OS's waitable handle */
@@ -68,6 +52,15 @@ typedef struct ithread_s {
 #endif
 } ithread;
 
+#define MY_CXT_KEY "threads::_guts" XS_VERSION
+
+typedef struct {
+    ithread *thread;
+} my_cxt_t;
+
+START_MY_CXT
+
+
 ithread *threads;
 
 /* Macros to supply the aTHX_ in an embed.h like manner */
@@ -83,16 +76,66 @@ static perl_mutex create_destruct_mutex;  /* protects the creation and destructi
 I32 tid_counter = 0;
 I32 known_threads = 0;
 I32 active_threads = 0;
-perl_key self_key;
+
+
+void Perl_ithread_set (pTHX_ ithread* thread)
+{
+    dMY_CXT;
+    MY_CXT.thread = thread;
+}
+
+ithread* Perl_ithread_get (pTHX) {
+    dMY_CXT;
+    return MY_CXT.thread;
+}
+
+
+/* free any data (such as the perl interpreter) attached to an
+ * ithread structure. This is a bit like undef on SVs, where the SV
+ * isn't freed, but the PVX is.
+ * Must be called with thread->mutex already held
+ */
+
+static void
+S_ithread_clear(pTHX_ ithread* thread)
+{
+    PerlInterpreter *interp;
+    assert(thread->state & PERL_ITHR_FINISHED &&
+           (thread->state & PERL_ITHR_DETACHED ||
+           thread->state & PERL_ITHR_JOINED));
+
+    interp = thread->interp;
+    if (interp) {
+       dTHXa(interp);
+       ithread* current_thread;
+#ifdef OEMVS
+       void *ptr;
+#endif
+       PERL_SET_CONTEXT(interp);
+       current_thread = Perl_ithread_get(aTHX);
+       Perl_ithread_set(aTHX_ thread);
+       
+       SvREFCNT_dec(thread->params);
+
+       thread->params = Nullsv;
+       perl_destruct(interp);
+       thread->interp = NULL;
+    }
+    if (interp)
+       perl_free(interp);
+    PERL_SET_CONTEXT(aTHX);
+}
+
 
 /*
- *  Clear up after thread is done with
+ *  free an ithread structure and any attached data if its count == 0
  */
 void
 Perl_ithread_destruct (pTHX_ ithread* thread, const char *why)
 {
        MUTEX_LOCK(&thread->mutex);
        if (!thread->next) {
+           MUTEX_UNLOCK(&thread->mutex);
            Perl_croak(aTHX_ "panic: destruct destroyed thread %p (%s)",thread, why);
        }
        if (thread->count != 0) {
@@ -122,18 +165,15 @@ Perl_ithread_destruct (pTHX_ ithread* thread, const char *why)
 #endif
        MUTEX_UNLOCK(&create_destruct_mutex);
        /* Thread is now disowned */
-       if (thread->interp) {
-           dTHXa(thread->interp);
-           PERL_SET_CONTEXT(thread->interp);
-           SvREFCNT_dec(thread->params);
-           thread->params = Nullsv;
-           perl_destruct(thread->interp);
-           perl_free(thread->interp);
-           thread->interp = NULL;
-       }
-       PERL_SET_CONTEXT(aTHX);
+
+       S_ithread_clear(aTHX_ thread);
        MUTEX_UNLOCK(&thread->mutex);
        MUTEX_DESTROY(&thread->mutex);
+#ifdef WIN32
+       if (thread->handle)
+           CloseHandle(thread->handle);
+       thread->handle = 0;
+#endif
         PerlMemShared_free(thread);
 }
 
