diff options
Diffstat (limited to 'libpthread/nptl/pthread_create.c')
| -rw-r--r-- | libpthread/nptl/pthread_create.c | 586 |
1 files changed, 586 insertions, 0 deletions
diff --git a/libpthread/nptl/pthread_create.c b/libpthread/nptl/pthread_create.c new file mode 100644 index 000000000..8b53cb199 --- /dev/null +++ b/libpthread/nptl/pthread_create.c @@ -0,0 +1,586 @@ +/* Copyright (C) 2002-2007,2008,2009 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <errno.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include "pthreadP.h" +#include <hp-timing.h> +#include <ldsodefs.h> +#include <atomic.h> +#include <libc-internal.h> +#include <resolv.h> +#include <bits/kernel-features.h> + + +/* Local function to start thread and handle cleanup. */ +static int start_thread (void *arg); + + +/* Nozero if debugging mode is enabled. */ +int __pthread_debug; + +/* Globally enabled events. */ +static td_thr_events_t __nptl_threads_events __attribute_used__; + +/* Pointer to descriptor with the last event. */ +static struct pthread *__nptl_last_event __attribute_used__; + +/* Number of threads running. */ +unsigned int __nptl_nthreads = 1; + + +/* Code to allocate and deallocate a stack. */ +#include "allocatestack.c" + +/* Code to create the thread. */ +#include <createthread.c> + + +struct pthread * +internal_function +__find_in_stack_list ( + struct pthread *pd) +{ + list_t *entry; + struct pthread *result = NULL; + + lll_lock (stack_cache_lock, LLL_PRIVATE); + + list_for_each (entry, &stack_used) + { + struct pthread *curp; + + curp = list_entry (entry, struct pthread, list); + if (curp == pd) + { + result = curp; + break; + } + } + + if (result == NULL) + list_for_each (entry, &__stack_user) + { + struct pthread *curp; + + curp = list_entry (entry, struct pthread, list); + if (curp == pd) + { + result = curp; + break; + } + } + + lll_unlock (stack_cache_lock, LLL_PRIVATE); + + return result; +} + + +/* Deallocate POSIX thread-local-storage. */ +void +attribute_hidden +__nptl_deallocate_tsd (void) +{ + struct pthread *self = THREAD_SELF; + + /* Maybe no data was ever allocated. This happens often so we have + a flag for this. */ + if (THREAD_GETMEM (self, specific_used)) + { + size_t round; + size_t cnt; + + round = 0; + do + { + size_t idx; + + /* So far no new nonzero data entry. */ + THREAD_SETMEM (self, specific_used, false); + + for (cnt = idx = 0; cnt < PTHREAD_KEY_1STLEVEL_SIZE; ++cnt) + { + struct pthread_key_data *level2; + + level2 = THREAD_GETMEM_NC (self, specific, cnt); + + if (level2 != NULL) + { + size_t inner; + + for (inner = 0; inner < PTHREAD_KEY_2NDLEVEL_SIZE; + ++inner, ++idx) + { + void *data = level2[inner].data; + + if (data != NULL) + { + /* Always clear the data. */ + level2[inner].data = NULL; + + /* Make sure the data corresponds to a valid + key. This test fails if the key was + deallocated and also if it was + re-allocated. It is the user's + responsibility to free the memory in this + case. */ + if (level2[inner].seq + == __pthread_keys[idx].seq + /* It is not necessary to register a destructor + function. */ + && __pthread_keys[idx].destr != NULL) + /* Call the user-provided destructor. */ + __pthread_keys[idx].destr (data); + } + } + } + else + idx += PTHREAD_KEY_1STLEVEL_SIZE; + } + + if (THREAD_GETMEM (self, specific_used) == 0) + /* No data has been modified. */ + goto just_free; + } + /* We only repeat the process a fixed number of times. */ + while (__builtin_expect (++round < PTHREAD_DESTRUCTOR_ITERATIONS, 0)); + + /* Just clear the memory of the first block for reuse. */ + memset (&THREAD_SELF->specific_1stblock, '\0', + sizeof (self->specific_1stblock)); + + just_free: + /* Free the memory for the other blocks. */ + for (cnt = 1; cnt < PTHREAD_KEY_1STLEVEL_SIZE; ++cnt) + { + struct pthread_key_data *level2; + + level2 = THREAD_GETMEM_NC (self, specific, cnt); + if (level2 != NULL) + { + /* The first block is allocated as part of the thread + descriptor. */ + free (level2); + THREAD_SETMEM_NC (self, specific, cnt, NULL); + } + } + + THREAD_SETMEM (self, specific_used, false); + } +} + + +/* Deallocate a thread's stack after optionally making sure the thread + descriptor is still valid. */ +void +internal_function +__free_tcb (struct pthread *pd) +{ + /* The thread is exiting now. */ + if (__builtin_expect (atomic_bit_test_set (&pd->cancelhandling, + TERMINATED_BIT) == 0, 1)) + { + /* Remove the descriptor from the list. */ + if (DEBUGGING_P && __find_in_stack_list (pd) == NULL) + /* Something is really wrong. The descriptor for a still + running thread is gone. */ + abort (); + + /* Free TPP data. */ + if (__builtin_expect (pd->tpp != NULL, 0)) + { + struct priority_protection_data *tpp = pd->tpp; + + pd->tpp = NULL; + free (tpp); + } + + /* Queue the stack memory block for reuse and exit the process. The + kernel will signal via writing to the address returned by + QUEUE-STACK when the stack is available. */ + __deallocate_stack (pd); + } +} + + +static int +start_thread (void *arg) +{ + struct pthread *pd = (struct pthread *) arg; + +#if HP_TIMING_AVAIL + /* Remember the time when the thread was started. */ + hp_timing_t now; + HP_TIMING_NOW (now); + THREAD_SETMEM (pd, cpuclock_offset, now); +#endif + + /* Initialize resolver state pointer. */ + __resp = &pd->res; + +#ifdef __NR_set_robust_list +# ifndef __ASSUME_SET_ROBUST_LIST + if (__set_robust_list_avail >= 0) +# endif + { + INTERNAL_SYSCALL_DECL (err); + /* This call should never fail because the initial call in init.c + succeeded. */ + INTERNAL_SYSCALL (set_robust_list, err, 2, &pd->robust_head, + sizeof (struct robust_list_head)); + } +#endif + + /* If the parent was running cancellation handlers while creating + the thread the new thread inherited the signal mask. Reset the + cancellation signal mask. */ + if (__builtin_expect (pd->parent_cancelhandling & CANCELING_BITMASK, 0)) + { + INTERNAL_SYSCALL_DECL (err); + sigset_t mask; + __sigemptyset (&mask); + __sigaddset (&mask, SIGCANCEL); + (void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &mask, + NULL, _NSIG / 8); + } + + /* This is where the try/finally block should be created. For + compilers without that support we do use setjmp. */ + struct pthread_unwind_buf unwind_buf; + + /* No previous handlers. */ + unwind_buf.priv.data.prev = NULL; + unwind_buf.priv.data.cleanup = NULL; + + int not_first_call; + not_first_call = setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf); + if (__builtin_expect (! not_first_call, 1)) + { + /* Store the new cleanup handler info. */ + THREAD_SETMEM (pd, cleanup_jmp_buf, &unwind_buf); + + if (__builtin_expect (pd->stopped_start, 0)) + { + int oldtype = CANCEL_ASYNC (); + + /* Get the lock the parent locked to force synchronization. */ + lll_lock (pd->lock, LLL_PRIVATE); + /* And give it up right away. */ + lll_unlock (pd->lock, LLL_PRIVATE); + + CANCEL_RESET (oldtype); + } + + /* Run the code the user provided. */ +#ifdef CALL_THREAD_FCT + THREAD_SETMEM (pd, result, CALL_THREAD_FCT (pd)); +#else + THREAD_SETMEM (pd, result, pd->start_routine (pd->arg)); +#endif + } + + /* Run the destructor for the thread-local data. */ + __nptl_deallocate_tsd (); + + /* Clean up any state libc stored in thread-local variables. */ + /* disable for now + __libc_thread_freeres (); + */ + /* If this is the last thread we terminate the process now. We + do not notify the debugger, it might just irritate it if there + is no thread left. */ + if (__builtin_expect (atomic_decrement_and_test (&__nptl_nthreads), 0)) + /* This was the last thread. */ + exit (0); + + /* Report the death of the thread if this is wanted. */ + if (__builtin_expect (pd->report_events, 0)) + { + /* See whether TD_DEATH is in any of the mask. */ + const int idx = __td_eventword (TD_DEATH); + const uint32_t mask = __td_eventmask (TD_DEATH); + + if ((mask & (__nptl_threads_events.event_bits[idx] + | pd->eventbuf.eventmask.event_bits[idx])) != 0) + { + /* Yep, we have to signal the death. Add the descriptor to + the list but only