pid_t
__libc_fork (void)
{
pid_t pid;
struct used_handler
{
struct fork_handler *handler;
struct used_handler *next;
} *allp = NULL;
/* 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;
}
__UCLIBC_IO_MUTEX_LOCK_CANCEL_UNSAFE(_stdio_openlist_add_lock);
#ifndef NDEBUG
pid_t ppid = THREAD_GETMEM (THREAD_SELF, tid);
#endif
/* We need to prevent the getpid() code to update the PID field so
that, if a signal arrives in the child very early and the signal
handler uses getpid(), the value returned is correct. */
pid_t parentpid = THREAD_GETMEM (THREAD_SELF, pid);
THREAD_SETMEM (THREAD_SELF, pid, -parentpid);
#ifdef ARCH_FORK
pid = ARCH_FORK ();
#else
# error "ARCH_FORK must be defined so that the CLONE_SETTID flag is used"
pid = INLINE_SYSCALL (fork, 0);
#endif
if (pid == 0)
{
struct pthread *self = THREAD_SELF;
assert (THREAD_GETMEM (self, tid) != ppid);
if (__fork_generation_pointer != NULL)
*__fork_generation_pointer += 4;
/* Adjust the PID field for the new process. */
THREAD_SETMEM (self, pid, THREAD_GETMEM (self, tid));
#if HP_TIMING_AVAIL
/* The CPU clock of the thread and process have to be set to zero. */
hp_timing_t now;
HP_TIMING_NOW (now);
THREAD_SETMEM (self, cpuclock_offset, now);
GL(dl_cpuclock_offset) = now;
#endif
/* Reset the file list. These are recursive mutexes. */
fresetlockfiles ();
/* Reset locks in the I/O code. */
STDIO_INIT_MUTEX(_stdio_openlist_add_lock);
/* XXX reset any locks in dynamic loader */
/* 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;
}
else
{
assert (THREAD_GETMEM (THREAD_SELF, tid) == ppid);
/* Restore the PID value. */
THREAD_SETMEM (THREAD_SELF, pid, parentpid);
/* We execute this even if the 'fork' call failed. */
__UCLIBC_IO_MUTEX_UNLOCK_CANCEL_UNSAFE(_stdio_openlist_add_lock);
/* 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)
lll_futex_wake (allp->handler->refcntr, 1, LLL_PRIVATE);
allp = allp->next;
}
}
return pid;
}
int sem_timedwait(sem_t *sem, const struct timespec *abstime)
{
pthread_descr self = thread_self();
pthread_extricate_if extr;
int already_canceled = 0;
int spurious_wakeup_count;
__pthread_lock(&sem->__sem_lock, self);
if (sem->__sem_value > 0) {
--sem->__sem_value;
__pthread_unlock(&sem->__sem_lock);
return 0;
}
if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) {
/* The standard requires that if the function would block and the
time value is illegal, the function returns with an error. */
__pthread_unlock(&sem->__sem_lock);
__set_errno (EINVAL);
return -1;
}
/* Set up extrication interface */
extr.pu_object = sem;
extr.pu_extricate_func = new_sem_extricate_func;
/* Register extrication interface */
THREAD_SETMEM(self, p_sem_avail, 0);
__pthread_set_own_extricate_if(self, &extr);
/* Enqueue only if not already cancelled. */
if (!(THREAD_GETMEM(self, p_canceled)
&& THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE))
enqueue(&sem->__sem_waiting, self);
else
already_canceled = 1;
__pthread_unlock(&sem->__sem_lock);
if (already_canceled) {
__pthread_set_own_extricate_if(self, 0);
__pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME);
}
spurious_wakeup_count = 0;
while (1)
{
if (timedsuspend(self, abstime) == 0) {
int was_on_queue;
/* __pthread_lock will queue back any spurious restarts that
may happen to it. */
__pthread_lock(&sem->__sem_lock, self);
was_on_queue = remove_from_queue(&sem->__sem_waiting, self);
__pthread_unlock(&sem->__sem_lock);
if (was_on_queue) {
__pthread_set_own_extricate_if(self, 0);
__set_errno (ETIMEDOUT);
return -1;
}
/* Eat the outstanding restart() from the signaller */
suspend(self);
}
if (THREAD_GETMEM(self, p_sem_avail) == 0
&& (THREAD_GETMEM(self, p_woken_by_cancel) == 0
|| THREAD_GETMEM(self, p_cancelstate) != PTHREAD_CANCEL_ENABLE))
{
/* Count resumes that don't belong to us. */
spurious_wakeup_count++;
continue;
}
break;
}
__pthread_set_own_extricate_if(self, 0);
/* Terminate only if the wakeup came from cancellation. */
/* Otherwise ignore cancellation because we got the semaphore. */
if (THREAD_GETMEM(self, p_woken_by_cancel)
&& THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE) {
THREAD_SETMEM(self, p_woken_by_cancel, 0);
__pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME);
}
/* We got the semaphore */
return 0;
}
int sem_wait(sem_t * sem)
{
volatile pthread_descr self = thread_self();
pthread_extricate_if extr;
int already_canceled = 0;
int spurious_wakeup_count;
/* Set up extrication interface */
extr.pu_object = sem;
extr.pu_extricate_func = new_sem_extricate_func;
__pthread_lock(&sem->__sem_lock, self);
if (sem->__sem_value > 0) {
sem->__sem_value--;
__pthread_unlock(&sem->__sem_lock);
return 0;
}
/* Register extrication interface */
THREAD_SETMEM(self, p_sem_avail, 0);
__pthread_set_own_extricate_if(self, &extr);
/* Enqueue only if not already cancelled. */
if (!(THREAD_GETMEM(self, p_canceled)
&& THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE))
enqueue(&sem->__sem_waiting, self);
else
already_canceled = 1;
__pthread_unlock(&sem->__sem_lock);
if (already_canceled) {
__pthread_set_own_extricate_if(self, 0);
__pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME);
}
/* Wait for sem_post or cancellation, or fall through if already canceled */
spurious_wakeup_count = 0;
while (1)
{
suspend(self);
if (THREAD_GETMEM(self, p_sem_avail) == 0
&& (THREAD_GETMEM(self, p_woken_by_cancel) == 0
|| THREAD_GETMEM(self, p_cancelstate) != PTHREAD_CANCEL_ENABLE))
{
/* Count resumes that don't belong to us. */
spurious_wakeup_count++;
continue;
}
break;
}
__pthread_set_own_extricate_if(self, 0);
/* Terminate only if the wakeup came from cancellation. */
/* Otherwise ignore cancellation because we got the semaphore. */
if (THREAD_GETMEM(self, p_woken_by_cancel)
&& THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE) {
THREAD_SETMEM(self, p_woken_by_cancel, 0);
__pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME);
}
/* We got the semaphore */
return 0;
}
int
__pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
{
pthread_descr torestart;
pthread_descr th;
__pthread_lock (&rwlock->__rw_lock, NULL);
if (rwlock->__rw_writer != NULL)
{
/* Unlocking a write lock. */
if (rwlock->__rw_writer != thread_self ())
{
__pthread_unlock (&rwlock->__rw_lock);
return EPERM;
}
rwlock->__rw_writer = NULL;
if ((rwlock->__rw_kind == PTHREAD_RWLOCK_PREFER_READER_NP
&& !queue_is_empty(&rwlock->__rw_read_waiting))
|| (th = dequeue(&rwlock->__rw_write_waiting)) == NULL)
