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freebsd-dev/lib/libpthread/thread/thr_kern.c
Daniel Eischen b8bbeeda02 After forking and initializing the library to single-threaded 
mode (where the forked thread is the one and only thread and
is marked as system scope), set the system scope flag before
initializing the signal mask.  This prevents trying to use
internal locks that haven't yet been initialized.

Reported by:	Dan Nelson <dnelson at allantgroup.com>
Reviewed by:	davidxu
2004-04-08 23:16:21 +00:00

2502 lines
67 KiB
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/*
* Copyright (C) 2003 Daniel M. Eischen <deischen@freebsd.org>
* Copyright (C) 2002 Jonathon Mini <mini@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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/kse.h>
#include <sys/signalvar.h>
#include <sys/queue.h>
#include <machine/atomic.h>
#include <machine/sigframe.h>
#include <assert.h>
#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <ucontext.h>
#include <unistd.h>
#include "atomic_ops.h"
#include "thr_private.h"
#include "libc_private.h"
/*#define DEBUG_THREAD_KERN */
#ifdef DEBUG_THREAD_KERN
#define DBG_MSG stdout_debug
#else
#define DBG_MSG(x...)
#endif
/*
* Define a high water mark for the maximum number of threads that
* will be cached. Once this level is reached, any extra threads
* will be free()'d.
*/
#define MAX_CACHED_THREADS 100
/*
* Define high water marks for the maximum number of KSEs and KSE groups
* that will be cached. Because we support 1:1 threading, there could have
* same number of KSEs and KSE groups as threads. Once these levels are
* reached, any extra KSE and KSE groups will be free()'d.
*/
#ifdef SYSTEM_SCOPE_ONLY
#define MAX_CACHED_KSES 100
#define MAX_CACHED_KSEGS 100
#else
#define MAX_CACHED_KSES 50
#define MAX_CACHED_KSEGS 50
#endif
#define KSE_SET_MBOX(kse, thrd) \
(kse)->k_kcb->kcb_kmbx.km_curthread = &(thrd)->tcb->tcb_tmbx
#define KSE_SET_EXITED(kse) (kse)->k_flags |= KF_EXITED
/*
* Macros for manipulating the run queues. The priority queue
* routines use the thread's pqe link and also handle the setting
* and clearing of the thread's THR_FLAGS_IN_RUNQ flag.
*/
#define KSE_RUNQ_INSERT_HEAD(kse, thrd) \
_pq_insert_head(&(kse)->k_schedq->sq_runq, thrd)
#define KSE_RUNQ_INSERT_TAIL(kse, thrd) \
_pq_insert_tail(&(kse)->k_schedq->sq_runq, thrd)
#define KSE_RUNQ_REMOVE(kse, thrd) \
_pq_remove(&(kse)->k_schedq->sq_runq, thrd)
#define KSE_RUNQ_FIRST(kse) _pq_first(&(kse)->k_schedq->sq_runq)
#define KSE_RUNQ_THREADS(kse) ((kse)->k_schedq->sq_runq.pq_threads)
#define THR_NEED_CANCEL(thrd) \
(((thrd)->cancelflags & THR_CANCELLING) != 0 && \
((thrd)->cancelflags & PTHREAD_CANCEL_DISABLE) == 0 && \
(((thrd)->cancelflags & THR_AT_CANCEL_POINT) != 0 || \
((thrd)->cancelflags & PTHREAD_CANCEL_ASYNCHRONOUS) != 0))
#define THR_NEED_ASYNC_CANCEL(thrd) \
(((thrd)->cancelflags & THR_CANCELLING) != 0 && \
((thrd)->cancelflags & PTHREAD_CANCEL_DISABLE) == 0 && \
(((thrd)->cancelflags & THR_AT_CANCEL_POINT) == 0 && \
((thrd)->cancelflags & PTHREAD_CANCEL_ASYNCHRONOUS) != 0))
/*
* We've got to keep track of everything that is allocated, not only
* to have a speedy free list, but also so they can be deallocated
* after a fork().
*/
static TAILQ_HEAD(, kse) active_kseq;
static TAILQ_HEAD(, kse) free_kseq;
static TAILQ_HEAD(, kse_group) free_kse_groupq;
static TAILQ_HEAD(, kse_group) active_kse_groupq;
static TAILQ_HEAD(, kse_group) gc_ksegq;
static struct lock kse_lock; /* also used for kseg queue */
static int free_kse_count = 0;
static int free_kseg_count = 0;
static TAILQ_HEAD(, pthread) free_threadq;
static struct lock thread_lock;
static int free_thread_count = 0;
static int inited = 0;
static int active_kse_count = 0;
static int active_kseg_count = 0;
static u_int64_t next_uniqueid = 1;
LIST_HEAD(thread_hash_head, pthread);
#define THREAD_HASH_QUEUES 127
static struct thread_hash_head thr_hashtable[THREAD_HASH_QUEUES];
#define THREAD_HASH(thrd) ((unsigned long)thrd % THREAD_HASH_QUEUES)
#ifdef DEBUG_THREAD_KERN
static void dump_queues(struct kse *curkse);
#endif
static void kse_check_completed(struct kse *kse);
static void kse_check_waitq(struct kse *kse);
static void kse_fini(struct kse *curkse);
static void kse_reinit(struct kse *kse, int sys_scope);
static void kse_sched_multi(struct kse_mailbox *kmbx);
static void kse_sched_single(struct kse_mailbox *kmbx);
static void kse_switchout_thread(struct kse *kse, struct pthread *thread);
static void kse_wait(struct kse *kse, struct pthread *td_wait, int sigseq);
static void kse_free_unlocked(struct kse *kse);
static void kse_destroy(struct kse *kse);
static void kseg_free_unlocked(struct kse_group *kseg);
static void kseg_init(struct kse_group *kseg);
static void kseg_reinit(struct kse_group *kseg);
static void kseg_destroy(struct kse_group *kseg);
static void kse_waitq_insert(struct pthread *thread);
static void kse_wakeup_multi(struct kse *curkse);
static struct kse_mailbox *kse_wakeup_one(struct pthread *thread);
static void thr_cleanup(struct kse *kse, struct pthread *curthread);
static void thr_link(struct pthread *thread);
static void thr_resume_wrapper(int sig, siginfo_t *, ucontext_t *);
static void thr_resume_check(struct pthread *curthread, ucontext_t *ucp,
struct pthread_sigframe *psf);
static int thr_timedout(struct pthread *thread, struct timespec *curtime);
static void thr_unlink(struct pthread *thread);
static void thr_destroy(struct pthread *thread);
static void thread_gc(struct pthread *thread);
static void kse_gc(struct pthread *thread);
static void kseg_gc(struct pthread *thread);
static void __inline
thr_accounting(struct pthread *thread)
{
if ((thread->slice_usec != -1) &&
(thread->slice_usec <= TIMESLICE_USEC) &&
(thread->attr.sched_policy != SCHED_FIFO)) {
thread->slice_usec += (thread->tcb->tcb_tmbx.tm_uticks
+ thread->tcb->tcb_tmbx.tm_sticks) * _clock_res_usec;
/* Check for time quantum exceeded: */
if (thread->slice_usec > TIMESLICE_USEC)
thread->slice_usec = -1;
}
thread->tcb->tcb_tmbx.tm_uticks = 0;
thread->tcb->tcb_tmbx.tm_sticks = 0;
}
/*
* This is called after a fork().
* No locks need to be taken here since we are guaranteed to be
* single threaded.
*
* XXX
* POSIX says for threaded process, fork() function is used
* only to run new programs, and the effects of calling functions
* that require certain resources between the call to fork() and
* the call to an exec function are undefined.
*
* It is not safe to free memory after fork(), because these data
* structures may be in inconsistent state.
*/
void
_kse_single_thread(struct pthread *curthread)
{
#ifdef NOTYET
struct kse *kse;
struct kse_group *kseg;
struct pthread *thread;
kse_critical_t crit;
int i;
if (__isthreaded) {
_thr_rtld_fini();
_thr_signal_deinit();
}
__isthreaded = 0;
/*
* Restore signal mask early, so any memory problems could
* dump core.
*/
sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
_thr_active_threads = 1;
/*
* Enter a loop to remove and free all threads other than
* the running thread from the active thread list:
*/
while ((thread = TAILQ_FIRST(&_thread_list)) != NULL) {
THR_GCLIST_REMOVE(thread);
/*
* Remove this thread from the list (the current
* thread will be removed but re-added by libpthread
* initialization.
*/
TAILQ_REMOVE(&_thread_list, thread, tle);
/* Make sure this isn't the running thread: */
if (thread != curthread) {
_thr_stack_free(&thread->attr);
if (thread->specific != NULL)
free(thread->specific);
thr_destroy(thread);
}
}
TAILQ_INIT(&curthread->mutexq); /* initialize mutex queue */
curthread->joiner = NULL; /* no joining threads yet */
curthread->refcount = 0;
SIGEMPTYSET(curthread->sigpend); /* clear pending signals */
if (curthread->specific != NULL) {
free(curthread->specific);
curthread->specific = NULL;
curthread->specific_data_count = 0;
}
/* Free the free KSEs: */
while ((kse = TAILQ_FIRST(&free_kseq)) != NULL) {
TAILQ_REMOVE(&free_kseq, kse, k_qe);
kse_destroy(kse);
}
free_kse_count = 0;
/* Free the active KSEs: */
while ((kse = TAILQ_FIRST(&active_kseq)) != NULL) {
TAILQ_REMOVE(&active_kseq, kse, k_qe);
kse_destroy(kse);
}
active_kse_count = 0;
/* Free the free KSEGs: */
while ((kseg = TAILQ_FIRST(&free_kse_groupq)) != NULL) {
TAILQ_REMOVE(&free_kse_groupq, kseg, kg_qe);
kseg_destroy(kseg);
}
free_kseg_count = 0;
/* Free the active KSEGs: */
while ((kseg = TAILQ_FIRST(&active_kse_groupq)) != NULL) {
TAILQ_REMOVE(&active_kse_groupq, kseg, kg_qe);
kseg_destroy(kseg);
}
active_kseg_count = 0;
/* Free the free threads. */
while ((thread = TAILQ_FIRST(&free_threadq)) != NULL) {
TAILQ_REMOVE(&free_threadq, thread, tle);
thr_destroy(thread);
}
free_thread_count = 0;
/* Free the to-be-gc'd threads. */
while ((thread = TAILQ_FIRST(&_thread_gc_list)) != NULL) {
TAILQ_REMOVE(&_thread_gc_list, thread, gcle);
thr_destroy(thread);
}
TAILQ_INIT(&gc_ksegq);
_gc_count = 0;
if (inited != 0) {
/*
* Destroy these locks; they'll be recreated to assure they
* are in the unlocked state.
