WebSVN – HelenOS – Diff – /branches/tracing/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/avl.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",
    "Lingering"
};
 
/** Lock protecting the threads_tree AVL tree.
 *
 * For locking rules, see declaration thereof.
 */
SPINLOCK_INITIALIZE(threads_lock);
 
/** ALV tree of all threads.
 *
 * When a thread is found in the threads_tree AVL tree, it is guaranteed to
 * exist as long as the threads_lock is held.
 */
avltree_t threads_tree;    
 
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;
    }
 
    spinlock_initialize(&t->debug_lock, "thread_debug_lock");
 
    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
 
    avltree_create(&threads_tree);
}
 
/** 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;
 
    avltree_node_initialize(&t->threads_tree_node);
    t->threads_tree_node.key = (uintptr_t) t;
   
    /* Init debugging stuff */
    waitq_initialize(&t->go_wq);
    t->debug_go_call = NULL;
    t->uspace_state = NULL;
    t->debug_stop = true;
    t->debug_stoppable = true;
    t->debug_active = false;
    t->cur_event = 0;   /* none */
 
    /* might depend on previous initialization */
    thread_create_arch(t); 
 
    if (!(flags & THREAD_FLAG_NOATTACH))
        thread_attach(t, task);
 
    return t;
}
 
/** Destroy thread structure of an unattached thread.
 *
 * Thread t must only have been created and never attached.
 */
void thread_unattached_free(thread_t *t)
{
    slab_free(thread_slab, 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 == Lingering);
    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);
    avltree_delete(&threads_tree, &t->threads_tree_node);
    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);
   
    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_tree.
 *
 * @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 specified task.
     */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    ipl = interrupts_disable();
 
 
 
 
 
 
 
 
 
    spinlock_lock(&task->lock);
    atomic_inc(&task->refcount);
 
 
    /* Must not count kbox thread into lifecount */
    if (t->flags & THREAD_FLAG_USPACE)
        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);
    avltree_insert(&threads_tree, &t->threads_tree_node);
    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 (THREAD->flags & THREAD_FLAG_USPACE) {
        if (atomic_predec(&TASK->lifecount) == 0) {
            /*
             * We are the last userspace thread in the task that
             * still has not exited. With the exception of the
             * moment the task was created, new userspace threads
             * can only be created by threads of the same task.
             * We are safe to perform cleanup.
             */
 
            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 Lingering
 * 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 == Lingering) {
        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);
}
 
static bool thread_walker(avltree_node_t *node, void *arg)
{
    thread_t *t;
       
    t = avltree_get_instance(node, thread_t, threads_tree_node);
 
    uint64_t cycles;
    char suffix;
    order(t->cycles, &cycles, &suffix);
   
    if (sizeof(void *) == 4)
        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);
    else
        printf("%-6llu %-10s %#18zx %-8s %#18zx %-3ld %#18zx %#18zx %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) {
        if (sizeof(uintptr_t) == 4)
            printf(" %#10zx", t->sleep_queue);
        else
            printf(" %#18zx", t->sleep_queue);
    }
           
    printf("\n");
 
    return true;
}
 
/** Print list of threads debug info */
void thread_print_list(void)
{
    ipl_t ipl;
   
    /* Messing with thread structures, avoid deadlock */
    ipl = interrupts_disable();
    spinlock_lock(&threads_lock);
   
    if (sizeof(uintptr_t) == 4) {
        printf("tid    name       address    state    task       "
            "ctx code       stack      cycles     cpu  "
            "waitqueue\n");
        printf("------ ---------- ---------- -------- ---------- "
            "--- ---------- ---------- ---------- ---- "
            "----------\n");
    } else {
        printf("tid    name       address            state    task               "
            "ctx code               stack              cycles     cpu  "
            "waitqueue\n");
        printf("------ ---------- ------------------ -------- ------------------ "
            "--- ------------------ ------------------ ---------- ---- "
            "------------------\n");
    }
 
    avltree_walk(&threads_tree, thread_walker, NULL);
 
