WebSVN – HelenOS – Diff – /branches/sparc/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>
 
 
#ifndef LOADED_PROG_STACK_PAGES_NO
#define LOADED_PROG_STACK_PAGES_NO 1
#endif
 
 
/** 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);
 
/** AVL 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;
    }
 
#ifdef CONFIG_UDEBUG
    mutex_initialize(&t->udebug.lock, MUTEX_PASSIVE);
#endif
 
    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. The caller must
 *          guarantee that the task won't cease to exist during the
 *          call. The task's lock may not be held.
 * @param flags     Thread flags.
 * @param name      Symbolic name (a copy is made).
 * @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(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->name[THREAD_NAME_BUFLEN - 1] = '\0';
   
    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;
 
#ifdef CONFIG_UDEBUG
    /* Init debugging stuff */
    udebug_thread_initialize(&t->udebug);
#endif
 
    /* 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 == 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) {
#ifdef CONFIG_UDEBUG
        /* Generate udebug THREAD_E event */
        udebug_thread_e_event();
#endif
        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();
            LOG("Cleanup of task %" PRIu64" 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 = avltree_get_instance(node, thread_t, threads_tree_node);
   
    uint64_t cycles;
    char suffix;
    order(t->cycles, &cycles, &suffix);
 
#ifdef __32_BITS__
    printf("%-6" PRIu64" %-10s %10p %-8s %10p %-3" PRIu32 " %10p %10p %9" PRIu64 "%c ",
        t->tid, t->name, t, thread_states[t->state], t->task,
        t->task->context, t->thread_code, t->kstack, cycles, suffix);
#endif
 
#ifdef __64_BITS__
    printf("%-6" PRIu64" %-10s %18p %-8s %18p %-3" PRIu32 " %18p %18p %9" PRIu64 "%c ",
        t->tid, t->name, t, thread_states[t->state], t->task,
        t->task->context, t->thread_code, t->kstack, cycles, suffix);
#endif
           
    if (t->cpu)
        printf("%-4u", t->cpu->id);
    else
        printf("none");
           
    if (t->state == Sleeping) {
#ifdef __32_BITS__
        printf(" %10p", t->sleep_queue);
#endif
 
#ifdef __64_BITS__
        printf(" %18p", t->sleep_queue);
#endif
    }
           
    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);
 
#ifdef __32_BITS__  
    printf("tid    name       address    state    task       "
        "ctx code       stack      cycles     cpu  "
        "waitqueue\n");
    printf("------ ---------- ---------- -------- ---------- "
        "--- ---------- ---------- ---------- ---- "
        "----------\n");
#endif
 
#ifdef __64_BITS__
    printf("tid    name       address            state    task               "
        "ctx code               stack              cycles     cpu  "
        "waitqueue\n");
    printf("------ ---------- ------------------ -------- ------------------ "
        "--- ------------------ ------------------ ---------- ---- "
        "------------------\n");
#endif
 
    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,
    size_t name_len, thread_id_t *uspace_thread_id)
{
    thread_t *t;
    char namebuf[THREAD_NAME_BUFLEN];
    uspace_arg_t *kernel_uarg;
    int rc;
 
    if (name_len > THREAD_NAME_BUFLEN - 1)
        name_len = THREAD_NAME_BUFLEN - 1;
 
    rc = copy_from_uspace(namebuf, uspace_name, name_len);
    if (rc != 0)
        return (unative_t) rc;
 
    namebuf[name_len] = '\0';
 
