X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=ext%2Fthreads%2Fthreads.xs;h=95746539a639f4a25358b6774de18e9a1a13a948;hb=b762d8667351cb765bc1d6419d30acff085da502;hp=aa9376727f2a1717cb8fe1552ad61405a46a599e;hpb=da140a4068f95cc339e9327c1579a94f9f241dd8;p=p5sagit%2Fp5-mst-13.2.git diff --git a/ext/threads/threads.xs b/ext/threads/threads.xs index aa93767..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 @@ -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 @@ -142,12 +181,19 @@ 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); @@ -169,6 +215,7 @@ S_ithread_clear(pTHX_ ithread *thread) } PERL_SET_CONTEXT(aTHX); + S_set_sigmask(&origmask); } @@ -356,7 +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 { @@ -415,6 +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; { @@ -448,11 +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)); } } @@ -660,6 +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 @@ -688,10 +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); @@ -776,6 +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 */ { @@ -848,7 +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; @@ -872,7 +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; } @@ -1124,7 +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_VOID)) { + if ((thread->gimme & G_WANT) != G_VOID) { AV *params_copy; PerlInterpreter *other_perl; CLONE_PARAMS clone_params; @@ -1461,9 +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 */