WebSVN – HelenOS – Diff – /trunk/kernel/generic/src/proc/thread.c


/*
 * Copyright (c) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
 */
 
/** @addtogroup genericproc
 * @{
 */
 
/**
 * @file
 * @brief   Thread management functions.
 */
 
#include <proc/scheduler.h>
#include <proc/thread.h>
#include <proc/task.h>
#include <proc/uarg.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <arch/asm.h>
#include <arch/cycle.h>
#include <arch.h>
#include <synch/synch.h>
#include <synch/spinlock.h>
#include <synch/waitq.h>
#include <synch/rwlock.h>
#include <cpu.h>
#include <func.h>
#include <context.h>
#include <adt/btree.h>
#include <adt/list.h>
#include <time/clock.h>
#include <time/timeout.h>
#include <config.h>
#include <arch/interrupt.h>
#include <smp/ipi.h>
#include <arch/faddr.h>
#include <atomic.h>
#include <memstr.h>
#include <print.h>
#include <mm/slab.h>
#include <debug.h>
#include <main/uinit.h>
#include <syscall/copy.h>
#include <errno.h>
#include <console/klog.h>
 
 
/** Thread states */
char *thread_states[] = {
    "Invalid",
    "Running",
    "Sleeping",
    "Ready",
    "Entering",
    "Exiting",
    "JoinMe"
};
 
/** Lock protecting the threads_btree B+tree.
 *
 * For locking rules, see declaration thereof.
 */
SPINLOCK_INITIALIZE(threads_lock);
 
/** B+tree of all threads.
 *
 * When a thread is found in the threads_btree B+tree, it is guaranteed to
 * exist as long as the threads_lock is held.
 */
btree_t threads_btree;     
 
SPINLOCK_INITIALIZE(tidlock);
thread_id_t last_tid = 0;
 
static slab_cache_t *thread_slab;
#ifdef ARCH_HAS_FPU
slab_cache_t *fpu_context_slab;
#endif
 
/** Thread wrapper.
 *
 * This wrapper is provided to ensure that every thread makes a call to
 * thread_exit() when its implementing function returns.
 *
 * interrupts_disable() is assumed.
 *
 */
static void cushion(void)
{
    void (*f)(void *) = THREAD->thread_code;
    void *arg = THREAD->thread_arg;
    THREAD->last_cycle = get_cycle();
 
    /* This is where each thread wakes up after its creation */
    spinlock_unlock(&THREAD->lock);
    interrupts_enable();
 
    f(arg);
   
    /* Accumulate accounting to the task */
    ipl_t ipl = interrupts_disable();
   
    spinlock_lock(&THREAD->lock);
    if (!THREAD->uncounted) {
        thread_update_accounting();
        uint64_t cycles = THREAD->cycles;
        THREAD->cycles = 0;
        spinlock_unlock(&THREAD->lock);
       
        spinlock_lock(&TASK->lock);
        TASK->cycles += cycles;
        spinlock_unlock(&TASK->lock);
    } else
        spinlock_unlock(&THREAD->lock);
   
    interrupts_restore(ipl);
   
    thread_exit();
    /* not reached */
}
 
/** Initialization and allocation for thread_t structure */
static int thr_constructor(void *obj, int kmflags)
{
    thread_t *t = (thread_t *) obj;
 
    spinlock_initialize(&t->lock, "thread_t_lock");
    link_initialize(&t->rq_link);
    link_initialize(&t->wq_link);
    link_initialize(&t->th_link);
 
    /* call the architecture-specific part of the constructor */
    thr_constructor_arch(t);
   
#ifdef ARCH_HAS_FPU
#ifdef CONFIG_FPU_LAZY
    t->saved_fpu_context = NULL;
#else
    t->saved_fpu_context = slab_alloc(fpu_context_slab, kmflags);
    if (!t->saved_fpu_context)
        return -1;
#endif
#endif  
 
    t->kstack = (uint8_t *) frame_alloc(STACK_FRAMES, FRAME_KA | kmflags);
    if (!t->kstack) {
#ifdef ARCH_HAS_FPU
        if (t->saved_fpu_context)
            slab_free(fpu_context_slab, t->saved_fpu_context);
#endif
        return -1;
    }
 
    return 0;
}
 
/** Destruction of thread_t object */
static int thr_destructor(void *obj)
{
    thread_t *t = (thread_t *) obj;
 
    /* call the architecture-specific part of the destructor */
    thr_destructor_arch(t);
 
    frame_free(KA2PA(t->kstack));
#ifdef ARCH_HAS_FPU
    if (t->saved_fpu_context)
        slab_free(fpu_context_slab, t->saved_fpu_context);
#endif
    return 1; /* One page freed */
}
 
/** Initialize threads
 *
 * Initialize kernel threads support.
 *
 */
void thread_init(void)
{
    THREAD = NULL;
    atomic_set(&nrdy,0);
    thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,
        thr_constructor, thr_destructor, 0);
 
#ifdef ARCH_HAS_FPU
    fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),
        FPU_CONTEXT_ALIGN, NULL, NULL, 0);
#endif
 
    btree_create(&threads_btree);
}
 
/** Make thread ready
 *
 * Switch thread t to the ready state.
 *
 * @param t Thread to make ready.
 *
 */
void thread_ready(thread_t *t)
{
    cpu_t *cpu;
    runq_t *r;
    ipl_t ipl;
    int i, avg;
 
    ipl = interrupts_disable();
 
    spinlock_lock(&t->lock);
 
    ASSERT(!(t->state == Ready));
 
    i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;
   
    cpu = CPU;
    if (t->flags & THREAD_FLAG_WIRED) {
        ASSERT(t->cpu != NULL);
        cpu = t->cpu;
    }
    t->state = Ready;
    spinlock_unlock(&t->lock);
   