*/
_lock_destroy(&kse_lock);
_lock_destroy(&thread_lock);
_lock_destroy(&_thread_list_lock);
inited = 0;
}
/*
* After a fork(), the leftover thread goes back to being
* scope process.
*/
curthread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
curthread->attr.flags |= PTHREAD_SCOPE_PROCESS;
/*
* After a fork, we are still operating on the thread's original
* stack. Don't clear the THR_FLAGS_USER from the thread's
* attribute flags.
*/
/* Initialize the threads library. */
curthread->kse = NULL;
curthread->kseg = NULL;
_kse_initial = NULL;
_libpthread_init(curthread);
#else
int i;
/* Reset the current thread and KSE lock data. */
for (i = 0; i < curthread->locklevel; i++) {
_lockuser_reinit(&curthread->lockusers[i], (void *)curthread);
}
curthread->locklevel = 0;
for (i = 0; i < curthread->kse->k_locklevel; i++) {
_lockuser_reinit(&curthread->kse->k_lockusers[i],
(void *)curthread->kse);
_LCK_SET_PRIVATE2(&curthread->kse->k_lockusers[i], NULL);
}
curthread->kse->k_locklevel = 0;
_thr_spinlock_init();
if (__isthreaded) {
_thr_rtld_fini();
_thr_signal_deinit();
}
__isthreaded = 0;
curthread->kse->k_kcb->kcb_kmbx.km_curthread = NULL;
curthread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
/*
* Restore signal mask early, so any memory problems could
* dump core.
*/
sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
_thr_active_threads = 1;
#endif
}
/*
* This is used to initialize housekeeping and to initialize the
* KSD for the KSE.
*/
void
_kse_init(void)
{
if (inited == 0) {
TAILQ_INIT(&active_kseq);
TAILQ_INIT(&active_kse_groupq);
TAILQ_INIT(&free_kseq);
TAILQ_INIT(&free_kse_groupq);
TAILQ_INIT(&free_threadq);
TAILQ_INIT(&gc_ksegq);
if (_lock_init(&kse_lock, LCK_ADAPTIVE,
_kse_lock_wait, _kse_lock_wakeup) != 0)
PANIC("Unable to initialize free KSE queue lock");
if (_lock_init(&thread_lock, LCK_ADAPTIVE,
_kse_lock_wait, _kse_lock_wakeup) != 0)
PANIC("Unable to initialize free thread queue lock");
if (_lock_init(&_thread_list_lock, LCK_ADAPTIVE,
_kse_lock_wait, _kse_lock_wakeup) != 0)
PANIC("Unable to initialize thread list lock");
active_kse_count = 0;
active_kseg_count = 0;
_gc_count = 0;
inited = 1;
}
}
/*
* This is called when the first thread (other than the initial
* thread) is created.
*/
int
_kse_setthreaded(int threaded)
{
sigset_t sigset;
if ((threaded != 0) && (__isthreaded == 0)) {
SIGFILLSET(sigset);
__sys_sigprocmask(SIG_SETMASK, &sigset, &_thr_initial->sigmask);
/*
* Tell the kernel to create a KSE for the initial thread
* and enable upcalls in it.
*/
_kse_initial->k_flags |= KF_STARTED;
#ifdef SYSTEM_SCOPE_ONLY
/*
* For bound thread, kernel reads mailbox pointer once,
* we'd set it here before calling kse_create
*/
_tcb_set(_kse_initial->k_kcb, _thr_initial->tcb);
KSE_SET_MBOX(_kse_initial, _thr_initial);
_kse_initial->k_kcb->kcb_kmbx.km_flags |= KMF_BOUND;
#else
_thr_initial->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
_kse_initial->k_kseg->kg_flags &= ~KGF_SINGLE_THREAD;
_kse_initial->k_kcb->kcb_kmbx.km_curthread = NULL;
#endif
/*
* Locking functions in libc are required when there are
* threads other than the initial thread.
*/
_thr_rtld_init();
__isthreaded = 1;
if (kse_create(&_kse_initial->k_kcb->kcb_kmbx, 0) != 0) {
_kse_initial->k_flags &= ~KF_STARTED;
__isthreaded = 0;
PANIC("kse_create() failed\n");
return (-1);
}
#ifndef SYSTEM_SCOPE_ONLY
/* Set current thread to initial thread */
_tcb_set(_kse_initial->k_kcb, _thr_initial->tcb);
KSE_SET_MBOX(_kse_initial, _thr_initial);
_thr_start_sig_daemon();
_thr_setmaxconcurrency();
#else
__sys_sigprocmask(SIG_SETMASK, &_thr_initial->sigmask, NULL);
#endif
}
return (0);
}
/*
* Lock wait and wakeup handlers for KSE locks. These are only used by
* KSEs, and should never be used by threads. KSE locks include the
* KSE group lock (used for locking the scheduling queue) and the
* kse_lock defined above.
*
* When a KSE lock attempt blocks, the entire KSE blocks allowing another
* KSE to run. For the most part, it doesn't make much sense to try and
* schedule another thread because you need to lock the scheduling queue
* in order to do that. And since the KSE lock is used to lock the scheduling
* queue, you would just end up blocking again.
*/
void
_kse_lock_wait(struct lock *lock, struct lockuser *lu)
{
struct kse *curkse = (struct kse *)_LCK_GET_PRIVATE(lu);
struct timespec ts;
int saved_flags;
if (curkse->k_kcb->kcb_kmbx.km_curthread != NULL)
PANIC("kse_lock_wait does not disable upcall.\n");
/*
* Enter a loop to wait until we get the lock.
*/
ts.tv_sec = 0;
ts.tv_nsec = 1000000; /* 1 sec */
while (!_LCK_GRANTED(lu)) {
/*
* Yield the kse and wait to be notified when the lock
* is granted.
*/
saved_flags = curkse->k_kcb->kcb_kmbx.km_flags;
curkse->k_kcb->kcb_kmbx.km_flags |= KMF_NOUPCALL |
KMF_NOCOMPLETED;
kse_release(&ts);
curkse->k_kcb->kcb_kmbx.km_flags = saved_flags;
}
}
void
_kse_lock_wakeup(struct lock *lock, struct lockuser *lu)
{
struct kse *curkse;
struct kse *kse;
struct kse_mailbox *mbx;
curkse = _get_curkse();
kse = (struct kse *)_LCK_GET_PRIVATE(lu);
if (kse == curkse)
PANIC("KSE trying to wake itself up in lock");
else {
mbx = &kse->k_kcb->kcb_kmbx;
_lock_grant(lock, lu);
/*
* Notify the owning kse that it has the lock.
* It is safe to pass invalid address to kse_wakeup
* even if the mailbox is not in kernel at all,
* and waking up a wrong kse is also harmless.
*/
kse_wakeup(mbx);
}
}
/*
* Thread wait and wakeup handlers for thread locks. These are only used
* by threads, never by KSEs. Thread locks include the per-thread lock
* (defined in its structure), and condition variable and mutex locks.
*/
void
_thr_lock_wait(struct lock *lock, struct lockuser *lu)
{
struct pthread *curthread = (struct pthread *)lu->lu_private;
do {
THR_LOCK_SWITCH(curthread);
THR_SET_STATE(curthread, PS_LOCKWAIT);
_thr_sched_switch_unlocked(curthread);
} while (!_LCK_GRANTED(lu));
}
void
_thr_lock_wakeup(struct lock *lock, struct lockuser *lu)
{
struct pthread *thread;
struct pthread *curthread;
struct kse_mailbox *kmbx;
curthread = _get_curthread();
thread = (struct pthread *)_LCK_GET_PRIVATE(lu);
THR_SCHED_LOCK(curthread, thread);
_lock_grant(lock, lu);
kmbx = _thr_setrunnable_unlocked(thread);
THR_SCHED_UNLOCK(curthread, thread);
if (kmbx != NULL)
kse_wakeup(kmbx);
}
kse_critical_t
_kse_critical_enter(void)
{
kse_critical_t crit;
crit = (kse_critical_t)_kcb_critical_enter();
return (crit);
}
void
_kse_critical_leave(kse_critical_t crit)
{
struct pthread *curthread;
_kcb_critical_leave((struct kse_thr_mailbox *)crit);
if ((crit != NULL) && ((curthread = _get_curthread()) != NULL))
THR_YIELD_CHECK(curthread);
}
int
_kse_in_critical(void)
{
return (_kcb_in_critical());
}
void
_thr_critical_enter(struct pthread *thread)
{
thread->critical_count++;
}
void
_thr_critical_leave(struct pthread *thread)
{
thread->critical_count--;
THR_YIELD_CHECK(thread);
}
void
_thr_sched_switch(struct pthread *curthread)
{
struct kse *curkse;
(void)_kse_critical_enter();
curkse = _get_curkse();
KSE_SCHED_LOCK(curkse, curkse->k_kseg);
_thr_sched_switch_unlocked(curthread);
}
/*
* XXX - We may need to take the scheduling lock before calling
* this, or perhaps take the lock within here before
* doing anything else.