    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)
{
    avltree_node_t *node;
 
    node = avltree_search(&threads_tree, (avltree_key_t) ((uintptr_t) t));
   
    return node != 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;
 
    /*
     * In case of failure, kernel_uarg will be deallocated in this function.
     * In case of success, kernel_uarg will be freed in uinit().
     */
    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);
 
        udebug_new_thread_event(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 2898	Rev 2902
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/avl.h>	54	#include <adt/avl.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	#include <console/klog.h>
71		71
72		72
73	/** Thread states */	73	/** Thread states */
74	char *thread_states[] = {	74	char *thread_states[] = {
75	"Invalid",	75	"Invalid",
76	"Running",	76	"Running",
77	"Sleeping",	77	"Sleeping",
78	"Ready",	78	"Ready",
79	"Entering",	79	"Entering",
80	"Exiting",	80	"Exiting",
81	"Lingering"	81	"Lingering"
82	};	82	};
83		83
84	/** Lock protecting the threads_tree AVL tree.	84	/** Lock protecting the threads_tree AVL tree.
85	*	85	*
86	* For locking rules, see declaration thereof.	86	* For locking rules, see declaration thereof.
87	*/	87	*/
88	SPINLOCK_INITIALIZE(threads_lock);	88	SPINLOCK_INITIALIZE(threads_lock);
89		89
90	/** ALV tree of all threads.	90	/** ALV tree of all threads.
91	*	91	*
92	* When a thread is found in the threads_tree AVL tree, it is guaranteed to	92	* When a thread is found in the threads_tree AVL tree, it is guaranteed to
93	* exist as long as the threads_lock is held.	93	* exist as long as the threads_lock is held.
94	*/	94	*/
95	avltree_t threads_tree;	95	avltree_t threads_tree;
96		96
97	SPINLOCK_INITIALIZE(tidlock);	97	SPINLOCK_INITIALIZE(tidlock);
98	thread_id_t last_tid = 0;	98	thread_id_t last_tid = 0;
99		99
100	static slab_cache_t *thread_slab;	100	static slab_cache_t *thread_slab;
101	#ifdef ARCH_HAS_FPU	101	#ifdef ARCH_HAS_FPU
102	slab_cache_t *fpu_context_slab;	102	slab_cache_t *fpu_context_slab;
103	#endif	103	#endif
104		104
105	/** Thread wrapper.	105	/** Thread wrapper.
106	*	106	*
107	* 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
108	* thread_exit() when its implementing function returns.	108	* thread_exit() when its implementing function returns.
109	*	109	*
110	* interrupts_disable() is assumed.	110	* interrupts_disable() is assumed.
111	*	111	*
112	*/	112	*/
113	static void cushion(void)	113	static void cushion(void)
114	{	114	{
115	void (f)(void ) = THREAD->thread_code;	115	void (f)(void ) = THREAD->thread_code;
116	void *arg = THREAD->thread_arg;	116	void *arg = THREAD->thread_arg;
117	THREAD->last_cycle = get_cycle();	117	THREAD->last_cycle = get_cycle();
118		118
119	/* This is where each thread wakes up after its creation */	119	/* This is where each thread wakes up after its creation */
120	spinlock_unlock(&THREAD->lock);	120	spinlock_unlock(&THREAD->lock);
121	interrupts_enable();	121	interrupts_enable();
122		122
123	f(arg);	123	f(arg);
124		124
125	/* Accumulate accounting to the task */	125	/* Accumulate accounting to the task */
126	ipl_t ipl = interrupts_disable();	126	ipl_t ipl = interrupts_disable();
127		127
128	spinlock_lock(&THREAD->lock);	128	spinlock_lock(&THREAD->lock);
129	if (!THREAD->uncounted) {	129	if (!THREAD->uncounted) {