    /*
     * Append t to respective ready queue on respective processor.
     */
    r = &cpu->rq[i];
    spinlock_lock(&r->lock);
    list_append(&t->rq_link, &r->rq_head);
    r->n++;
    spinlock_unlock(&r->lock);
 
    atomic_inc(&nrdy);
    avg = atomic_get(&nrdy) / config.cpu_active;
    atomic_inc(&cpu->nrdy);
 
    interrupts_restore(ipl);
}
 
/** Create new thread
 *
 * Create a new thread.
 *
 * @param func      Thread's implementing function.
 * @param arg       Thread's implementing function argument.
 * @param task      Task to which the thread belongs.
 * @param flags     Thread flags.
 * @param name      Symbolic name.
 * @param uncounted Thread's accounting doesn't affect accumulated task
 *          accounting.
 *
 * @return New thread's structure on success, NULL on failure.
 *
 */
thread_t *thread_create(void (* func)(void *), void *arg, task_t *task,
    int flags, char *name, bool uncounted)
{
    thread_t *t;
    ipl_t ipl;
   
    t = (thread_t *) slab_alloc(thread_slab, 0);
    if (!t)
        return NULL;
   
    /* Not needed, but good for debugging */
    memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES,
        0);
   
    ipl = interrupts_disable();
    spinlock_lock(&tidlock);
    t->tid = ++last_tid;
    spinlock_unlock(&tidlock);
    interrupts_restore(ipl);
   
    context_save(&t->saved_context);
    context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,
        THREAD_STACK_SIZE);
   
    the_initialize((the_t *) t->kstack);
   
    ipl = interrupts_disable();
    t->saved_context.ipl = interrupts_read();
    interrupts_restore(ipl);
   
    memcpy(t->name, name, THREAD_NAME_BUFLEN);
   
    t->thread_code = func;
    t->thread_arg = arg;
    t->ticks = -1;
    t->cycles = 0;
    t->uncounted = uncounted;
    t->priority = -1;       /* start in rq[0] */
    t->cpu = NULL;
    t->flags = flags;
    t->state = Entering;
    t->call_me = NULL;
    t->call_me_with = NULL;
   
    timeout_initialize(&t->sleep_timeout);
    t->sleep_interruptible = false;
    t->sleep_queue = NULL;
    t->timeout_pending = 0;
 
    t->in_copy_from_uspace = false;
    t->in_copy_to_uspace = false;
 
    t->interrupted = false;
 
    t->detached = false;
    waitq_initialize(&t->join_wq);
   
    t->rwlock_holder_type = RWLOCK_NONE;
       
    t->task = task;
   
    t->fpu_context_exists = 0;
    t->fpu_context_engaged = 0;
 
    /* might depend on previous initialization */
    thread_create_arch(t); 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    if (!(flags & THREAD_FLAG_NOATTACH))
        thread_attach(t, task);
 
    return t;
}
 
/** Destroy thread memory structure
 *
 * Detach thread from all queues, cpus etc. and destroy it.
 *
 * Assume thread->lock is held!!
 */
void thread_destroy(thread_t *t)
{
 
 
    ASSERT(t->state == Exiting || t->state == JoinMe);
    ASSERT(t->task);
    ASSERT(t->cpu);
 
    spinlock_lock(&t->cpu->lock);
    if (t->cpu->fpu_owner == t)
        t->cpu->fpu_owner = NULL;
    spinlock_unlock(&t->cpu->lock);
 
    spinlock_unlock(&t->lock);
 
    spinlock_lock(&threads_lock);
    btree_remove(&threads_btree, (btree_key_t) ((uintptr_t ) t), NULL);
    spinlock_unlock(&threads_lock);
 
    /*
     * Detach from the containing task.
     */
    spinlock_lock(&t->task->lock);
    list_remove(&t->th_link);
 
 
 
 
    spinlock_unlock(&t->task->lock);   
 
    /*
     * t is guaranteed to be the very last thread of its task.
     * It is safe to destroy the task.
     */
    if (atomic_predec(&t->task->refcount) == 0)
        task_destroy(t->task);
   
    /*
     * If the thread had a userspace context, free up its kernel_uarg
     * structure.
     */
    if (t->flags & THREAD_FLAG_USPACE) {
        ASSERT(t->thread_arg);
        free(t->thread_arg);
    }
 
    slab_free(thread_slab, t);
}
 
/** Make the thread visible to the system.
 *
 * Attach the thread structure to the current task and make it visible in the
 * threads_btree.
 *
 * @param t Thread to be attached to the task.
 * @param task  Task to which the thread is to be attached.
 */
void thread_attach(thread_t *t, task_t *task)
{
    ipl_t ipl;
 
    /*
     * Attach to the current task.
     */
    ipl = interrupts_disable();
    spinlock_lock(&task->lock);
    atomic_inc(&task->refcount);
    atomic_inc(&task->lifecount);
    list_append(&t->th_link, &task->th_head);
 
 
    spinlock_unlock(&task->lock);
 
    /*
     * Register this thread in the system-wide list.
     */
    spinlock_lock(&threads_lock);
    btree_insert(&threads_btree, (btree_key_t) ((uintptr_t) t), (void *) t,
        NULL);
    spinlock_unlock(&threads_lock);
   
    interrupts_restore(ipl);
}
 
/** Terminate thread.
 *
 * End current thread execution and switch it to the exiting state. All pending
 * timeouts are executed.
 */
void thread_exit(void)
{
    ipl_t ipl;
 
    if (atomic_predec(&TASK->lifecount) == 0) {
        /*
         * We are the last thread in the task that still has not exited.
         * With the exception of the moment the task was created, new
         * threads can only be created by threads of the same task.
         * We are safe to perform cleanup.
         */
        if (THREAD->flags & THREAD_FLAG_USPACE) {
            ipc_cleanup();
                futex_cleanup();
            klog_printf("Cleanup of task %llu completed.",
                TASK->taskid);
        }
    }
 
restart:
    ipl = interrupts_disable();
    spinlock_lock(&THREAD->lock);
    if (THREAD->timeout_pending) {
        /* busy waiting for timeouts in progress */
        spinlock_unlock(&THREAD->lock);
        interrupts_restore(ipl);
        goto restart;
    }
   