*/
void
_thr_sched_switch_unlocked(struct pthread *curthread)
{
struct pthread_sigframe psf;
struct kse *curkse;
volatile int resume_once = 0;
ucontext_t *uc;
/* We're in the scheduler, 5 by 5: */
curkse = _get_curkse();
curthread->need_switchout = 1; /* The thread yielded on its own. */
curthread->critical_yield = 0; /* No need to yield anymore. */
/* Thread can unlock the scheduler lock. */
curthread->lock_switch = 1;
/*
* The signal frame is allocated off the stack because
* a thread can be interrupted by other signals while
* it is running down pending signals.
*/
psf.psf_valid = 0;
curthread->curframe = &psf;
if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
kse_sched_single(&curkse->k_kcb->kcb_kmbx);
else {
KSE_SET_SWITCH(curkse);
_thread_enter_uts(curthread->tcb, curkse->k_kcb);
}
/*
* It is ugly we must increase critical count, because we
* have a frame saved, we must backout state in psf
* before we can process signals.
*/
curthread->critical_count += psf.psf_valid;
/*
* Unlock the scheduling queue and leave the
* critical region.
*/
/* Don't trust this after a switch! */
curkse = _get_curkse();
curthread->lock_switch = 0;
KSE_SCHED_UNLOCK(curkse, curkse->k_kseg);
_kse_critical_leave(&curthread->tcb->tcb_tmbx);
/*
* This thread is being resumed; check for cancellations.
*/
if ((psf.psf_valid ||
((curthread->check_pending || THR_NEED_ASYNC_CANCEL(curthread))
&& !THR_IN_CRITICAL(curthread)))) {
uc = alloca(sizeof(ucontext_t));
resume_once = 0;
THR_GETCONTEXT(uc);
if (resume_once == 0) {
resume_once = 1;
curthread->check_pending = 0;
thr_resume_check(curthread, uc, &psf);
}
}
THR_ACTIVATE_LAST_LOCK(curthread);
}
/*
* This is the scheduler for a KSE which runs a scope system thread.
* The multi-thread KSE scheduler should also work for a single threaded
* KSE, but we use a separate scheduler so that it can be fine-tuned
* to be more efficient (and perhaps not need a separate stack for
* the KSE, allowing it to use the thread's stack).
*/
static void
kse_sched_single(struct kse_mailbox *kmbx)
{
struct kse *curkse;
struct pthread *curthread;
struct timespec ts;
sigset_t sigmask;
int i, sigseqno, level, first = 0;
curkse = (struct kse *)kmbx->km_udata;
curthread = curkse->k_curthread;
if (__predict_false((curkse->k_flags & KF_INITIALIZED) == 0)) {
/* Setup this KSEs specific data. */
_kcb_set(curkse->k_kcb);
_tcb_set(curkse->k_kcb, curthread->tcb);
curkse->k_flags |= KF_INITIALIZED;
first = 1;
curthread->active = 1;
/* Setup kernel signal masks for new thread. */
__sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
/*
* Enter critical region, this is meanless for bound thread,
* It is used to let other code work, those code want mailbox
* to be cleared.
*/
(void)_kse_critical_enter();
} else {
/*
* Bound thread always has tcb set, this prevent some
* code from blindly setting bound thread tcb to NULL,
* buggy code ?
*/
_tcb_set(curkse->k_kcb, curthread->tcb);
}
curthread->critical_yield = 0;
curthread->need_switchout = 0;
/*
* Lock the scheduling queue.
*
* There is no scheduling queue for single threaded KSEs,
* but we need a lock for protection regardless.
*/
if (curthread->lock_switch == 0)
KSE_SCHED_LOCK(curkse, curkse->k_kseg);
/*
* This has to do the job of kse_switchout_thread(), only
* for a single threaded KSE/KSEG.
*/
switch (curthread->state) {
case PS_MUTEX_WAIT:
case PS_COND_WAIT:
if (THR_NEED_CANCEL(curthread)) {
curthread->interrupted = 1;
curthread->continuation = _thr_finish_cancellation;
THR_SET_STATE(curthread, PS_RUNNING);
}
break;
case PS_LOCKWAIT:
/*
* This state doesn't timeout.
*/
curthread->wakeup_time.tv_sec = -1;
curthread->wakeup_time.tv_nsec = -1;
level = curthread->locklevel - 1;
if (_LCK_GRANTED(&curthread->lockusers[level]))
THR_SET_STATE(curthread, PS_RUNNING);
break;
case PS_DEAD:
curthread->check_pending = 0;
/* Unlock the scheduling queue and exit the KSE and thread. */
thr_cleanup(curkse, curthread);
KSE_SCHED_UNLOCK(curkse, curkse->k_kseg);
PANIC("bound thread shouldn't get here\n");
break;
case PS_JOIN:
if (THR_NEED_CANCEL(curthread)) {
curthread->join_status.thread = NULL;
THR_SET_STATE(curthread, PS_RUNNING);
} else {
/*
* This state doesn't timeout.
*/
curthread->wakeup_time.tv_sec = -1;
curthread->wakeup_time.tv_nsec = -1;
}
break;
case PS_SUSPENDED:
if (THR_NEED_CANCEL(curthread)) {
curthread->interrupted = 1;
THR_SET_STATE(curthread, PS_RUNNING);
} else {
/*
* These states don't timeout.
*/
curthread->wakeup_time.tv_sec = -1;
curthread->wakeup_time.tv_nsec = -1;
}
break;
case PS_RUNNING:
if ((curthread->flags & THR_FLAGS_SUSPENDED) != 0 &&
!THR_NEED_CANCEL(curthread)) {
THR_SET_STATE(curthread, PS_SUSPENDED);
/*
* These states don't timeout.
*/
curthread->wakeup_time.tv_sec = -1;
curthread->wakeup_time.tv_nsec = -1;
}
break;
case PS_SIGWAIT:
PANIC("bound thread does not have SIGWAIT state\n");
case PS_SLEEP_WAIT:
PANIC("bound thread does not have SLEEP_WAIT state\n");
case PS_SIGSUSPEND:
PANIC("bound thread does not have SIGSUSPEND state\n");
case PS_DEADLOCK:
/*
* These states don't timeout and don't need
* to be in the waiting queue.
*/
curthread->wakeup_time.tv_sec = -1;
curthread->wakeup_time.tv_nsec = -1;
break;
default:
PANIC("Unknown state\n");
break;
}
while (curthread->state != PS_RUNNING) {
sigseqno = curkse->k_sigseqno;
if (curthread->check_pending != 0) {
/*
* Install pending signals into the frame, possible
* cause mutex or condvar backout.
*/
curthread->check_pending = 0;
SIGFILLSET(sigmask);
/*
* Lock out kernel signal code when we are processing
* signals, and get a fresh copy of signal mask.
*/
__sys_sigprocmask(SIG_SETMASK, &sigmask,
&curthread->sigmask);
for (i = 1; i <= _SIG_MAXSIG; i++) {
if (SIGISMEMBER(curthread->sigmask, i))
continue;
if (SIGISMEMBER(curthread->sigpend, i))
(void)_thr_sig_add(curthread, i,
&curthread->siginfo[i-1]);
}
__sys_sigprocmask(SIG_SETMASK, &curthread->sigmask,
NULL);
/* The above code might make thread runnable */
if (curthread->state == PS_RUNNING)
break;
}
THR_DEACTIVATE_LAST_LOCK(curthread);
kse_wait(curkse, curthread, sigseqno);
THR_ACTIVATE_LAST_LOCK(curthread);
KSE_GET_TOD(curkse, &ts);
if (thr_timedout(curthread, &ts)) {
/* Indicate the thread timedout: */
curthread->timeout = 1;
/* Make the thread runnable. */
THR_SET_STATE(curthread, PS_RUNNING);
}
}
/* Remove the frame reference. */
curthread->curframe = NULL;
if (curthread->lock_switch == 0) {
/* Unlock the scheduling queue. */
KSE_SCHED_UNLOCK(curkse, curkse->k_kseg);
}
DBG_MSG("Continuing bound thread %p\n", curthread);
if (first) {
_kse_critical_leave(&curthread->tcb->tcb_tmbx);
pthread_exit(curthread->start_routine(curthread->arg));
}
}
#ifdef DEBUG_THREAD_KERN
static void
dump_queues(struct kse *curkse)
{
struct pthread *thread;
DBG_MSG("Threads in waiting queue:\n");
TAILQ_FOREACH(thread, &curkse->k_kseg->kg_schedq.sq_waitq, pqe) {
DBG_MSG(" thread %p, state %d, blocked %d\n",
thread, thread->state, thread->blocked);
}
}
#endif
/*
* This is the scheduler for a KSE which runs multiple threads.
*/
static void
kse_sched_multi(struct kse_mailbox *kmbx)
{
struct kse *curkse;
struct pthread *curthread, *td_wait;
struct pthread_sigframe *curframe;
int ret;
curkse = (struct kse *)kmbx->km_udata;
THR_ASSERT(curkse->k_kcb->kcb_kmbx.km_curthread == NULL,
"Mailbox not null in kse_sched_multi");
/* Check for first time initialization: */
if (__predict_false((curkse->k_flags & KF_INITIALIZED) == 0)) {
/* Setup this KSEs specific data. */
_kcb_set(curkse->k_kcb);
/* Set this before grabbing the context. */
curkse->k_flags |= KF_INITIALIZED;
}
/*
* No current thread anymore, calling _get_curthread in UTS
* should dump core
*/
_tcb_set(curkse->k_kcb, NULL);
/* If this is an upcall; take the scheduler lock. */
if (!KSE_IS_SWITCH(curkse))
KSE_SCHED_LOCK(curkse, curkse->k_kseg);
else
KSE_CLEAR_SWITCH(curkse);
if (KSE_IS_IDLE(curkse)) {
KSE_CLEAR_IDLE(curkse);
curkse->k_kseg->kg_idle_kses--;
}
/*
* Now that the scheduler lock is held, get the current
* thread. The KSE's current thread cannot be safely
* examined without the lock because it could have returned
* as completed on another KSE. See kse_check_completed().
