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


/*
 * Copyright (c) 2001-2004 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup genericproc
 * @{
 */
 
/**
 * @file
 * @brief   Thread management functions.
 */
 
#include <proc/scheduler.h>
#include <proc/thread.h>
#include <proc/task.h>
#include <proc/uarg.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <arch/asm.h>
#include <arch/cycle.h>
#include <arch.h>
#include <synch/synch.h>
#include <synch/spinlock.h>
#include <synch/waitq.h>
#include <synch/rwlock.h>
#include <cpu.h>
#include <func.h>
#include <context.h>
#include <adt/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;
    }
 
    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.
 * @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->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;
 
    /* 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 current task.
     */
    ipl = interrupts_disable();
    spinlock_lock(&task->lock);
    atomic_inc(&task->refcount);
    atomic_inc(&task->lifecount);
    list_append(&t->th_link, &task->th_head);
    spinlock_unlock(&task->lock);
 
    /*
     * Register this thread in the system-wide list.
     */
    spinlock_lock(&threads_lock);
    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 (atomic_predec(&TASK->lifecount) == 0) {
        /*
         * We are the last thread in the task that still has not exited.
         * With the exception of the moment the task was created, new
         * threads can only be created by threads of the same task.
         * We are safe to perform cleanup.
         */
        if (THREAD->flags & THREAD_FLAG_USPACE) {
            ipc_cleanup();
            futex_cleanup();
            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;
}
 
 
/** Create new user task with 1 thread from image
 *
 * @param program_addr Address of program executable image.
 * @param name Program name.
 *
 * @return Initialized main thread of the task or NULL on error.
 */
thread_t *thread_create_program(void *program_addr, char *name)
{
    as_t *as;
    as_area_t *area;
    unsigned int rc;
    task_t *task;
    uspace_arg_t *kernel_uarg;
   
    kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
    if (kernel_uarg == NULL)
        return NULL;
   
    kernel_uarg->uspace_entry =
        (void *) ((elf_header_t *) program_addr)->e_entry;
    kernel_uarg->uspace_stack = (void *) USTACK_ADDRESS;
    kernel_uarg->uspace_thread_function = NULL;
    kernel_uarg->uspace_thread_arg = NULL;
    kernel_uarg->uspace_uarg = NULL;
 
    as = as_create(0);
    if (as == NULL) {
        free(kernel_uarg);
        return NULL;
    }
 
    rc = elf_load((elf_header_t *) program_addr, as);
    if (rc != EE_OK) {
        free(kernel_uarg);
        as_destroy(as);
        return NULL;
    }
   
    /*
     * Create the data as_area.
     */
    area = as_area_create(as,
        AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE,
        LOADED_PROG_STACK_PAGES_NO * PAGE_SIZE, USTACK_ADDRESS,
        AS_AREA_ATTR_NONE, &anon_backend, NULL);
    if (area == NULL) {
        free(kernel_uarg);
        as_destroy(as);
        return NULL;
    }
   
    task = task_create(as, name);
    if (task == NULL) {
        free(kernel_uarg);
        as_destroy(as);
        return NULL;
    }
   
    /*
     * Create the main thread.
     */
    return thread_create(uinit, kernel_uarg, task, THREAD_FLAG_USPACE,
        "uinit", false);
}
 
 
/** 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);
 