130	thread_update_accounting();	130	thread_update_accounting();
131	uint64_t cycles = THREAD->cycles;	131	uint64_t cycles = THREAD->cycles;
132	THREAD->cycles = 0;	132	THREAD->cycles = 0;
133	spinlock_unlock(&THREAD->lock);	133	spinlock_unlock(&THREAD->lock);
134		134
135	spinlock_lock(&TASK->lock);	135	spinlock_lock(&TASK->lock);
136	TASK->cycles += cycles;	136	TASK->cycles += cycles;
137	spinlock_unlock(&TASK->lock);	137	spinlock_unlock(&TASK->lock);
138	} else	138	} else
139	spinlock_unlock(&THREAD->lock);	139	spinlock_unlock(&THREAD->lock);
140		140
141	interrupts_restore(ipl);	141	interrupts_restore(ipl);
142		142
143	thread_exit();	143	thread_exit();
144	/* not reached */	144	/* not reached */
145	}	145	}
146		146
147	/** Initialization and allocation for thread_t structure */	147	/** Initialization and allocation for thread_t structure */
148	static int thr_constructor(void *obj, int kmflags)	148	static int thr_constructor(void *obj, int kmflags)
149	{	149	{
150	thread_t t = (thread_t ) obj;	150	thread_t t = (thread_t ) obj;
151		151
152	spinlock_initialize(&t->lock, "thread_t_lock");	152	spinlock_initialize(&t->lock, "thread_t_lock");
153	link_initialize(&t->rq_link);	153	link_initialize(&t->rq_link);
154	link_initialize(&t->wq_link);	154	link_initialize(&t->wq_link);
155	link_initialize(&t->th_link);	155	link_initialize(&t->th_link);
156		156
157	/* call the architecture-specific part of the constructor */	157	/* call the architecture-specific part of the constructor */
158	thr_constructor_arch(t);	158	thr_constructor_arch(t);
159		159
160	#ifdef ARCH_HAS_FPU	160	#ifdef ARCH_HAS_FPU
161	#ifdef CONFIG_FPU_LAZY	161	#ifdef CONFIG_FPU_LAZY
162	t->saved_fpu_context = NULL;	162	t->saved_fpu_context = NULL;
163	#else	163	#else
164	t->saved_fpu_context = slab_alloc(fpu_context_slab, kmflags);	164	t->saved_fpu_context = slab_alloc(fpu_context_slab, kmflags);
165	if (!t->saved_fpu_context)	165	if (!t->saved_fpu_context)
166	return -1;	166	return -1;
167	#endif	167	#endif
168	#endif	168	#endif
169		169
170	t->kstack = (uint8_t *) frame_alloc(STACK_FRAMES, FRAME_KA \| kmflags);	170	t->kstack = (uint8_t *) frame_alloc(STACK_FRAMES, FRAME_KA \| kmflags);
171	if (!t->kstack) {	171	if (!t->kstack) {
172	#ifdef ARCH_HAS_FPU	172	#ifdef ARCH_HAS_FPU
173	if (t->saved_fpu_context)	173	if (t->saved_fpu_context)
174	slab_free(fpu_context_slab, t->saved_fpu_context);	174	slab_free(fpu_context_slab, t->saved_fpu_context);
175	#endif	175	#endif
176	return -1;	176	return -1;
177	}	177	}
178		178
179	spinlock_initialize(&t->debug_lock, "thread_debug_lock");	179	spinlock_initialize(&t->debug_lock, "thread_debug_lock");
180		180
181	return 0;	181	return 0;
182	}	182	}
183		183
184	/** Destruction of thread_t object */	184	/** Destruction of thread_t object */
185	static int thr_destructor(void *obj)	185	static int thr_destructor(void *obj)
186	{	186	{
187	thread_t t = (thread_t ) obj;	187	thread_t t = (thread_t ) obj;
188		188
189	/* call the architecture-specific part of the destructor */	189	/* call the architecture-specific part of the destructor */
190	thr_destructor_arch(t);	190	thr_destructor_arch(t);
191		191
192	frame_free(KA2PA(t->kstack));	192	frame_free(KA2PA(t->kstack));
193	#ifdef ARCH_HAS_FPU	193	#ifdef ARCH_HAS_FPU
194	if (t->saved_fpu_context)	194	if (t->saved_fpu_context)
195	slab_free(fpu_context_slab, t->saved_fpu_context);	195	slab_free(fpu_context_slab, t->saved_fpu_context);