*/
curthread = curkse->k_curthread;
/*
* If the current thread was completed in another KSE, then
* it will be in the run queue. Don't mark it as being blocked.
*/
if ((curthread != NULL) &&
((curthread->flags & THR_FLAGS_IN_RUNQ) == 0) &&
(curthread->need_switchout == 0)) {
/*
* Assume the current thread is blocked; when the
* completed threads are checked and if the current
* thread is among the completed, the blocked flag
* will be cleared.
*/
curthread->blocked = 1;
}
/* Check for any unblocked threads in the kernel. */
kse_check_completed(curkse);
/*
* Check for threads that have timed-out.
*/
kse_check_waitq(curkse);
/*
* Switchout the current thread, if necessary, as the last step
* so that it is inserted into the run queue (if it's runnable)
* _after_ any other threads that were added to it above.
*/
if (curthread == NULL)
; /* Nothing to do here. */
else if ((curthread->need_switchout == 0) &&
(curthread->blocked == 0) && (THR_IN_CRITICAL(curthread))) {
/*
* Resume the thread and tell it to yield when
* it leaves the critical region.
*/
curthread->critical_yield = 1;
curthread->active = 1;
if ((curthread->flags & THR_FLAGS_IN_RUNQ) != 0)
KSE_RUNQ_REMOVE(curkse, curthread);
curkse->k_curthread = curthread;
curthread->kse = curkse;
DBG_MSG("Continuing thread %p in critical region\n",
curthread);
kse_wakeup_multi(curkse);
KSE_SCHED_UNLOCK(curkse, curkse->k_kseg);
ret = _thread_switch(curkse->k_kcb, curthread->tcb, 1);
if (ret != 0)
PANIC("Can't resume thread in critical region\n");
}
else if ((curthread->flags & THR_FLAGS_IN_RUNQ) == 0)
kse_switchout_thread(curkse, curthread);
curkse->k_curthread = NULL;
#ifdef DEBUG_THREAD_KERN
dump_queues(curkse);
#endif
/* Check if there are no threads ready to run: */
while (((curthread = KSE_RUNQ_FIRST(curkse)) == NULL) &&
(curkse->k_kseg->kg_threadcount != 0) &&
((curkse->k_flags & KF_TERMINATED) == 0)) {
/*
* Wait for a thread to become active or until there are
* no more threads.
*/
td_wait = KSE_WAITQ_FIRST(curkse);
kse_wait(curkse, td_wait, 0);
kse_check_completed(curkse);
kse_check_waitq(curkse);
}
/* Check for no more threads: */
if ((curkse->k_kseg->kg_threadcount == 0) ||
((curkse->k_flags & KF_TERMINATED) != 0)) {
/*
* Normally this shouldn't return, but it will if there
* are other KSEs running that create new threads that
* are assigned to this KSE[G]. For instance, if a scope
* system thread were to create a scope process thread
* and this kse[g] is the initial kse[g], then that newly
* created thread would be assigned to us (the initial
* kse[g]).
*/
kse_wakeup_multi(curkse);
KSE_SCHED_UNLOCK(curkse, curkse->k_kseg);
kse_fini(curkse);
/* never returns */
}
THR_ASSERT(curthread != NULL,
"Return from kse_wait/fini without thread.");
THR_ASSERT(curthread->state != PS_DEAD,
"Trying to resume dead thread!");
KSE_RUNQ_REMOVE(curkse, curthread);
/*
* Make the selected thread the current thread.
*/
curkse->k_curthread = curthread;
/*
* Make sure the current thread's kse points to this kse.
*/
curthread->kse = curkse;
/*
* Reset the time slice if this thread is running for the first
* time or running again after using its full time slice allocation.
*/
if (curthread->slice_usec == -1)
curthread->slice_usec = 0;
/* Mark the thread active. */
curthread->active = 1;
/* Remove the frame reference. */
curframe = curthread->curframe;
curthread->curframe = NULL;
/*
* The thread's current signal frame will only be NULL if it
* is being resumed after being blocked in the kernel. In
* this case, and if the thread needs to run down pending
* signals or needs a cancellation check, we need to add a
* signal frame to the thread's context.
*/
if ((curframe == NULL) && (curthread->state == PS_RUNNING) &&
(curthread->check_pending != 0 ||
THR_NEED_ASYNC_CANCEL(curthread)) &&
!THR_IN_CRITICAL(curthread)) {
curthread->check_pending = 0;
signalcontext(&curthread->tcb->tcb_tmbx.tm_context, 0,
(__sighandler_t *)thr_resume_wrapper);
}
kse_wakeup_multi(curkse);
/*
* Continue the thread at its current frame:
*/
if (curthread->lock_switch != 0) {
/*
* This thread came from a scheduler switch; it will
* unlock the scheduler lock and set the mailbox.
*/
ret = _thread_switch(curkse->k_kcb, curthread->tcb, 0);
} else {
/* This thread won't unlock the scheduler lock. */
KSE_SCHED_UNLOCK(curkse, curkse->k_kseg);
ret = _thread_switch(curkse->k_kcb, curthread->tcb, 1);
}
if (ret != 0)
PANIC("Thread has returned from _thread_switch");
/* This point should not be reached. */
PANIC("Thread has returned from _thread_switch");
}
static void
thr_resume_wrapper(int sig, siginfo_t *siginfo, ucontext_t *ucp)
{
struct pthread *curthread = _get_curthread();
struct kse *curkse;
int ret, err_save = errno;
DBG_MSG(">>> sig wrapper\n");
if (curthread->lock_switch)
PANIC("thr_resume_wrapper, lock_switch != 0\n");
thr_resume_check(curthread, ucp, NULL);
errno = err_save;
_kse_critical_enter();
curkse = _get_curkse();
curthread->tcb->tcb_tmbx.tm_context = *ucp;
ret = _thread_switch(curkse->k_kcb, curthread->tcb, 1);
if (ret != 0)
PANIC("thr_resume_wrapper: thread has returned "
"from _thread_switch");
/* THR_SETCONTEXT(ucp); */ /* not work, why ? */
}
static void
thr_resume_check(struct pthread *curthread, ucontext_t *ucp,
struct pthread_sigframe *psf)
{
_thr_sig_rundown(curthread, ucp, psf);
if (THR_NEED_ASYNC_CANCEL(curthread))
pthread_testcancel();
}
/*
* Clean up a thread. This must be called with the thread's KSE
* scheduling lock held. The thread must be a thread from the
* KSE's group.
*/
static void
thr_cleanup(struct kse *curkse, struct pthread *thread)
{
struct pthread *joiner;
struct kse_mailbox *kmbx = NULL;
int sys_scope;
if ((joiner = thread->joiner) != NULL) {
/* Joinee scheduler lock held; joiner won't leave. */
if (joiner->kseg == curkse->k_kseg) {
if (joiner->join_status.thread == thread) {
joiner->join_status.thread = NULL;
joiner->join_status.ret = thread->ret;
(void)_thr_setrunnable_unlocked(joiner);
}
} else {
KSE_SCHED_UNLOCK(curkse, curkse->k_kseg);
/* The joiner may have removed itself and exited. */
if (_thr_ref_add(thread, joiner, 0) == 0) {
KSE_SCHED_LOCK(curkse, joiner->kseg);
if (joiner->join_status.thread == thread) {
joiner->join_status.thread = NULL;
joiner->join_status.ret = thread->ret;
kmbx = _thr_setrunnable_unlocked(joiner);
}
KSE_SCHED_UNLOCK(curkse, joiner->kseg);
_thr_ref_delete(thread, joiner);
if (kmbx != NULL)
kse_wakeup(kmbx);
}
KSE_SCHED_LOCK(curkse, curkse->k_kseg);
}
thread->attr.flags |= PTHREAD_DETACHED;
}
if (!(sys_scope = (thread->attr.flags & PTHREAD_SCOPE_SYSTEM))) {
/*
* Remove the thread from the KSEG's list of threads.
*/
KSEG_THRQ_REMOVE(thread->kseg, thread);
/*
* Migrate the thread to the main KSE so that this
* KSE and KSEG can be cleaned when their last thread
* exits.
*/
thread->kseg = _kse_initial->k_kseg;
thread->kse = _kse_initial;
}
thread->flags |= THR_FLAGS_GC_SAFE;
/*
* We can't hold the thread list lock while holding the
* scheduler lock.
*/
KSE_SCHED_UNLOCK(curkse, curkse->k_kseg);
DBG_MSG("Adding thread %p to GC list\n", thread);
KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock);
THR_GCLIST_ADD(thread);
KSE_LOCK_RELEASE(curkse, &_thread_list_lock);
if (sys_scope) {
/*
* System scope thread is single thread group,
* when thread is exited, its kse and ksegrp should
* be recycled as well.
* kse upcall stack belongs to thread, clear it here.
*/
curkse->k_stack.ss_sp = 0;
curkse->k_stack.ss_size = 0;
kse_exit();
PANIC("kse_exit() failed for system scope thread");
}
KSE_SCHED_LOCK(curkse, curkse->k_kseg);
}
void
_thr_gc(struct pthread *curthread)
{
thread_gc(curthread);
kse_gc(curthread);
kseg_gc(curthread);
}
static void
thread_gc(struct pthread *curthread)
{
struct pthread *td, *td_next;
kse_critical_t crit;
TAILQ_HEAD(, pthread) worklist;
TAILQ_INIT(&worklist);
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock);
/* Check the threads waiting for GC. */
for (td = TAILQ_FIRST(&_thread_gc_list); td != NULL; td = td_next) {
td_next = TAILQ_NEXT(td, gcle);
if ((td->flags & THR_FLAGS_GC_SAFE) == 0)
continue;
else if (((td->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) &&
((td->kse->k_kcb->kcb_kmbx.km_flags & KMF_DONE) == 0)) {
/*
* The thread and KSE are operating on the same
* stack. Wait for the KSE to exit before freeing
* the thread's stack as well as everything else.