    THREAD->state = Exiting;
    spinlock_unlock(&THREAD->lock);
    scheduler();
 
    /* Not reached */
    while (1)
        ;
}
 
 
/** Thread sleep
 *
 * Suspend execution of the current thread.
 *
 * @param sec Number of seconds to sleep.
 *
 */
void thread_sleep(uint32_t sec)
{
    thread_usleep(sec * 1000000);
}
 
/** Wait for another thread to exit.
 *
 * @param t Thread to join on exit.
 * @param usec Timeout in microseconds.
 * @param flags Mode of operation.
 *
 * @return An error code from errno.h or an error code from synch.h.
 */
int thread_join_timeout(thread_t *t, uint32_t usec, int flags)
{
    ipl_t ipl;
    int rc;
 
    if (t == THREAD)
        return EINVAL;
 
    /*
     * Since thread join can only be called once on an undetached thread,
     * the thread pointer is guaranteed to be still valid.
     */
   
    ipl = interrupts_disable();
    spinlock_lock(&t->lock);
    ASSERT(!t->detached);
    spinlock_unlock(&t->lock);
    interrupts_restore(ipl);
   
    rc = waitq_sleep_timeout(&t->join_wq, usec, flags);
   
    return rc; 
}
 
/** Detach thread.
 *
 * Mark the thread as detached, if the thread is already in the JoinMe state,
 * deallocate its resources.
 *
 * @param t Thread to be detached.
 */
void thread_detach(thread_t *t)
{
    ipl_t ipl;
 
    /*
     * Since the thread is expected not to be already detached,
     * pointer to it must be still valid.
     */
    ipl = interrupts_disable();
    spinlock_lock(&t->lock);
    ASSERT(!t->detached);
    if (t->state == JoinMe) {
        thread_destroy(t);  /* unlocks &t->lock */
        interrupts_restore(ipl);
        return;
    } else {
        t->detached = true;
    }
    spinlock_unlock(&t->lock);
    interrupts_restore(ipl);
}
 
/** Thread usleep
 *
 * Suspend execution of the current thread.
 *
 * @param usec Number of microseconds to sleep.
 *
 */
void thread_usleep(uint32_t usec)
{
    waitq_t wq;
                 
    waitq_initialize(&wq);
 
    (void) waitq_sleep_timeout(&wq, usec, SYNCH_FLAGS_NON_BLOCKING);
}
 
/** Register thread out-of-context invocation
 *
 * Register a function and its argument to be executed
 * on next context switch to the current thread.
 *
 * @param call_me      Out-of-context function.
 * @param call_me_with Out-of-context function argument.
 *
 */
void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
{
    ipl_t ipl;
   
    ipl = interrupts_disable();
    spinlock_lock(&THREAD->lock);
    THREAD->call_me = call_me;
    THREAD->call_me_with = call_me_with;
    spinlock_unlock(&THREAD->lock);
    interrupts_restore(ipl);
}
 
/** Print list of threads debug info */
void thread_print_list(void)
{
    link_t *cur;
    ipl_t ipl;
   
    /* Messing with thread structures, avoid deadlock */
    ipl = interrupts_disable();
    spinlock_lock(&threads_lock);
   
    printf("tid    name       address    state    task       ctx code    "
        "   stack      cycles     cpu  kstack     waitqueue\n");
    printf("------ ---------- ---------- -------- ---------- --- --------"
        "-- ---------- ---------- ---- ---------- ----------\n");
 
    for (cur = threads_btree.leaf_head.next;
        cur != &threads_btree.leaf_head; cur = cur->next) {
        btree_node_t *node;
        unsigned int i;
 
        node = list_get_instance(cur, btree_node_t, leaf_link);
        for (i = 0; i < node->keys; i++) {
            thread_t *t;
       
            t = (thread_t *) node->value[i];
           
            uint64_t cycles;
            char suffix;
            order(t->cycles, &cycles, &suffix);
           
            printf("%-6llu %-10s %#10zx %-8s %#10zx %-3ld %#10zx "
                "%#10zx %9llu%c ", t->tid, t->name, t,
                thread_states[t->state], t->task, t->task->context,
                t->thread_code, t->kstack, cycles, suffix);
           
            if (t->cpu)
                printf("%-4zd", t->cpu->id);
            else
                printf("none");
           
            if (t->state == Sleeping)
                printf(" %#10zx %#10zx", t->kstack,
                    t->sleep_queue);
           
            printf("\n");
        }
    }
 
    spinlock_unlock(&threads_lock);
    interrupts_restore(ipl);
}
 
/** Check whether thread exists.
 *
 * Note that threads_lock must be already held and
 * interrupts must be already disabled.
 *
 * @param t Pointer to thread.
 *
 * @return True if thread t is known to the system, false otherwise.
 */
bool thread_exists(thread_t *t)
{
    btree_node_t *leaf;
   
    return btree_search(&threads_btree, (btree_key_t) ((uintptr_t) t),
        &leaf) != NULL;
}
 
 
/** Update accounting of current thread.
 *
 * Note that thread_lock on THREAD must be already held and
 * interrupts must be already disabled.
 *
 */
void thread_update_accounting(void)
{
    uint64_t time = get_cycle();
    THREAD->cycles += time - THREAD->last_cycle;
    THREAD->last_cycle = time;
}
 