    /*
     * 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;
             }
        }
#ifdef CONFIG_UDEBUG
        /*
         * Generate udebug THREAD_B event and attach the thread.
         * This must be done atomically (with the debug locks held),
         * otherwise we would either miss some thread or receive
         * THREAD_B events for threads that already existed
         * and could be detected with THREAD_READ before.
         */
        udebug_thread_b_event_attach(t, TASK);
#else
        thread_attach(t, TASK);
#endif
        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 3742	Rev 3745
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		70
71		71
72	#ifndef LOADED_PROG_STACK_PAGES_NO	72	#ifndef LOADED_PROG_STACK_PAGES_NO
73	#define LOADED_PROG_STACK_PAGES_NO 1	73	#define LOADED_PROG_STACK_PAGES_NO 1
74	#endif	74	#endif
75		75
76		76
77	/** Thread states */	77	/** Thread states */
78	char *thread_states[] = {	78	char *thread_states[] = {
79	"Invalid",	79	"Invalid",
80	"Running",	80	"Running",
81	"Sleeping",	81	"Sleeping",
82	"Ready",	82	"Ready",
83	"Entering",	83	"Entering",
84	"Exiting",	84	"Exiting",
85	"Lingering"	85	"Lingering"
86	};	86	};
87		87
88	/** Lock protecting the threads_tree AVL tree.	88	/** Lock protecting the threads_tree AVL tree.
89	*	89	*
90	* For locking rules, see declaration thereof.	90	* For locking rules, see declaration thereof.
91	*/	91	*/
92	SPINLOCK_INITIALIZE(threads_lock);	92	SPINLOCK_INITIALIZE(threads_lock);
93		93
94	/** AVL tree of all threads.	94	/** AVL tree of all threads.
95	*	95	*
96	* When a thread is found in the threads_tree AVL tree, it is guaranteed to	96	* When a thread is found in the threads_tree AVL tree, it is guaranteed to
97	* exist as long as the threads_lock is held.	97	* exist as long as the threads_lock is held.
98	*/	98	*/
99	avltree_t threads_tree;	99	avltree_t threads_tree;
100		100
101	SPINLOCK_INITIALIZE(tidlock);	101	SPINLOCK_INITIALIZE(tidlock);
102	thread_id_t last_tid = 0;	102	thread_id_t last_tid = 0;
103		103
104	static slab_cache_t *thread_slab;	104	static slab_cache_t *thread_slab;
105	#ifdef ARCH_HAS_FPU	105	#ifdef ARCH_HAS_FPU
106	slab_cache_t *fpu_context_slab;	106	slab_cache_t *fpu_context_slab;
107	#endif	107	#endif
108		108
109	/** Thread wrapper.	109	/** Thread wrapper.
110	*	110	*
111	* This wrapper is provided to ensure that every thread makes a call to	111	* This wrapper is provided to ensure that every thread makes a call to
112	* thread_exit() when its implementing function returns.	112	* thread_exit() when its implementing function returns.
113	*	113	*
114	* interrupts_disable() is assumed.	114	* interrupts_disable() is assumed.
115	*	115	*
116	*/	116	*/
117	static void cushion(void)	117	static void cushion(void)
118	{	118	{
119	void (f)(void ) = THREAD->thread_code;	119	void (f)(void ) = THREAD->thread_code;
120	void *arg = THREAD->thread_arg;	120	void *arg = THREAD->thread_arg;
121	THREAD->last_cycle = get_cycle();	121	THREAD->last_cycle = get_cycle();
122		122
123	/* This is where each thread wakes up after its creation */	123	/* This is where each thread wakes up after its creation */
124	spinlock_unlock(&THREAD->lock);	124	spinlock_unlock(&THREAD->lock);
125	interrupts_enable();	125	interrupts_enable();
126		126
127	f(arg);	127	f(arg);
128		128
129	/* Accumulate accounting to the task */	129	/* Accumulate accounting to the task */
130	ipl_t ipl = interrupts_disable();	130	ipl_t ipl = interrupts_disable();
131		131
132	spinlock_lock(&THREAD->lock);	132	spinlock_lock(&THREAD->lock);
133	if (!THREAD->uncounted) {	133	if (!THREAD->uncounted) {
134	thread_update_accounting();	134	thread_update_accounting();