196	#endif	196	#endif
197	return 1; /* One page freed */	197	return 1; /* One page freed */
198	}	198	}
199		199
200	/** Initialize threads	200	/** Initialize threads
201	*	201	*
202	* Initialize kernel threads support.	202	* Initialize kernel threads support.
203	*	203	*
204	*/	204	*/
205	void thread_init(void)	205	void thread_init(void)
206	{	206	{
207	THREAD = NULL;	207	THREAD = NULL;
208	atomic_set(&nrdy,0);	208	atomic_set(&nrdy,0);
209	thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,	209	thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,
210	thr_constructor, thr_destructor, 0);	210	thr_constructor, thr_destructor, 0);
211		211
212	#ifdef ARCH_HAS_FPU	212	#ifdef ARCH_HAS_FPU
213	fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),	213	fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),
214	FPU_CONTEXT_ALIGN, NULL, NULL, 0);	214	FPU_CONTEXT_ALIGN, NULL, NULL, 0);
215	#endif	215	#endif
216		216
217	avltree_create(&threads_tree);	217	avltree_create(&threads_tree);
218	}	218	}
219		219
220	/** Make thread ready	220	/** Make thread ready
221	*	221	*
222	* Switch thread t to the ready state.	222	* Switch thread t to the ready state.
223	*	223	*
224	* @param t Thread to make ready.	224	* @param t Thread to make ready.
225	*	225	*
226	*/	226	*/
227	void thread_ready(thread_t *t)	227	void thread_ready(thread_t *t)
228	{	228	{
229	cpu_t *cpu;	229	cpu_t *cpu;
230	runq_t *r;	230	runq_t *r;
231	ipl_t ipl;	231	ipl_t ipl;
232	int i, avg;	232	int i, avg;
233		233
234	ipl = interrupts_disable();	234	ipl = interrupts_disable();
235		235
236	spinlock_lock(&t->lock);	236	spinlock_lock(&t->lock);
237		237
238	ASSERT(!(t->state == Ready));	238	ASSERT(!(t->state == Ready));
239		239
240	i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;	240	i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;
241		241
242	cpu = CPU;	242	cpu = CPU;
243	if (t->flags & THREAD_FLAG_WIRED) {	243	if (t->flags & THREAD_FLAG_WIRED) {
244	ASSERT(t->cpu != NULL);	244	ASSERT(t->cpu != NULL);
245	cpu = t->cpu;	245	cpu = t->cpu;
246	}	246	}
247	t->state = Ready;	247	t->state = Ready;
248	spinlock_unlock(&t->lock);	248	spinlock_unlock(&t->lock);
249		249
250	/*	250	/*
251	* Append t to respective ready queue on respective processor.	251	* Append t to respective ready queue on respective processor.
252	*/	252	*/
253	r = &cpu->rq[i];	253	r = &cpu->rq[i];
254	spinlock_lock(&r->lock);	254	spinlock_lock(&r->lock);
255	list_append(&t->rq_link, &r->rq_head);	255	list_append(&t->rq_link, &r->rq_head);
256	r->n++;	256	r->n++;
257	spinlock_unlock(&r->lock);	257	spinlock_unlock(&r->lock);
258		258
259	atomic_inc(&nrdy);	259	atomic_inc(&nrdy);
260	avg = atomic_get(&nrdy) / config.cpu_active;	260	avg = atomic_get(&nrdy) / config.cpu_active;
261	atomic_inc(&cpu->nrdy);	261	atomic_inc(&cpu->nrdy);
262		262
263	interrupts_restore(ipl);	263	interrupts_restore(ipl);
264	}	264	}
265		265
266	/** Create new thread	266	/** Create new thread
267	*	267	*
268	* Create a new thread.	268	* Create a new thread.
269	*	269	*
270	* @param func Thread's implementing function.	270	* @param func Thread's implementing function.
271	* @param arg Thread's implementing function argument.	271	* @param arg Thread's implementing function argument.
272	* @param task Task to which the thread belongs.	272	* @param task Task to which the thread belongs.