/** Process syscall to create new thread.
 *
 */
unative_t sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name,
    thread_id_t *uspace_thread_id)
{
    thread_t *t;
    char namebuf[THREAD_NAME_BUFLEN];
    uspace_arg_t *kernel_uarg;
    int rc;
 
    rc = copy_from_uspace(namebuf, uspace_name, THREAD_NAME_BUFLEN);
    if (rc != 0)
        return (unative_t) rc;
 
    kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
    rc = copy_from_uspace(kernel_uarg, uspace_uarg, sizeof(uspace_arg_t));
    if (rc != 0) {
        free(kernel_uarg);
        return (unative_t) rc;
    }
 
    t = thread_create(uinit, kernel_uarg, TASK,
        THREAD_FLAG_USPACE | THREAD_FLAG_NOATTACH, namebuf, false);
    if (t) {
        if (uspace_thread_id != NULL) {
            int rc;
 
            rc = copy_to_uspace(uspace_thread_id, &t->tid,
                sizeof(t->tid));
            if (rc != 0) {
 
 
                /*
                 * We have encountered a failure, but the thread
                 * has already been created. We need to undo its
                 * creation now.
                 */
 
                /*
                 * The new thread structure is initialized, but
                 * is still not visible to the system.
                 * We can safely deallocate it.
                 */
                slab_free(thread_slab, t);
                free(kernel_uarg);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                return (unative_t) rc;
             }
        }
        thread_attach(t, TASK);
        thread_ready(t);
 
        return 0;
    } else
        free(kernel_uarg);
 
    return (unative_t) ENOMEM;
}
 
/** Process syscall to terminate thread.
 *
 */
unative_t sys_thread_exit(int uspace_status)
{
    thread_exit();
    /* Unreachable */
    return 0;
}
 
/** Syscall for getting TID.
 *
 * @param uspace_thread_id Userspace address of 8-byte buffer where to store
 * current thread ID.
 *
 * @return 0 on success or an error code from @ref errno.h.
 */
unative_t sys_thread_get_id(thread_id_t *uspace_thread_id)
{
    /*
     * No need to acquire lock on THREAD because tid
     * remains constant for the lifespan of the thread.
     */
    return (unative_t) copy_to_uspace(uspace_thread_id, &THREAD->tid,
        sizeof(THREAD->tid));
}
 