135	uint64_t cycles = THREAD->cycles;	135	uint64_t cycles = THREAD->cycles;
136	THREAD->cycles = 0;	136	THREAD->cycles = 0;
137	spinlock_unlock(&THREAD->lock);	137	spinlock_unlock(&THREAD->lock);
138		138
139	spinlock_lock(&TASK->lock);	139	spinlock_lock(&TASK->lock);
140	TASK->cycles += cycles;	140	TASK->cycles += cycles;
141	spinlock_unlock(&TASK->lock);	141	spinlock_unlock(&TASK->lock);
142	} else	142	} else
143	spinlock_unlock(&THREAD->lock);	143	spinlock_unlock(&THREAD->lock);
144		144
145	interrupts_restore(ipl);	145	interrupts_restore(ipl);
146		146
147	thread_exit();	147	thread_exit();
148	/* not reached */	148	/* not reached */
149	}	149	}
150		150
151	/** Initialization and allocation for thread_t structure */	151	/** Initialization and allocation for thread_t structure */
152	static int thr_constructor(void *obj, int kmflags)	152	static int thr_constructor(void *obj, int kmflags)
153	{	153	{
154	thread_t t = (thread_t ) obj;	154	thread_t t = (thread_t ) obj;
155		155
156	spinlock_initialize(&t->lock, "thread_t_lock");	156	spinlock_initialize(&t->lock, "thread_t_lock");
157	link_initialize(&t->rq_link);	157	link_initialize(&t->rq_link);
158	link_initialize(&t->wq_link);	158	link_initialize(&t->wq_link);
159	link_initialize(&t->th_link);	159	link_initialize(&t->th_link);
160		160
161	/* call the architecture-specific part of the constructor */	161	/* call the architecture-specific part of the constructor */
162	thr_constructor_arch(t);	162	thr_constructor_arch(t);
163		163
164	#ifdef ARCH_HAS_FPU	164	#ifdef ARCH_HAS_FPU
165	#ifdef CONFIG_FPU_LAZY	165	#ifdef CONFIG_FPU_LAZY
166	t->saved_fpu_context = NULL;	166	t->saved_fpu_context = NULL;
167	#else	167	#else
168	t->saved_fpu_context = slab_alloc(fpu_context_slab, kmflags);	168	t->saved_fpu_context = slab_alloc(fpu_context_slab, kmflags);
169	if (!t->saved_fpu_context)	169	if (!t->saved_fpu_context)
170	return -1;	170	return -1;
171	#endif	171	#endif
172	#endif	172	#endif
173		173
174	t->kstack = (uint8_t *) frame_alloc(STACK_FRAMES, FRAME_KA \| kmflags);	174	t->kstack = (uint8_t *) frame_alloc(STACK_FRAMES, FRAME_KA \| kmflags);
175	if (!t->kstack) {	175	if (!t->kstack) {
176	#ifdef ARCH_HAS_FPU	176	#ifdef ARCH_HAS_FPU
177	if (t->saved_fpu_context)	177	if (t->saved_fpu_context)
178	slab_free(fpu_context_slab, t->saved_fpu_context);	178	slab_free(fpu_context_slab, t->saved_fpu_context);
179	#endif	179	#endif
180	return -1;	180	return -1;
181	}	181	}
182		182
183	#ifdef CONFIG_UDEBUG	183	#ifdef CONFIG_UDEBUG
184	mutex_initialize(&t->udebug.lock, MUTEX_PASSIVE);	184	mutex_initialize(&t->udebug.lock, MUTEX_PASSIVE);
185	#endif	185	#endif
186		186
187	return 0;	187	return 0;
188	}	188	}
189		189
190	/** Destruction of thread_t object */	190	/** Destruction of thread_t object */
191	static int thr_destructor(void *obj)	191	static int thr_destructor(void *obj)
192	{	192	{
193	thread_t t = (thread_t ) obj;	193	thread_t t = (thread_t ) obj;
194		194
195	/* call the architecture-specific part of the destructor */	195	/* call the architecture-specific part of the destructor */
196	thr_destructor_arch(t);	196	thr_destructor_arch(t);
197		197
198	frame_free(KA2PA(t->kstack));	198	frame_free(KA2PA(t->kstack));
199	#ifdef ARCH_HAS_FPU	199	#ifdef ARCH_HAS_FPU
200	if (t->saved_fpu_context)	200	if (t->saved_fpu_context)
201	slab_free(fpu_context_slab, t->saved_fpu_context);	201	slab_free(fpu_context_slab, t->saved_fpu_context);
202	#endif	202	#endif
203	return 1; /* One page freed */	203	return 1; /* One page freed */
204	}	204	}
205		205
206	/** Initialize threads	206	/** Initialize threads
207	*	207	*