273	* @param flags Thread flags.	273	* @param flags Thread flags.
274	* @param name Symbolic name.	274	* @param name Symbolic name.
275	* @param uncounted Thread's accounting doesn't affect accumulated task	275	* @param uncounted Thread's accounting doesn't affect accumulated task
276	* accounting.	276	* accounting.
277	*	277	*
278	* @return New thread's structure on success, NULL on failure.	278	* @return New thread's structure on success, NULL on failure.
279	*	279	*
280	*/	280	*/
281	thread_t thread_create(void ( func)(void ), void arg, task_t *task,	281	thread_t thread_create(void ( func)(void ), void arg, task_t *task,
282	int flags, char *name, bool uncounted)	282	int flags, char *name, bool uncounted)
283	{	283	{
284	thread_t *t;	284	thread_t *t;
285	ipl_t ipl;	285	ipl_t ipl;
286		286
287	t = (thread_t *) slab_alloc(thread_slab, 0);	287	t = (thread_t *) slab_alloc(thread_slab, 0);
288	if (!t)	288	if (!t)
289	return NULL;	289	return NULL;
290		290
291	/* Not needed, but good for debugging */	291	/* Not needed, but good for debugging */
292	memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES,	292	memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES,
293	0);	293	0);
294		294
295	ipl = interrupts_disable();	295	ipl = interrupts_disable();
296	spinlock_lock(&tidlock);	296	spinlock_lock(&tidlock);
297	t->tid = ++last_tid;	297	t->tid = ++last_tid;
298	spinlock_unlock(&tidlock);	298	spinlock_unlock(&tidlock);
299	interrupts_restore(ipl);	299	interrupts_restore(ipl);
300		300
301	context_save(&t->saved_context);	301	context_save(&t->saved_context);
302	context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,	302	context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,
303	THREAD_STACK_SIZE);	303	THREAD_STACK_SIZE);
304		304
305	the_initialize((the_t *) t->kstack);	305	the_initialize((the_t *) t->kstack);
306		306
307	ipl = interrupts_disable();	307	ipl = interrupts_disable();
308	t->saved_context.ipl = interrupts_read();	308	t->saved_context.ipl = interrupts_read();
309	interrupts_restore(ipl);	309	interrupts_restore(ipl);
310		310
311	memcpy(t->name, name, THREAD_NAME_BUFLEN);	311	memcpy(t->name, name, THREAD_NAME_BUFLEN);
312		312
313	t->thread_code = func;	313	t->thread_code = func;
314	t->thread_arg = arg;	314	t->thread_arg = arg;
315	t->ticks = -1;	315	t->ticks = -1;
316	t->cycles = 0;	316	t->cycles = 0;
317	t->uncounted = uncounted;	317	t->uncounted = uncounted;
318	t->priority = -1; /* start in rq[0] */	318	t->priority = -1; /* start in rq[0] */
319	t->cpu = NULL;	319	t->cpu = NULL;
320	t->flags = flags;	320	t->flags = flags;
321	t->state = Entering;	321	t->state = Entering;
322	t->call_me = NULL;	322	t->call_me = NULL;
323	t->call_me_with = NULL;	323	t->call_me_with = NULL;
324		324
325	timeout_initialize(&t->sleep_timeout);	325	timeout_initialize(&t->sleep_timeout);
326	t->sleep_interruptible = false;	326	t->sleep_interruptible = false;
327	t->sleep_queue = NULL;	327	t->sleep_queue = NULL;
328	t->timeout_pending = 0;	328	t->timeout_pending = 0;
329		329
330	t->in_copy_from_uspace = false;	330	t->in_copy_from_uspace = false;
331	t->in_copy_to_uspace = false;	331	t->in_copy_to_uspace = false;
332		332
333	t->interrupted = false;	333	t->interrupted = false;
334	t->detached = false;	334	t->detached = false;
335	waitq_initialize(&t->join_wq);	335	waitq_initialize(&t->join_wq);
336		336
