freebsd-dev/lib/libpthread/thread/thr_init.c
Daniel Eischen 843d4004b3 Use a generic way to back threads out of wait queues when handling
signals instead of having more intricate knowledge of thread state
within signal handling.

Simplify signal code because of above (by David Xu).

Use macros for libpthread usage of pthread_cleanup_push() and
pthread_cleanup_pop().  This removes some instances of malloc()
and free() from the semaphore and pthread_once() implementations.

When single threaded and forking(), make sure that the current
thread's signal mask is inherited by the forked thread.

Use private mutexes for libc and libpthread.  Signals are
deferred while threads hold private mutexes.  This fix also
breaks www/linuxpluginwrapper; a patch that fixes it is at
http://people.freebsd.org/~deischen/kse/linuxpluginwrapper.diff

Fix race condition in condition variables where handling a
signal (pthread_kill() or kill()) may not see a wakeup
(pthread_cond_signal() or pthread_cond_broadcast()).

In collaboration with:	davidxu
2004-12-18 18:07:37 +00:00

486 lines
15 KiB
C

/*
* Copyright (c) 2003 Daniel M. Eischen <deischen@freebsd.org>
* Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/* Allocate space for global thread variables here: */
#define GLOBAL_PTHREAD_PRIVATE
#include "namespace.h"
#include <sys/param.h>
#include <sys/types.h>
#include <sys/signalvar.h>
#include <machine/reg.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <sys/event.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/ttycom.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <pthread.h>
#include <pthread_np.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "un-namespace.h"
#include "libc_private.h"
#include "thr_private.h"
int __pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *);
int __pthread_mutex_lock(pthread_mutex_t *);
int __pthread_mutex_trylock(pthread_mutex_t *);
void _thread_init_hack(void);
extern int _thread_state_running;
static void init_private(void);
static void init_main_thread(struct pthread *thread);
/*
* All weak references used within libc should be in this table.
* This is so that static libraries will work.
*/
static void *references[] = {
&_accept,
&_bind,
&_close,
&_connect,
&_dup,
&_dup2,
&_execve,
&_fcntl,
&_flock,
&_flockfile,
&_fstat,
&_fstatfs,
&_fsync,
&_funlockfile,
&_getdirentries,
&_getlogin,
&_getpeername,
&_getsockname,
&_getsockopt,
&_ioctl,
&_kevent,
&_listen,
&_nanosleep,
&_open,
&_pthread_getspecific,
&_pthread_key_create,
&_pthread_key_delete,
&_pthread_mutex_destroy,
&_pthread_mutex_init,
&_pthread_mutex_lock,
&_pthread_mutex_trylock,
&_pthread_mutex_unlock,
&_pthread_mutexattr_init,
&_pthread_mutexattr_destroy,
&_pthread_mutexattr_settype,
&_pthread_once,
&_pthread_setspecific,
&_read,
&_readv,
&_recvfrom,
&_recvmsg,
&_select,
&_sendmsg,
&_sendto,
&_setsockopt,
&_sigaction,
&_sigprocmask,
&_sigsuspend,
&_socket,
&_socketpair,
&_thread_init_hack,
&_wait4,
&_write,
&_writev
};
/*
* These are needed when linking statically. All references within
* libgcc (and in the future libc) to these routines are weak, but
* if they are not (strongly) referenced by the application or other
* libraries, then the actual functions will not be loaded.
*/
static void *libgcc_references[] = {
&_pthread_once,
&_pthread_key_create,
&_pthread_key_delete,
&_pthread_getspecific,
&_pthread_setspecific,
&_pthread_mutex_init,
