X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=ext%2Fthreads%2Fthreads.xs;h=95746539a639f4a25358b6774de18e9a1a13a948;hb=b762d8667351cb765bc1d6419d30acff085da502;hp=4fc60db73270b137e348c03f638d843c40546ac2;hpb=ae3fba3defe4ed89f6b20b720860824178f77f52;p=p5sagit%2Fp5-mst-13.2.git diff --git a/ext/threads/threads.xs b/ext/threads/threads.xs index 4fc60db..9574653 100755 --- a/ext/threads/threads.xs +++ b/ext/threads/threads.xs @@ -12,7 +12,7 @@ #ifdef HAS_PPPORT_H # define NEED_PL_signals # define NEED_newRV_noinc -# define NEED_sv_2pv_nolen +# define NEED_sv_2pv_flags # include "ppport.h" # include "threads.h" #endif @@ -45,12 +45,12 @@ typedef perl_os_thread pthread_t; #endif /* Values for 'state' member */ -#define PERL_ITHR_DETACHED 1 /* thread has been detached */ -#define PERL_ITHR_JOINED 2 /* thread has been joined */ -#define PERL_ITHR_FINISHED 4 /* thread has finished execution */ +#define PERL_ITHR_DETACHED 1 /* Thread has been detached */ +#define PERL_ITHR_JOINED 2 /* Thread has been joined */ +#define PERL_ITHR_FINISHED 4 /* Thread has finished execution */ #define PERL_ITHR_THREAD_EXIT_ONLY 8 /* exit() only exits current thread */ -#define PERL_ITHR_NONVIABLE 16 /* thread creation failed */ -#define PERL_ITHR_DIED 32 /* thread finished by dying */ +#define PERL_ITHR_NONVIABLE 16 /* Thread creation failed */ +#define PERL_ITHR_DIED 32 /* Thread finished by dying */ #define PERL_ITHR_UNCALLABLE (PERL_ITHR_DETACHED|PERL_ITHR_JOINED) @@ -61,7 +61,7 @@ typedef struct _ithread { PerlInterpreter *interp; /* The threads interpreter */ UV tid; /* Threads module's thread id */ perl_mutex mutex; /* Mutex for updating things in this struct */ - int count; /* reference count. See S_ithread_create */ + int count; /* Reference count. See S_ithread_create. */ int state; /* Detached, joined, finished, etc. */ int gimme; /* Context of create */ SV *init_function; /* Code to run */ @@ -75,6 +75,7 @@ typedef struct _ithread { IV stack_size; SV *err; /* Error from abnormally terminated thread */ char *err_class; /* Error object's classname if applicable */ + sigset_t initial_sigmask; /* Thread wakes up with signals blocked */ } ithread; @@ -114,6 +115,44 @@ typedef struct { #define MY_POOL (*my_poolp) +/* Block most signals for calling thread, setting the old signal mask to + * oldmask, if it is not NULL */ +STATIC int +S_block_most_signals(sigset_t *oldmask) +{ + sigset_t newmask; + + sigfillset(&newmask); + /* Don't block certain "important" signals (stolen from mg.c) */ +#ifdef SIGILL + sigdelset(&newmask, SIGILL); +#endif +#ifdef SIGBUS + sigdelset(&newmask, SIGBUS); +#endif +#ifdef SIGSEGV + sigdelset(&newmask, SIGSEGV); +#endif + +#ifdef WIN32 + /* XXX: How to do this on win32? */ + return 0; +#else + return pthread_sigmask(SIG_BLOCK, &newmask, oldmask); +#endif /* WIN32 */ +} + +/* Set the signal mask for this thread to newmask */ +STATIC int +S_set_sigmask(sigset_t *newmask) +{ +#ifdef WIN32 + /* XXX: How to do this on win32? */ + return 0; +#else + return pthread_sigmask(SIG_SETMASK, newmask, NULL); +#endif /* WIN32 */ +} /* Used by Perl interpreter for thread context switching */ STATIC void @@ -133,18 +172,28 @@ S_ithread_get(pTHX) /* 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. + * but the PVX is. Must be called with thread->mutex already locked. Also, + * must be called with MY_POOL.create_destruct_mutex unlocked as destruction + * of the interpreter can lead to recursive destruction calls that could + * lead to a deadlock on that mutex. */ STATIC void