*/
continue;
}
/*
* Remove the thread from the GC list. If the thread
* isn't yet detached, it will get added back to the
* GC list at a later time.
*/
THR_GCLIST_REMOVE(td);
DBG_MSG("Freeing thread %p stack\n", td);
/*
* We can free the thread stack since it's no longer
* in use.
*/
_thr_stack_free(&td->attr);
if (((td->attr.flags & PTHREAD_DETACHED) != 0) &&
(td->refcount == 0)) {
/*
* The thread has detached and is no longer
* referenced. It is safe to remove all
* remnants of the thread.
*/
THR_LIST_REMOVE(td);
TAILQ_INSERT_HEAD(&worklist, td, gcle);
}
}
KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock);
_kse_critical_leave(crit);
while ((td = TAILQ_FIRST(&worklist)) != NULL) {
TAILQ_REMOVE(&worklist, td, gcle);
/*
* XXX we don't free initial thread and its kse
* (if thread is a bound thread), because there might
* have some code referencing initial thread and kse.
*/
if (td == _thr_initial) {
DBG_MSG("Initial thread won't be freed\n");
continue;
}
if ((td->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) {
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock);
kse_free_unlocked(td->kse);
kseg_free_unlocked(td->kseg);
KSE_LOCK_RELEASE(curthread->kse, &kse_lock);
_kse_critical_leave(crit);
}
DBG_MSG("Freeing thread %p\n", td);
_thr_free(curthread, td);
}
}
static void
kse_gc(struct pthread *curthread)
{
kse_critical_t crit;
TAILQ_HEAD(, kse) worklist;
struct kse *kse;
if (free_kse_count <= MAX_CACHED_KSES)
return;
TAILQ_INIT(&worklist);
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock);
while (free_kse_count > MAX_CACHED_KSES) {
kse = TAILQ_FIRST(&free_kseq);
TAILQ_REMOVE(&free_kseq, kse, k_qe);
TAILQ_INSERT_HEAD(&worklist, kse, k_qe);
free_kse_count--;
}
KSE_LOCK_RELEASE(curthread->kse, &kse_lock);
_kse_critical_leave(crit);
while ((kse = TAILQ_FIRST(&worklist))) {
TAILQ_REMOVE(&worklist, kse, k_qe);
kse_destroy(kse);
}
}
static void
kseg_gc(struct pthread *curthread)
{
kse_critical_t crit;
TAILQ_HEAD(, kse_group) worklist;
struct kse_group *kseg;
if (free_kseg_count <= MAX_CACHED_KSEGS)
return;
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock);
while (free_kseg_count > MAX_CACHED_KSEGS) {
kseg = TAILQ_FIRST(&free_kse_groupq);
TAILQ_REMOVE(&free_kse_groupq, kseg, kg_qe);
free_kseg_count--;
TAILQ_INSERT_HEAD(&worklist, kseg, kg_qe);
}
KSE_LOCK_RELEASE(curthread->kse, &kse_lock);
_kse_critical_leave(crit);
while ((kseg = TAILQ_FIRST(&worklist))) {
TAILQ_REMOVE(&worklist, kseg, kg_qe);
kseg_destroy(kseg);
}
}
/*
* Only new threads that are running or suspended may be scheduled.
*/
int
_thr_schedule_add(struct pthread *curthread, struct pthread *newthread)
{
kse_critical_t crit;
int ret;
/* Add the new thread. */
thr_link(newthread);
/*
* If this is the first time creating a thread, make sure
* the mailbox is set for the current thread.
*/
if ((newthread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) {
/* We use the thread's stack as the KSE's stack. */
newthread->kse->k_kcb->kcb_kmbx.km_stack.ss_sp =
newthread->attr.stackaddr_attr;
newthread->kse->k_kcb->kcb_kmbx.km_stack.ss_size =
newthread->attr.stacksize_attr;
/*
* No need to lock the scheduling queue since the
* KSE/KSEG pair have not yet been started.
*/
KSEG_THRQ_ADD(newthread->kseg, newthread);
/* this thread never gives up kse */
newthread->active = 1;
newthread->kse->k_curthread = newthread;
newthread->kse->k_kcb->kcb_kmbx.km_flags = KMF_BOUND;
newthread->kse->k_kcb->kcb_kmbx.km_func =
(kse_func_t *)kse_sched_single;
newthread->kse->k_kcb->kcb_kmbx.km_quantum = 0;
KSE_SET_MBOX(newthread->kse, newthread);
/*
* This thread needs a new KSE and KSEG.
*/
newthread->kse->k_flags &= ~KF_INITIALIZED;
newthread->kse->k_flags |= KF_STARTED;
/* Fire up! */
ret = kse_create(&newthread->kse->k_kcb->kcb_kmbx, 1);
if (ret != 0)
ret = errno;
}
else {
/*
* Lock the KSE and add the new thread to its list of
* assigned threads. If the new thread is runnable, also
* add it to the KSE's run queue.
*/
crit = _kse_critical_enter();
KSE_SCHED_LOCK(curthread->kse, newthread->kseg);
KSEG_THRQ_ADD(newthread->kseg, newthread);
if (newthread->state == PS_RUNNING)
THR_RUNQ_INSERT_TAIL(newthread);
if ((newthread->kse->k_flags & KF_STARTED) == 0) {
/*
* This KSE hasn't been started yet. Start it
* outside of holding the lock.
*/
newthread->kse->k_flags |= KF_STARTED;
newthread->kse->k_kcb->kcb_kmbx.km_func =
(kse_func_t *)kse_sched_multi;
newthread->kse->k_kcb->kcb_kmbx.km_flags = 0;
kse_create(&newthread->kse->k_kcb->kcb_kmbx, 0);
} else if ((newthread->state == PS_RUNNING) &&
KSE_IS_IDLE(newthread->kse)) {
/*
* The thread is being scheduled on another KSEG.
*/
kse_wakeup_one(newthread);
}
KSE_SCHED_UNLOCK(curthread->kse, newthread->kseg);
_kse_critical_leave(crit);
ret = 0;
}
if (ret != 0)
thr_unlink(newthread);
return (ret);
}
void
kse_waitq_insert(struct pthread *thread)
{
struct pthread *td;
if (thread->wakeup_time.tv_sec == -1)
TAILQ_INSERT_TAIL(&thread->kse->k_schedq->sq_waitq, thread,
pqe);
else {
td = TAILQ_FIRST(&thread->kse->k_schedq->sq_waitq);
while ((td != NULL) && (td->wakeup_time.tv_sec != -1) &&
((td->wakeup_time.tv_sec < thread->wakeup_time.tv_sec) ||
((td->wakeup_time.tv_sec == thread->wakeup_time.tv_sec) &&
(td->wakeup_time.tv_nsec <= thread->wakeup_time.tv_nsec))))
td = TAILQ_NEXT(td, pqe);
if (td == NULL)
TAILQ_INSERT_TAIL(&thread->kse->k_schedq->sq_waitq,
thread, pqe);
else
TAILQ_INSERT_BEFORE(td, thread, pqe);
}
thread->flags |= THR_FLAGS_IN_WAITQ;
}
/*
* This must be called with the scheduling lock held.
*/
static void
kse_check_completed(struct kse *kse)
{
struct pthread *thread;
struct kse_thr_mailbox *completed;
int sig;
if ((completed = kse->k_kcb->kcb_kmbx.km_completed) != NULL) {
kse->k_kcb->kcb_kmbx.km_completed = NULL;
while (completed != NULL) {
thread = completed->tm_udata;
DBG_MSG("Found completed thread %p, name %s\n",
thread,
(thread->name == NULL) ? "none" : thread->name);
thread->blocked = 0;
if (thread != kse->k_curthread) {
thr_accounting(thread);
if ((thread->flags & THR_FLAGS_SUSPENDED) != 0)
THR_SET_STATE(thread, PS_SUSPENDED);
else
KSE_RUNQ_INSERT_TAIL(kse, thread);
if ((thread->kse != kse) &&
(thread->kse->k_curthread == thread)) {
/*
* Remove this thread from its
* previous KSE so that it (the KSE)
* doesn't think it is still active.
*/
thread->kse->k_curthread = NULL;
thread->active = 0;
}
}
if ((sig = thread->tcb->tcb_tmbx.tm_syncsig.si_signo)
!= 0) {
if (SIGISMEMBER(thread->sigmask, sig))
SIGADDSET(thread->sigpend, sig);
else if (THR_IN_CRITICAL(thread))
kse_thr_interrupt(NULL, KSE_INTR_SIGEXIT, sig);
else
(void)_thr_sig_add(thread, sig,
&thread->tcb->tcb_tmbx.tm_syncsig);
thread->tcb->tcb_tmbx.tm_syncsig.si_signo = 0;
}
completed = completed->tm_next;
}
}
}
/*
* This must be called with the scheduling lock held.
*/
static void
kse_check_waitq(struct kse *kse)
{
struct pthread *pthread;
struct timespec ts;
KSE_GET_TOD(kse, &ts);
/*
* Wake up threads that have timedout. This has to be
* done before adding the current thread to the run queue
* so that a CPU intensive thread doesn't get preference
* over waiting threads.
*/
while (((pthread = KSE_WAITQ_FIRST(kse)) != NULL) &&
thr_timedout(pthread, &ts)) {
/* Remove the thread from the wait queue: */
KSE_WAITQ_REMOVE(kse, pthread);
DBG_MSG("Found timedout thread %p in waitq\n", pthread);
/* Indicate the thread timedout: */
pthread->timeout = 1;
/* Add the thread to the priority queue: */
if ((pthread->flags & THR_FLAGS_SUSPENDED) != 0)
THR_SET_STATE(pthread, PS_SUSPENDED);
else {
THR_SET_STATE(pthread, PS_RUNNING);
KSE_RUNQ_INSERT_TAIL(kse, pthread);
}
}
}
static int
thr_timedout(struct pthread *thread, struct timespec *curtime)
{
if (thread->wakeup_time.tv_sec < 0)
return (0);
else if (thread->wakeup_time.tv_sec > curtime->tv_sec)
return (0);
else if ((thread->wakeup_time.tv_sec == curtime->tv_sec) &&
(thread->wakeup_time.tv_nsec > curtime->tv_nsec))
return (0);
else
return (1);
}
/*
* This must be called with the scheduling lock held.