{
/* Restart all waiting readers. */
torestart = rwlock->__rw_read_waiting;
rwlock->__rw_read_waiting = NULL;
__pthread_unlock (&rwlock->__rw_lock);
while ((th = dequeue (&torestart)) != NULL)
restart (th);
}
else
{
/* Restart one waiting writer. */
__pthread_unlock (&rwlock->__rw_lock);
restart (th);
}
}
else
{
/* Unlocking a read lock. */
if (rwlock->__rw_readers == 0)
{
__pthread_unlock (&rwlock->__rw_lock);
return EPERM;
}
--rwlock->__rw_readers;
if (rwlock->__rw_readers == 0)
/* Restart one waiting writer, if any. */
th = dequeue (&rwlock->__rw_write_waiting);
else
th = NULL;
__pthread_unlock (&rwlock->__rw_lock);
if (th != NULL)
restart (th);
/* Recursive lock fixup */
if (rwlock->__rw_kind == PTHREAD_RWLOCK_PREFER_WRITER_NP)
{
pthread_descr self = thread_self();
pthread_readlock_info *victim = rwlock_remove_from_list(self, rwlock);
if (victim != NULL)
{
if (victim->pr_lock_count == 0)
{
victim->pr_next = THREAD_GETMEM (self, p_readlock_free);
THREAD_SETMEM (self, p_readlock_free, victim);
}
}
else
{
int val = THREAD_GETMEM (self, p_untracked_readlock_count);
if (val > 0)
THREAD_SETMEM (self, p_untracked_readlock_count, val - 1);
}
}
}
return 0;
}
static int
do_clone (struct pthread *pd, const struct pthread_attr *attr,
int clone_flags, int (*fct) (void *), STACK_VARIABLES_PARMS,
int stopped)
{
flexsc_check_enabled();
#ifdef PREPARE_CREATE
PREPARE_CREATE;
#endif
if (__builtin_expect (stopped != 0, 0))
/* We make sure the thread does not run far by forcing it to get a
lock. We lock it here too so that the new thread cannot continue
until we tell it to. */
lll_lock (pd->lock, LLL_PRIVATE);
/* One more thread. We cannot have the thread do this itself, since it
might exist but not have been scheduled yet by the time we've returned
and need to check the value to behave correctly. We must do it before
creating the thread, in case it does get scheduled first and then
might mistakenly think it was the only thread. In the failure case,
we momentarily store a false value; this doesn't matter because there
is no kosher thing a signal handler interrupting us right here can do
that cares whether the thread count is correct. */
atomic_increment (&__nptl_nthreads);
if (ARCH_CLONE (fct, STACK_VARIABLES_ARGS, clone_flags,
pd, &pd->tid, TLS_VALUE, &pd->tid) == -1)
{
atomic_decrement (&__nptl_nthreads); /* Oops, we lied for a second. */
/* Failed. If the thread is detached, remove the TCB here since
the caller cannot do this. The caller remembered the thread
as detached and cannot reverify that it is not since it must
not access the thread descriptor again. */
if (IS_DETACHED (pd))
__deallocate_stack (pd);
/* We have to translate error codes. */
return errno == ENOMEM ? EAGAIN : errno;
}
/* Now we have the possibility to set scheduling parameters etc. */
if (__builtin_expect (stopped != 0, 0))
{
INTERNAL_SYSCALL_DECL (err);
int res = 0;
/* Set the affinity mask if necessary. */
if (attr->cpuset != NULL)
{
res = INTERNAL_SYSCALL (sched_setaffinity, err, 3, pd->tid,
attr->cpusetsize, attr->cpuset);
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (res, err), 0))
{
/* The operation failed. We have to kill the thread. First
send it the cancellation signal. */
INTERNAL_SYSCALL_DECL (err2);
err_out:
#if __ASSUME_TGKILL
(void) INTERNAL_SYSCALL (tgkill, err2, 3,
THREAD_GETMEM (THREAD_SELF, pid),
pd->tid, SIGCANCEL);
#else
(void) INTERNAL_SYSCALL (tkill, err2, 2, pd->tid, SIGCANCEL);
#endif
return (INTERNAL_SYSCALL_ERROR_P (res, err)
? INTERNAL_SYSCALL_ERRNO (res, err)
: 0);
}
}
/* Set the scheduling parameters. */
if ((attr->flags & ATTR_FLAG_NOTINHERITSCHED) != 0)
{
res = INTERNAL_SYSCALL (sched_setscheduler, err, 3, pd->tid,
pd->schedpolicy, &pd->schedparam);
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (res, err), 0))
goto err_out;
}
}
/* We now have for sure more than one thread. The main thread might
not yet have the flag set. No need to set the global variable
again if this is what we use. */
THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
return 0;
}
int pthread_join(pthread_t thread_id, void ** thread_return)
{
volatile pthread_descr self = thread_self();
struct pthread_request request;
pthread_handle handle = thread_handle(thread_id);
pthread_descr th;
pthread_extricate_if extr;
int already_canceled = 0;
PDEBUG("\n");
/* Set up extrication interface */
extr.pu_object = handle;
extr.pu_extricate_func = join_extricate_func;
__pthread_lock(&handle->h_lock, self);
if (invalid_handle(handle, thread_id)) {
__pthread_unlock(&handle->h_lock);
return ESRCH;
}
th = handle->h_descr;
if (th == self) {
__pthread_unlock(&handle->h_lock);
return EDEADLK;
}
/* If detached or already joined, error */
if (th->p_detached || th->p_joining != NULL) {
__pthread_unlock(&handle->h_lock);
return EINVAL;
}
/* If not terminated yet, suspend ourselves. */
if (! th->p_terminated) {
/* Register extrication interface */
__pthread_set_own_extricate_if(self, &extr);
if (!(THREAD_GETMEM(self, p_canceled)
&& THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE))
th->p_joining = self;
else
already_canceled = 1;
__pthread_unlock(&handle->h_lock);
if (already_canceled) {
__pthread_set_own_extricate_if(self, 0);
__pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME);
}
PDEBUG("before suspend\n");
suspend(self);
PDEBUG("after suspend\n");
/* Deregister extrication interface */
__pthread_set_own_extricate_if(self, 0);
/* This is a cancellation point */
if (THREAD_GETMEM(self, p_woken_by_cancel)
&& THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE) {
THREAD_SETMEM(self, p_woken_by_cancel, 0);
__pthread_do_exit(PTHREAD_CANCELED, CURRENT_STACK_FRAME);
}
__pthread_lock(&handle->h_lock, self);
}
/* Get return value */
if (thread_return != NULL) *thread_return = th->p_retval;
__pthread_unlock(&handle->h_lock);
/* Send notification to thread manager */
if (__pthread_manager_request >= 0) {
request.req_thread = self;
request.req_kind = REQ_FREE;
request.req_args.free.thread_id = thread_id;
TEMP_FAILURE_RETRY(__libc_write(__pthread_manager_request,
(char *) &request, sizeof(request)));
}
return 0;
}
void __pthread_do_exit(void *retval, char *currentframe)
{
pthread_descr self = thread_self();
pthread_descr joining;
struct pthread_request request;
PDEBUG("self=%p, pid=%d\n", self, self->p_pid);
/* obey POSIX behavior and prevent cancellation functions from
* being called more than once.
