diff options
Diffstat (limited to 'signal.c')
| -rw-r--r-- | signal.c | 76 |
1 files changed, 74 insertions, 2 deletions
@@ -23,13 +23,68 @@ * MA 02111-1307, USA */ -/* errno.h or a replacement file is included by pthread.h */ -//#include <errno.h> +/* + * Strategy for implementing pthread_kill() + * ======================================== + * + * Win32 does not implement signals. + * Signals are simply software interrupts. + * pthread_kill() asks the system to deliver a specified + * signal (interrupt) to a specified thread in the same + * process. + * Signals are always asynchronous (no deferred signals). + * Pthread-win32 has an async cancelation mechanism. + * A similar system can be written to deliver signals + * within the same process (on ix86 processors at least). + * + * Each thread maintains information about which + * signals it will respond to. Handler routines + * are set on a per-process basis - not per-thread. + * When signalled, a thread will check it's sigmask + * and, if the signal is not being ignored, call the + * handler routine associated with the signal. The + * thread must then (except for some signals) return to + * the point where it was interrupted. + * + * Ideally the system itself would check the target thread's + * mask before possibly needlessly bothering the thread + * itself. This could be done by pthread_kill(), that is, + * in the signaling thread since it has access to + * all pthread_t structures. It could also retrieve + * the handler routine address to minimise the target + * threads response overhead. This may also simplify + * serialisation of the access to the per-thread signal + * structures. + * + * pthread_kill() eventually calls a routine similar to + * ptw32_cancel_thread() which manipulates the target + * threads processor context to cause the thread to + * run the handler launcher routine. pthread_kill() must + * save the target threads current context so that the + * handler launcher routine can restore the context after + * the signal handler has returned. Some handlers will not + * return, eg. the default SIGKILL handler may simply + * call pthread_exit(). + * + * The current context is saved in the target threads + * pthread_t structure. + */ #include "pthread.h" #include "implement.h" #if HAVE_SIGSET_T + +static void +ptw32_signal_thread() +{ +} + +static void +ptw32_signal_callhandler() +{ +} + int pthread_sigmask(int how, sigset_t const *set, sigset_t *oset) { @@ -97,4 +152,21 @@ pthread_sigmask(int how, sigset_t const *set, sigset_t *oset) return 0; } + +int pthread_kill(pthread_t thread, + int signo) +{ +} + +int sigwait(const sigset_t *set, + int *sig) +{ +} + +int sigaction(int signum, + const struct sigaction *act, + struct sigaction *oldact) +{ +} + #endif /* HAVE_SIGSET_T */ |