        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 3063	Rev 3104
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	return 0;	183	return 0;
184	}	184	}
185		185
186	/** Destruction of thread_t object */	186	/** Destruction of thread_t object */
187	static int thr_destructor(void *obj)	187	static int thr_destructor(void *obj)
188	{	188	{
189	thread_t t = (thread_t ) obj;	189	thread_t t = (thread_t ) obj;
190		190
191	/* call the architecture-specific part of the destructor */	191	/* call the architecture-specific part of the destructor */
192	thr_destructor_arch(t);	192	thr_destructor_arch(t);
193		193
194	frame_free(KA2PA(t->kstack));	194	frame_free(KA2PA(t->kstack));
195	#ifdef ARCH_HAS_FPU	195	#ifdef ARCH_HAS_FPU
196	if (t->saved_fpu_context)	196	if (t->saved_fpu_context)
197	slab_free(fpu_context_slab, t->saved_fpu_context);	197	slab_free(fpu_context_slab, t->saved_fpu_context);
198	#endif	198	#endif
199	return 1; /* One page freed */	199	return 1; /* One page freed */
200	}	200	}
201		201
202	/** Initialize threads	202	/** Initialize threads
203	*	203	*
204	* Initialize kernel threads support.	204	* Initialize kernel threads support.
205	*	205	*
206	*/	206	*/
207	void thread_init(void)	207	void thread_init(void)
208	{	208	{
209	THREAD = NULL;	209	THREAD = NULL;
210	atomic_set(&nrdy,0);	210	atomic_set(&nrdy,0);
211	thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,	211	thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,
212	thr_constructor, thr_destructor, 0);	212	thr_constructor, thr_destructor, 0);
213		213
214	#ifdef ARCH_HAS_FPU	214	#ifdef ARCH_HAS_FPU
215	fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),	215	fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),
216	FPU_CONTEXT_ALIGN, NULL, NULL, 0);	216	FPU_CONTEXT_ALIGN, NULL, NULL, 0);
217	#endif	217	#endif
218		218
219	avltree_create(&threads_tree);	219	avltree_create(&threads_tree);
220	}	220	}
221		221
222	/** Make thread ready	222	/** Make thread ready
223	*	223	*
224	* Switch thread t to the ready state.	224	* Switch thread t to the ready state.
225	*	225	*
226	* @param t Thread to make ready.	226	* @param t Thread to make ready.
227	*	227	*
228	*/	228	*/
229	void thread_ready(thread_t *t)	229	void thread_ready(thread_t *t)
230	{	230	{
231	cpu_t *cpu;	231	cpu_t *cpu;
232	runq_t *r;	232	runq_t *r;
233	ipl_t ipl;	233	ipl_t ipl;
234	int i, avg;	234	int i, avg;
235		235
236	ipl = interrupts_disable();	236	ipl = interrupts_disable();
237		237
238	spinlock_lock(&t->lock);	238	spinlock_lock(&t->lock);
239		239
240	ASSERT(!(t->state == Ready));	240	ASSERT(!(t->state == Ready));
241		241
242	i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;	242	i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;
243		243
244	cpu = CPU;	244	cpu = CPU;
245	if (t->flags & THREAD_FLAG_WIRED) {	245	if (t->flags & THREAD_FLAG_WIRED) {
246	ASSERT(t->cpu != NULL);	246	ASSERT(t->cpu != NULL);
247	cpu = t->cpu;	247	cpu = t->cpu;
248	}	248	}
249	t->state = Ready;	249	t->state = Ready;
250	spinlock_unlock(&t->lock);	250	spinlock_unlock(&t->lock);
251		251
252	/*	252	/*
253	* Append t to respective ready queue on respective processor.	253	* Append t to respective ready queue on respective processor.
254	*/	254	*/
255	r = &cpu->rq[i];	255	r = &cpu->rq[i];
256	spinlock_lock(&r->lock);	256	spinlock_lock(&r->lock);
257	list_append(&t->rq_link, &r->rq_head);	257	list_append(&t->rq_link, &r->rq_head);
258	r->n++;	258	r->n++;
259	spinlock_unlock(&r->lock);	259	spinlock_unlock(&r->lock);
260		260
261	atomic_inc(&nrdy);	261	atomic_inc(&nrdy);
262	avg = atomic_get(&nrdy) / config.cpu_active;	262	avg = atomic_get(&nrdy) / config.cpu_active;
263	atomic_inc(&cpu->nrdy);	263	atomic_inc(&cpu->nrdy);
264		264
265	interrupts_restore(ipl);	265	interrupts_restore(ipl);
266	}	266	}
267		267
268	/** Create new thread	268	/** Create new thread
269	*	269	*
270	* Create a new thread.	270	* Create a new thread.
271	*	271	*
272	* @param func Thread's implementing function.	272	* @param func Thread's implementing function.
273	* @param arg Thread's implementing function argument.	273	* @param arg Thread's implementing function argument.