S_ithread_clear(pTHX_ ithread *thread) { PerlInterpreter *interp; + sigset_t origmask; assert(((thread->state & PERL_ITHR_FINISHED) && (thread->state & PERL_ITHR_UNCALLABLE)) || (thread->state & PERL_ITHR_NONVIABLE)); + /* We temporarily set the interpreter context to the interpreter being + * destroyed. It's in no condition to handle signals while it's being + * taken apart. + */ + S_block_most_signals(&origmask); + interp = thread->interp; if (interp) { dTHXa(interp); @@ -166,13 +215,14 @@ S_ithread_clear(pTHX_ ithread *thread) } PERL_SET_CONTEXT(aTHX); + S_set_sigmask(&origmask); } /* Decrement the refcount of an ithread, and if it reaches zero, free it. * Must be called with the mutex held. - * On return, mutex is released (or destroyed) */ - + * On return, mutex is released (or destroyed). + */ STATIC void S_ithread_free(pTHX_ ithread *thread) { @@ -187,8 +237,8 @@ S_ithread_free(pTHX_ ithread *thread) MUTEX_UNLOCK(&thread->mutex); return; } - assert((thread->state & PERL_ITHR_FINISHED) - && (thread->state & PERL_ITHR_UNCALLABLE)); + assert((thread->state & PERL_ITHR_FINISHED) && + (thread->state & PERL_ITHR_UNCALLABLE)); } MUTEX_UNLOCK(&thread->mutex); @@ -221,17 +271,13 @@ S_ithread_free(pTHX_ ithread *thread) } #endif - /* Call PerlMemShared_free() in the context of the "first" interpreter - * per http://www.nntp.perl.org/group/perl.perl5.porters/110772 - */ - aTHX = MY_POOL.main_thread.interp; PerlMemShared_free(thread); /* total_threads >= 1 is used to veto cleanup by the main thread, * should it happen to exit while other threads still exist. - * Decrement this as the very last thing in the thread's existence, - * otherwise MY_POOL and global state such as PL_op_mutex may get - * freed while we're still using it + * Decrement this as the very last thing in the thread's existence. + * Otherwise, MY_POOL and global state such as PL_op_mutex may get + * freed while we're still using it. */ MUTEX_LOCK(&MY_POOL.create_destruct_mutex); MY_POOL.total_threads--; @@ -239,7 +285,6 @@ S_ithread_free(pTHX_ ithread *thread) } - static void S_ithread_count_inc(pTHX_ ithread *thread) { @@ -249,7 +294,6 @@ S_ithread_count_inc(pTHX_ ithread *thread) } - /* Warn if exiting with any unjoined threads */ STATIC int S_exit_warning(pTHX) @@ -277,10 +321,10 @@ S_exit_warning(pTHX) return (veto_cleanup); } -/* Called from perl_destruct() in each thread. If it's the main thread, - * stop it from freeing everything if there are other threads still - * running */ +/* Called from perl_destruct() in each thread. If it's the main thread, + * stop it from freeing everything if there are other threads still running. + */ int Perl_ithread_hook(pTHX) { @@ -305,11 +349,10 @@ ithread_mg_free(pTHX_ SV *sv, MAGIC *mg) { ithread *thread = (ithread *)mg->mg_ptr; MUTEX_LOCK(&thread->mutex); - S_ithread_free(aTHX_ thread); /* releases MUTEX */ + S_ithread_free(aTHX_ thread); /* Releases MUTEX */ return (0); } - int ithread_mg_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param) { @@ -360,7 +403,7 @@ S_good_stack_size(pTHX_ IV stack_size) # endif if ((long)MY_POOL.page_size < 0) { if (errno) { - SV * const error = get_sv("@", FALSE); + SV * const error = get_sv("@", 0); (void)SvUPGRADE(error, SVt_PV); Perl_croak(aTHX_ "PANIC: sysconf: %s", SvPV_nolen(error)); } else { @@ -419,6 +462,11 @@ S_ithread_run(void * arg) PERL_SET_CONTEXT(thread->interp); S_ithread_set(aTHX_ thread); + /* Thread starts with most signals blocked - restore the signal mask from + * the ithread struct. + */ + S_set_sigmask(&thread->initial_sigmask); + PL_perl_destruct_level = 2; { @@ -452,11 +500,17 @@ S_ithread_run(void * arg) } JMPENV_POP; + /* The interpreter is finished, so this thread can stop receiving + * signals. This way, our signal handler doesn't get called in the + * middle of our parent thread calling perl_destruct()... + */ + S_block_most_signals(NULL); + /* Remove args from stack and put back in params array */ SPAGAIN; for (ii=len-1; ii >= 0; ii--) { SV *sv = POPs; - if (jmp_rc == 0) { + if (jmp_rc == 0 && (thread->gimme & G_WANT) != G_VOID) { av_store(params, ii, SvREFCNT_inc(sv)); } } @@ -539,8 +593,14 @@ S_ithread_run(void * arg) my_exit(exit_code); } + /* At this point, the interpreter may have been freed, so call + * free in the the context of of the 'main' interpreter which + * can't have been freed due to the veto_cleanup mechanism. + */ + aTHX = MY_POOL.main_thread.interp; + MUTEX_LOCK(&thread->mutex); - S_ithread_free(aTHX_ thread); /* releases MUTEX */ + S_ithread_free(aTHX_ thread); /* Releases MUTEX */ #ifdef WIN32 return ((DWORD)0); @@ -629,13 +689,13 @@ S_ithread_create( thread->prev->next = thread; MY_POOL.total_threads++; - /* 1 ref to be held by the local var 'thread' in S_ithread_run() + /* 1 ref to be held by the local var 'thread' in S_ithread_run(). * 1 ref to be held by the threads object that we assume we will - * be embedded in upon our return - * 1 ref to be the responsibility of join/detach, so we don't get freed - until join/detach, even if no thread objects remain. This - allows the following to work: - { threads->new(sub{...}); } threads->object(1)->join; + * be embedded in upon our return. + * 1 ref to be the responsibility of join/detach, so we don't get + * freed until join/detach, even if no thread objects remain. + * This allows the following to work: + * { threads->create(sub{...}); } threads->object(1)->join; */ thread->count = 3; @@ -658,6 +718,25 @@ S_ithread_create( PL_srand_called = FALSE; /* Set it to false so we can detect if it gets set during the clone */ + /* perl_clone() will leave us the new interpreter's context. This poses + * two problems for our signal handler. First, it sets the new context + * before the new interpreter struct is fully initialized, so our signal + * handler might find bogus data in the interpreter struct it gets. + * Second, even if the interpreter is initialized before a signal comes in, + * we would like to avoid that interpreter receiving notifications for + * signals (especially when they ought to be for the one running in this + * thread), until it is running in its own thread. Another problem is that + * the new thread will not have set the context until some time after it + * has started, so it won't be safe for our signal handler to run until + * that time. + * + * So we block most signals here, so the new thread will inherit the signal + * mask, and unblock them right after the thread creation. The original + * mask is saved in the thread struct so that the new thread can restore + * the original mask. + */ + S_block_most_signals(&thread->initial_sigmask); + #ifdef WIN32 thread->interp = perl_clone(aTHX, CLONEf_KEEP_PTR_TABLE | CLONEf_CLONE_HOST); #else @@ -686,10 +765,8 @@ S_ithread_create( thread->init_function = newSV(0); sv_copypv(thread->init_function, init_function); } else { - thread->init_function = sv_dup(init_function, &clone_param); - if (SvREFCNT(thread->init_function) == 0) { - SvREFCNT_inc_void(thread->init_function); - } + thread->init_function = + SvREFCNT_inc(sv_dup(init_function, &clone_param)); } thread->params = sv_dup(params, &clone_param); @@ -774,6 +851,11 @@ S_ithread_create( # endif } + /* Now it's safe to accept signals, since we're in our own interpreter's + * context and we have created the thread. + */ + S_set_sigmask(&thread->initial_sigmask); + # ifdef _POSIX_THREAD_ATTR_STACKSIZE /* Try to get thread's actual stack size */ { @@ -801,7 +883,7 @@ S_ithread_create( MUTEX_UNLOCK(&MY_POOL.create_destruct_mutex); sv_2mortal(params); thread->state |= PERL_ITHR_NONVIABLE; - S_ithread_free(aTHX_ thread); /* releases MUTEX */ + S_ithread_free(aTHX_ thread); /* Releases MUTEX */ #ifndef WIN32 if (ckWARN_d(WARN_THREADS)) { if (rc_stack_size) { @@ -846,7 +928,7 @@ ithread_create(...) CODE: if ((items >= 2) && SvROK(ST(1)) && SvTYPE(SvRV(ST(1)))==SVt_PVHV) { if (--items < 2) { - Perl_croak(aTHX_ "Usage: threads->create(\\%specs, function, ...)"); + Perl_croak(aTHX_ "Usage: threads->create(\\%%specs, function, ...)"); } specs = (HV*)SvRV(ST(1)); idx = 1; @@ -870,7 +952,7 @@ ithread_create(...) /* threads->create() */ classname = (char *)SvPV_nolen(ST(0)); stack_size = MY_POOL.default_stack_size; - thread_exit_only = get_sv("threads::thread_exit_only", TRUE); + thread_exit_only = get_sv("threads::thread_exit_only", GV_ADD); exit_opt = (SvTRUE(thread_exit_only)) ? PERL_ITHR_THREAD_EXIT_ONLY : 0; } @@ -894,6 +976,8 @@ ithread_create(...) switch (*str) { case 'a': case 'A': + case 'l': + case 'L': context = G_ARRAY; break; case 's': @@ -911,6 +995,10 @@ ithread_create(...) if (SvTRUE(*hv_fetch(specs, "array", 5, 0))) { context = G_ARRAY; } + } else if (hv_exists(specs, "list", 4)) { + if (SvTRUE(*hv_fetch(specs, "list", 4, 0))) { + context = G_ARRAY; + } } else if (hv_exists(specs, "scalar", 6)) { if (SvTRUE(*hv_fetch(specs, "scalar", 6, 0))) { context = G_SCALAR; @@ -1062,12 +1150,10 @@ ithread_join(...) ithread *thread; ithread *current_thread; int join_err; - AV *params; + AV *params = NULL; int len; int ii; -#ifdef WIN32 - DWORD waitcode; -#else +#ifndef WIN32 int rc_join; void *retval; #endif @@ -1118,7 +1204,7 @@ ithread_join(...) MUTEX_LOCK(&thread->mutex); /* Get the return value from the call_sv */ /* Objects do not survive this process - FIXME */ - { + if ((thread->gimme & G_WANT) != G_VOID) { AV *params_copy; PerlInterpreter *other_perl; CLONE_PARAMS clone_params; @@ -1145,7 +1231,7 @@ ithread_join(...) if (! (thread->state & PERL_ITHR_DIED)) { S_ithread_clear(aTHX_ thread); } - S_ithread_free(aTHX_ thread); /* releases MUTEX */ + S_ithread_free(aTHX_ thread); /* Releases MUTEX */ /* If no return values, then just return */ if (! params) { @@ -1215,8 +1301,7 @@ ithread_detach(...) { S_ithread_clear(aTHX_ thread); } - S_ithread_free(aTHX_ thread); /* releases MUTEX */ - + S_ithread_free(aTHX_ thread); /* Releases MUTEX */ void @@ -1390,6 +1475,9 @@ ithread_set_stack_size(...) if (sv_isobject(ST(0))) { Perl_croak(aTHX_ "Cannot change stack size of an existing thread"); } + if (! looks_like_number(ST(1))) { + Perl_croak(aTHX_ "Stack size must be numeric"); + } old_size = MY_POOL.default_stack_size; MY_POOL.default_stack_size = S_good_stack_size(aTHX_ SvIV(ST(1))); @@ -1453,9 +1541,9 @@ ithread_wantarray(...) CODE: PERL_UNUSED_VAR(items); thread = S_SV_to_ithread(aTHX_ ST(0)); - ST(0) = (thread->gimme & G_ARRAY) ? &PL_sv_yes : - (thread->gimme & G_VOID) ? &PL_sv_undef - /* G_SCALAR */ : &PL_sv_no; + ST(0) = ((thread->gimme & G_WANT) == G_ARRAY) ? &PL_sv_yes : + ((thread->gimme & G_WANT) == G_VOID) ? &PL_sv_undef + /* G_SCALAR */ : &PL_sv_no; /* XSRETURN(1); - implied */