* http://sourceware.org/ml/libc-ports/2006-10/msg00043.html
*/
THREAD_SETMEM(self, p_cancelstate, PTHREAD_CANCEL_DISABLE);
THREAD_SETMEM(self, p_canceltype, PTHREAD_CANCEL_DEFERRED);
/* Call cleanup functions and destroy the thread-specific data */
__pthread_perform_cleanup(currentframe);
__pthread_destroy_specifics();
/* Store return value */
__pthread_lock(THREAD_GETMEM(self, p_lock), self);
THREAD_SETMEM(self, p_retval, retval);
/* See whether we have to signal the death. */
if (THREAD_GETMEM(self, p_report_events))
{
/* See whether TD_DEATH is in any of the mask. */
int idx = __td_eventword (TD_DEATH);
uint32_t mask = __td_eventmask (TD_DEATH);
if ((mask & (__pthread_threads_events.event_bits[idx]
| THREAD_GETMEM_NC(self,
p_eventbuf.eventmask).event_bits[idx]))
!= 0)
{
/* Yep, we have to signal the death. */
THREAD_SETMEM(self, p_eventbuf.eventnum, TD_DEATH);
THREAD_SETMEM(self, p_eventbuf.eventdata, self);
__pthread_last_event = self;
/* Now call the function to signal the event. */
__linuxthreads_death_event();
}
}
/* Say that we've terminated */
THREAD_SETMEM(self, p_terminated, 1);
/* See if someone is joining on us */
joining = THREAD_GETMEM(self, p_joining);
PDEBUG("joining = %p, pid=%d\n", joining, joining->p_pid);
__pthread_unlock(THREAD_GETMEM(self, p_lock));
/* Restart joining thread if any */
if (joining != NULL) restart(joining);
/* If this is the initial thread, block until all threads have terminated.
If another thread calls exit, we'll be terminated from our signal
handler. */
if (self == __pthread_main_thread && __pthread_manager_request >= 0) {
request.req_thread = self;
request.req_kind = REQ_MAIN_THREAD_EXIT;
TEMP_FAILURE_RETRY(__libc_write(__pthread_manager_request,
(char *)&request, sizeof(request)));
suspend(self);
/* Main thread flushes stdio streams and runs atexit functions.
* It also calls a handler within LinuxThreads which sends a process exit
* request to the thread manager. */
exit(0);
}
/* Exit the process (but don't flush stdio streams, and don't run
atexit functions). */
_exit(0);
}
pid_t
__libc_fork (void)
{
pid_t pid;
struct used_handler
{
struct fork_handler *handler;
struct used_handler *next;
} *allp = NULL;
/* 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;
}
_IO_list_lock ();
#ifndef NDEBUG
pid_t ppid = THREAD_GETMEM (THREAD_SELF, tid);
#endif
/* We need to prevent the getpid() code to update the PID field so
that, if a signal arrives in the child very early and the signal
handler uses getpid(), the value returned is correct. */
pid_t parentpid = THREAD_GETMEM (THREAD_SELF, pid);
THREAD_SETMEM (THREAD_SELF, pid, -parentpid);
#ifdef ARCH_FORK
pid = ARCH_FORK ();
#else
# error "ARCH_FORK must be defined so that the CLONE_SETTID flag is used"
pid = INLINE_SYSCALL (fork, 0);
#endif
if (pid == 0)
{
struct pthread *self = THREAD_SELF;
assert (THREAD_GETMEM (self, tid) != ppid);
if (__fork_generation_pointer != NULL)
*__fork_generation_pointer += 4;
/* Adjust the PID field for the new process. */
THREAD_SETMEM (self, pid, THREAD_GETMEM (self, tid));
#if HP_TIMING_AVAIL
/* The CPU clock of the thread and process have to be set to zero. */
hp_timing_t now;
HP_TIMING_NOW (now);
THREAD_SETMEM (self, cpuclock_offset, now);
GL(dl_cpuclock_offset) = now;
#endif
#ifdef __NR_set_robust_list
/* Initialize the robust mutex list which has been reset during
the fork. We do not check for errors since if it fails here
it failed at process start as well and noone could have used
robust mutexes. We also do not have to set
self->robust_head.futex_offset since we inherit the correct
value from the parent. */
# ifdef SHARED
if (__builtin_expect (__libc_pthread_functions_init, 0))
PTHFCT_CALL (ptr_set_robust, (self));
# else
extern __typeof (__nptl_set_robust) __nptl_set_robust
__attribute__((weak));
if (__builtin_expect (__nptl_set_robust != NULL, 0))
__nptl_set_robust (self);
# endif
#endif
/* Reset the file list. These are recursive mutexes. */
fresetlockfiles ();
/* Reset locks in the I/O code. */
_IO_list_resetlock ();
/* Reset the lock the dynamic loader uses to protect its data. */
__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;
}
else
{
void
__pthread_initialize_minimal_internal (void)
{
/* Minimal initialization of the thread descriptor. */
struct pthread *pd = THREAD_SELF;
__pthread_initialize_pids (pd);
THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
THREAD_SETMEM (pd, user_stack, true);
if (LLL_LOCK_INITIALIZER != 0)
