diff options
Diffstat (limited to 'signal.c')
| -rw-r--r-- | signal.c | 125 |
1 files changed, 99 insertions, 26 deletions
@@ -62,10 +62,6 @@ ruby_atomic_compare_and_swap(rb_atomic_t *ptr, rb_atomic_t cmp, } #endif -#ifndef NSIG -# define NSIG (_SIGMAX + 1) /* For QNX */ -#endif - #define FOREACH_SIGNAL(sig, offset) \ for (sig = siglist + (offset); sig < siglist + numberof(siglist); ++sig) enum { LONGEST_SIGNAME = 7 }; /* MIGRATE and RETRACT */ @@ -132,15 +128,9 @@ static const struct signals { #ifdef SIGCONT {"CONT", SIGCONT}, #endif -#ifdef SIGCHLD - {"CHLD", SIGCHLD}, -#endif -#ifdef SIGCLD - {"CLD", SIGCLD}, -#else -# ifdef SIGCHLD - {"CLD", SIGCHLD}, -# endif +#if RUBY_SIGCHLD + {"CHLD", RUBY_SIGCHLD }, + {"CLD", RUBY_SIGCHLD }, #endif #ifdef SIGTTIN {"TTIN", SIGTTIN}, @@ -708,12 +698,29 @@ signal_enque(int sig) ATOMIC_INC(signal_buff.size); } +static rb_atomic_t sigchld_hit; + +/* Prevent compiler from reordering access */ +#define ACCESS_ONCE(type,x) (*((volatile type *)&(x))) + static RETSIGTYPE sighandler(int sig) { int old_errnum = errno; - signal_enque(sig); + /* the VM always needs to handle SIGCHLD for rb_waitpid */ + if (sig == RUBY_SIGCHLD) { + rb_vm_t *vm = GET_VM(); + ATOMIC_EXCHANGE(sigchld_hit, 1); + + /* avoid spurious wakeup in main thread iff nobody uses trap(:CHLD) */ + if (vm && ACCESS_ONCE(VALUE, vm->trap_list.cmd[sig])) { + signal_enque(sig); + } + } + else { + signal_enque(sig); + } rb_thread_wakeup_timer_thread(); #if !defined(BSD_SIGNAL) && !defined(POSIX_SIGNAL) ruby_signal(sig, sighandler); @@ -748,6 +755,7 @@ rb_enable_interrupt(void) #ifdef HAVE_PTHREAD_SIGMASK sigset_t mask; sigemptyset(&mask); + sigaddset(&mask, RUBY_SIGCHLD); /* timer-thread handles this */ pthread_sigmask(SIG_SETMASK, &mask, NULL); #endif } @@ -1058,6 +1066,17 @@ rb_trap_exit(void) } } +void ruby_waitpid_all(rb_vm_t *); /* process.c */ + +/* only runs in the timer-thread */ +void +ruby_sigchld_handler(rb_vm_t *vm) +{ + if (SIGCHLD_LOSSY || ATOMIC_EXCHANGE(sigchld_hit, 0)) { + ruby_waitpid_all(vm); + } +} + void rb_signal_exec(rb_thread_t *th, int sig) { @@ -1124,6 +1143,9 @@ default_handler(int sig) #ifdef SIGUSR2 case SIGUSR2: #endif +#if RUBY_SIGCHLD + case RUBY_SIGCHLD: +#endif func = sighandler; break; #ifdef SIGBUS @@ -1161,6 +1183,9 @@ trap_handler(VALUE *cmd, int sig) VALUE command; if (NIL_P(*cmd)) { + if (sig == RUBY_SIGCHLD) { + goto sig_dfl; + } func = SIG_IGN; } else { @@ -1181,6 +1206,9 @@ trap_handler(VALUE *cmd, int sig) break; case 14: if (memcmp(cptr, "SYSTEM_DEFAULT", 14) == 0) { + if (sig == RUBY_SIGCHLD) { + goto sig_dfl; + } func = SIG_DFL; *cmd = 0; } @@ -1188,6 +1216,9 @@ trap_handler(VALUE *cmd, int sig) case 7: if (memcmp(cptr, "SIG_IGN", 7) == 0) { sig_ign: + if (sig == RUBY_SIGCHLD) { + goto sig_dfl; + } func = SIG_IGN; *cmd = Qtrue; } @@ -1274,7 +1305,7 @@ trap(int sig, sighandler_t func, VALUE command) break; } - vm->trap_list.cmd[sig] = command; + ACCESS_ONCE(VALUE, vm->trap_list.cmd[sig]) = command; vm->trap_list.safe[sig] = rb_safe_level(); return oldcmd; @@ -1419,20 +1450,18 @@ install_sighandler(int signum, sighandler_t handler) # define install_sighandler(signum, handler) \ INSTALL_SIGHANDLER(install_sighandler(signum, handler), #signum, signum) -#if defined(SIGCLD) || defined(SIGCHLD) +#if RUBY_SIGCHLD static int init_sigchld(int sig) { sighandler_t oldfunc; + sighandler_t func = sighandler; oldfunc = ruby_signal(sig, SIG_DFL); if (oldfunc == SIG_ERR) return -1; - if (oldfunc != SIG_DFL && oldfunc != SIG_IGN) { - ruby_signal(sig, oldfunc); - } - else { - GET_VM()->trap_list.cmd[sig] = 0; - } + ruby_signal(sig, func); + ACCESS_ONCE(VALUE, GET_VM()->trap_list.cmd[sig]) = 0; + return 0; } @@ -1548,11 +1577,55 @@ Init_signal(void) install_sighandler(SIGSYS, sig_do_nothing); #endif -#if defined(SIGCLD) - init_sigchld(SIGCLD); -#elif defined(SIGCHLD) - init_sigchld(SIGCHLD); +#if RUBY_SIGCHLD + init_sigchld(RUBY_SIGCHLD); #endif rb_enable_interrupt(); } + +#if defined(HAVE_GRANTPT) +extern int grantpt(int); +#else +static int +fake_grantfd(int masterfd) +{ + errno = ENOSYS; + return -1; +} +#define grantpt(fd) fake_grantfd(fd) +#endif + +int +rb_grantpt(int masterfd) +{ + if (RUBY_SIGCHLD) { + rb_vm_t *vm = GET_VM(); + int ret, e; + + /* + * Prevent waitpid calls from Ruby by taking waitpid_lock. + * Pedantically, grantpt(3) is undefined if a non-default + * SIGCHLD handler is defined, but preventing conflicting + * waitpid calls ought to be sufficient. + * + * We could install the default sighandler temporarily, but that + * could cause SIGCHLD to be missed by other threads. Blocking + * SIGCHLD won't work here, either, unless we stop and restart + * timer-thread (as only timer-thread sees SIGCHLD), but that + * seems like overkill. + */ + rb_nativethread_lock_lock(&vm->waitpid_lock); + { + ret = grantpt(masterfd); /* may spawn `pt_chown' and wait on it */ + if (ret < 0) e = errno; + } + rb_nativethread_lock_unlock(&vm->waitpid_lock); + + if (ret < 0) errno = e; + return ret; + } + else { + return grantpt(masterfd); + } +} |