/** @}
 */
 

Rev 2440	Rev 2446
1	/*	1	/*
2	* Copyright (c) 2001-2004 Jakub Jermar	2	* Copyright (c) 2001-2004 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup genericproc	29	/** @addtogroup genericproc
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file	34	* @file
35	* @brief Thread management functions.	35	* @brief Thread management functions.
36	*/	36	*/
37		37
38	#include <proc/scheduler.h>	38	#include <proc/scheduler.h>
39	#include <proc/thread.h>	39	#include <proc/thread.h>
40	#include <proc/task.h>	40	#include <proc/task.h>
41	#include <proc/uarg.h>	41	#include <proc/uarg.h>
42	#include <mm/frame.h>	42	#include <mm/frame.h>
43	#include <mm/page.h>	43	#include <mm/page.h>
44	#include <arch/asm.h>	44	#include <arch/asm.h>
45	#include <arch/cycle.h>	45	#include <arch/cycle.h>
46	#include <arch.h>	46	#include <arch.h>
47	#include <synch/synch.h>	47	#include <synch/synch.h>
48	#include <synch/spinlock.h>	48	#include <synch/spinlock.h>
49	#include <synch/waitq.h>	49	#include <synch/waitq.h>
50	#include <synch/rwlock.h>	50	#include <synch/rwlock.h>
51	#include <cpu.h>	51	#include <cpu.h>
52	#include <func.h>	52	#include <func.h>
53	#include <context.h>	53	#include <context.h>
54	#include <adt/btree.h>	54	#include <adt/btree.h>
55	#include <adt/list.h>	55	#include <adt/list.h>
56	#include <time/clock.h>	56	#include <time/clock.h>
57	#include <time/timeout.h>	57	#include <time/timeout.h>
58	#include <config.h>	58	#include <config.h>
59	#include <arch/interrupt.h>	59	#include <arch/interrupt.h>
60	#include <smp/ipi.h>	60	#include <smp/ipi.h>
61	#include <arch/faddr.h>	61	#include <arch/faddr.h>
62	#include <atomic.h>	62	#include <atomic.h>
63	#include <memstr.h>	63	#include <memstr.h>
64	#include <print.h>	64	#include <print.h>
65	#include <mm/slab.h>	65	#include <mm/slab.h>
66	#include <debug.h>	66	#include <debug.h>
67	#include <main/uinit.h>	67	#include <main/uinit.h>
68	#include <syscall/copy.h>	68	#include <syscall/copy.h>
69	#include <errno.h>	69	#include <errno.h>
-		70	#include <console/klog.h>
70		71
71		72
72	/** Thread states */	73	/** Thread states */
73	char *thread_states[] = {	74	char *thread_states[] = {
74	"Invalid",	75	"Invalid",
75	"Running",	76	"Running",
76	"Sleeping",	77	"Sleeping",
77	"Ready",	78	"Ready",
78	"Entering",	79	"Entering",
79	"Exiting",	80	"Exiting",
80	"Undead"	81	"JoinMe"
81	};	82	};
82		83
83	/** Lock protecting the threads_btree B+tree.	84	/** Lock protecting the threads_btree B+tree.
84	*	85	*
85	* For locking rules, see declaration thereof.	86	* For locking rules, see declaration thereof.
86	*/	87	*/
87	SPINLOCK_INITIALIZE(threads_lock);	88	SPINLOCK_INITIALIZE(threads_lock);
88		89
89	/** B+tree of all threads.	90	/** B+tree of all threads.
90	*	91	*
91	* When a thread is found in the threads_btree B+tree, it is guaranteed to	92	* When a thread is found in the threads_btree B+tree, it is guaranteed to
92	* exist as long as the threads_lock is held.	93	* exist as long as the threads_lock is held.
93	*/	94	*/
94	btree_t threads_btree;	95	btree_t threads_btree;
95		96
96	SPINLOCK_INITIALIZE(tidlock);	97	SPINLOCK_INITIALIZE(tidlock);
97	thread_id_t last_tid = 0;	98	thread_id_t last_tid = 0;
98		99
99	static slab_cache_t *thread_slab;	100	static slab_cache_t *thread_slab;
100	#ifdef ARCH_HAS_FPU	101	#ifdef ARCH_HAS_FPU
101	slab_cache_t *fpu_context_slab;	102	slab_cache_t *fpu_context_slab;
102	#endif	103	#endif
103		104
104	/** Thread wrapper.	105	/** Thread wrapper.
105	*	106	*
106	* This wrapper is provided to ensure that every thread makes a call to	107	* This wrapper is provided to ensure that every thread makes a call to
107	* thread_exit() when its implementing function returns.	108	* thread_exit() when its implementing function returns.
108	*	109	*
109	* interrupts_disable() is assumed.	110	* interrupts_disable() is assumed.
110	*	111	*
111	*/	112	*/
112	static void cushion(void)	113	static void cushion(void)
113	{	114	{
114	void (f)(void ) = THREAD->thread_code;	115	void (f)(void ) = THREAD->thread_code;
115	void *arg = THREAD->thread_arg;	116	void *arg = THREAD->thread_arg;
116	THREAD->last_cycle = get_cycle();	117	THREAD->last_cycle = get_cycle();
117		118
118	/* This is where each thread wakes up after its creation */	119	/* This is where each thread wakes up after its creation */
119	spinlock_unlock(&THREAD->lock);	120	spinlock_unlock(&THREAD->lock);
120	interrupts_enable();	121	interrupts_enable();
121		122
122	f(arg);	123	f(arg);
123		124
124	/* Accumulate accounting to the task */	125	/* Accumulate accounting to the task */
125	ipl_t ipl = interrupts_disable();	126	ipl_t ipl = interrupts_disable();
126		127
127	spinlock_lock(&THREAD->lock);	128	spinlock_lock(&THREAD->lock);
128	if (!THREAD->uncounted) {	129	if (!THREAD->uncounted) {
129	thread_update_accounting();	130	thread_update_accounting();
130	uint64_t cycles = THREAD->cycles;	131	uint64_t cycles = THREAD->cycles;
131	THREAD->cycles = 0;	132	THREAD->cycles = 0;
132	spinlock_unlock(&THREAD->lock);	133	spinlock_unlock(&THREAD->lock);
133		134
134	spinlock_lock(&TASK->lock);	135	spinlock_lock(&TASK->lock);
135	TASK->cycles += cycles;	136	TASK->cycles += cycles;
136	spinlock_unlock(&TASK->lock);	137	spinlock_unlock(&TASK->lock);
137	} else	138	} else
138	spinlock_unlock(&THREAD->lock);	139	spinlock_unlock(&THREAD->lock);
139		140
140	interrupts_restore(ipl);	141	interrupts_restore(ipl);
141		142
142	thread_exit();	143	thread_exit();
143	/* not reached */	144	/* not reached */
144	}	145	}