if it is not already on it. */ + if (pd->nextevent == NULL) + { + pd->eventbuf.eventnum = TD_DEATH; + pd->eventbuf.eventdata = pd; + + do + pd->nextevent = __nptl_last_event; + while (atomic_compare_and_exchange_bool_acq (&__nptl_last_event, + pd, pd->nextevent)); + } + + /* Now call the function to signal the event. */ + __nptl_death_event (); + } + } + + /* The thread is exiting now. Don't set this bit until after we've hit + the event-reporting breakpoint, so that td_thr_get_info on us while at + the breakpoint reports TD_THR_RUN state rather than TD_THR_ZOMBIE. */ + atomic_bit_set (&pd->cancelhandling, EXITING_BIT); + +#ifndef __ASSUME_SET_ROBUST_LIST + /* If this thread has any robust mutexes locked, handle them now. */ +# if __WORDSIZE == 64 + void *robust = pd->robust_head.list; +# else + __pthread_slist_t *robust = pd->robust_list.__next; +# endif + /* We let the kernel do the notification if it is able to do so. + If we have to do it here there for sure are no PI mutexes involved + since the kernel support for them is even more recent. */ + if (__set_robust_list_avail < 0 + && __builtin_expect (robust != (void *) &pd->robust_head, 0)) + { + do + { + struct __pthread_mutex_s *this = (struct __pthread_mutex_s *) + ((char *) robust - offsetof (struct __pthread_mutex_s, + __list.__next)); + robust = *((void **) robust); + +# ifdef __PTHREAD_MUTEX_HAVE_PREV + this->__list.__prev = NULL; +# endif + this->__list.__next = NULL; + + lll_robust_dead (this->__lock, /* XYZ */ LLL_SHARED); + } + while (robust != (void *) &pd->robust_head); + } +#endif + + /* Mark the memory of the stack as usable to the kernel. We free + everything except for the space used for the TCB itself. */ + size_t pagesize_m1 = __getpagesize () - 1; +#ifdef _STACK_GROWS_DOWN + char *sp = CURRENT_STACK_FRAME; + size_t freesize = (sp - (char *) pd->stackblock) & ~pagesize_m1; +#else +# error "to do" +#endif + assert (freesize < pd->stackblock_size); + if (freesize > PTHREAD_STACK_MIN) + madvise (pd->stackblock, freesize - PTHREAD_STACK_MIN, MADV_DONTNEED); + + /* If the thread is detached free the TCB. */ + if (IS_DETACHED (pd)) + /* Free the TCB. */ + __free_tcb (pd); + else if (__builtin_expect (pd->cancelhandling & SETXID_BITMASK, 0)) + { + /* Some other thread might call any of the setXid functions and expect + us to reply. In this case wait until we did that. */ + do + lll_futex_wait (&pd->setxid_futex, 0, LLL_PRIVATE); + while (pd->cancelhandling & SETXID_BITMASK); + + /* Reset the value so that the stack can be reused. */ + pd->setxid_futex = 0; + } + + /* We cannot call '_exit' here. '_exit' will terminate the process. + + The 'exit' implementation in the kernel will signal when the + process is really dead since 'clone' got passed the CLONE_CLEARTID + flag. The 'tid' field in the TCB will be set to zero. + + The exit code is zero since in case all threads exit by calling + 'pthread_exit' the exit status must be 0 (zero). */ + __exit_thread_inline (0); + + /* NOTREACHED */ + return 0; +} + + +/* Default thread attributes for the case when the user does not + provide any. */ +static const struct pthread_attr default_attr = + { + /* Just some value > 0 which gets rounded to the nearest page size. */ + .guardsize = 1, + }; + + +int +__pthread_create_2_1 ( + pthread_t *newthread, + const pthread_attr_t *attr, + void *(*start_routine) (void *), + void *arg) +{ + STACK_VARIABLES; + + const struct pthread_attr *iattr = (struct pthread_attr *) attr; + if (iattr == NULL) + /* Is this the best idea? On NUMA machines this could mean + accessing far-away memory. */ + iattr = &default_attr; + + struct pthread *pd = NULL; + int err = ALLOCATE_STACK (iattr, &pd); + if (__builtin_expect (err != 0, 0)) + /* Something went wrong. Maybe a parameter of the attributes is + invalid or we could not allocate memory. */ + return err; + + + /* Initialize the TCB. All initializations with zero should be + performed in 'get_cached_stack'. This way we avoid doing this if + the stack