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glibc/nptl/pthread_create.c
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/* Copyright (C) 2002, 2003, 2004, 2005 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 <shlib-compat.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; | |
/* Pointer to descriptor with the last event. */ | |
static struct pthread *__nptl_last_event; | |
/* 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 (pd) | |
struct pthread *pd; | |
{ | |
list_t *entry; | |
struct pthread *result = NULL; | |
lll_lock (stack_cache_lock); | |
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); | |
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 (); | |
/* 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; | |
/* 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); | |
/* And give it up right away. */ | |
lll_unlock (pd->lock); | |
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. */ | |
__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); | |
/* If this thread has any robust mutexes locked, handle them now. */ | |
pthread_mutex_t *robust = THREAD_GETMEM (pd, robust_list); | |
if (__builtin_expect (robust != NULL, 0)) | |
{ | |
do | |
{ | |
pthread_mutex_t *this = robust; | |
robust = robust->__data.__next; | |
assert (lll_mutex_islocked (this->__data.__lock)); | |
this->__data.__count = 0; | |
--this->__data.__nusers; | |
assert (this->__data.__owner != PTHREAD_MUTEX_NOTRECOVERABLE); | |
this->__data.__owner = PTHREAD_MUTEX_OWNERDEAD; | |
this->__data.__next = NULL; | |
#ifdef __PTHREAD_MUTEX_HAVE_PREV | |
this->__data.__prev = NULL; | |
#endif | |
lll_mutex_unlock (this->__data.__lock); | |
} | |
while (robust != NULL); | |
/* Clean up so that the thread descriptor can be reused. */ | |
THREAD_SETMEM (pd, robust_list, NULL); | |
} | |
/* 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); | |
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 (newthread, attr, start_routine, arg) | |
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; | |
} | |
versioned_symbol (libpthread, __pthread_create_2_1, pthread_create, GLIBC_2_1); | |
#if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1) | |
int | |
__pthread_create_2_0 (newthread, attr, start_routine, arg) | |
pthread_t *newthread; | |
const pthread_attr_t *attr; | |
void *(*start_routine) (void *); | |
void *arg; | |
{ | |
/* The ATTR attribute is not really of type `pthread_attr_t *'. It has | |
the old size and access to the new members might crash the program. | |
We convert the struct now. */ | |
struct pthread_attr new_attr; | |
if (attr != NULL) | |
{ | |
struct pthread_attr *iattr = (struct pthread_attr *) attr; | |
size_t ps = __getpagesize (); | |
/* Copy values from the user-provided attributes. */ | |
new_attr.schedparam = iattr->schedparam; | |
new_attr.schedpolicy = iattr->schedpolicy; | |
new_attr.flags = iattr->flags; | |
/* Fill in default values for the fields not present in the old | |
implementation. */ | |
new_attr.guardsize = ps; | |
new_attr.stackaddr = NULL; | |
new_attr.stacksize = 0; | |
new_attr.cpuset = NULL; | |
/* We will pass this value on to the real implementation. */ | |
attr = (pthread_attr_t *) &new_attr; | |
} | |
return __pthread_create_2_1 (newthread, attr, start_routine, arg); | |
} | |
compat_symbol (libpthread, __pthread_create_2_0, pthread_create, | |
GLIBC_2_0); | |
#endif | |
/* 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_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_setspecific) | |
PTHREAD_STATIC_FN_REQUIRE (pthread_getspecific) |