diff options
Diffstat (limited to 'cancel.c')
| -rw-r--r-- | cancel.c | 241 |
1 files changed, 241 insertions, 0 deletions
@@ -10,6 +10,245 @@ #include "pthread.h" #include "implement.h" +/* + * Code contributed by John E. Bossom <JEB>. + */ + +int +pthread_setcancelstate (int state, int *oldstate) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function atomically sets the calling thread's + * cancelability state to 'state' and returns the previous + * cancelability state at the location referenced by + * 'oldstate' + * + * PARAMETERS + * type, + * oldtype + * PTHREAD_CANCEL_ENABLE + * cancellation is enabled, + * + * PTHREAD_CANCEL_DISABLE + * cancellation is disabled + * + * + * DESCRIPTION + * This function atomically sets the calling thread's + * cancelability state to 'state' and returns the previous + * cancelability state at the location referenced by + * 'oldstate' + * + * NOTES: + * 1) Use to disable cancellation around 'atomic' code that + * includes cancellation points + * + * RESULTS + * 0 successfully set cancelability type, + * EINVAL 'state' is invalid + * + * ------------------------------------------------------ + */ +{ + pthread_t self; + int result; + + if (((self = pthread_self ()) != NULL) && + (state == PTHREAD_CANCEL_ENABLE || + state == PTHREAD_CANCEL_DISABLE)) + { + + *oldstate = self->cancelState; + self->cancelState = state; + result = 0; + + } + else + { + result = EINVAL; + } + + return (result); + +} /* pthread_setcancelstate */ + + +int +pthread_setcanceltype (int type, int *oldtype) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function atomically sets the calling thread's + * cancelability type to 'type' and returns the previous + * cancelability type at the location referenced by + * 'oldtype' + * + * PARAMETERS + * type, + * oldtype + * PTHREAD_CANCEL_DEFERRED + * only deferred cancelation is allowed, + * + * PTHRAD_CANCEL_ASYNCHRONOUS + * Asynchronous cancellation is allowed + * + * + * DESCRIPTION + * This function atomically sets the calling thread's + * cancelability type to 'type' and returns the previous + * cancelability type at the location referenced by + * 'oldtype' + * + * NOTES: + * 1) Use with caution; most code is not safe for use + * with asynchronous cancelability. + * + * RESULTS + * 0 successfully set cancelability type, + * EINVAL 'type' is invalid + * + * ------------------------------------------------------ + */ +{ + pthread_t self; + int result; + + if (((self = pthread_self ()) != NULL) && + (type == PTHREAD_CANCEL_DEFERRED || + type == PTHREAD_CANCEL_ASYNCHRONOUS)) + { + + *oldtype = self->cancelType; + self->cancelType = type; + result = 0; + + } + else + { + result = EINVAL; + } + + return (result); + +} /* pthread_setcanceltype */ + +void +pthread_testcancel (void) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function creates a deferred cancellation point + * in the calling thread. The call has no effect if the + * current cancelability state is + * PTHREAD_CANCEL_DISABLE + * + * PARAMETERS + * N/A + * + * + * DESCRIPTION + * This function creates a deferred cancellation point + * in the calling thread. The call has no effect if the + * current cancelability state is + * PTHREAD_CANCEL_DISABLE + * + * NOTES: + * 1) Cancellation is asynchronous. Use pthread_join + * to wait for termination of thread if necessary + * + * RESULTS + * N/A + * + * ------------------------------------------------------ + */ +{ + pthread_t self; + + if ((self = pthread_getspecific (_pthread_selfThreadKey)) != NULL) + { + + if (self->cancelState == PTHREAD_CANCEL_ENABLE) + { + + if (WaitForSingleObject (self->cancelEvent, 0) == + WAIT_OBJECT_0) + { + /* + * Canceling! + */ + DWORD exceptionInformation[3]; + + exceptionInformation[0] = (DWORD) (0); + exceptionInformation[1] = (DWORD) (0); + + RaiseException ( + EXCEPTION_PTHREAD_SERVICES, + 0, + 3, + exceptionInformation); + } + } + } + +} /* pthread_testcancel */ + +int +pthread_cancel (pthread_t thread) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function requests cancellation of 'thread'. + * + * PARAMETERS + * thread + * reference to an instance of pthread_t + * + * + * DESCRIPTION + * This function requests cancellation of 'thread'. + * NOTE: cancellation is asynchronous; use pthread_join to + * wait for termination of 'thread' if necessary. + * + * RESULTS + * 0 successfully created semaphore, + * ESRCH no thread found corresponding to 'thread', + * + * ------------------------------------------------------ + */ +{ + int result; + + if (thread != NULL) + { + + if (!SetEvent (thread->cancelEvent)) + { + result = ESRCH; + } + else + { + result = 0; + } + + } + else + { + result = ESRCH; + } + + return (result); +} + +/* </JEB> */ + +#if 0 /* Pre Bossom */ + +#include <errno.h> + +#include "pthread.h" +#include "implement.h" + int pthread_setcancelstate(int state, int *oldstate) @@ -82,3 +321,5 @@ pthread_testcancel(void) } /* Never reached. */ } + +#endif /* Pre Bossom */ |