145		146
146	/** Initialization and allocation for thread_t structure */	147	/** Initialization and allocation for thread_t structure */
147	static int thr_constructor(void *obj, int kmflags)	148	static int thr_constructor(void *obj, int kmflags)
148	{	149	{
149	thread_t t = (thread_t ) obj;	150	thread_t t = (thread_t ) obj;
150		151
151	spinlock_initialize(&t->lock, "thread_t_lock");	152	spinlock_initialize(&t->lock, "thread_t_lock");
152	link_initialize(&t->rq_link);	153	link_initialize(&t->rq_link);
153	link_initialize(&t->wq_link);	154	link_initialize(&t->wq_link);
154	link_initialize(&t->th_link);	155	link_initialize(&t->th_link);
155		156
156	/* call the architecture-specific part of the constructor */	157	/* call the architecture-specific part of the constructor */
157	thr_constructor_arch(t);	158	thr_constructor_arch(t);
158		159
159	#ifdef ARCH_HAS_FPU	160	#ifdef ARCH_HAS_FPU
160	#ifdef CONFIG_FPU_LAZY	161	#ifdef CONFIG_FPU_LAZY
161	t->saved_fpu_context = NULL;	162	t->saved_fpu_context = NULL;
162	#else	163	#else
163	t->saved_fpu_context = slab_alloc(fpu_context_slab, kmflags);	164	t->saved_fpu_context = slab_alloc(fpu_context_slab, kmflags);
164	if (!t->saved_fpu_context)	165	if (!t->saved_fpu_context)
165	return -1;	166	return -1;
166	#endif	167	#endif
167	#endif	168	#endif
168		169
169	t->kstack = (uint8_t *) frame_alloc(STACK_FRAMES, FRAME_KA \| kmflags);	170	t->kstack = (uint8_t *) frame_alloc(STACK_FRAMES, FRAME_KA \| kmflags);
170	if (!t->kstack) {	171	if (!t->kstack) {
171	#ifdef ARCH_HAS_FPU	172	#ifdef ARCH_HAS_FPU
172	if (t->saved_fpu_context)	173	if (t->saved_fpu_context)
173	slab_free(fpu_context_slab, t->saved_fpu_context);	174	slab_free(fpu_context_slab, t->saved_fpu_context);
174	#endif	175	#endif
175	return -1;	176	return -1;
176	}	177	}
177		178
178	return 0;	179	return 0;
179	}	180	}
180		181
181	/** Destruction of thread_t object */	182	/** Destruction of thread_t object */
182	static int thr_destructor(void *obj)	183	static int thr_destructor(void *obj)
183	{	184	{
184	thread_t t = (thread_t ) obj;	185	thread_t t = (thread_t ) obj;
185		186
186	/* call the architecture-specific part of the destructor */	187	/* call the architecture-specific part of the destructor */
187	thr_destructor_arch(t);	188	thr_destructor_arch(t);
188		189
189	frame_free(KA2PA(t->kstack));	190	frame_free(KA2PA(t->kstack));
190	#ifdef ARCH_HAS_FPU	191	#ifdef ARCH_HAS_FPU
191	if (t->saved_fpu_context)	192	if (t->saved_fpu_context)
192	slab_free(fpu_context_slab, t->saved_fpu_context);	193	slab_free(fpu_context_slab, t->saved_fpu_context);
193	#endif	194	#endif
194	return 1; /* One page freed */	195	return 1; /* One page freed */
195	}	196	}
196		197
197	/** Initialize threads	198	/** Initialize threads
198	*	199	*
199	* Initialize kernel threads support.	200	* Initialize kernel threads support.
200	*	201	*
201	*/	202	*/
202	void thread_init(void)	203	void thread_init(void)
203	{	204	{
204	THREAD = NULL;	205	THREAD = NULL;
205	atomic_set(&nrdy,0);	206	atomic_set(&nrdy,0);
206	thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,	207	thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,
207	thr_constructor, thr_destructor, 0);	208	thr_constructor, thr_destructor, 0);
208		209
209	#ifdef ARCH_HAS_FPU	210	#ifdef ARCH_HAS_FPU
210	fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),	211	fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),
211	FPU_CONTEXT_ALIGN, NULL, NULL, 0);	212	FPU_CONTEXT_ALIGN, NULL, NULL, 0);
212	#endif	213	#endif
213		214
214	btree_create(&threads_btree);	215	btree_create(&threads_btree);
215	}	216	}
216		217
217	/** Make thread ready	218	/** Make thread ready
218	*	219	*
219	* Switch thread t to the ready state.	220	* Switch thread t to the ready state.
220	*	221	*
221	* @param t Thread to make ready.	222	* @param t Thread to make ready.
222	*	223	*
223	*/	224	*/
224	void thread_ready(thread_t *t)	225	void thread_ready(thread_t *t)
225	{	226	{
226	cpu_t *cpu;	227	cpu_t *cpu;
227	runq_t *r;	228	runq_t *r;
228	ipl_t ipl;	229	ipl_t ipl;
229	int i, avg;	230	int i, avg;
230		231
231	ipl = interrupts_disable();	232	ipl = interrupts_disable();
232		233
233	spinlock_lock(&t->lock);	234	spinlock_lock(&t->lock);
234		235
235	ASSERT(!(t->state == Ready));	236	ASSERT(!(t->state == Ready));
236		237
237	i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;	238	i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;
238		239
239	cpu = CPU;	240	cpu = CPU;
240	if (t->flags & THREAD_FLAG_WIRED) {	241	if (t->flags & THREAD_FLAG_WIRED) {
241	ASSERT(t->cpu != NULL);	242	ASSERT(t->cpu != NULL);
242	cpu = t->cpu;	243	cpu = t->cpu;
243	}	244	}
244	t->state = Ready;	245	t->state = Ready;
245	spinlock_unlock(&t->lock);	246	spinlock_unlock(&t->lock);
246		247
247	/*	248	/*
248	* Append t to respective ready queue on respective processor.	249	* Append t to respective ready queue on respective processor.
249	*/	250	*/
250	r = &cpu->rq[i];	251	r = &cpu->rq[i];
251	spinlock_lock(&r->lock);	252	spinlock_lock(&r->lock);
252	list_append(&t->rq_link, &r->rq_head);	253	list_append(&t->rq_link, &r->rq_head);
253	r->n++;	254	r->n++;
254	spinlock_unlock(&r->lock);	255	spinlock_unlock(&r->lock);
255		256
256	atomic_inc(&nrdy);	257	atomic_inc(&nrdy);
257	avg = atomic_get(&nrdy) / config.cpu_active;	258	avg = atomic_get(&nrdy) / config.cpu_active;
258	atomic_inc(&cpu->nrdy);	259	atomic_inc(&cpu->nrdy);
259		260
260	interrupts_restore(ipl);	261	interrupts_restore(ipl);
261	}	262	}
262		263