337	t->rwlock_holder_type = RWLOCK_NONE;	337	t->rwlock_holder_type = RWLOCK_NONE;
338		338
339	t->task = task;	339	t->task = task;
340		340
341	t->fpu_context_exists = 0;	341	t->fpu_context_exists = 0;
342	t->fpu_context_engaged = 0;	342	t->fpu_context_engaged = 0;
343		343
344	avltree_node_initialize(&t->threads_tree_node);	344	avltree_node_initialize(&t->threads_tree_node);
345	t->threads_tree_node.key = (uintptr_t) t;	345	t->threads_tree_node.key = (uintptr_t) t;
346		346
347	/* Init debugging stuff */	347	/* Init debugging stuff */
348	waitq_initialize(&t->go_wq);	348	waitq_initialize(&t->go_wq);
349	t->debug_go_call = NULL;	349	t->debug_go_call = NULL;
350	t->uspace_state = NULL;	350	t->uspace_state = NULL;
351	t->debug_stop = true;	351	t->debug_stop = true;
352	t->debug_stoppable = true;	352	t->debug_stoppable = true;
353	t->debug_active = false;	353	t->debug_active = false;
354	t->cur_event = 0; /* none */	354	t->cur_event = 0; /* none */
355		355
356	/* might depend on previous initialization */	356	/* might depend on previous initialization */
357	thread_create_arch(t);	357	thread_create_arch(t);
358		358
359	if (!(flags & THREAD_FLAG_NOATTACH))	359	if (!(flags & THREAD_FLAG_NOATTACH))
360	thread_attach(t, task);	360	thread_attach(t, task);
361		361
362	return t;	362	return t;
363	}	363	}
364		364
365	/** Destroy thread structure of an unattached thread.	365	/** Destroy thread structure of an unattached thread.
366	*	366	*
367	* Thread t must only have been created and never attached.	367	* Thread t must only have been created and never attached.
368	*/	368	*/
369	void thread_unattached_free(thread_t *t)	369	void thread_unattached_free(thread_t *t)
370	{	370	{
371	slab_free(thread_slab, t);	371	slab_free(thread_slab, t);
372	}	372	}
373		373
374		374
375	/** Destroy thread memory structure	375	/** Destroy thread memory structure
376	*	376	*
377	* Detach thread from all queues, cpus etc. and destroy it.	377	* Detach thread from all queues, cpus etc. and destroy it.
378	*	378	*
379	* Assume thread->lock is held!!	379	* Assume thread->lock is held!!
380	*/	380	*/
381	void thread_destroy(thread_t *t)	381	void thread_destroy(thread_t *t)
382	{	382	{
383	ASSERT(t->state == Exiting \|\| t->state == Lingering);	383	ASSERT(t->state == Exiting \|\| t->state == Lingering);
384	ASSERT(t->task);	384	ASSERT(t->task);
385	ASSERT(t->cpu);	385	ASSERT(t->cpu);
386		386
387	spinlock_lock(&t->cpu->lock);	387	spinlock_lock(&t->cpu->lock);
388	if (t->cpu->fpu_owner == t)	388	if (t->cpu->fpu_owner == t)
389	t->cpu->fpu_owner = NULL;	389	t->cpu->fpu_owner = NULL;
390	spinlock_unlock(&t->cpu->lock);	390	spinlock_unlock(&t->cpu->lock);
391		391
392	spinlock_unlock(&t->lock);	392	spinlock_unlock(&t->lock);
393		393
394	spinlock_lock(&threads_lock);	394	spinlock_lock(&threads_lock);
395	avltree_delete(&threads_tree, &t->threads_tree_node);	395	avltree_delete(&threads_tree, &t->threads_tree_node);
396	spinlock_unlock(&threads_lock);	396	spinlock_unlock(&threads_lock);
397		397
398	/*	398	/*
399	* Detach from the containing task.	399	* Detach from the containing task.
400	*/	400	*/
401	spinlock_lock(&t->task->lock);	401	spinlock_lock(&t->task->lock);
402	list_remove(&t->th_link);	402	list_remove(&t->th_link);
403	spinlock_unlock(&t->task->lock);	403	spinlock_unlock(&t->task->lock);
404		404
405	/*	405	/*
406	* t is guaranteed to be the very last thread of its task.	406	* t is guaranteed to be the very last thread of its task.