208	* Initialize kernel threads support.	208	* Initialize kernel threads support.
209	*	209	*
210	*/	210	*/
211	void thread_init(void)	211	void thread_init(void)
212	{	212	{
213	THREAD = NULL;	213	THREAD = NULL;
214	atomic_set(&nrdy,0);	214	atomic_set(&nrdy, 0);
215	thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,	215	thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,
216	thr_constructor, thr_destructor, 0);	216	thr_constructor, thr_destructor, 0);
217		217
218	#ifdef ARCH_HAS_FPU	218	#ifdef ARCH_HAS_FPU
219	fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),	219	fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),
220	FPU_CONTEXT_ALIGN, NULL, NULL, 0);	220	FPU_CONTEXT_ALIGN, NULL, NULL, 0);
221	#endif	221	#endif
222		222
223	avltree_create(&threads_tree);	223	avltree_create(&threads_tree);
224	}	224	}
225		225
226	/** Make thread ready	226	/** Make thread ready
227	*	227	*
228	* Switch thread t to the ready state.	228	* Switch thread t to the ready state.
229	*	229	*
230	* @param t Thread to make ready.	230	* @param t Thread to make ready.
231	*	231	*
232	*/	232	*/
233	void thread_ready(thread_t *t)	233	void thread_ready(thread_t *t)
234	{	234	{
235	cpu_t *cpu;	235	cpu_t *cpu;
236	runq_t *r;	236	runq_t *r;
237	ipl_t ipl;	237	ipl_t ipl;
238	int i, avg;	238	int i, avg;
239		239
240	ipl = interrupts_disable();	240	ipl = interrupts_disable();
241		241
242	spinlock_lock(&t->lock);	242	spinlock_lock(&t->lock);
243		243
244	ASSERT(!(t->state == Ready));	244	ASSERT(!(t->state == Ready));
245		245
246	i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;	246	i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;
247		247
248	cpu = CPU;	248	cpu = CPU;
249	if (t->flags & THREAD_FLAG_WIRED) {	249	if (t->flags & THREAD_FLAG_WIRED) {
250	ASSERT(t->cpu != NULL);	250	ASSERT(t->cpu != NULL);
251	cpu = t->cpu;	251	cpu = t->cpu;
252	}	252	}
253	t->state = Ready;	253	t->state = Ready;
254	spinlock_unlock(&t->lock);	254	spinlock_unlock(&t->lock);
255		255
256	/*	256	/*
257	* Append t to respective ready queue on respective processor.	257	* Append t to respective ready queue on respective processor.
258	*/	258	*/
259	r = &cpu->rq[i];	259	r = &cpu->rq[i];
260	spinlock_lock(&r->lock);	260	spinlock_lock(&r->lock);
261	list_append(&t->rq_link, &r->rq_head);	261	list_append(&t->rq_link, &r->rq_head);
262	r->n++;	262	r->n++;
263	spinlock_unlock(&r->lock);	263	spinlock_unlock(&r->lock);
264		264
265	atomic_inc(&nrdy);	265	atomic_inc(&nrdy);
266	avg = atomic_get(&nrdy) / config.cpu_active;	266	avg = atomic_get(&nrdy) / config.cpu_active;
267	atomic_inc(&cpu->nrdy);	267	atomic_inc(&cpu->nrdy);
268		268
269	interrupts_restore(ipl);	269	interrupts_restore(ipl);
270	}	270	}
271		271
272	/** Create new thread	272	/** Create new thread
273	*	273	*
274	* Create a new thread.	274	* Create a new thread.
275	*	275	*
276	* @param func Thread's implementing function.	276	* @param func Thread's implementing function.
277	* @param arg Thread's implementing function argument.	277	* @param arg Thread's implementing function argument.
278	* @param task Task to which the thread belongs. The caller must	278	* @param task Task to which the thread belongs. The caller must
279	* guarantee that the task won't cease to exist during the	279	* guarantee that the task won't cease to exist during the
280	* call. The task's lock may not be held.	280	* call. The task's lock may not be held.
281	* @param flags Thread flags.	281	* @param flags Thread flags.
282	* @param name Symbolic name (a copy is made).	282	* @param name Symbolic name (a copy is made).
283	* @param uncounted Thread's accounting doesn't affect accumulated task	283	* @param uncounted Thread's accounting doesn't affect accumulated task