263	/** Create new thread	264	/** Create new thread
264	*	265	*
265	* Create a new thread.	266	* Create a new thread.
266	*	267	*
267	* @param func Thread's implementing function.	268	* @param func Thread's implementing function.
268	* @param arg Thread's implementing function argument.	269	* @param arg Thread's implementing function argument.
269	* @param task Task to which the thread belongs.	270	* @param task Task to which the thread belongs.
270	* @param flags Thread flags.	271	* @param flags Thread flags.
271	* @param name Symbolic name.	272	* @param name Symbolic name.
272	* @param uncounted Thread's accounting doesn't affect accumulated task	273	* @param uncounted Thread's accounting doesn't affect accumulated task
273	* accounting.	274	* accounting.
274	*	275	*
275	* @return New thread's structure on success, NULL on failure.	276	* @return New thread's structure on success, NULL on failure.
276	*	277	*
277	*/	278	*/
278	thread_t thread_create(void ( func)(void ), void arg, task_t *task,	279	thread_t thread_create(void ( func)(void ), void arg, task_t *task,
279	int flags, char *name, bool uncounted)	280	int flags, char *name, bool uncounted)
280	{	281	{
281	thread_t *t;	282	thread_t *t;
282	ipl_t ipl;	283	ipl_t ipl;
283		284
284	t = (thread_t *) slab_alloc(thread_slab, 0);	285	t = (thread_t *) slab_alloc(thread_slab, 0);
285	if (!t)	286	if (!t)
286	return NULL;	287	return NULL;
287		288
288	/* Not needed, but good for debugging */	289	/* Not needed, but good for debugging */
289	memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES,	290	memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES,
290	0);	291	0);
291		292
292	ipl = interrupts_disable();	293	ipl = interrupts_disable();
293	spinlock_lock(&tidlock);	294	spinlock_lock(&tidlock);
294	t->tid = ++last_tid;	295	t->tid = ++last_tid;
295	spinlock_unlock(&tidlock);	296	spinlock_unlock(&tidlock);
296	interrupts_restore(ipl);	297	interrupts_restore(ipl);
297		298
298	context_save(&t->saved_context);	299	context_save(&t->saved_context);
299	context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,	300	context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,
300	THREAD_STACK_SIZE);	301	THREAD_STACK_SIZE);
301		302
302	the_initialize((the_t *) t->kstack);	303	the_initialize((the_t *) t->kstack);
303		304
304	ipl = interrupts_disable();	305	ipl = interrupts_disable();
305	t->saved_context.ipl = interrupts_read();	306	t->saved_context.ipl = interrupts_read();
306	interrupts_restore(ipl);	307	interrupts_restore(ipl);
307		308
308	memcpy(t->name, name, THREAD_NAME_BUFLEN);	309	memcpy(t->name, name, THREAD_NAME_BUFLEN);
309		310
310	t->thread_code = func;	311	t->thread_code = func;
311	t->thread_arg = arg;	312	t->thread_arg = arg;
312	t->ticks = -1;	313	t->ticks = -1;
313	t->cycles = 0;	314	t->cycles = 0;
314	t->uncounted = uncounted;	315	t->uncounted = uncounted;
315	t->priority = -1; /* start in rq[0] */	316	t->priority = -1; /* start in rq[0] */
316	t->cpu = NULL;	317	t->cpu = NULL;
317	t->flags = flags;	318	t->flags = flags;
318	t->state = Entering;	319	t->state = Entering;
319	t->call_me = NULL;	320	t->call_me = NULL;
320	t->call_me_with = NULL;	321	t->call_me_with = NULL;
321		322
322	timeout_initialize(&t->sleep_timeout);	323	timeout_initialize(&t->sleep_timeout);
323	t->sleep_interruptible = false;	324	t->sleep_interruptible = false;
324	t->sleep_queue = NULL;	325	t->sleep_queue = NULL;
325	t->timeout_pending = 0;	326	t->timeout_pending = 0;
326		327
327	t->in_copy_from_uspace = false;	328	t->in_copy_from_uspace = false;
328	t->in_copy_to_uspace = false;	329	t->in_copy_to_uspace = false;
329		330
330	t->interrupted = false;	331	t->interrupted = false;
331	t->join_type = None;	-
332	t->detached = false;	332	t->detached = false;
333	waitq_initialize(&t->join_wq);	333	waitq_initialize(&t->join_wq);
334		334
335	t->rwlock_holder_type = RWLOCK_NONE;	335	t->rwlock_holder_type = RWLOCK_NONE;
336		336
337	t->task = task;	337	t->task = task;
338		338
339	t->fpu_context_exists = 0;	339	t->fpu_context_exists = 0;
340	t->fpu_context_engaged = 0;	340	t->fpu_context_engaged = 0;
341		341
342	/* might depend on previous initialization */	342	/* might depend on previous initialization */
343	thread_create_arch(t);	343	thread_create_arch(t);
344		344
345	ipl = interrupts_disable();	-
346	spinlock_lock(&task->lock);	-
347	if (!task->accept_new_threads) {	-
348	spinlock_unlock(&task->lock);	-
349	slab_free(thread_slab, t);	-
350	interrupts_restore(ipl);	-
351	return NULL;	-
352	} else {	-
353	/*	-
354	* Bump the reference count so that this task cannot be	-
355	* destroyed while the new thread is being attached to it.	-
356	*/	-
357	task->refcount++;	-
358	}	-
359	spinlock_unlock(&task->lock);	-
360	interrupts_restore(ipl);	-
361		-
362	if (!(flags & THREAD_FLAG_NOATTACH))	345	if (!(flags & THREAD_FLAG_NOATTACH))
363	thread_attach(t, task);	346	thread_attach(t, task);
364		347
365	return t;	348	return t;
366	}	349	}
367		350
368	/** Destroy thread memory structure	351	/** Destroy thread memory structure
369	*	352	*
370	* Detach thread from all queues, cpus etc. and destroy it.	353	* Detach thread from all queues, cpus etc. and destroy it.
371	*	354	*
372	* Assume thread->lock is held!!	355	* Assume thread->lock is held!!
373	*/	356	*/
374	void thread_destroy(thread_t *t)	357	void thread_destroy(thread_t *t)
375	{	358	{
376	bool destroy_task = false;	-
377		-
378	ASSERT(t->state == Exiting \|\| t->state == Undead);	359	ASSERT(t->state == Exiting \|\| t->state == JoinMe);