THREAD_SETMEM (pd, lock, LLL_LOCK_INITIALIZER);
#if HP_TIMING_AVAIL
THREAD_SETMEM (pd, cpuclock_offset, GL(dl_cpuclock_offset));
#endif
/* Initialize the robust mutex data. */
{
#ifdef __PTHREAD_MUTEX_HAVE_PREV
pd->robust_prev = &pd->robust_head;
#endif
pd->robust_head.list = &pd->robust_head;
#ifdef __NR_set_robust_list
pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock)
- offsetof (pthread_mutex_t,
__data.__list.__next));
INTERNAL_SYSCALL_DECL (err);
int res = INTERNAL_SYSCALL (set_robust_list, err, 2, &pd->robust_head,
sizeof (struct robust_list_head));
if (INTERNAL_SYSCALL_ERROR_P (res, err))
#endif
set_robust_list_not_avail ();
}
#ifdef __NR_futex
# ifndef __ASSUME_PRIVATE_FUTEX
/* Private futexes are always used (at least internally) so that
doing the test once this early is beneficial. */
{
int word = 0;
INTERNAL_SYSCALL_DECL (err);
word = INTERNAL_SYSCALL (futex, err, 3, &word,
FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1);
if (!INTERNAL_SYSCALL_ERROR_P (word, err))
THREAD_SETMEM (pd, header.private_futex, FUTEX_PRIVATE_FLAG);
}
/* Private futexes have been introduced earlier than the
FUTEX_CLOCK_REALTIME flag. We don't have to run the test if we
know the former are not supported. This also means we know the
kernel will return ENOSYS for unknown operations. */
if (THREAD_GETMEM (pd, header.private_futex) != 0)
# endif
# ifndef __ASSUME_FUTEX_CLOCK_REALTIME
{
int word = 0;
/* NB: the syscall actually takes six parameters. The last is the
bit mask. But since we will not actually wait at all the value
is irrelevant. Given that passing six parameters is difficult
on some architectures we just pass whatever random value the
calling convention calls for to the kernel. It causes no harm. */
INTERNAL_SYSCALL_DECL (err);
word = INTERNAL_SYSCALL (futex, err, 5, &word,
FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME
| FUTEX_PRIVATE_FLAG, 1, NULL, 0);
assert (INTERNAL_SYSCALL_ERROR_P (word, err));
if (INTERNAL_SYSCALL_ERRNO (word, err) != ENOSYS)
__set_futex_clock_realtime ();
}
# endif
#endif
/* Set initial thread's stack block from 0 up to __libc_stack_end.
It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
purposes this is good enough. */
THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end);
/* Initialize the list of all running threads with the main thread. */
INIT_LIST_HEAD (&__stack_user);
list_add (&pd->list, &__stack_user);
/* Before initializing __stack_user, the debugger could not find us and
had to set __nptl_initial_report_events. Propagate its setting. */
THREAD_SETMEM (pd, report_events, __nptl_initial_report_events);
#if defined SIGCANCEL || defined SIGSETXID
struct sigaction sa;
__sigemptyset (&sa.sa_mask);
# ifdef SIGCANCEL
/* Install the cancellation signal handler. If for some reason we
cannot install the handler we do not abort. Maybe we should, but
it is only asynchronous cancellation which is affected. */
sa.sa_sigaction = sigcancel_handler;
sa.sa_flags = SA_SIGINFO;
(void) __libc_sigaction (SIGCANCEL, &sa, NULL);
# endif
# ifdef SIGSETXID
/* Install the handle to change the threads' uid/gid. */
sa.sa_sigaction = sighandler_setxid;
sa.sa_flags = SA_SIGINFO | SA_RESTART;
(void) __libc_sigaction (SIGSETXID, &sa, NULL);
# endif
/* The parent process might have left the signals blocked. Just in
case, unblock it. We reuse the signal mask in the sigaction
structure. It is already cleared. */
# ifdef SIGCANCEL
__sigaddset (&sa.sa_mask, SIGCANCEL);
# endif
# ifdef SIGSETXID
__sigaddset (&sa.sa_mask, SIGSETXID);
# endif
{
INTERNAL_SYSCALL_DECL (err);
(void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &sa.sa_mask,
NULL, _NSIG / 8);
}
#endif
/* Get the size of the static and alignment requirements for the TLS
block. */
size_t static_tls_align;
_dl_get_tls_static_info (&__static_tls_size, &static_tls_align);
/* Make sure the size takes all the alignments into account. */
if (STACK_ALIGN > static_tls_align)
static_tls_align = STACK_ALIGN;
__static_tls_align_m1 = static_tls_align - 1;
__static_tls_size = roundup (__static_tls_size, static_tls_align);
/* Determine the default allowed stack size. This is the size used
in case the user does not specify one. */
struct rlimit limit;
if (__getrlimit (RLIMIT_STACK, &limit) != 0
|| limit.rlim_cur == RLIM_INFINITY)
/* The system limit is not usable. Use an architecture-specific
default. */
limit.rlim_cur = ARCH_STACK_DEFAULT_SIZE;
else if (limit.rlim_cur < PTHREAD_STACK_MIN)
/* The system limit is unusably small.