274	* @param task Task to which the thread belongs. The caller must	274	* @param task Task to which the thread belongs. The caller must
275	* guarantee that the task won't cease to exist during the	275	* guarantee that the task won't cease to exist during the
276	* call. The task's lock may not be held.	276	* call. The task's lock may not be held.
277	* @param flags Thread flags.	277	* @param flags Thread flags.
278	* @param name Symbolic name.	278	* @param name Symbolic name.
279	* @param uncounted Thread's accounting doesn't affect accumulated task	279	* @param uncounted Thread's accounting doesn't affect accumulated task
280	* accounting.	280	* accounting.
281	*	281	*
282	* @return New thread's structure on success, NULL on failure.	282	* @return New thread's structure on success, NULL on failure.
283	*	283	*
284	*/	284	*/
285	thread_t thread_create(void ( func)(void ), void arg, task_t *task,	285	thread_t thread_create(void ( func)(void ), void arg, task_t *task,
286	int flags, char *name, bool uncounted)	286	int flags, char *name, bool uncounted)
287	{	287	{
288	thread_t *t;	288	thread_t *t;
289	ipl_t ipl;	289	ipl_t ipl;
290		290
291	t = (thread_t *) slab_alloc(thread_slab, 0);	291	t = (thread_t *) slab_alloc(thread_slab, 0);
292	if (!t)	292	if (!t)
293	return NULL;	293	return NULL;
294		294
295	/* Not needed, but good for debugging */	295	/* Not needed, but good for debugging */
296	memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES,	296	memsetb(t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES, 0);
297	0);	-
298		297
299	ipl = interrupts_disable();	298	ipl = interrupts_disable();
300	spinlock_lock(&tidlock);	299	spinlock_lock(&tidlock);
301	t->tid = ++last_tid;	300	t->tid = ++last_tid;
302	spinlock_unlock(&tidlock);	301	spinlock_unlock(&tidlock);
303	interrupts_restore(ipl);	302	interrupts_restore(ipl);
304		303
305	context_save(&t->saved_context);	304	context_save(&t->saved_context);
306	context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,	305	context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,
307	THREAD_STACK_SIZE);	306	THREAD_STACK_SIZE);
308		307
309	the_initialize((the_t *) t->kstack);	308	the_initialize((the_t *) t->kstack);
310		309
311	ipl = interrupts_disable();	310	ipl = interrupts_disable();
312	t->saved_context.ipl = interrupts_read();	311	t->saved_context.ipl = interrupts_read();
313	interrupts_restore(ipl);	312	interrupts_restore(ipl);
314		313
315	memcpy(t->name, name, THREAD_NAME_BUFLEN);	314	memcpy(t->name, name, THREAD_NAME_BUFLEN);
316		315
317	t->thread_code = func;	316	t->thread_code = func;
318	t->thread_arg = arg;	317	t->thread_arg = arg;
319	t->ticks = -1;	318	t->ticks = -1;
320	t->cycles = 0;	319	t->cycles = 0;
321	t->uncounted = uncounted;	320	t->uncounted = uncounted;
322	t->priority = -1; /* start in rq[0] */	321	t->priority = -1; /* start in rq[0] */
323	t->cpu = NULL;	322	t->cpu = NULL;
324	t->flags = flags;	323	t->flags = flags;
325	t->state = Entering;	324	t->state = Entering;
326	t->call_me = NULL;	325	t->call_me = NULL;
327	t->call_me_with = NULL;	326	t->call_me_with = NULL;
328		327
329	timeout_initialize(&t->sleep_timeout);	328	timeout_initialize(&t->sleep_timeout);
330	t->sleep_interruptible = false;	329	t->sleep_interruptible = false;
331	t->sleep_queue = NULL;	330	t->sleep_queue = NULL;
332	t->timeout_pending = 0;	331	t->timeout_pending = 0;
333		332
334	t->in_copy_from_uspace = false;	333	t->in_copy_from_uspace = false;
335	t->in_copy_to_uspace = false;	334	t->in_copy_to_uspace = false;
336		335
337	t->interrupted = false;	336	t->interrupted = false;
338	t->detached = false;	337	t->detached = false;
339	waitq_initialize(&t->join_wq);	338	waitq_initialize(&t->join_wq);
340		339
341	t->rwlock_holder_type = RWLOCK_NONE;	340	t->rwlock_holder_type = RWLOCK_NONE;
342		341
343	t->task = task;	342	t->task = task;
344		343
345	t->fpu_context_exists = 0;	344	t->fpu_context_exists = 0;
346	t->fpu_context_engaged = 0;	345	t->fpu_context_engaged = 0;
347		346
348	avltree_node_initialize(&t->threads_tree_node);	347	avltree_node_initialize(&t->threads_tree_node);