freshly allocated with 'mmap'. */ + +#ifdef TLS_TCB_AT_TP + /* Reference to the TCB itself. */ + pd->header.self = pd; + + /* Self-reference for TLS. */ + pd->header.tcb = pd; +#endif + + /* Store the address of the start routine and the parameter. Since + we do not start the function directly the stillborn thread will + get the information from its thread descriptor. */ + pd->start_routine = start_routine; + pd->arg = arg; + + /* Copy the thread attribute flags. */ + struct pthread *self = THREAD_SELF; + pd->flags = ((iattr->flags & ~(ATTR_FLAG_SCHED_SET | ATTR_FLAG_POLICY_SET)) + | (self->flags & (ATTR_FLAG_SCHED_SET | ATTR_FLAG_POLICY_SET))); + + /* Initialize the field for the ID of the thread which is waiting + for us. This is a self-reference in case the thread is created + detached. */ + pd->joinid = iattr->flags & ATTR_FLAG_DETACHSTATE ? pd : NULL; + + /* The debug events are inherited from the parent. */ + pd->eventbuf = self->eventbuf; + + + /* Copy the parent's scheduling parameters. The flags will say what + is valid and what is not. */ + pd->schedpolicy = self->schedpolicy; + pd->schedparam = self->schedparam; + + /* Copy the stack guard canary. */ +#ifdef THREAD_COPY_STACK_GUARD + THREAD_COPY_STACK_GUARD (pd); +#endif + + /* Copy the pointer guard value. */ +#ifdef THREAD_COPY_POINTER_GUARD + THREAD_COPY_POINTER_GUARD (pd); +#endif + + /* Determine scheduling parameters for the thread. */ + if (attr != NULL + && __builtin_expect ((iattr->flags & ATTR_FLAG_NOTINHERITSCHED) != 0, 0) + && (iattr->flags & (ATTR_FLAG_SCHED_SET | ATTR_FLAG_POLICY_SET)) != 0) + { + INTERNAL_SYSCALL_DECL (scerr); + + /* Use the scheduling parameters the user provided. */ + if (iattr->flags & ATTR_FLAG_POLICY_SET) + pd->schedpolicy = iattr->schedpolicy; + else if ((pd->flags & ATTR_FLAG_POLICY_SET) == 0) + { + pd->schedpolicy = INTERNAL_SYSCALL (sched_getscheduler, scerr, 1, 0); + pd->flags |= ATTR_FLAG_POLICY_SET; + } + + if (iattr->flags & ATTR_FLAG_SCHED_SET) + memcpy (&pd->schedparam, &iattr->schedparam, + sizeof (struct sched_param)); + else if ((pd->flags & ATTR_FLAG_SCHED_SET) == 0) + { + INTERNAL_SYSCALL (sched_getparam, scerr, 2, 0, &pd->schedparam); + pd->flags |= ATTR_FLAG_SCHED_SET; + } + + /* Check for valid priorities. */ + int minprio = INTERNAL_SYSCALL (sched_get_priority_min, scerr, 1, + iattr->schedpolicy); + int maxprio = INTERNAL_SYSCALL (sched_get_priority_max, scerr, 1, + iattr->schedpolicy); + if (pd->schedparam.sched_priority < minprio + || pd->schedparam.sched_priority > maxprio) + { + err = EINVAL; + goto errout; + } + } + + /* Pass the descriptor to the caller. */ + *newthread = (pthread_t) pd; + + /* Remember whether the thread is detached or not. In case of an + error we have to free the stacks of non-detached stillborn + threads. */ + bool is_detached = IS_DETACHED (pd); + + /* Start the thread. */ + err = create_thread (pd, iattr, STACK_VARIABLES_ARGS); + if (err != 0) + { + /* Something went wrong. Free the resources. */ + if (!is_detached) + { + errout: + __deallocate_stack (pd); + } + return err; + } + + return 0; +} +weak_alias(__pthread_create_2_1, pthread_create) + +/* Information for libthread_db. */ + +#include "../nptl_db/db_info.c" + +/* If pthread_create is present, libgcc_eh.a and libsupc++.a expects some other POSIX thread + functions to be present as well. */ +PTHREAD_STATIC_FN_REQUIRE (pthread_mutex_lock) +PTHREAD_STATIC_FN_REQUIRE (pthread_mutex_trylock) +PTHREAD_STATIC_FN_REQUIRE (pthread_mutex_unlock) + +PTHREAD_STATIC_FN_REQUIRE (pthread_once) +PTHREAD_STATIC_FN_REQUIRE (pthread_cancel) + +PTHREAD_STATIC_FN_REQUIRE (pthread_key_create) +PTHREAD_STATIC_FN_REQUIRE (pthread_key_delete) +PTHREAD_STATIC_FN_REQUIRE (pthread_setspecific) +PTHREAD_STATIC_FN_REQUIRE (pthread_getspecific) + +/* UCLIBC_MUTEX_xxx macros expects to have these as well */ +PTHREAD_STATIC_FN_REQUIRE (pthread_mutex_init) +PTHREAD_STATIC_FN_REQUIRE (_pthread_cleanup_push_defer) +PTHREAD_STATIC_FN_REQUIRE (_pthread_cleanup_pop_restore) |