&_pthread_mutex_destroy,
&_pthread_mutex_lock,
&_pthread_mutex_trylock,
&_pthread_mutex_unlock
};
#define DUAL_ENTRY(entry) \
(pthread_func_t)entry, (pthread_func_t)entry
static pthread_func_t jmp_table[][2] = {
{DUAL_ENTRY(_pthread_cond_broadcast)}, /* PJT_COND_BROADCAST */
{DUAL_ENTRY(_pthread_cond_destroy)}, /* PJT_COND_DESTROY */
{DUAL_ENTRY(_pthread_cond_init)}, /* PJT_COND_INIT */
{DUAL_ENTRY(_pthread_cond_signal)}, /* PJT_COND_SIGNAL */
{(pthread_func_t)__pthread_cond_wait,
(pthread_func_t)_pthread_cond_wait}, /* PJT_COND_WAIT */
{DUAL_ENTRY(_pthread_getspecific)}, /* PJT_GETSPECIFIC */
{DUAL_ENTRY(_pthread_key_create)}, /* PJT_KEY_CREATE */
{DUAL_ENTRY(_pthread_key_delete)}, /* PJT_KEY_DELETE*/
{DUAL_ENTRY(_pthread_main_np)}, /* PJT_MAIN_NP */
{DUAL_ENTRY(_pthread_mutex_destroy)}, /* PJT_MUTEX_DESTROY */
{DUAL_ENTRY(_pthread_mutex_init)}, /* PJT_MUTEX_INIT */
{(pthread_func_t)__pthread_mutex_lock,
(pthread_func_t)_pthread_mutex_lock}, /* PJT_MUTEX_LOCK */
{(pthread_func_t)__pthread_mutex_trylock,
(pthread_func_t)_pthread_mutex_trylock},/* PJT_MUTEX_TRYLOCK */
{DUAL_ENTRY(_pthread_mutex_unlock)}, /* PJT_MUTEX_UNLOCK */
{DUAL_ENTRY(_pthread_mutexattr_destroy)}, /* PJT_MUTEXATTR_DESTROY */
{DUAL_ENTRY(_pthread_mutexattr_init)}, /* PJT_MUTEXATTR_INIT */
{DUAL_ENTRY(_pthread_mutexattr_settype)}, /* PJT_MUTEXATTR_SETTYPE */
{DUAL_ENTRY(_pthread_once)}, /* PJT_ONCE */
{DUAL_ENTRY(_pthread_rwlock_destroy)}, /* PJT_RWLOCK_DESTROY */
{DUAL_ENTRY(_pthread_rwlock_init)}, /* PJT_RWLOCK_INIT */
{DUAL_ENTRY(_pthread_rwlock_rdlock)}, /* PJT_RWLOCK_RDLOCK */
{DUAL_ENTRY(_pthread_rwlock_tryrdlock)},/* PJT_RWLOCK_TRYRDLOCK */
{DUAL_ENTRY(_pthread_rwlock_trywrlock)},/* PJT_RWLOCK_TRYWRLOCK */
{DUAL_ENTRY(_pthread_rwlock_unlock)}, /* PJT_RWLOCK_UNLOCK */
{DUAL_ENTRY(_pthread_rwlock_wrlock)}, /* PJT_RWLOCK_WRLOCK */
{DUAL_ENTRY(_pthread_self)}, /* PJT_SELF */
{DUAL_ENTRY(_pthread_setspecific)}, /* PJT_SETSPECIFIC */
{DUAL_ENTRY(_pthread_sigmask)} /* PJT_SIGMASK */
};
static int init_once = 0;
/*
* Threaded process initialization.
*
* This is only called under two conditions:
*
* 1) Some thread routines have detected that the library hasn't yet
* been initialized (_thr_initial == NULL && curthread == NULL), or
*
* 2) An explicit call to reinitialize after a fork (indicated
* by curthread != NULL)
*/
void
_libpthread_init(struct pthread *curthread)
{
int fd;
/* Check if this function has already been called: */
if ((_thr_initial != NULL) && (curthread == NULL))
/* Only initialize the threaded application once. */
return;
/*
* Make gcc quiescent about {,libgcc_}references not being
* referenced:
*/
if ((references[0] == NULL) || (libgcc_references[0] == NULL))
PANIC("Failed loading mandatory references in _thread_init");
/* Pull debug symbols in for static binary */
_thread_state_running = PS_RUNNING;
/*
* Check the size of the jump table to make sure it is preset
* with the correct number of entries.
*/
if (sizeof(jmp_table) != (sizeof(pthread_func_t) * PJT_MAX * 2))
PANIC("Thread jump table not properly initialized");
memcpy(__thr_jtable, jmp_table, sizeof(jmp_table));
/*
* Check for the special case of this process running as
* or in place of init as pid = 1:
*/
if ((_thr_pid = getpid()) == 1) {
/*
* Setup a new session for this process which is
* assumed to be running as root.
*/
if (setsid() == -1)
PANIC("Can't set session ID");
if (revoke(_PATH_CONSOLE) != 0)
