diff options
Diffstat (limited to 'sysdeps/nptl/fork.c')
-rw-r--r-- | sysdeps/nptl/fork.c | 96 |
1 files changed, 3 insertions, 93 deletions
diff --git a/sysdeps/nptl/fork.c b/sysdeps/nptl/fork.c index 846fa49..f00dd64 100644 --- a/sysdeps/nptl/fork.c +++ b/sysdeps/nptl/fork.c @@ -48,11 +48,6 @@ pid_t __libc_fork (void) { pid_t pid; - struct used_handler - { - struct fork_handler *handler; - struct used_handler *next; - } *allp = NULL; /* Determine if we are running multiple threads. We skip some fork handlers in the single-thread case, to make fork safer to use in @@ -60,60 +55,7 @@ __libc_fork (void) but our current fork implementation is not. */ bool multiple_threads = THREAD_GETMEM (THREAD_SELF, header.multiple_threads); - /* Run all the registered preparation handlers. In reverse order. - While doing this we build up a list of all the entries. */ - struct fork_handler *runp; - while ((runp = __fork_handlers) != NULL) - { - /* Make sure we read from the current RUNP pointer. */ - atomic_full_barrier (); - - unsigned int oldval = runp->refcntr; - - if (oldval == 0) - /* This means some other thread removed the list just after - the pointer has been loaded. Try again. Either the list - is empty or we can retry it. */ - continue; - - /* Bump the reference counter. */ - if (atomic_compare_and_exchange_bool_acq (&__fork_handlers->refcntr, - oldval + 1, oldval)) - /* The value changed, try again. */ - continue; - - /* We bumped the reference counter for the first entry in the - list. That means that none of the following entries will - just go away. The unloading code works in the order of the - list. - - While executing the registered handlers we are building a - list of all the entries so that we can go backward later on. */ - while (1) - { - /* Execute the handler if there is one. */ - if (runp->prepare_handler != NULL) - runp->prepare_handler (); - - /* Create a new element for the list. */ - struct used_handler *newp - = (struct used_handler *) alloca (sizeof (*newp)); - newp->handler = runp; - newp->next = allp; - allp = newp; - - /* Advance to the next handler. */ - runp = runp->next; - if (runp == NULL) - break; - - /* Bump the reference counter for the next entry. */ - atomic_increment (&runp->refcntr); - } - - /* We are done. */ - break; - } + __run_fork_handlers (atfork_run_prepare); /* If we are not running multiple threads, we do not have to preserve lock state. If fork runs from a signal handler, only @@ -198,29 +140,7 @@ __libc_fork (void) __rtld_lock_initialize (GL(dl_load_lock)); /* Run the handlers registered for the child. */ - while (allp != NULL) - { - if (allp->handler->child_handler != NULL) - allp->handler->child_handler (); - - /* Note that we do not have to wake any possible waiter. - This is the only thread in the new process. The count - may have been bumped up by other threads doing a fork. - We reset it to 1, to avoid waiting for non-existing - thread(s) to release the count. */ - allp->handler->refcntr = 1; - - /* XXX We could at this point look through the object pool - and mark all objects not on the __fork_handlers list as - unused. This is necessary in case the fork() happened - while another thread called dlclose() and that call had - to create a new list. */ - - allp = allp->next; - } - - /* Initialize the fork lock. */ - __fork_lock = LLL_LOCK_INITIALIZER; + __run_fork_handlers (atfork_run_child); } else { @@ -235,17 +155,7 @@ __libc_fork (void) } /* Run the handlers registered for the parent. */ - while (allp != NULL) - { - if (allp->handler->parent_handler != NULL) - allp->handler->parent_handler (); - - if (atomic_decrement_and_test (&allp->handler->refcntr) - && allp->handler->need_signal) - futex_wake (&allp->handler->refcntr, 1, FUTEX_PRIVATE); - - allp = allp->next; - } + __run_fork_handlers (atfork_run_parent); } return pid; |