*
* Each thread has a time slice, a wakeup time (used when it wants
* to wait for a specified amount of time), a run state, and an
* active flag.
*
* When a thread gets run by the scheduler, the active flag is
* set to non-zero (1). When a thread performs an explicit yield
* or schedules a state change, it enters the scheduler and the
* active flag is cleared. When the active flag is still seen
* set in the scheduler, that means that the thread is blocked in
* the kernel (because it is cleared before entering the scheduler
* in all other instances).
*
* The wakeup time is only set for those states that can timeout.
* It is set to (-1, -1) for all other instances.
*
* The thread's run state, aside from being useful when debugging,
* is used to place the thread in an appropriate queue. There
* are 2 basic queues:
*
* o run queue - queue ordered by priority for all threads
* that are runnable
* o waiting queue - queue sorted by wakeup time for all threads
* that are not otherwise runnable (not blocked
* in kernel, not waiting for locks)
*
* The thread's time slice is used for round-robin scheduling
* (the default scheduling policy). While a SCHED_RR thread
* is runnable it's time slice accumulates. When it reaches
* the time slice interval, it gets reset and added to the end
* of the queue of threads at its priority. When a thread no
* longer becomes runnable (blocks in kernel, waits, etc), its
* time slice is reset.
*
* The job of kse_switchout_thread() is to handle all of the above.
*/
static void
kse_switchout_thread(struct kse *kse, struct pthread *thread)
{
int level;
int i;
int restart;
siginfo_t siginfo;
/*
* Place the currently running thread into the
* appropriate queue(s).
*/
DBG_MSG("Switching out thread %p, state %d\n", thread, thread->state);
THR_DEACTIVATE_LAST_LOCK(thread);
if (thread->blocked != 0) {
thread->active = 0;
thread->need_switchout = 0;
/* This thread must have blocked in the kernel. */
/*
* Check for pending signals and cancellation for
* this thread to see if we need to interrupt it
* in the kernel.
*/
if (THR_NEED_CANCEL(thread)) {
kse_thr_interrupt(&thread->tcb->tcb_tmbx,
KSE_INTR_INTERRUPT, 0);
} else if (thread->check_pending != 0) {
for (i = 1; i <= _SIG_MAXSIG; ++i) {
if (SIGISMEMBER(thread->sigpend, i) &&
!SIGISMEMBER(thread->sigmask, i)) {
restart = _thread_sigact[i - 1].sa_flags & SA_RESTART;
kse_thr_interrupt(&thread->tcb->tcb_tmbx,
restart ? KSE_INTR_RESTART : KSE_INTR_INTERRUPT, 0);
break;
}
}
}
}
else {
switch (thread->state) {
case PS_MUTEX_WAIT:
case PS_COND_WAIT:
if (THR_NEED_CANCEL(thread)) {
thread->interrupted = 1;
thread->continuation = _thr_finish_cancellation;
THR_SET_STATE(thread, PS_RUNNING);
} else {
/* Insert into the waiting queue: */
KSE_WAITQ_INSERT(kse, thread);
}
break;
case PS_LOCKWAIT:
/*
* This state doesn't timeout.
*/
thread->wakeup_time.tv_sec = -1;
thread->wakeup_time.tv_nsec = -1;
level = thread->locklevel - 1;
if (!_LCK_GRANTED(&thread->lockusers[level]))
KSE_WAITQ_INSERT(kse, thread);
else
THR_SET_STATE(thread, PS_RUNNING);
break;
case PS_SLEEP_WAIT:
case PS_SIGWAIT:
if (THR_NEED_CANCEL(thread)) {
thread->interrupted = 1;
THR_SET_STATE(thread, PS_RUNNING);
} else {
KSE_WAITQ_INSERT(kse, thread);
}
break;
case PS_JOIN:
if (THR_NEED_CANCEL(thread)) {
thread->join_status.thread = NULL;
THR_SET_STATE(thread, PS_RUNNING);
} else {
/*
* This state doesn't timeout.
*/
thread->wakeup_time.tv_sec = -1;
thread->wakeup_time.tv_nsec = -1;
/* Insert into the waiting queue: */
KSE_WAITQ_INSERT(kse, thread);
}
break;
case PS_SIGSUSPEND:
case PS_SUSPENDED:
if (THR_NEED_CANCEL(thread)) {
thread->interrupted = 1;
THR_SET_STATE(thread, PS_RUNNING);
} else {
/*
* These states don't timeout.
*/
thread->wakeup_time.tv_sec = -1;
thread->wakeup_time.tv_nsec = -1;
/* Insert into the waiting queue: */
KSE_WAITQ_INSERT(kse, thread);
}
break;
case PS_DEAD:
/*
* The scheduler is operating on a different
* stack. It is safe to do garbage collecting
* here.
*/
thread->active = 0;
thread->need_switchout = 0;
thread->lock_switch = 0;
thr_cleanup(kse, thread);
return;
break;
case PS_RUNNING:
if ((thread->flags & THR_FLAGS_SUSPENDED) != 0 &&
!THR_NEED_CANCEL(thread))
THR_SET_STATE(thread, PS_SUSPENDED);
break;
case PS_DEADLOCK:
/*
* These states don't timeout.
*/
thread->wakeup_time.tv_sec = -1;
thread->wakeup_time.tv_nsec = -1;
/* Insert into the waiting queue: */
KSE_WAITQ_INSERT(kse, thread);
break;
default:
PANIC("Unknown state\n");
break;
}
thr_accounting(thread);
if (thread->state == PS_RUNNING) {
if (thread->slice_usec == -1) {
/*
* The thread exceeded its time quantum or
* it yielded the CPU; place it at the tail
* of the queue for its priority.
*/
KSE_RUNQ_INSERT_TAIL(kse, thread);
} else {
/*
* The thread hasn't exceeded its interval
* Place it at the head of the queue for its
* priority.
*/
KSE_RUNQ_INSERT_HEAD(kse, thread);
}
}
}
thread->active = 0;
thread->need_switchout = 0;
if (thread->check_pending != 0) {
/* Install pending signals into the frame. */
thread->check_pending = 0;
KSE_LOCK_ACQUIRE(kse, &_thread_signal_lock);
for (i = 1; i <= _SIG_MAXSIG; i++) {
if (SIGISMEMBER(thread->sigmask, i))
continue;
if (SIGISMEMBER(thread->sigpend, i))
(void)_thr_sig_add(thread, i,
&thread->siginfo[i-1]);
else if (SIGISMEMBER(_thr_proc_sigpending, i) &&
_thr_getprocsig_unlocked(i, &siginfo)) {
(void)_thr_sig_add(thread, i, &siginfo);
}
}
KSE_LOCK_RELEASE(kse, &_thread_signal_lock);
}
}
/*
* This function waits for the smallest timeout value of any waiting
* thread, or until it receives a message from another KSE.
*
* This must be called with the scheduling lock held.
*/
static void
kse_wait(struct kse *kse, struct pthread *td_wait, int sigseqno)
{
struct timespec ts, ts_sleep;
int saved_flags;
KSE_GET_TOD(kse, &ts);
if ((td_wait == NULL) || (td_wait->wakeup_time.tv_sec < 0)) {
/* Limit sleep to no more than 1 minute. */
ts_sleep.tv_sec = 60;
ts_sleep.tv_nsec = 0;
} else {
TIMESPEC_SUB(&ts_sleep, &td_wait->wakeup_time, &ts);
if (ts_sleep.tv_sec > 60) {
ts_sleep.tv_sec = 60;
ts_sleep.tv_nsec = 0;
}
}
/* Don't sleep for negative times. */
if ((ts_sleep.tv_sec >= 0) && (ts_sleep.tv_nsec >= 0)) {
KSE_SET_IDLE(kse);
kse->k_kseg->kg_idle_kses++;
KSE_SCHED_UNLOCK(kse, kse->k_kseg);
if ((kse->k_kseg->kg_flags & KGF_SINGLE_THREAD) &&
(kse->k_sigseqno != sigseqno))
; /* don't sleep */
else {
saved_flags = kse->k_kcb->kcb_kmbx.km_flags;
kse->k_kcb->kcb_kmbx.km_flags |= KMF_NOUPCALL;
kse_release(&ts_sleep);
kse->k_kcb->kcb_kmbx.km_flags = saved_flags;
}
KSE_SCHED_LOCK(kse, kse->k_kseg);
if (KSE_IS_IDLE(kse)) {
KSE_CLEAR_IDLE(kse);
kse->k_kseg->kg_idle_kses--;
}
}
}
/*
* Avoid calling this kse_exit() so as not to confuse it with the
* system call of the same name.
*/
static void
kse_fini(struct kse *kse)
{
/* struct kse_group *free_kseg = NULL; */
struct timespec ts;
struct pthread *td;
/*
* Check to see if this is one of the main kses.
*/
if (kse->k_kseg != _kse_initial->k_kseg) {
PANIC("shouldn't get here");
/* This is for supporting thread groups. */
#ifdef NOT_YET
/* Remove this KSE from the KSEG's list of KSEs. */
KSE_SCHED_LOCK(kse, kse->k_kseg);
TAILQ_REMOVE(&kse->k_kseg->kg_kseq, kse, k_kgqe);
kse->k_kseg->kg_ksecount--;
if (TAILQ_EMPTY(&kse->k_kseg->kg_kseq))
free_kseg = kse->k_kseg;
KSE_SCHED_UNLOCK(kse, kse->k_kseg);
/*
* Add this KSE to the list of free KSEs along with
* the KSEG if is now orphaned.