PANIC("Can't revoke console");
if ((fd = __sys_open(_PATH_CONSOLE, O_RDWR)) < 0)
PANIC("Can't open console");
if (setlogin("root") == -1)
PANIC("Can't set login to root");
if (__sys_ioctl(fd, TIOCSCTTY, (char *) NULL) == -1)
PANIC("Can't set controlling terminal");
}
/* Initialize pthread private data. */
init_private();
_kse_init();
/* Initialize the initial kse and kseg. */
_kse_initial = _kse_alloc(NULL, _thread_scope_system > 0);
if (_kse_initial == NULL)
PANIC("Can't allocate initial kse.");
_kse_initial->k_kseg = _kseg_alloc(NULL);
if (_kse_initial->k_kseg == NULL)
PANIC("Can't allocate initial kseg.");
_kse_initial->k_kseg->kg_flags |= KGF_SINGLE_THREAD;
_kse_initial->k_schedq = &_kse_initial->k_kseg->kg_schedq;
TAILQ_INSERT_TAIL(&_kse_initial->k_kseg->kg_kseq, _kse_initial, k_kgqe);
_kse_initial->k_kseg->kg_ksecount = 1;
/* Set the initial thread. */
if (curthread == NULL) {
/* Create and initialize the initial thread. */
curthread = _thr_alloc(NULL);
if (curthread == NULL)
PANIC("Can't allocate initial thread");
_thr_initial = curthread;
init_main_thread(curthread);
} else {
/*
* The initial thread is the current thread. It is
* assumed that the current thread is already initialized
* because it is left over from a fork().
*/
_thr_initial = curthread;
}
_kse_initial->k_kseg->kg_threadcount = 0;
_thr_initial->kse = _kse_initial;
_thr_initial->kseg = _kse_initial->k_kseg;
_thr_initial->active = 1;
/*
* Add the thread to the thread list and to the KSEG's thread
* queue.
*/
THR_LIST_ADD(_thr_initial);
KSEG_THRQ_ADD(_kse_initial->k_kseg, _thr_initial);
/* Setup the KSE/thread specific data for the current KSE/thread. */
_thr_initial->kse->k_curthread = _thr_initial;
_kcb_set(_thr_initial->kse->k_kcb);
_tcb_set(_thr_initial->kse->k_kcb, _thr_initial->tcb);
_thr_initial->kse->k_flags |= KF_INITIALIZED;
_thr_signal_init();
_kse_critical_leave(&_thr_initial->tcb->tcb_tmbx);
/*
* activate threaded mode as soon as possible if we are
* being debugged
*/
if (_libkse_debug)
_kse_setthreaded(1);
}
/*
* This function and pthread_create() do a lot of the same things.
* It'd be nice to consolidate the common stuff in one place.
*/
static void
init_main_thread(struct pthread *thread)
{
/* Setup the thread attributes. */
thread->attr = _pthread_attr_default;
thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
/*
* Set up the thread stack.
*
* Create a red zone below the main stack. All other stacks
* are constrained to a maximum size by the parameters
* passed to mmap(), but this stack is only limited by
* resource limits, so this stack needs an explicitly mapped
* red zone to protect the thread stack that is just beyond.
*/
if (mmap((void *)_usrstack - THR_STACK_INITIAL -
_thr_guard_default, _thr_guard_default, 0, MAP_ANON,
-1, 0) == MAP_FAILED)
PANIC("Cannot allocate red zone for initial thread");
/*
* Mark the stack as an application supplied stack so that it
* isn't deallocated.
*
* XXX - I'm not sure it would hurt anything to deallocate
* the main thread stack because deallocation doesn't
* actually free() it; it just puts it in the free
* stack queue for later reuse.
*/
thread->attr.stackaddr_attr = (void *)_usrstack - THR_STACK_INITIAL;
thread->attr.stacksize_attr = THR_STACK_INITIAL;
thread->attr.guardsize_attr = _thr_guard_default;
thread->attr.flags |= THR_STACK_USER;
/*
* Write a magic value to the thread structure
