diff options
Diffstat (limited to 'lib/libkse/thread/thr_private.h')
| -rw-r--r-- | lib/libkse/thread/thr_private.h | 33 |
1 files changed, 16 insertions, 17 deletions
diff --git a/lib/libkse/thread/thr_private.h b/lib/libkse/thread/thr_private.h index e212a0b..3bfb7c0 100644 --- a/lib/libkse/thread/thr_private.h +++ b/lib/libkse/thread/thr_private.h @@ -403,6 +403,7 @@ struct pthread_attr { enum pthread_susp { SUSP_NO, /* Not suspended. */ SUSP_YES, /* Suspended. */ + SUSP_JOIN, /* Suspended, joining. */ SUSP_NOWAIT, /* Suspended, was in a mutex or condition queue. */ SUSP_MUTEX_WAIT,/* Suspended, still in a mutex queue. */ SUSP_COND_WAIT /* Suspended, still in a condition queue. */ @@ -573,7 +574,6 @@ union pthread_wait_data { FILE *fp; struct pthread_poll_data *poll_data; spinlock_t *spinlock; - struct pthread *thread; }; /* @@ -755,8 +755,8 @@ struct pthread { */ int error; - /* Join queue head and link for waiting threads: */ - TAILQ_HEAD(join_head, pthread) join_queue; + /* Pointer to a thread that is waiting to join (NULL if no joiner). */ + struct pthread *joiner; /* * The current thread can belong to only one scheduling queue at @@ -764,23 +764,24 @@ struct pthread { * * o A queue of threads waiting for a mutex * o A queue of threads waiting for a condition variable - * o A queue of threads waiting for another thread to terminate - * (the join queue above) * o A queue of threads waiting for a file descriptor lock * o A queue of threads needing work done by the kernel thread * (waiting for a spinlock or file I/O) * - * It is possible for a thread to belong to more than one of the - * above queues if it is handling a signal. A thread may only - * enter a mutex, condition variable, or join queue when it is - * not being called from a signal handler. If a thread is a + * A thread can also be joining a thread (the joiner field above). + * + * It must not be possible for a thread to belong to any of the + * above queues while it is handling a signal. Signal handlers + * may longjmp back to previous stack frames circumventing normal + * control flow. This could corrupt queue integrity if the thread + * retains membership in the queue. Therefore, if a thread is a * member of one of these queues when a signal handler is invoked, - * it must remain in the queue. For this reason, the links for - * these queues must not be (re)used for other queues. + * it must remove itself from the queue before calling the signal + * handler and reinsert itself after normal return of the handler. * * Use pqe for the scheduling queue link (both ready and waiting), - * sqe for synchronization (mutex, condition variable, and join) - * queue links, and qe for all other links. + * sqe for synchronization (mutex and condition variable) queue + * links, and qe for all other links. */ TAILQ_ENTRY(pthread) pqe; /* priority queue link */ TAILQ_ENTRY(pthread) sqe; /* synchronization queue link */ @@ -826,10 +827,9 @@ struct pthread { #define PTHREAD_FLAGS_IN_FDQ 0x0040 /* in fd lock queue using qe link */ #define PTHREAD_FLAGS_IN_CONDQ 0x0080 /* in condition queue using sqe link*/ #define PTHREAD_FLAGS_IN_MUTEXQ 0x0100 /* in mutex queue using sqe link */ -#define PTHREAD_FLAGS_IN_JOINQ 0x0200 /* in join queue using sqe link */ -#define PTHREAD_FLAGS_TRACE 0x0400 /* for debugging purposes */ +#define PTHREAD_FLAGS_TRACE 0x0200 /* for debugging purposes */ #define PTHREAD_FLAGS_IN_SYNCQ \ - (PTHREAD_FLAGS_IN_CONDQ | PTHREAD_FLAGS_IN_MUTEXQ | PTHREAD_FLAGS_IN_JOINQ) + (PTHREAD_FLAGS_IN_CONDQ | PTHREAD_FLAGS_IN_MUTEXQ) /* * Base priority is the user setable and retrievable priority @@ -1211,7 +1211,6 @@ int _find_dead_thread(pthread_t); int _find_thread(pthread_t); struct pthread *_get_curthread(void); void _set_curthread(struct pthread *); -void _join_backout(pthread_t); int _thread_create(pthread_t *,const pthread_attr_t *,void *(*start_routine)(void *),void *,pthread_t); int _thread_fd_lock(int, int, struct timespec *); int _thread_fd_lock_debug(int, int, struct timespec *,char *fname,int lineno); |