@@ -143,7 +183,9 @@ Perl_ithread_hook(pTHX)
     int veto_cleanup = 0;
     MUTEX_LOCK(&create_destruct_mutex);
     if (aTHX == PL_curinterp && active_threads != 1) {
-       Perl_warn(aTHX_ "Cleanup skipped %d active threads", active_threads);
+       if (ckWARN_d(WARN_THREADS))
+           Perl_warn(aTHX_ "A thread exited while %" IVdf " threads were running",
+                                                     (IV)active_threads);
        veto_cleanup = 1;
     }
     MUTEX_UNLOCK(&create_destruct_mutex);
@@ -179,7 +221,7 @@ int
 ithread_mg_get(pTHX_ SV *sv, MAGIC *mg)
 {
     ithread *thread = (ithread *) mg->mg_ptr;
-    SvIVX(sv) = PTR2IV(thread);
+    SvIV_set(sv, PTR2IV(thread));
     SvIOK_on(sv);
     return 0;
 }
@@ -198,7 +240,9 @@ ithread_mg_free(pTHX_ SV *sv, MAGIC *mg)
             MUTEX_UNLOCK(&thread->mutex);
             Perl_ithread_destruct(aTHX_ thread, "no reference");
        }
-       MUTEX_UNLOCK(&thread->mutex);
+       else {
+           MUTEX_UNLOCK(&thread->mutex);
+       }    
     }
     else {
        MUTEX_UNLOCK(&thread->mutex);
@@ -242,7 +286,7 @@ Perl_ithread_run(void * arg) {
        ithread* thread = (ithread*) arg;
        dTHXa(thread->interp);
        PERL_SET_CONTEXT(thread->interp);
-       PERL_THREAD_SETSPECIFIC(self_key,thread);
+       Perl_ithread_set(aTHX_ thread);
 
 #if 0
        /* Far from clear messing with ->thr child-side is a good idea */
@@ -270,14 +314,14 @@ Perl_ithread_run(void * arg) {
                }
                PUTBACK;
                len = call_sv(thread->init_function, thread->gimme|G_EVAL);
+
                SPAGAIN;
                for (i=len-1; i >= 0; i--) {
                  SV *sv = POPs;
                  av_store(params, i, SvREFCNT_inc(sv));
                }
-               PUTBACK;
-               if (SvTRUE(ERRSV)) {
-                   Perl_warn(aTHX_ "Died:%_",ERRSV);
+               if (SvTRUE(ERRSV) && ckWARN_d(WARN_THREADS)) {
+                   Perl_warn(aTHX_ "thread failed to start: %" SVf, ERRSV);
                }
                FREETMPS;
                LEAVE;
@@ -285,10 +329,6 @@ Perl_ithread_run(void * arg) {
        }
 
        PerlIO_flush((PerlIO*)NULL);
-       MUTEX_LOCK(&create_destruct_mutex);
-       active_threads--;
-       assert( active_threads >= 0 );
-       MUTEX_UNLOCK(&create_destruct_mutex);
        MUTEX_LOCK(&thread->mutex);
        thread->state |= PERL_ITHR_FINISHED;
 
@@ -298,6 +338,11 @@ Perl_ithread_run(void * arg) {
        } else {
                MUTEX_UNLOCK(&thread->mutex);
        }
+       MUTEX_LOCK(&create_destruct_mutex);
+       active_threads--;
+       assert( active_threads >= 0 );
+       MUTEX_UNLOCK(&create_destruct_mutex);
+
 #ifdef WIN32
        return (DWORD)0;
 #else
@@ -328,20 +373,18 @@ ithread_to_SV(pTHX_ SV *obj, ithread *thread, char *classname, bool inc)
 ithread *
 SV_to_ithread(pTHX_ SV *sv)
 {
-    ithread *thread;
     if (SvROK(sv))
      {
-      thread = INT2PTR(ithread*, SvIV(SvRV(sv)));
+      return INT2PTR(ithread*, SvIV(SvRV(sv)));
      }
     else
      {
-      PERL_THREAD_GETSPECIFIC(self_key,thread);
+      return Perl_ithread_get(aTHX);
      }
-    return thread;
 }
 
 /*
- * iThread->create(); ( aka iThread->new() )
+ * ithread->create(); ( aka ithread->new() )
  * Called in context of parent thread
  */
 
@@ -350,9 +393,24 @@ Perl_ithread_create(pTHX_ SV *obj, char* classname, SV* init_function, SV* param
 {
        ithread*        thread;
        CLONE_PARAMS    clone_param;
+       ithread*        current_thread = Perl_ithread_get(aTHX);
+
+       SV**            tmps_tmp = PL_tmps_stack;
+       I32             tmps_ix  = PL_tmps_ix;
+#ifndef WIN32
+       int             failure;
+       const char*     panic = NULL;
+#endif
+
 