284	* accounting.	284	* accounting.
285	*	285	*
286	* @return New thread's structure on success, NULL on failure.	286	* @return New thread's structure on success, NULL on failure.
287	*	287	*
288	*/	288	*/
289	thread_t thread_create(void ( func)(void ), void arg, task_t *task,	289	thread_t thread_create(void ( func)(void ), void arg, task_t *task,
290	int flags, char *name, bool uncounted)	290	int flags, char *name, bool uncounted)
291	{	291	{
292	thread_t *t;	292	thread_t *t;
293	ipl_t ipl;	293	ipl_t ipl;
294		294
295	t = (thread_t *) slab_alloc(thread_slab, 0);	295	t = (thread_t *) slab_alloc(thread_slab, 0);
296	if (!t)	296	if (!t)
297	return NULL;	297	return NULL;
298		298
299	/* Not needed, but good for debugging */	299	/* Not needed, but good for debugging */
300	memsetb(t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES, 0);	300	memsetb(t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES, 0);
301		301
302	ipl = interrupts_disable();	302	ipl = interrupts_disable();
303	spinlock_lock(&tidlock);	303	spinlock_lock(&tidlock);
304	t->tid = ++last_tid;	304	t->tid = ++last_tid;
305	spinlock_unlock(&tidlock);	305	spinlock_unlock(&tidlock);
306	interrupts_restore(ipl);	306	interrupts_restore(ipl);
307		307
308	context_save(&t->saved_context);	308	context_save(&t->saved_context);
309	context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,	309	context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,
310	THREAD_STACK_SIZE);	310	THREAD_STACK_SIZE);
311		311
312	the_initialize((the_t *) t->kstack);	312	the_initialize((the_t *) t->kstack);
313		313
314	ipl = interrupts_disable();	314	ipl = interrupts_disable();
315	t->saved_context.ipl = interrupts_read();	315	t->saved_context.ipl = interrupts_read();
316	interrupts_restore(ipl);	316	interrupts_restore(ipl);
317		317
318	memcpy(t->name, name, THREAD_NAME_BUFLEN);	318	memcpy(t->name, name, THREAD_NAME_BUFLEN);
319	t->name[THREAD_NAME_BUFLEN - 1] = '\0';	319	t->name[THREAD_NAME_BUFLEN - 1] = '\0';
320		320
321	t->thread_code = func;	321	t->thread_code = func;
322	t->thread_arg = arg;	322	t->thread_arg = arg;
323	t->ticks = -1;	323	t->ticks = -1;
324	t->cycles = 0;	324	t->cycles = 0;
325	t->uncounted = uncounted;	325	t->uncounted = uncounted;
326	t->priority = -1; /* start in rq[0] */	326	t->priority = -1; /* start in rq[0] */
327	t->cpu = NULL;	327	t->cpu = NULL;
328	t->flags = flags;	328	t->flags = flags;
329	t->state = Entering;	329	t->state = Entering;
330	t->call_me = NULL;	330	t->call_me = NULL;
331	t->call_me_with = NULL;	331	t->call_me_with = NULL;
332		332
333	timeout_initialize(&t->sleep_timeout);	333	timeout_initialize(&t->sleep_timeout);
334	t->sleep_interruptible = false;	334	t->sleep_interruptible = false;
335	t->sleep_queue = NULL;	335	t->sleep_queue = NULL;
336	t->timeout_pending = 0;	336	t->timeout_pending = 0;
337		337
338	t->in_copy_from_uspace = false;	338	t->in_copy_from_uspace = false;
339	t->in_copy_to_uspace = false;	339	t->in_copy_to_uspace = false;
340		340
341	t->interrupted = false;	341	t->interrupted = false;
342	t->detached = false;	342	t->detached = false;
343	waitq_initialize(&t->join_wq);	343	waitq_initialize(&t->join_wq);
344		344
345	t->rwlock_holder_type = RWLOCK_NONE;	345	t->rwlock_holder_type = RWLOCK_NONE;
346		346
347	t->task = task;	347	t->task = task;
348		348
349	t->fpu_context_exists = 0;	349	t->fpu_context_exists = 0;
350	t->fpu_context_engaged = 0;	350	t->fpu_context_engaged = 0;
351		351
352	avltree_node_initialize(&t->threads_tree_node);	352	avltree_node_initialize(&t->threads_tree_node);
353	t->threads_tree_node.key = (uintptr_t) t;	353	t->threads_tree_node.key = (uintptr_t) t;