Use the minimal size acceptable. */
limit.rlim_cur = PTHREAD_STACK_MIN;
/* Make sure it meets the minimum size that allocate_stack
(allocatestack.c) will demand, which depends on the page size. */
const uintptr_t pagesz = GLRO(dl_pagesize);
const size_t minstack = pagesz + __static_tls_size + MINIMAL_REST_STACK;
if (limit.rlim_cur < minstack)
limit.rlim_cur = minstack;
/* Round the resource limit up to page size. */
limit.rlim_cur = ALIGN_UP (limit.rlim_cur, pagesz);
lll_lock (__default_pthread_attr_lock, LLL_PRIVATE);
__default_pthread_attr.stacksize = limit.rlim_cur;
__default_pthread_attr.guardsize = GLRO (dl_pagesize);
lll_unlock (__default_pthread_attr_lock, LLL_PRIVATE);
#ifdef SHARED
/* Make __rtld_lock_{,un}lock_recursive use pthread_mutex_{,un}lock,
keep the lock count from the ld.so implementation. */
GL(dl_rtld_lock_recursive) = (void *) __pthread_mutex_lock;
GL(dl_rtld_unlock_recursive) = (void *) __pthread_mutex_unlock;
unsigned int rtld_lock_count = GL(dl_load_lock).mutex.__data.__count;
GL(dl_load_lock).mutex.__data.__count = 0;
while (rtld_lock_count-- > 0)
__pthread_mutex_lock (&GL(dl_load_lock).mutex);
GL(dl_make_stack_executable_hook) = &__make_stacks_executable;
#endif
GL(dl_init_static_tls) = &__pthread_init_static_tls;
GL(dl_wait_lookup_done) = &__wait_lookup_done;
/* Register the fork generation counter with the libc. */
#ifndef TLS_MULTIPLE_THREADS_IN_TCB
__libc_multiple_threads_ptr =
#endif
__libc_pthread_init (&__fork_generation, __reclaim_stacks,
ptr_pthread_functions);
/* Determine whether the machine is SMP or not. */
__is_smp = is_smp_system ();
}
int __pthread_initialize_manager(void)
{
int manager_pipe[2];
int pid;
int report_events;
struct pthread_request request;
*__libc_multiple_threads_ptr = 1;
/* If basic initialization not done yet (e.g. we're called from a
constructor run before our constructor), do it now */
if (__pthread_initial_thread_bos == NULL) pthread_initialize();
/* Setup stack for thread manager */
__pthread_manager_thread_bos = malloc(THREAD_MANAGER_STACK_SIZE);
if (__pthread_manager_thread_bos == NULL) return -1;
__pthread_manager_thread_tos =
__pthread_manager_thread_bos + THREAD_MANAGER_STACK_SIZE;
/* On non-MMU systems we make sure that the initial thread bounds don't overlap
* with the manager stack frame */
NOMMU_INITIAL_THREAD_BOUNDS(__pthread_manager_thread_tos,__pthread_manager_thread_bos);
PDEBUG("manager stack: size=%d, bos=%p, tos=%p\n", THREAD_MANAGER_STACK_SIZE,
__pthread_manager_thread_bos, __pthread_manager_thread_tos);
#if 0
PDEBUG("initial stack: estimate bos=%p, tos=%p\n",
__pthread_initial_thread_bos, __pthread_initial_thread_tos);
#endif
/* Setup pipe to communicate with thread manager */
if (pipe(manager_pipe) == -1) {
free(__pthread_manager_thread_bos);
return -1;
}
/* Start the thread manager */
pid = 0;
#ifdef USE_TLS
if (__linuxthreads_initial_report_events != 0)
THREAD_SETMEM (((pthread_descr) NULL), p_report_events,
__linuxthreads_initial_report_events);
report_events = THREAD_GETMEM (((pthread_descr) NULL), p_report_events);
#else
if (__linuxthreads_initial_report_events != 0)
__pthread_initial_thread.p_report_events
= __linuxthreads_initial_report_events;
report_events = __pthread_initial_thread.p_report_events;
#endif
if (__builtin_expect (report_events, 0))
{
/* It's a bit more complicated. We have to report the creation of
the manager thread. */
int idx = __td_eventword (TD_CREATE);
uint32_t mask = __td_eventmask (TD_CREATE);
if ((mask & (__pthread_threads_events.event_bits[idx]
| __pthread_initial_thread.p_eventbuf.eventmask.event_bits[idx]))
!= 0)
{
__pthread_lock(__pthread_manager_thread.p_lock, NULL);
#ifdef __ia64__
pid = __clone2(__pthread_manager_event,
(void **) __pthread_manager_thread_tos,
THREAD_MANAGER_STACK_SIZE,
CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND,
(void *)(long)manager_pipe[0]);
#else
pid = clone(__pthread_manager_event,
(void **) __pthread_manager_thread_tos,
CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND,
(void *)(long)manager_pipe[0]);
#endif
if (pid != -1)
{
/* Now fill in the information about the new thread in
the newly created thread's data structure. We cannot let
the new thread do this since we don't know whether it was
already scheduled when we send the event. */
__pthread_manager_thread.p_eventbuf.eventdata =
&__pthread_manager_thread;
__pthread_manager_thread.p_eventbuf.eventnum = TD_CREATE;
__pthread_last_event = &__pthread_manager_thread;
__pthread_manager_thread.p_tid = 2* PTHREAD_THREADS_MAX + 1;
__pthread_manager_thread.p_pid = pid;
/* Now call the function which signals the event. */
__linuxthreads_create_event ();
}
/* Now restart the thread. */
__pthread_unlock(__pthread_manager_thread.p_lock);
}
}
if (pid == 0) {
#ifdef __ia64__
pid = __clone2(__pthread_manager, (void **) __pthread_manager_thread_tos,
THREAD_MANAGER_STACK_SIZE,
CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND,
(void *)(long)manager_pipe[0]);
#else
pid = clone(__pthread_manager, (void **) __pthread_manager_thread_tos,
CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND,
(void *)(long)manager_pipe[0]);
#endif
}
if (pid == -1) {
free(__pthread_manager_thread_bos);
__libc_close(manager_pipe[0]);
__libc_close(manager_pipe[1]);
return -1;
}
__pthread_manager_request = manager_pipe[1]; /* writing end */
__pthread_manager_reader = manager_pipe[0]; /* reading end */
__pthread_manager_thread.p_tid = 2* PTHREAD_THREADS_MAX + 1;
__pthread_manager_thread.p_pid = pid;
/* Make gdb aware of new thread manager */
if (__pthread_threads_debug && __pthread_sig_debug > 0)
{
raise(__pthread_sig_debug);
/* We suspend ourself and gdb will wake us up when it is
ready to handle us. */
__pthread_wait_for_restart_signal(thread_self());
}
/* Synchronize debugging of the thread manager */
PDEBUG("send REQ_DEBUG to manager thread\n");
request.req_kind = REQ_DEBUG;
TEMP_FAILURE_RETRY(__libc_write(__pthread_manager_request,
(char *) &request, sizeof(request)));
return 0;
}
void
__pthread_initialize_minimal_internal (void)
{
#ifndef SHARED
/* Unlike in the dynamically linked case the dynamic linker has not
taken care of initializing the TLS data structures. */
__libc_setup_tls (TLS_TCB_SIZE, TLS_TCB_ALIGN);
/* We must prevent gcc from being clever and move any of the
following code ahead of the __libc_setup_tls call. This function
will initialize the thread register which is subsequently
used. */
__asm __volatile ("");
#endif
/* Minimal initialization of the thread descriptor. */
struct pthread *pd = THREAD_SELF;
INTERNAL_SYSCALL_DECL (err);
pd->pid = pd->tid = INTERNAL_SYSCALL (set_tid_address, err, 1, &pd->tid);
#ifdef __PTHREAD_MUTEX_HAVE_PREV
pd->robust_list.__prev = &pd->robust_list;
#endif
pd->robust_list.__next = &pd->robust_list;
THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
THREAD_SETMEM (pd, user_stack, true);
if (LLL_LOCK_INITIALIZER != 0)
THREAD_SETMEM (pd, lock, LLL_LOCK_INITIALIZER);
#if HP_TIMING_AVAIL
THREAD_SETMEM (pd, cpuclock_offset, GL(dl_cpuclock_offset));
#endif
/* Set initial thread's stack block from 0 up to __libc_stack_end.