*/
KSE_LOCK_ACQUIRE(kse, &kse_lock);
if (free_kseg != NULL)
kseg_free_unlocked(free_kseg);
kse_free_unlocked(kse);
KSE_LOCK_RELEASE(kse, &kse_lock);
kse_exit();
/* Never returns. */
PANIC("kse_exit()");
#endif
} else {
/*
* We allow program to kill kse in initial group (by
* lowering the concurrency).
*/
if ((kse != _kse_initial) &&
((kse->k_flags & KF_TERMINATED) != 0)) {
KSE_SCHED_LOCK(kse, kse->k_kseg);
TAILQ_REMOVE(&kse->k_kseg->kg_kseq, kse, k_kgqe);
kse->k_kseg->kg_ksecount--;
/*
* Migrate thread to _kse_initial if its lastest
* kse it ran on is the kse.
*/
td = TAILQ_FIRST(&kse->k_kseg->kg_threadq);
while (td != NULL) {
if (td->kse == kse)
td->kse = _kse_initial;
td = TAILQ_NEXT(td, kle);
}
KSE_SCHED_UNLOCK(kse, kse->k_kseg);
KSE_LOCK_ACQUIRE(kse, &kse_lock);
kse_free_unlocked(kse);
KSE_LOCK_RELEASE(kse, &kse_lock);
/* Make sure there is always at least one is awake */
KSE_WAKEUP(_kse_initial);
kse_exit();
/* Never returns. */
PANIC("kse_exit() failed for initial kseg");
}
KSE_SCHED_LOCK(kse, kse->k_kseg);
KSE_SET_IDLE(kse);
kse->k_kseg->kg_idle_kses++;
KSE_SCHED_UNLOCK(kse, kse->k_kseg);
ts.tv_sec = 120;
ts.tv_nsec = 0;
kse->k_kcb->kcb_kmbx.km_flags = 0;
kse_release(&ts);
/* Never reach */
}
}
void
_thr_set_timeout(const struct timespec *timeout)
{
struct pthread *curthread = _get_curthread();
struct timespec ts;
/* Reset the timeout flag for the running thread: */
curthread->timeout = 0;
/* Check if the thread is to wait forever: */
if (timeout == NULL) {
/*
* Set the wakeup time to something that can be recognised as
* different to an actual time of day:
*/
curthread->wakeup_time.tv_sec = -1;
curthread->wakeup_time.tv_nsec = -1;
}
/* Check if no waiting is required: */
else if ((timeout->tv_sec == 0) && (timeout->tv_nsec == 0)) {
/* Set the wake up time to 'immediately': */
curthread->wakeup_time.tv_sec = 0;
curthread->wakeup_time.tv_nsec = 0;
} else {
/* Calculate the time for the current thread to wakeup: */
KSE_GET_TOD(curthread->kse, &ts);
TIMESPEC_ADD(&curthread->wakeup_time, &ts, timeout);
}
}
void
_thr_panic_exit(char *file, int line, char *msg)
{
char buf[256];
snprintf(buf, sizeof(buf), "(%s:%d) %s\n", file, line, msg);
__sys_write(2, buf, strlen(buf));
abort();
}
void
_thr_setrunnable(struct pthread *curthread, struct pthread *thread)
{
kse_critical_t crit;
struct kse_mailbox *kmbx;
crit = _kse_critical_enter();
KSE_SCHED_LOCK(curthread->kse, thread->kseg);
kmbx = _thr_setrunnable_unlocked(thread);
KSE_SCHED_UNLOCK(curthread->kse, thread->kseg);
_kse_critical_leave(crit);
if ((kmbx != NULL) && (__isthreaded != 0))
kse_wakeup(kmbx);
}
struct kse_mailbox *
_thr_setrunnable_unlocked(struct pthread *thread)
{
struct kse_mailbox *kmbx = NULL;
if ((thread->kseg->kg_flags & KGF_SINGLE_THREAD) != 0) {
/* No silly queues for these threads. */
if ((thread->flags & THR_FLAGS_SUSPENDED) != 0)
THR_SET_STATE(thread, PS_SUSPENDED);
else {
THR_SET_STATE(thread, PS_RUNNING);
kmbx = kse_wakeup_one(thread);
}
} else if (thread->state != PS_RUNNING) {
if ((thread->flags & THR_FLAGS_IN_WAITQ) != 0)
KSE_WAITQ_REMOVE(thread->kse, thread);
if ((thread->flags & THR_FLAGS_SUSPENDED) != 0)
THR_SET_STATE(thread, PS_SUSPENDED);
else {
THR_SET_STATE(thread, PS_RUNNING);
if ((thread->blocked == 0) && (thread->active == 0) &&
(thread->flags & THR_FLAGS_IN_RUNQ) == 0)
THR_RUNQ_INSERT_TAIL(thread);
/*
* XXX - Threads are not yet assigned to specific
* KSEs; they are assigned to the KSEG. So
* the fact that a thread's KSE is waiting
* doesn't necessarily mean that it will be
* the KSE that runs the thread after the
* lock is granted. But we don't know if the
* other KSEs within the same KSEG are also
* in a waiting state or not so we err on the
* side of caution and wakeup the thread's
* last known KSE. We ensure that the
* threads KSE doesn't change while it's
* scheduling lock is held so it is safe to
* reference it (the KSE). If the KSE wakes
* up and doesn't find any more work it will
* again go back to waiting so no harm is
* done.
*/
kmbx = kse_wakeup_one(thread);
}
}
return (kmbx);
}
static struct kse_mailbox *
kse_wakeup_one(struct pthread *thread)
{
struct kse *ke;
if (KSE_IS_IDLE(thread->kse)) {
KSE_CLEAR_IDLE(thread->kse);
thread->kseg->kg_idle_kses--;
return (&thread->kse->k_kcb->kcb_kmbx);
} else {
TAILQ_FOREACH(ke, &thread->kseg->kg_kseq, k_kgqe) {
if (KSE_IS_IDLE(ke)) {
KSE_CLEAR_IDLE(ke);
ke->k_kseg->kg_idle_kses--;
return (&ke->k_kcb->kcb_kmbx);
}
}
}
return (NULL);
}
static void
kse_wakeup_multi(struct kse *curkse)
{
struct kse *ke;
int tmp;
if ((tmp = KSE_RUNQ_THREADS(curkse)) && curkse->k_kseg->kg_idle_kses) {
TAILQ_FOREACH(ke, &curkse->k_kseg->kg_kseq, k_kgqe) {
if (KSE_IS_IDLE(ke)) {
KSE_CLEAR_IDLE(ke);
ke->k_kseg->kg_idle_kses--;
KSE_WAKEUP(ke);
if (--tmp == 0)
break;
}
}
}
}
/*
* Allocate a new KSEG.
*
* We allow the current thread to be NULL in the case that this
* is the first time a KSEG is being created (library initialization).
* In this case, we don't need to (and can't) take any locks.
*/
struct kse_group *
_kseg_alloc(struct pthread *curthread)
{
struct kse_group *kseg = NULL;
kse_critical_t crit;
if ((curthread != NULL) && (free_kseg_count > 0)) {
/* Use the kse lock for the kseg queue. */
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock);
if ((kseg = TAILQ_FIRST(&free_kse_groupq)) != NULL) {
TAILQ_REMOVE(&free_kse_groupq, kseg, kg_qe);
free_kseg_count--;
active_kseg_count++;
TAILQ_INSERT_TAIL(&active_kse_groupq, kseg, kg_qe);
}
KSE_LOCK_RELEASE(curthread->kse, &kse_lock);
_kse_critical_leave(crit);
if (kseg)
kseg_reinit(kseg);
}
/*
* If requested, attempt to allocate a new KSE group only if the
* KSE allocation was successful and a KSE group wasn't found in
* the free list.
*/
if ((kseg == NULL) &&
((kseg = (struct kse_group *)malloc(sizeof(*kseg))) != NULL)) {
if (_pq_alloc(&kseg->kg_schedq.sq_runq,
THR_MIN_PRIORITY, THR_LAST_PRIORITY) != 0) {
free(kseg);
kseg = NULL;
} else {
kseg_init(kseg);
/* Add the KSEG to the list of active KSEGs. */
if (curthread != NULL) {
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock);
active_kseg_count++;
TAILQ_INSERT_TAIL(&active_kse_groupq,
kseg, kg_qe);
KSE_LOCK_RELEASE(curthread->kse, &kse_lock);
_kse_critical_leave(crit);
} else {
active_kseg_count++;
TAILQ_INSERT_TAIL(&active_kse_groupq,
kseg, kg_qe);
}
}
}
return (kseg);
}
static void
kseg_init(struct kse_group *kseg)
{
kseg_reinit(kseg);
_lock_init(&kseg->kg_lock, LCK_ADAPTIVE, _kse_lock_wait,
_kse_lock_wakeup);
}
static void
kseg_reinit(struct kse_group *kseg)
{
TAILQ_INIT(&kseg->kg_kseq);
TAILQ_INIT(&kseg->kg_threadq);
TAILQ_INIT(&kseg->kg_schedq.sq_waitq);
kseg->kg_threadcount = 0;
kseg->kg_ksecount = 0;
kseg->kg_idle_kses = 0;
kseg->kg_flags = 0;
}
/*
* This must be called with the kse lock held and when there are
* no more threads that reference it.
*/
static void
kseg_free_unlocked(struct kse_group *kseg)
{
TAILQ_REMOVE(&active_kse_groupq, kseg, kg_qe);
TAILQ_INSERT_HEAD(&free_kse_groupq, kseg, kg_qe);
free_kseg_count++;
active_kseg_count--;
}
void
_kseg_free(struct kse_group *kseg)
{
struct kse *curkse;
kse_critical_t crit;
crit = _kse_critical_enter();
curkse = _get_curkse();
KSE_LOCK_ACQUIRE(curkse, &kse_lock);
kseg_free_unlocked(kseg);
KSE_LOCK_RELEASE(curkse, &kse_lock);
_kse_critical_leave(crit);
}
static void
kseg_destroy(struct kse_group *kseg)
{
_lock_destroy(&kseg->kg_lock);
_pq_free(&kseg->kg_schedq.sq_runq);
free(kseg);
}
/*
* Allocate a new KSE.