354		354
355	#ifdef CONFIG_UDEBUG	355	#ifdef CONFIG_UDEBUG
356	/* Init debugging stuff */	356	/* Init debugging stuff */
357	udebug_thread_initialize(&t->udebug);	357	udebug_thread_initialize(&t->udebug);
358	#endif	358	#endif
359		359
360	/* might depend on previous initialization */	360	/* might depend on previous initialization */
361	thread_create_arch(t);	361	thread_create_arch(t);
362		362
363	if (!(flags & THREAD_FLAG_NOATTACH))	363	if (!(flags & THREAD_FLAG_NOATTACH))
364	thread_attach(t, task);	364	thread_attach(t, task);
365		365
366	return t;	366	return t;
367	}	367	}
368		368
369	/** Destroy thread memory structure	369	/** Destroy thread memory structure
370	*	370	*
371	* Detach thread from all queues, cpus etc. and destroy it.	371	* Detach thread from all queues, cpus etc. and destroy it.
372	*	372	*
373	* Assume thread->lock is held!!	373	* Assume thread->lock is held!!
374	*/	374	*/
375	void thread_destroy(thread_t *t)	375	void thread_destroy(thread_t *t)
376	{	376	{
377	ASSERT(t->state == Exiting \|\| t->state == Lingering);	377	ASSERT(t->state == Exiting \|\| t->state == Lingering);
378	ASSERT(t->task);	378	ASSERT(t->task);
379	ASSERT(t->cpu);	379	ASSERT(t->cpu);
380		380
381	spinlock_lock(&t->cpu->lock);	381	spinlock_lock(&t->cpu->lock);
382	if (t->cpu->fpu_owner == t)	382	if (t->cpu->fpu_owner == t)
383	t->cpu->fpu_owner = NULL;	383	t->cpu->fpu_owner = NULL;
384	spinlock_unlock(&t->cpu->lock);	384	spinlock_unlock(&t->cpu->lock);
385		385
386	spinlock_unlock(&t->lock);	386	spinlock_unlock(&t->lock);
387		387
388	spinlock_lock(&threads_lock);	388	spinlock_lock(&threads_lock);
389	avltree_delete(&threads_tree, &t->threads_tree_node);	389	avltree_delete(&threads_tree, &t->threads_tree_node);
390	spinlock_unlock(&threads_lock);	390	spinlock_unlock(&threads_lock);
391		391
392	/*	392	/*
393	* Detach from the containing task.	393	* Detach from the containing task.
394	*/	394	*/
395	spinlock_lock(&t->task->lock);	395	spinlock_lock(&t->task->lock);
396	list_remove(&t->th_link);	396	list_remove(&t->th_link);
397	spinlock_unlock(&t->task->lock);	397	spinlock_unlock(&t->task->lock);
398		398
399	/*	399	/*
400	* t is guaranteed to be the very last thread of its task.	400	* t is guaranteed to be the very last thread of its task.
401	* It is safe to destroy the task.	401	* It is safe to destroy the task.
402	*/	402	*/
403	if (atomic_predec(&t->task->refcount) == 0)	403	if (atomic_predec(&t->task->refcount) == 0)
404	task_destroy(t->task);	404	task_destroy(t->task);
405		405
406	slab_free(thread_slab, t);	406	slab_free(thread_slab, t);
407	}	407	}
408		408
409	/** Make the thread visible to the system.	409	/** Make the thread visible to the system.
410	*	410	*
411	* Attach the thread structure to the current task and make it visible in the	411	* Attach the thread structure to the current task and make it visible in the
412	* threads_tree.	412	* threads_tree.
413	*	413	*
414	* @param t Thread to be attached to the task.	414	* @param t Thread to be attached to the task.
415	* @param task Task to which the thread is to be attached.	415	* @param task Task to which the thread is to be attached.
416	*/	416	*/
417	void thread_attach(thread_t t, task_t task)	417	void thread_attach(thread_t t, task_t task)
418	{	418	{
419	ipl_t ipl;	419	ipl_t ipl;
420		420
421	/*	421	/*
422	* Attach to the specified task.	422	* Attach to the specified task.
423	*/	423	*/
424	ipl = interrupts_disable();	424	ipl = interrupts_disable();
425	spinlock_lock(&task->lock);	425	spinlock_lock(&task->lock);
426		426
427	atomic_inc(&task->refcount);	427	atomic_inc(&task->refcount);
428		428