It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
purposes this is good enough. */
THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end);
/* Initialize the list of all running threads with the main thread. */
INIT_LIST_HEAD (&__stack_user);
list_add (&pd->list, &__stack_user);
/* Install the cancellation signal handler. If for some reason we
cannot install the handler we do not abort. Maybe we should, but
it is only asynchronous cancellation which is affected. */
struct sigaction sa;
sa.sa_sigaction = sigcancel_handler;
sa.sa_flags = SA_SIGINFO;
__sigemptyset (&sa.sa_mask);
(void) __libc_sigaction (SIGCANCEL, &sa, NULL);
/* Install the handle to change the threads' uid/gid. */
sa.sa_sigaction = sighandler_setxid;
sa.sa_flags = SA_SIGINFO | SA_RESTART;
(void) __libc_sigaction (SIGSETXID, &sa, NULL);
/* The parent process might have left the signals blocked. Just in
case, unblock it. We reuse the signal mask in the sigaction
structure. It is already cleared. */
__sigaddset (&sa.sa_mask, SIGCANCEL);
__sigaddset (&sa.sa_mask, SIGSETXID);
(void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &sa.sa_mask,
NULL, _NSIG / 8);
/* Get the size of the static and alignment requirements for the TLS
block. */
size_t static_tls_align;
_dl_get_tls_static_info (&__static_tls_size, &static_tls_align);
/* Make sure the size takes all the alignments into account. */
if (STACK_ALIGN > static_tls_align)
static_tls_align = STACK_ALIGN;
__static_tls_align_m1 = static_tls_align - 1;
__static_tls_size = roundup (__static_tls_size, static_tls_align);
/* Determine the default allowed stack size. This is the size used
in case the user does not specify one. */
struct rlimit limit;
if (getrlimit (RLIMIT_STACK, &limit) != 0
|| limit.rlim_cur == RLIM_INFINITY)
/* The system limit is not usable. Use an architecture-specific
default. */
limit.rlim_cur = ARCH_STACK_DEFAULT_SIZE;
else if (limit.rlim_cur < PTHREAD_STACK_MIN)
/* The system limit is unusably small.
Use the minimal size acceptable. */
limit.rlim_cur = PTHREAD_STACK_MIN;
/* Make sure it meets the minimum size that allocate_stack
(allocatestack.c) will demand, which depends on the page size. */
const uintptr_t pagesz = __sysconf (_SC_PAGESIZE);
const size_t minstack = pagesz + __static_tls_size + MINIMAL_REST_STACK;
if (limit.rlim_cur < minstack)
limit.rlim_cur = minstack;
/* Round the resource limit up to page size. */
limit.rlim_cur = (limit.rlim_cur + pagesz - 1) & -pagesz;
__default_stacksize = limit.rlim_cur;
#ifdef SHARED
/* Transfer the old value from the dynamic linker's internal location. */
*__libc_dl_error_tsd () = *(*GL(dl_error_catch_tsd)) ();
GL(dl_error_catch_tsd) = &__libc_dl_error_tsd;
/* Make __rtld_lock_{,un}lock_recursive use pthread_mutex_{,un}lock,
keep the lock count from the ld.so implementation. */
GL(dl_rtld_lock_recursive) = (void *) INTUSE (__pthread_mutex_lock);
GL(dl_rtld_unlock_recursive) = (void *) INTUSE (__pthread_mutex_unlock);
unsigned int rtld_lock_count = GL(dl_load_lock).mutex.__data.__count;
GL(dl_load_lock).mutex.__data.__count = 0;
while (rtld_lock_count-- > 0)
INTUSE (__pthread_mutex_lock) (&GL(dl_load_lock).mutex);
GL(dl_make_stack_executable_hook) = &__make_stacks_executable;
#endif
GL(dl_init_static_tls) = &__pthread_init_static_tls;
/* Register the fork generation counter with the libc. */
#ifndef TLS_MULTIPLE_THREADS_IN_TCB
__libc_multiple_threads_ptr =
#endif
__libc_pthread_init (&__fork_generation, __reclaim_stacks,
ptr_pthread_functions);
/* Determine whether the machine is SMP or not. */
__is_smp = is_smp_system ();
}
static int
__pthread_mutex_lock_full (pthread_mutex_t *mutex)
{
int oldval;
pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
switch (PTHREAD_MUTEX_TYPE (mutex))
{
case PTHREAD_MUTEX_ROBUST_RECURSIVE_NP:
case PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP:
case PTHREAD_MUTEX_ROBUST_NORMAL_NP:
case PTHREAD_MUTEX_ROBUST_ADAPTIVE_NP:
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
&mutex->__data.__list.__next);
oldval = mutex->__data.__lock;
do
{
again:
if ((oldval & FUTEX_OWNER_DIED) != 0)
{
/* The previous owner died. Try locking the mutex. */
int newval = id;
#ifdef NO_INCR
newval |= FUTEX_WAITERS;
#else
newval |= (oldval & FUTEX_WAITERS);
#endif
newval
= atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
newval, oldval);
if (newval != oldval)
{
oldval = newval;
goto again;
}
/* We got the mutex. */
mutex->__data.__count = 1;
/* But it is inconsistent unless marked otherwise. */
mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT;
ENQUEUE_MUTEX (mutex);
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
/* Note that we deliberately exit here. If we fall
through to the end of the function __nusers would be
incremented which is not correct because the old
owner has to be discounted. If we are not supposed
to increment __nusers we actually have to decrement
it here. */
#ifdef NO_INCR
--mutex->__data.__nusers;
#endif
return EOWNERDEAD;
}
/* Check whether we already hold the mutex. */
if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0))
{
int kind = PTHREAD_MUTEX_TYPE (mutex);
if (kind == PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP)
{
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
NULL);
return EDEADLK;
}
if (kind == PTHREAD_MUTEX_ROBUST_RECURSIVE_NP)
{
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
NULL);
/* Just bump the counter. */
if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
/* Overflow of the counter. */
return EAGAIN;
++mutex->__data.__count;
return 0;
}
}
oldval = LLL_ROBUST_MUTEX_LOCK (mutex, id);
if (__builtin_expect (mutex->__data.__owner
== PTHREAD_MUTEX_NOTRECOVERABLE, 0))
{
/* This mutex is now not recoverable. */
mutex->__data.__count = 0;