*
* We allow the current thread to be NULL in the case that this
* is the first time a KSE is being created (library initialization).
* In this case, we don't need to (and can't) take any locks.
*/
struct kse *
_kse_alloc(struct pthread *curthread, int sys_scope)
{
struct kse *kse = NULL;
char *stack;
kse_critical_t crit;
int i;
if ((curthread != NULL) && (free_kse_count > 0)) {
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock);
/* Search for a finished KSE. */
kse = TAILQ_FIRST(&free_kseq);
while ((kse != NULL) &&
((kse->k_kcb->kcb_kmbx.km_flags & KMF_DONE) == 0)) {
kse = TAILQ_NEXT(kse, k_qe);
}
if (kse != NULL) {
DBG_MSG("found an unused kse.\n");
TAILQ_REMOVE(&free_kseq, kse, k_qe);
free_kse_count--;
TAILQ_INSERT_TAIL(&active_kseq, kse, k_qe);
active_kse_count++;
}
KSE_LOCK_RELEASE(curthread->kse, &kse_lock);
_kse_critical_leave(crit);
if (kse != NULL)
kse_reinit(kse, sys_scope);
}
if ((kse == NULL) &&
((kse = (struct kse *)malloc(sizeof(*kse))) != NULL)) {
if (sys_scope != 0)
stack = NULL;
else if ((stack = malloc(KSE_STACKSIZE)) == NULL) {
free(kse);
return (NULL);
}
bzero(kse, sizeof(*kse));
/* Initialize KCB without the lock. */
if ((kse->k_kcb = _kcb_ctor(kse)) == NULL) {
if (stack != NULL)
free(stack);
free(kse);
return (NULL);
}
/* Initialize the lockusers. */
for (i = 0; i < MAX_KSE_LOCKLEVEL; i++) {
_lockuser_init(&kse->k_lockusers[i], (void *)kse);
_LCK_SET_PRIVATE2(&kse->k_lockusers[i], NULL);
}
/* _lock_init(kse->k_lock, ...) */
if (curthread != NULL) {
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock);
}
kse->k_flags = 0;
TAILQ_INSERT_TAIL(&active_kseq, kse, k_qe);
active_kse_count++;
if (curthread != NULL) {
KSE_LOCK_RELEASE(curthread->kse, &kse_lock);
_kse_critical_leave(crit);
}
/*
* Create the KSE context.
* Scope system threads (one thread per KSE) are not required
* to have a stack for an unneeded kse upcall.
*/
if (!sys_scope) {
kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_multi;
kse->k_stack.ss_sp = stack;
kse->k_stack.ss_size = KSE_STACKSIZE;
} else {
kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_single;
kse->k_stack.ss_sp = NULL;
kse->k_stack.ss_size = 0;
}
kse->k_kcb->kcb_kmbx.km_udata = (void *)kse;
kse->k_kcb->kcb_kmbx.km_quantum = 20000;
/*
* We need to keep a copy of the stack in case it
* doesn't get used; a KSE running a scope system
* thread will use that thread's stack.
*/
kse->k_kcb->kcb_kmbx.km_stack = kse->k_stack;
}
return (kse);
}
static void
kse_reinit(struct kse *kse, int sys_scope)
{
if (!sys_scope) {
kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_multi;
if (kse->k_stack.ss_sp == NULL) {
/* XXX check allocation failure */
kse->k_stack.ss_sp = (char *) malloc(KSE_STACKSIZE);
kse->k_stack.ss_size = KSE_STACKSIZE;
}
kse->k_kcb->kcb_kmbx.km_quantum = 20000;
} else {
kse->k_kcb->kcb_kmbx.km_func = (kse_func_t *)kse_sched_single;
if (kse->k_stack.ss_sp)
free(kse->k_stack.ss_sp);
kse->k_stack.ss_sp = NULL;
kse->k_stack.ss_size = 0;
kse->k_kcb->kcb_kmbx.km_quantum = 0;
}
kse->k_kcb->kcb_kmbx.km_stack = kse->k_stack;
kse->k_kcb->kcb_kmbx.km_udata = (void *)kse;
kse->k_kcb->kcb_kmbx.km_curthread = NULL;
kse->k_kcb->kcb_kmbx.km_flags = 0;
kse->k_curthread = NULL;
kse->k_kseg = 0;
kse->k_schedq = 0;
kse->k_locklevel = 0;
kse->k_flags = 0;
kse->k_error = 0;
kse->k_cpu = 0;
kse->k_sigseqno = 0;
}
void
kse_free_unlocked(struct kse *kse)
{
TAILQ_REMOVE(&active_kseq, kse, k_qe);
active_kse_count--;
kse->k_kseg = NULL;
kse->k_kcb->kcb_kmbx.km_quantum = 20000;
kse->k_flags = 0;
TAILQ_INSERT_HEAD(&free_kseq, kse, k_qe);
free_kse_count++;
}
void
_kse_free(struct pthread *curthread, struct kse *kse)
{
kse_critical_t crit;
if (curthread == NULL)
kse_free_unlocked(kse);
else {
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &kse_lock);
kse_free_unlocked(kse);
KSE_LOCK_RELEASE(curthread->kse, &kse_lock);
_kse_critical_leave(crit);
}
}
static void
kse_destroy(struct kse *kse)
{
int i;
if (kse->k_stack.ss_sp != NULL)
free(kse->k_stack.ss_sp);
_kcb_dtor(kse->k_kcb);
for (i = 0; i < MAX_KSE_LOCKLEVEL; ++i)
_lockuser_destroy(&kse->k_lockusers[i]);
_lock_destroy(&kse->k_lock);
free(kse);
}
struct pthread *
_thr_alloc(struct pthread *curthread)
{
kse_critical_t crit;
struct pthread *thread = NULL;
int i;
if (curthread != NULL) {
if (GC_NEEDED())
_thr_gc(curthread);
if (free_thread_count > 0) {
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &thread_lock);
if ((thread = TAILQ_FIRST(&free_threadq)) != NULL) {
TAILQ_REMOVE(&free_threadq, thread, tle);
free_thread_count--;
}
KSE_LOCK_RELEASE(curthread->kse, &thread_lock);
_kse_critical_leave(crit);
}
}
if ((thread == NULL) &&
((thread = malloc(sizeof(struct pthread))) != NULL)) {
bzero(thread, sizeof(struct pthread));
if ((thread->tcb = _tcb_ctor(thread)) == NULL) {
free(thread);
thread = NULL;
} else {
thread->siginfo = calloc(_SIG_MAXSIG,
sizeof(siginfo_t));
/*
* Initialize thread locking.
* Lock initializing needs malloc, so don't
* enter critical region before doing this!
*/
if (_lock_init(&thread->lock, LCK_ADAPTIVE,
_thr_lock_wait, _thr_lock_wakeup) != 0)
PANIC("Cannot initialize thread lock");
for (i = 0; i < MAX_THR_LOCKLEVEL; i++) {
_lockuser_init(&thread->lockusers[i],
(void *)thread);
_LCK_SET_PRIVATE2(&thread->lockusers[i],
(void *)thread);
}
}
}
return (thread);
}
void
_thr_free(struct pthread *curthread, struct pthread *thread)
{
kse_critical_t crit;
DBG_MSG("Freeing thread %p\n", thread);
if (thread->name) {
free(thread->name);
thread->name = NULL;
}
if ((curthread == NULL) || (free_thread_count >= MAX_CACHED_THREADS)) {
thr_destroy(thread);
} else {
/* Add the thread to the free thread list. */
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &thread_lock);
TAILQ_INSERT_TAIL(&free_threadq, thread, tle);
free_thread_count++;
KSE_LOCK_RELEASE(curthread->kse, &thread_lock);
_kse_critical_leave(crit);
}
}
static void
thr_destroy(struct pthread *thread)
{
int i;
for (i = 0; i < MAX_THR_LOCKLEVEL; i++)
_lockuser_destroy(&thread->lockusers[i]);
_lock_destroy(&thread->lock);
_tcb_dtor(thread->tcb);
free(thread->siginfo);
free(thread);
}
/*
* Add an active thread:
*
* o Assign the thread a unique id (which GDB uses to track
* threads.
* o Add the thread to the list of all threads and increment
* number of active threads.
*/
static void
thr_link(struct pthread *thread)
{
kse_critical_t crit;
struct kse *curkse;
crit = _kse_critical_enter();
curkse = _get_curkse();
KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock);
/*
* Initialize the unique id (which GDB uses to track
* threads), add the thread to the list of all threads,
* and
*/
thread->uniqueid = next_uniqueid++;
THR_LIST_ADD(thread);
_thr_active_threads++;
KSE_LOCK_RELEASE(curkse, &_thread_list_lock);
_kse_critical_leave(crit);
}
/*
* Remove an active thread.
*/
static void
thr_unlink(struct pthread *thread)
{
kse_critical_t crit;
struct kse *curkse;
crit = _kse_critical_enter();
curkse = _get_curkse();
KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock);
THR_LIST_REMOVE(thread);
_thr_active_threads--;
KSE_LOCK_RELEASE(curkse, &_thread_list_lock);
_kse_critical_leave(crit);
}
void
_thr_hash_add(struct pthread *thread)
{
struct thread_hash_head *head;
head = &thr_hashtable[THREAD_HASH(thread)];
LIST_INSERT_HEAD(head, thread, hle);
}
void
_thr_hash_remove(struct pthread *thread)
{
LIST_REMOVE(thread, hle);
}
struct pthread *
_thr_hash_find(struct pthread *thread)
{
struct pthread *td;
struct thread_hash_head *head;
head = &thr_hashtable[THREAD_HASH(thread)];
LIST_FOREACH(td, head, hle) {
if (td == thread)
return (thread);
}
return (NULL);
}
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