429	/* Must not count kbox thread into lifecount */	429	/* Must not count kbox thread into lifecount */
430	if (t->flags & THREAD_FLAG_USPACE)	430	if (t->flags & THREAD_FLAG_USPACE)
431	atomic_inc(&task->lifecount);	431	atomic_inc(&task->lifecount);
432		432
433	list_append(&t->th_link, &task->th_head);	433	list_append(&t->th_link, &task->th_head);
434	spinlock_unlock(&task->lock);	434	spinlock_unlock(&task->lock);
435		435
436	/*	436	/*
437	* Register this thread in the system-wide list.	437	* Register this thread in the system-wide list.
438	*/	438	*/
439	spinlock_lock(&threads_lock);	439	spinlock_lock(&threads_lock);
440	avltree_insert(&threads_tree, &t->threads_tree_node);	440	avltree_insert(&threads_tree, &t->threads_tree_node);
441	spinlock_unlock(&threads_lock);	441	spinlock_unlock(&threads_lock);
442		442
443	interrupts_restore(ipl);	443	interrupts_restore(ipl);
444	}	444	}
445		445
446	/** Terminate thread.	446	/** Terminate thread.
447	*	447	*
448	* End current thread execution and switch it to the exiting state. All pending	448	* End current thread execution and switch it to the exiting state. All pending
449	* timeouts are executed.	449	* timeouts are executed.
450	*/	450	*/
451	void thread_exit(void)	451	void thread_exit(void)
452	{	452	{
453	ipl_t ipl;	453	ipl_t ipl;
454		454
455	if (THREAD->flags & THREAD_FLAG_USPACE) {	455	if (THREAD->flags & THREAD_FLAG_USPACE) {
456	#ifdef CONFIG_UDEBUG	456	#ifdef CONFIG_UDEBUG
457	/* Generate udebug THREAD_E event */	457	/* Generate udebug THREAD_E event */
458	udebug_thread_e_event();	458	udebug_thread_e_event();
459	#endif	459	#endif
460	if (atomic_predec(&TASK->lifecount) == 0) {	460	if (atomic_predec(&TASK->lifecount) == 0) {
461	/*	461	/*
462	* We are the last userspace thread in the task that	462	* We are the last userspace thread in the task that
463	* still has not exited. With the exception of the	463	* still has not exited. With the exception of the
464	* moment the task was created, new userspace threads	464	* moment the task was created, new userspace threads
465	* can only be created by threads of the same task.	465	* can only be created by threads of the same task.
466	* We are safe to perform cleanup.	466	* We are safe to perform cleanup.
467	*/	467	*/
468	ipc_cleanup();	468	ipc_cleanup();
469	futex_cleanup();	469	futex_cleanup();
470	LOG("Cleanup of task %" PRIu64" completed.", TASK->taskid);	470	LOG("Cleanup of task %" PRIu64" completed.", TASK->taskid);
471	}	471	}
472	}	472	}
473		473
474	restart:	474	restart:
475	ipl = interrupts_disable();	475	ipl = interrupts_disable();
476	spinlock_lock(&THREAD->lock);	476	spinlock_lock(&THREAD->lock);
477	if (THREAD->timeout_pending) {	477	if (THREAD->timeout_pending) {
478	/* busy waiting for timeouts in progress */	478	/* busy waiting for timeouts in progress */
479	spinlock_unlock(&THREAD->lock);	479	spinlock_unlock(&THREAD->lock);
480	interrupts_restore(ipl);	480	interrupts_restore(ipl);
481	goto restart;	481	goto restart;
482	}	482	}
483		483
484	THREAD->state = Exiting;	484	THREAD->state = Exiting;
485	spinlock_unlock(&THREAD->lock);	485	spinlock_unlock(&THREAD->lock);
486	scheduler();	486	scheduler();
487		487
488	/* Not reached */	488	/* Not reached */
489	while (1)	489	while (1)
490	;	490	;
491	}	491	}
492		492
493		493
494	/** Thread sleep	494	/** Thread sleep
495	*	495	*
496	* Suspend execution of the current thread.	496	* Suspend execution of the current thread.
497	*	497	*
498	* @param sec Number of seconds to sleep.	498	* @param sec Number of seconds to sleep.
499	*	499	*
500	*/	500	*/

Subversion Repositories HelenOS

(root)/branches/sparc/kernel/generic/src/proc/thread.c – Rev 3742 → 3745