407	* It is safe to destroy the task.	407	* It is safe to destroy the task.
408	*/	408	*/
409	if (atomic_predec(&t->task->refcount) == 0)	409	if (atomic_predec(&t->task->refcount) == 0)
410	task_destroy(t->task);	410	task_destroy(t->task);
411		411
412	slab_free(thread_slab, t);	412	slab_free(thread_slab, t);
413	}	413	}
414		414
415	/** Attach thread to the given task.	-
416	*	-
417	* The task's lock must already be held and interrupts must be disabled.	-
418	*	-
419	* @param t Thread to be attached to the task.	-
420	* @param task Task to which the thread is to be attached.	-
421	*/	-
422	static void _thread_attach_task(thread_t t, task_t task)	-
423	{	-
424	atomic_inc(&task->refcount);	-
425	atomic_inc(&task->lifecount);	-
426		-
427	list_append(&t->th_link, &task->th_head);	-
428		-
429	/*	-
430	* Copy task debugging state to thread struct.	-
431	* The thread needs to know it is being debugged,	-
432	* otherwise it would neither stop nor respond to	-
433	* debug ops.	-
434	*/	-
435	if (t->flags & THREAD_FLAG_USPACE) {	-
436	if (task->dt_state == UDEBUG_TS_BEGINNING \|\|	-
437	task->dt_state == UDEBUG_TS_ACTIVE) {	-
438	t->debug_active = true;	-
439	}	-
440	}	-
441	}	-
442		-
443	/** Add thread to the threads tree.	-
444	*	-
445	* Interrupts must be already disabled.	-
446	*	-
447	* @param t Thread to be attached to the task.	-
448	* @param task Task to which the thread is to be attached.	-
449	*/	-
450	static void _thread_attach_tree(thread_t *t)	-
451	{	-
452	/*	-
453	* Register this thread in the system-wide list.	-
454	*/	-
455	spinlock_lock(&threads_lock);	-
456	avltree_insert(&threads_tree, &t->threads_tree_node);	-
457	spinlock_unlock(&threads_lock);	-
458	}	-
459		-
460		-
461	/** Make the thread visible to the system.	415	/** Make the thread visible to the system.
462	*	416	*
463	* Attach the thread structure to the current task and make it visible in the	417	* Attach the thread structure to the current task and make it visible in the
464	* threads_tree.	418	* threads_tree.
465	*	419	*
466	* @param t Thread to be attached to the task.	420	* @param t Thread to be attached to the task.
467	* @param task Task to which the thread is to be attached.	421	* @param task Task to which the thread is to be attached.
468	*/	422	*/
469	void thread_attach(thread_t t, task_t task)	423	void thread_attach(thread_t t, task_t task)
470	{	424	{
471	ipl_t ipl;	425	ipl_t ipl;
472		426
473	ipl = interrupts_disable();	-
474		-
475	/*	-
476	* Attach to the current task.	-
477	*/	-
478	spinlock_lock(&task->lock);	-
479	_thread_attach_task(t, task);	-
480	spinlock_unlock(&task->lock);	-
481		-
482	/*	427	/*
483	* Register this thread in the system-wide list.	428	* Attach to the specified task.
484	*/	429	*/
485	_thread_attach_tree(t);	-
486		-
487	interrupts_restore(ipl);	-
488	}	-
489		-
490	/** Attach thread to a task given by its ID.	-
491	*	-
492	* Unlike thread_attach(), this function allows to attach a thread	-
493	* to an arbitrary task.	-
494	*	-
495	* @param t Thread to be attached to the task.	-
496	* @param taskid Task id to which the thread is to be attached.	-
497	* @return An error code from errno.h	-
498	*/	-
499	int thread_attach_by_id(thread_t *t, task_id_t taskid)	-
500	{	-

Subversion Repositories HelenOS

(root)/branches/tracing/kernel/generic/src/proc/thread.c @ 3674 – Rev 2898 → 2902