379	ASSERT(t->task);	360	ASSERT(t->task);
380	ASSERT(t->cpu);	361	ASSERT(t->cpu);
381		362
382	spinlock_lock(&t->cpu->lock);	363	spinlock_lock(&t->cpu->lock);
383	if (t->cpu->fpu_owner == t)	364	if (t->cpu->fpu_owner == t)
384	t->cpu->fpu_owner = NULL;	365	t->cpu->fpu_owner = NULL;
385	spinlock_unlock(&t->cpu->lock);	366	spinlock_unlock(&t->cpu->lock);
386		367
387	spinlock_unlock(&t->lock);	368	spinlock_unlock(&t->lock);
388		369
389	spinlock_lock(&threads_lock);	370	spinlock_lock(&threads_lock);
390	btree_remove(&threads_btree, (btree_key_t) ((uintptr_t ) t), NULL);	371	btree_remove(&threads_btree, (btree_key_t) ((uintptr_t ) t), NULL);
391	spinlock_unlock(&threads_lock);	372	spinlock_unlock(&threads_lock);
392		373
393	/*	374	/*
394	* Detach from the containing task.	375	* Detach from the containing task.
395	*/	376	*/
396	spinlock_lock(&t->task->lock);	377	spinlock_lock(&t->task->lock);
397	list_remove(&t->th_link);	378	list_remove(&t->th_link);
398	if (--t->task->refcount == 0) {	-
399	t->task->accept_new_threads = false;	-
400	destroy_task = true;	-
401	}	-
402	spinlock_unlock(&t->task->lock);	379	spinlock_unlock(&t->task->lock);
403		380
-		381	/*
-		382	* t is guaranteed to be the very last thread of its task.
404	if (destroy_task)	383	* It is safe to destroy the task.
-		384	*/
-		385	if (atomic_predec(&t->task->refcount) == 0)
405	task_destroy(t->task);	386	task_destroy(t->task);
406		387
407	/*	388	/*
408	* If the thread had a userspace context, free up its kernel_uarg	389	* If the thread had a userspace context, free up its kernel_uarg
409	* structure.	390	* structure.
410	*/	391	*/
411	if (t->flags & THREAD_FLAG_USPACE) {	392	if (t->flags & THREAD_FLAG_USPACE) {
412	ASSERT(t->thread_arg);	393	ASSERT(t->thread_arg);
413	free(t->thread_arg);	394	free(t->thread_arg);
414	}	395	}
415		396
416	slab_free(thread_slab, t);	397	slab_free(thread_slab, t);
417	}	398	}
418		399
419	/** Make the thread visible to the system.	400	/** Make the thread visible to the system.
420	*	401	*
421	* Attach the thread structure to the current task and make it visible in the	402	* Attach the thread structure to the current task and make it visible in the
422	* threads_btree.	403	* threads_btree.
423	*	404	*
424	* @param t Thread to be attached to the task.	405	* @param t Thread to be attached to the task.
425	* @param task Task to which the thread is to be attached.	406	* @param task Task to which the thread is to be attached.
426	*/	407	*/
427	void thread_attach(thread_t t, task_t task)	408	void thread_attach(thread_t t, task_t task)
428	{	409	{
429	ipl_t ipl;	410	ipl_t ipl;
430		411
431	/*	412	/*
432	* Attach to the current task.	413	* Attach to the current task.
433	*/	414	*/
434	ipl = interrupts_disable();	415	ipl = interrupts_disable();
435	spinlock_lock(&task->lock);	416	spinlock_lock(&task->lock);
436	ASSERT(task->refcount);	417	atomic_inc(&task->refcount);
-		418	atomic_inc(&task->lifecount);
437	list_append(&t->th_link, &task->th_head);	419	list_append(&t->th_link, &task->th_head);
438	if (task->refcount == 1)	-
439	task->main_thread = t;	-
440	spinlock_unlock(&task->lock);	420	spinlock_unlock(&task->lock);
441		421
442	/*	422	/*
443	* Register this thread in the system-wide list.	423	* Register this thread in the system-wide list.
444	*/	424	*/
445	spinlock_lock(&threads_lock);	425	spinlock_lock(&threads_lock);
446	btree_insert(&threads_btree, (btree_key_t) ((uintptr_t) t), (void *) t,	426	btree_insert(&threads_btree, (btree_key_t) ((uintptr_t) t), (void *) t,
447	NULL);	427	NULL);
448	spinlock_unlock(&threads_lock);	428	spinlock_unlock(&threads_lock);
449		429
450	interrupts_restore(ipl);	430	interrupts_restore(ipl);
451	}	431	}
452		432
453	/** Terminate thread.	433	/** Terminate thread.
454	*	434	*
455	* End current thread execution and switch it to the exiting state. All pending	435	* End current thread execution and switch it to the exiting state. All pending
456	* timeouts are executed.	436	* timeouts are executed.
457	*/	437	*/
458	void thread_exit(void)	438	void thread_exit(void)
459	{	439	{
460	ipl_t ipl;	440	ipl_t ipl;
461		441
-		442	if (atomic_predec(&TASK->lifecount) == 0) {
-		443	/*
-		444	* We are the last thread in the task that still has not exited.
-		445	* With the exception of the moment the task was created, new
-		446	* threads can only be created by threads of the same task.
-		447	* We are safe to perform cleanup.
-		448	*/
-		449	if (THREAD->flags & THREAD_FLAG_USPACE) {
-		450	ipc_cleanup();
-		451	futex_cleanup();
-		452	klog_printf("Cleanup of task %llu completed.",
-		453	TASK->taskid);
-		454	}
-		455	}
-		456
462	restart:	457	restart:
463	ipl = interrupts_disable();	458	ipl = interrupts_disable();
464	spinlock_lock(&THREAD->lock);	459	spinlock_lock(&THREAD->lock);
465	if (THREAD->timeout_pending) {	460	if (THREAD->timeout_pending) {
466	/* busy waiting for timeouts in progress */	461	/* busy waiting for timeouts in progress */
467	spinlock_unlock(&THREAD->lock);	462	spinlock_unlock(&THREAD->lock);
468	interrupts_restore(ipl);	463	interrupts_restore(ipl);
469	goto restart;	464	goto restart;
470	}	465	}
-		466
471	THREAD->state = Exiting;	467	THREAD->state = Exiting;
472	spinlock_unlock(&THREAD->lock);	468	spinlock_unlock(&THREAD->lock);
473	scheduler();	469	scheduler();
474		470
475	/* Not reached */	471	/* Not reached */
476	while (1)	472	while (1)
477	;	473	;
478	}	474	}

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/proc/thread.c – Rev 2440 → 2446