* to help identify valid ones:
*/
thread->magic = THR_MAGIC;
thread->slice_usec = -1;
thread->cancelflags = PTHREAD_CANCEL_ENABLE | PTHREAD_CANCEL_DEFERRED;
thread->name = strdup("initial thread");
/* Initialize the thread for signals: */
SIGEMPTYSET(thread->sigmask);
/*
* Set up the thread mailbox. The threads saved context
* is also in the mailbox.
*/
thread->tcb->tcb_tmbx.tm_udata = thread;
thread->tcb->tcb_tmbx.tm_context.uc_stack.ss_size =
thread->attr.stacksize_attr;
thread->tcb->tcb_tmbx.tm_context.uc_stack.ss_sp =
thread->attr.stackaddr_attr;
/* Default the priority of the initial thread: */
thread->base_priority = THR_DEFAULT_PRIORITY;
thread->active_priority = THR_DEFAULT_PRIORITY;
thread->inherited_priority = 0;
/* Initialize the mutex queue: */
TAILQ_INIT(&thread->mutexq);
/* Initialize hooks in the thread structure: */
thread->specific = NULL;
thread->cleanup = NULL;
thread->flags = 0;
thread->sigbackout = NULL;
thread->continuation = NULL;
thread->state = PS_RUNNING;
thread->uniqueid = 0;
}
static void
init_private(void)
{
struct clockinfo clockinfo;
size_t len;
int mib[2];
/*
* Avoid reinitializing some things if they don't need to be,
* e.g. after a fork().
*/
if (init_once == 0) {
/* Find the stack top */
mib[0] = CTL_KERN;
mib[1] = KERN_USRSTACK;
len = sizeof (_usrstack);
if (sysctl(mib, 2, &_usrstack, &len, NULL, 0) == -1)
PANIC("Cannot get kern.usrstack from sysctl");
/* Get the kernel clockrate: */
mib[0] = CTL_KERN;
mib[1] = KERN_CLOCKRATE;
len = sizeof (struct clockinfo);
if (sysctl(mib, 2, &clockinfo, &len, NULL, 0) == 0)
_clock_res_usec = clockinfo.tick;
else
_clock_res_usec = CLOCK_RES_USEC;
_thr_page_size = getpagesize();
_thr_guard_default = _thr_page_size;
init_once = 1; /* Don't do this again. */
} else {
/*
* Destroy the locks before creating them. We don't
* know what state they are in so it is better to just
* recreate them.
*/
_lock_destroy(&_thread_signal_lock);
_lock_destroy(&_mutex_static_lock);
_lock_destroy(&_rwlock_static_lock);
_lock_destroy(&_keytable_lock);
}
/* Initialize everything else. */
TAILQ_INIT(&_thread_list);
TAILQ_INIT(&_thread_gc_list);
TAILQ_INIT(&_thr_atfork_list);
_pthread_mutex_init(&_thr_atfork_mutex, NULL);
/*
* Initialize the lock for temporary installation of signal
* handlers (to support sigwait() semantics) and for the
* process signal mask and pending signal sets.
*/
if (_lock_init(&_thread_signal_lock, LCK_ADAPTIVE,
_kse_lock_wait, _kse_lock_wakeup) != 0)
PANIC("Cannot initialize _thread_signal_lock");
if (_lock_init(&_mutex_static_lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup) != 0)
PANIC("Cannot initialize mutex static init lock");
if (_lock_init(&_rwlock_static_lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup) != 0)
PANIC("Cannot initialize rwlock static init lock");
if (_lock_init(&_keytable_lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup) != 0)
PANIC("Cannot initialize thread specific keytable lock");
_thr_spinlock_init();
/* Clear pending signals and get the process signal mask. */
SIGEMPTYSET(_thr_proc_sigpending);
/* Are we in M:N mode (default) or 1:1 mode? */
#ifdef SYSTEM_SCOPE_ONLY
_thread_scope_system = 1;
#else
if (getenv("LIBPTHREAD_SYSTEM_SCOPE") != NULL)
_thread_scope_system = 1;
else if (getenv("LIBPTHREAD_PROCESS_SCOPE") != NULL)
_thread_scope_system = -1;
#endif
/*
* _thread_list_lock and _kse_count are initialized
* by _kse_init()
*/
}