        MUTEX_LOCK(&create_destruct_mutex);
-       thread = PerlMemShared_malloc(sizeof(ithread));
+       thread = (ithread *) PerlMemShared_malloc(sizeof(ithread));
+       if (!thread) {  
+           MUTEX_UNLOCK(&create_destruct_mutex);
+           PerlLIO_write(PerlIO_fileno(Perl_error_log),
+                         PL_no_mem, strlen(PL_no_mem));
+           my_exit(1);
+       }
        Zero(thread,1,ithread);
        thread->next = threads;
        thread->prev = threads->prev;
@@ -365,13 +423,18 @@ Perl_ithread_create(pTHX_ SV *obj, char* classname, SV* init_function, SV* param
        MUTEX_INIT(&thread->mutex);
        thread->tid = tid_counter++;
        thread->gimme = GIMME_V;
-       thread->state = (thread->gimme == G_VOID) ? 1 : 0;
 
        /* "Clone" our interpreter into the thread's interpreter
         * This gives thread access to "static data" and code.
         */
 
        PerlIO_flush((PerlIO*)NULL);
+       Perl_ithread_set(aTHX_ thread);
+
+       SAVEBOOL(PL_srand_called); /* Save this so it becomes the correct
+                                     value */
+       PL_srand_called = FALSE; /* Set it to false so we can detect
+                                   if it gets set during the clone */
 
 #ifdef WIN32
        thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE | CLONEf_CLONE_HOST);
@@ -379,12 +442,15 @@ Perl_ithread_create(pTHX_ SV *obj, char* classname, SV* init_function, SV* param
        thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE);
 #endif
        /* perl_clone leaves us in new interpreter's context.
-          As it is tricky to spot implcit aTHX create a new scope
+          As it is tricky to spot an implicit aTHX, create a new scope
           with aTHX matching the context for the duration of
           our work for new interpreter.
         */
        {
            dTHXa(thread->interp);
+
+           MY_CXT_CLONE;
+
             /* Here we remove END blocks since they should only run
               in the thread they are created
             */
@@ -395,23 +461,55 @@ Perl_ithread_create(pTHX_ SV *obj, char* classname, SV* init_function, SV* param
            if (SvREFCNT(thread->init_function) == 0) {
                SvREFCNT_inc(thread->init_function);
            }
+           
+
 
            thread->params = sv_dup(params, &clone_param);
            SvREFCNT_inc(thread->params);
+
+
+           /* The code below checks that anything living on
+              the tmps stack and has been cloned (so it lives in the
+              ptr_table) has a refcount higher than 0
+
+              If the refcount is 0 it means that a something on the
+              stack/context was holding a reference to it and
+              since we init_stacks() in perl_clone that won't get
+              cleaned and we will get a leaked scalar.
+              The reason it was cloned was that it lived on the
+              @_ stack.
+
+              Example of this can be found in bugreport 15837
+              where calls in the parameter list end up as a temp
+
+              One could argue that this fix should be in perl_clone
+           */
+              
+
+           while (tmps_ix > 0) { 
+             SV* sv = (SV*)ptr_table_fetch(PL_ptr_table, tmps_tmp[tmps_ix]);
+             tmps_ix--;
+             if (sv && SvREFCNT(sv) == 0) {
+               SvREFCNT_inc(sv);
+               SvREFCNT_dec(sv);
+             }
+           }
+           
+
+
            SvTEMP_off(thread->init_function);
            ptr_table_free(PL_ptr_table);
            PL_ptr_table = NULL;
+           PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
        }
-
+       Perl_ithread_set(aTHX_ current_thread);
        PERL_SET_CONTEXT(aTHX);
 
        /* Start the thread */
 
 #ifdef WIN32
-
        thread->handle = CreateThread(NULL, 0, Perl_ithread_run,
                        (LPVOID)thread, 0, &thread->thr);
-
 #else
        {
          static pthread_attr_t attr;
@@ -426,29 +524,56 @@ Perl_ithread_create(pTHX_ SV *obj, char* classname, SV* init_function, SV* param
 #  endif
 #  ifdef THREAD_CREATE_NEEDS_STACK
            if(pthread_attr_setstacksize(&attr, THREAD_CREATE_NEEDS_STACK))
-             croak("panic: pthread_attr_setstacksize failed");
+             panic = "panic: pthread_attr_setstacksize failed";
 #  endif
 