lll_unlock (mutex->__data.__lock,
PTHREAD_ROBUST_MUTEX_PSHARED (mutex));
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
return ENOTRECOVERABLE;
}
}
while ((oldval & FUTEX_OWNER_DIED) != 0);
mutex->__data.__count = 1;
ENQUEUE_MUTEX (mutex);
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
break;
case PTHREAD_MUTEX_PI_RECURSIVE_NP:
case PTHREAD_MUTEX_PI_ERRORCHECK_NP:
case PTHREAD_MUTEX_PI_NORMAL_NP:
case PTHREAD_MUTEX_PI_ADAPTIVE_NP:
case PTHREAD_MUTEX_PI_ROBUST_RECURSIVE_NP:
case PTHREAD_MUTEX_PI_ROBUST_ERRORCHECK_NP:
case PTHREAD_MUTEX_PI_ROBUST_NORMAL_NP:
case PTHREAD_MUTEX_PI_ROBUST_ADAPTIVE_NP:
{
int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP;
int robust = mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP;
if (robust)
/* Note: robust PI futexes are signaled by setting bit 0. */
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
(void *) (((uintptr_t) &mutex->__data.__list.__next)
| 1));
oldval = mutex->__data.__lock;
/* Check whether we already hold the mutex. */
if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0))
{
if (kind == PTHREAD_MUTEX_ERRORCHECK_NP)
{
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
return EDEADLK;
}
if (kind == PTHREAD_MUTEX_RECURSIVE_NP)
{
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
/* Just bump the counter. */
if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
/* Overflow of the counter. */
return EAGAIN;
++mutex->__data.__count;
return 0;
}
}
int newval = id;
#ifdef NO_INCR
newval |= FUTEX_WAITERS;
#endif
oldval = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
newval, 0);
if (oldval != 0)
{
/* The mutex is locked. The kernel will now take care of
everything. */
int private = (robust
? PTHREAD_ROBUST_MUTEX_PSHARED (mutex)
: PTHREAD_MUTEX_PSHARED (mutex));
INTERNAL_SYSCALL_DECL (__err);
int e = INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
__lll_private_flag (FUTEX_LOCK_PI,
private), 1, 0);
if (INTERNAL_SYSCALL_ERROR_P (e, __err)
&& (INTERNAL_SYSCALL_ERRNO (e, __err) == ESRCH
|| INTERNAL_SYSCALL_ERRNO (e, __err) == EDEADLK))
{
assert (INTERNAL_SYSCALL_ERRNO (e, __err) != EDEADLK
|| (kind != PTHREAD_MUTEX_ERRORCHECK_NP
&& kind != PTHREAD_MUTEX_RECURSIVE_NP));
/* ESRCH can happen only for non-robust PI mutexes where
the owner of the lock died. */
assert (INTERNAL_SYSCALL_ERRNO (e, __err) != ESRCH || !robust);
/* Delay the thread indefinitely. */
while (1)
pause_not_cancel ();
}
oldval = mutex->__data.__lock;
assert (robust || (oldval & FUTEX_OWNER_DIED) == 0);
}
if (__builtin_expect (oldval & FUTEX_OWNER_DIED, 0))
{
atomic_and (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);
/* We got the mutex. */
mutex->__data.__count = 1;
/* But it is inconsistent unless marked otherwise. */
mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT;
ENQUEUE_MUTEX_PI (mutex);
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
/* Note that we deliberately exit here. If we fall
through to the end of the function __nusers would be
incremented which is not correct because the old owner
has to be discounted. If we are not supposed to
increment __nusers we actually have to decrement it here. */
#ifdef NO_INCR
--mutex->__data.__nusers;
#endif
return EOWNERDEAD;
}
if (robust
&& __builtin_expect (mutex->__data.__owner
== PTHREAD_MUTEX_NOTRECOVERABLE, 0))
{
/* This mutex is now not recoverable. */
mutex->__data.__count = 0;
INTERNAL_SYSCALL_DECL (__err);
INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
__lll_private_flag (FUTEX_UNLOCK_PI,
PTHREAD_ROBUST_MUTEX_PSHARED (mutex)),
0, 0);
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
return ENOTRECOVERABLE;
}
mutex->__data.__count = 1;
if (robust)
{
ENQUEUE_MUTEX_PI (mutex);
THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
}
}
break;
case PTHREAD_MUTEX_PP_RECURSIVE_NP:
case PTHREAD_MUTEX_PP_ERRORCHECK_NP:
case PTHREAD_MUTEX_PP_NORMAL_NP:
case PTHREAD_MUTEX_PP_ADAPTIVE_NP:
{
int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP;
oldval = mutex->__data.__lock;
/* Check whether we already hold the mutex. */
if (mutex->__data.__owner == id)
{
if (kind == PTHREAD_MUTEX_ERRORCHECK_NP)
return EDEADLK;
if (kind == PTHREAD_MUTEX_RECURSIVE_NP)
{
/* Just bump the counter. */
if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
/* Overflow of the counter. */
return EAGAIN;
++mutex->__data.__count;
return 0;
}
}
int oldprio = -1, ceilval;
do
{
int ceiling = (oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK)
>> PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
if (__pthread_current_priority () > ceiling)
{
if (oldprio != -1)
__pthread_tpp_change_priority (oldprio, -1);
return EINVAL;
}
int retval = __pthread_tpp_change_priority (oldprio, ceiling);
if (retval)
return retval;
ceilval = ceiling << PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
oldprio = ceiling;
oldval
= atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
#ifdef NO_INCR
ceilval | 2,
#else
ceilval | 1,
#endif
ceilval);
if (oldval == ceilval)
break;
do
{
oldval
= atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
ceilval | 2,
ceilval | 1);
if ((oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) != ceilval)
break;
if (oldval != ceilval)
lll_futex_wait (&mutex->__data.__lock, ceilval | 2,
PTHREAD_MUTEX_PSHARED (mutex));
}
while (atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
ceilval | 2, ceilval)
!= ceilval);
}
while ((oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) != ceilval);
assert (mutex->__data.__owner == 0);
mutex->__data.__count = 1;
}
break;
default:
/* Correct code cannot set any other type. */
return EINVAL;
}
int
__pthread_timedsuspend_old(pthread_descr self, const struct timespec *abstime)
{
sigset_t unblock, initial_mask;
int was_signalled = 0;
sigjmp_buf jmpbuf;