 #ifdef OLD_PTHREADS_API
-         pthread_create( &thread->thr, attr, Perl_ithread_run, (void *)thread);
+           failure
+             = panic ? 1 : pthread_create( &thread->thr, attr,
+                                           Perl_ithread_run, (void *)thread);
 #else
-         pthread_create( &thread->thr, &attr, Perl_ithread_run, (void *)thread);
+#  if defined(HAS_PTHREAD_ATTR_SETSCOPE) && defined(PTHREAD_SCOPE_SYSTEM)
+         pthread_attr_setscope( &attr, PTHREAD_SCOPE_SYSTEM );
+#  endif
+         failure
+           = panic ? 1 : pthread_create( &thread->thr, &attr,
+                                         Perl_ithread_run, (void *)thread);
 #endif
        }
 #endif
        known_threads++;
+       if (
+#ifdef WIN32
+           thread->handle == NULL
+#else
+           failure
+#endif
+           ) {
+         MUTEX_UNLOCK(&create_destruct_mutex);
+         sv_2mortal(params);
+         Perl_ithread_destruct(aTHX_ thread, "create failed");
+#ifndef WIN32
+         if (panic)
+           Perl_croak(aTHX_ panic);
+#endif
+         return &PL_sv_undef;
+       }
        active_threads++;
        MUTEX_UNLOCK(&create_destruct_mutex);
        sv_2mortal(params);
+
        return ithread_to_SV(aTHX_ obj, thread, classname, FALSE);
 }
 
 SV*
 Perl_ithread_self (pTHX_ SV *obj, char* Class)
 {
-    ithread *thread;
-    PERL_THREAD_GETSPECIFIC(self_key,thread);
-    return ithread_to_SV(aTHX_ obj, thread, Class, TRUE);
+   ithread *thread = Perl_ithread_get(aTHX);
+   if (thread)
+       return ithread_to_SV(aTHX_ obj, thread, Class, TRUE);
+   else
+       Perl_croak(aTHX_ "panic: cannot find thread data");
+   return NULL; /* silence compiler warning */
 }
 
 /*
@@ -459,14 +584,12 @@ Perl_ithread_self (pTHX_ SV *obj, char* Class)
 void
 Perl_ithread_CLONE(pTHX_ SV *obj)
 {
- if (SvROK(obj))
-  {
-   ithread *thread = SV_to_ithread(aTHX_ obj);
-  }
- else
-  {
-   Perl_warn(aTHX_ "CLONE %_",obj);
-  }
+    if (SvROK(obj)) {
+       ithread *thread = SV_to_ithread(aTHX_ obj);
+    }
+    else if (ckWARN_d(WARN_THREADS)) {
+       Perl_warn(aTHX_ "CLONE %" SVf,obj);
+    }
 }
 
 AV*
@@ -492,6 +615,8 @@ Perl_ithread_join(pTHX_ SV *obj)
        MUTEX_UNLOCK(&thread->mutex);
 #ifdef WIN32
        waitcode = WaitForSingleObject(thread->handle, INFINITE);
+       CloseHandle(thread->handle);
+       thread->handle = 0;
 #else
        pthread_join(thread->thr,&retval);
 #endif
@@ -499,20 +624,51 @@ Perl_ithread_join(pTHX_ SV *obj)
        
        /* sv_dup over the args */
        {
+         ithread*        current_thread;
          AV* params = (AV*) SvRV(thread->params);      
+         PerlInterpreter *other_perl = thread->interp;
          CLONE_PARAMS clone_params;
          clone_params.stashes = newAV();
+         clone_params.flags |= CLONEf_JOIN_IN;
          PL_ptr_table = ptr_table_new();
+         current_thread = Perl_ithread_get(aTHX);
+         Perl_ithread_set(aTHX_ thread);
+         /* ensure 'meaningful' addresses retain their meaning */
+         ptr_table_store(PL_ptr_table, &other_perl->Isv_undef, &PL_sv_undef);
+         ptr_table_store(PL_ptr_table, &other_perl->Isv_no, &PL_sv_no);
+         ptr_table_store(PL_ptr_table, &other_perl->Isv_yes, &PL_sv_yes);
+
+#if 0
+         {
+           I32 len = av_len(params)+1;
+           I32 i;
+           for(i = 0; i < len; i++) {
+             sv_dump(SvRV(AvARRAY(params)[i]));
+           }
+         }
+#endif
          retparam = (AV*) sv_dup((SV*)params, &clone_params);
+#if 0
+         {
+           I32 len = av_len(retparam)+1;
+           I32 i;
+           for(i = 0; i < len; i++) {
+               sv_dump(SvRV(AvARRAY(retparam)[i]));
+           }
+         }
+#endif
+         Perl_ithread_set(aTHX_ current_thread);
          SvREFCNT_dec(clone_params.stashes);
          SvREFCNT_inc(retparam);
          ptr_table_free(PL_ptr_table);
          PL_ptr_table = NULL;
 
        }
-       /* We have finished with it */
+       /* We are finished with it */
        thread->state |= PERL_ITHR_JOINED;
+       S_ithread_clear(aTHX_ thread);
        MUTEX_UNLOCK(&thread->mutex);
+       
        return retparam;
     }
     return (AV*)NULL;
@@ -550,6 +706,28 @@ CODE:
 }
 
 void
+ithread_list(char *classname)
+PPCODE:
+{
+  ithread *curr_thread;
+  MUTEX_LOCK(&create_destruct_mutex);
+  curr_thread = threads;
+  if(curr_thread->tid != 0)    
+    XPUSHs( sv_2mortal(ithread_to_SV(aTHX_ NULL, curr_thread, classname, TRUE)));
+  while(curr_thread) {
+    curr_thread = curr_thread->next;
+    if(curr_thread == threads)
+      break;
+    if(curr_thread->state & PERL_ITHR_DETACHED ||
+       curr_thread->state & PERL_ITHR_JOINED)
+         continue;
+     XPUSHs( sv_2mortal(ithread_to_SV(aTHX_ NULL, curr_thread, classname, TRUE)));
+  }    
+  MUTEX_UNLOCK(&create_destruct_mutex);
+}
+
+
+void
 ithread_self(char *classname)
 CODE:
 {
@@ -576,7 +754,12 @@ PPCODE:
 }
 
 void
-ithread_yield(ithread *thread)
+yield(...)
+CODE:
+{
+    YIELD;
+}
+       
 
 void
 ithread_detach(ithread *thread)
@@ -588,14 +771,19 @@ ithread_DESTROY(SV *thread)
 
 BOOT:
 {
+        MY_CXT_INIT;
 #ifdef USE_ITHREADS
        ithread* thread;
        PL_perl_destruct_level = 2;
-       PERL_THREAD_ALLOC_SPECIFIC(self_key);
        MUTEX_INIT(&create_destruct_mutex);
        MUTEX_LOCK(&create_destruct_mutex);
        PL_threadhook = &Perl_ithread_hook;
-       thread  = PerlMemShared_malloc(sizeof(ithread));
+       thread  = (ithread *) PerlMemShared_malloc(sizeof(ithread));
+       if (!thread) {
+           PerlLIO_write(PerlIO_fileno(Perl_error_log),
+                         PL_no_mem, strlen(PL_no_mem));
+           my_exit(1);
+       }
        Zero(thread,1,ithread);
        PL_perl_destruct_level = 2;
        MUTEX_INIT(&thread->mutex);
@@ -603,18 +791,18 @@ BOOT:
        thread->next = thread;
         thread->prev = thread;
        thread->interp = aTHX;
-       thread->count  = 1;  /* imortal */
+       thread->count  = 1;  /* Immortal. */
        thread->tid = tid_counter++;
        known_threads++;
        active_threads++;
-       thread->state = 1;
+       thread->state = PERL_ITHR_DETACHED;
 #ifdef WIN32
        thread->thr = GetCurrentThreadId();
 #else
        thread->thr = pthread_self();
 #endif
 
-       PERL_THREAD_SETSPECIFIC(self_key,thread);
+       Perl_ithread_set(aTHX_ thread);
        MUTEX_UNLOCK(&create_destruct_mutex);
 #endif /* USE_ITHREADS */
 }