if (atomic_decrement(&self->p_resume_count) == 0) {
/* Set up a longjmp handler for the restart signal, unblock
the signal and sleep. */
if (sigsetjmp(jmpbuf, 1) == 0) {
THREAD_SETMEM(self, p_signal_jmp, &jmpbuf);
THREAD_SETMEM(self, p_signal, 0);
/* Unblock the restart signal */
sigemptyset(&unblock);
sigaddset(&unblock, __pthread_sig_restart);
sigprocmask(SIG_UNBLOCK, &unblock, &initial_mask);
while (1) {
struct timeval now;
struct timespec reltime;
/* Compute a time offset relative to now. */
__gettimeofday (&now, NULL);
reltime.tv_nsec = abstime->tv_nsec - now.tv_usec * 1000;
reltime.tv_sec = abstime->tv_sec - now.tv_sec;
if (reltime.tv_nsec < 0) {
reltime.tv_nsec += 1000000000;
reltime.tv_sec -= 1;
}
/* Sleep for the required duration. If woken by a signal,
resume waiting as required by Single Unix Specification. */
if (reltime.tv_sec < 0 || __libc_nanosleep(&reltime, NULL) == 0)
break;
}
/* Block the restart signal again */
sigprocmask(SIG_SETMASK, &initial_mask, NULL);
was_signalled = 0;
} else {
was_signalled = 1;
}
THREAD_SETMEM(self, p_signal_jmp, NULL);
}
/* Now was_signalled is true if we exited the above code
due to the delivery of a restart signal. In that case,
we know we have been dequeued and resumed and that the
resume count is balanced. Otherwise, there are some
cases to consider. First, try to bump up the resume count
back to zero. If it goes to 1, it means restart() was
invoked on this thread. The signal must be consumed
and the count bumped down and everything is cool. We
can return a 1 to the caller.
Otherwise, no restart was delivered yet, so a potential
race exists; we return a 0 to the caller which must deal
with this race in an appropriate way; for example by
atomically removing the thread from consideration for a
wakeup---if such a thing fails, it means a restart is
being delivered. */
if (!was_signalled) {
if (atomic_increment(&self->p_resume_count) != -1) {
__pthread_wait_for_restart_signal(self);
atomic_decrement(&self->p_resume_count); /* should be zero now! */
/* woke spontaneously and consumed restart signal */
return 1;
}
/* woke spontaneously but did not consume restart---caller must resolve */
return 0;
}
/* woken due to restart signal */
return 1;
}
static int
do_clone (struct pthread *pd, const struct pthread_attr *attr,
int clone_flags, int (*fct) (void *), STACK_VARIABLES_PARMS,
int stopped)
{
#if 0
PREPARE_CREATE;
#endif
if (__builtin_expect (stopped != 0, 0))
/* We make sure the thread does not run far by forcing it to get a
lock. We lock it here too so that the new thread cannot continue
until we tell it to. */
lll_lock (pd->lock, LLL_PRIVATE);
/* One more thread. We cannot have the thread do this itself, since it
might exist but not have been scheduled yet by the time we've returned
and need to check the value to behave correctly. We must do it before
creating the thread, in case it does get scheduled first and then
might mistakenly think it was the only thread. In the failure case,
we momentarily store a false value; this doesn't matter because there
is no kosher thing a signal handler interrupting us right here can do
that cares whether the thread count is correct. */
atomic_increment (&__nptl_nthreads);
#if !defined(__native_client__) && !defined(__ZRT_HOST)
#error "This code was changed to work only in Native Client"
#endif
/* Native Client does not have a notion of a thread ID, so we make
one up. This must be small enough to leave space for number identifying
the clock. Use CLOCK_IDFIELD_SIZE to guarantee that. */
pd->tid = ((unsigned int) pd) >> CLOCK_IDFIELD_SIZE;
/* Native Client syscall thread_create does not push return address onto stack
as opposed to the kernel. We emulate this behavior on x86-64 to meet the
ABI requirement ((%rsp + 8) mod 16 == 0). On x86-32 the attribute
'force_align_arg_pointer' does the same for start_thread (). */
#ifdef __x86_64__
STACK_VARIABLES_ARGS -= 8;
#endif
if (__nacl_irt_thread_create (fct, STACK_VARIABLES_ARGS, pd) != 0)
{
pd->tid = 0;
atomic_decrement (&__nptl_nthreads); /* Oops, we lied for a second. */
/* Failed. If the thread is detached, remove the TCB here since
the caller cannot do this. The caller remembered the thread
as detached and cannot reverify that it is not since it must
not access the thread descriptor again. */
if (IS_DETACHED (pd))
__deallocate_stack (pd);
/* We have to translate error codes. */
return errno == ENOMEM ? EAGAIN : errno;
}
/* Now we have the possibility to set scheduling parameters etc. */
if (__builtin_expect (stopped != 0, 0))
{
INTERNAL_SYSCALL_DECL (err);
int res = 0;
/* Set the affinity mask if necessary. */
if (attr->cpuset != NULL)
{
res = INTERNAL_SYSCALL (sched_setaffinity, err, 3, pd->tid,
attr->cpusetsize, attr->cpuset);
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (res, err), 0))
{
/* The operation failed. We have to kill the thread. First
send it the cancellation signal. */
INTERNAL_SYSCALL_DECL (err2);
err_out:
#if __ASSUME_TGKILL
(void) INTERNAL_SYSCALL (tgkill, err2, 3,
THREAD_GETMEM (THREAD_SELF, pid),
pd->tid, SIGCANCEL);
#else
(void) INTERNAL_SYSCALL (tkill, err2, 2, pd->tid, SIGCANCEL);
#endif
return (INTERNAL_SYSCALL_ERROR_P (res, err)
? INTERNAL_SYSCALL_ERRNO (res, err)
: 0);
}
}
/* Set the scheduling parameters. */
if ((attr->flags & ATTR_FLAG_NOTINHERITSCHED) != 0)
{
res = INTERNAL_SYSCALL (sched_setscheduler, err, 3, pd->tid,
pd->schedpolicy, &pd->schedparam);
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (res, err), 0))
goto err_out;
}
}
/* We now have for sure more than one thread. The main thread might
not yet have the flag set. No need to set the global variable
again if this is what we use. */
THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1);
return 0;
}