349	t->threads_tree_node.key = (uintptr_t) t;	348	t->threads_tree_node.key = (uintptr_t) t;
350		349
351	/* might depend on previous initialization */	350	/* might depend on previous initialization */
352	thread_create_arch(t);	351	thread_create_arch(t);
353		352
354	if (!(flags & THREAD_FLAG_NOATTACH))	353	if (!(flags & THREAD_FLAG_NOATTACH))
355	thread_attach(t, task);	354	thread_attach(t, task);
356		355
357	return t;	356	return t;
358	}	357	}
359		358
360	/** Destroy thread memory structure	359	/** Destroy thread memory structure
361	*	360	*
362	* Detach thread from all queues, cpus etc. and destroy it.	361	* Detach thread from all queues, cpus etc. and destroy it.
363	*	362	*
364	* Assume thread->lock is held!!	363	* Assume thread->lock is held!!
365	*/	364	*/
366	void thread_destroy(thread_t *t)	365	void thread_destroy(thread_t *t)
367	{	366	{
368	ASSERT(t->state == Exiting \|\| t->state == Lingering);	367	ASSERT(t->state == Exiting \|\| t->state == Lingering);
369	ASSERT(t->task);	368	ASSERT(t->task);
370	ASSERT(t->cpu);	369	ASSERT(t->cpu);
371		370
372	spinlock_lock(&t->cpu->lock);	371	spinlock_lock(&t->cpu->lock);
373	if (t->cpu->fpu_owner == t)	372	if (t->cpu->fpu_owner == t)
374	t->cpu->fpu_owner = NULL;	373	t->cpu->fpu_owner = NULL;
375	spinlock_unlock(&t->cpu->lock);	374	spinlock_unlock(&t->cpu->lock);
376		375
377	spinlock_unlock(&t->lock);	376	spinlock_unlock(&t->lock);
378		377
379	spinlock_lock(&threads_lock);	378	spinlock_lock(&threads_lock);
380	avltree_delete(&threads_tree, &t->threads_tree_node);	379	avltree_delete(&threads_tree, &t->threads_tree_node);
381	spinlock_unlock(&threads_lock);	380	spinlock_unlock(&threads_lock);
382		381
383	/*	382	/*
384	* Detach from the containing task.	383	* Detach from the containing task.
385	*/	384	*/
386	spinlock_lock(&t->task->lock);	385	spinlock_lock(&t->task->lock);
387	list_remove(&t->th_link);	386	list_remove(&t->th_link);
388	spinlock_unlock(&t->task->lock);	387	spinlock_unlock(&t->task->lock);
389		388
390	/*	389	/*
391	* t is guaranteed to be the very last thread of its task.	390	* t is guaranteed to be the very last thread of its task.
392	* It is safe to destroy the task.	391	* It is safe to destroy the task.
393	*/	392	*/
394	if (atomic_predec(&t->task->refcount) == 0)	393	if (atomic_predec(&t->task->refcount) == 0)
395	task_destroy(t->task);	394	task_destroy(t->task);
396		395
397	slab_free(thread_slab, t);	396	slab_free(thread_slab, t);
398	}	397	}
399		398
400	/** Make the thread visible to the system.	399	/** Make the thread visible to the system.
401	*	400	*
402	* Attach the thread structure to the current task and make it visible in the	401	* Attach the thread structure to the current task and make it visible in the
403	* threads_tree.	402	* threads_tree.
404	*	403	*
405	* @param t Thread to be attached to the task.	404	* @param t Thread to be attached to the task.
406	* @param task Task to which the thread is to be attached.	405	* @param task Task to which the thread is to be attached.
407	*/	406	*/
408	void thread_attach(thread_t t, task_t task)	407	void thread_attach(thread_t t, task_t task)
409	{	408	{
410	ipl_t ipl;	409	ipl_t ipl;
411		410
412	/*	411	/*
413	* Attach to the current task.	412	* Attach to the current task.
414	*/	413	*/
415	ipl = interrupts_disable();	414	ipl = interrupts_disable();
416	spinlock_lock(&task->lock);	415	spinlock_lock(&task->lock);
417	atomic_inc(&task->refcount);	416	atomic_inc(&task->refcount);
418	atomic_inc(&task->lifecount);	417	atomic_inc(&task->lifecount);
419	list_append(&t->th_link, &task->th_head);	418	list_append(&t->th_link, &task->th_head);
420	spinlock_unlock(&task->lock);	419	spinlock_unlock(&task->lock);
421		420
422	/*	421	/*
423	* Register this thread in the system-wide list.	422	* Register this thread in the system-wide list.
424	*/	423	*/
425	spinlock_lock(&threads_lock);	424	spinlock_lock(&threads_lock);
426	avltree_insert(&threads_tree, &t->threads_tree_node);	425	avltree_insert(&threads_tree, &t->threads_tree_node);
427	spinlock_unlock(&threads_lock);	426	spinlock_unlock(&threads_lock);
428		427
429	interrupts_restore(ipl);	428	interrupts_restore(ipl);
430	}	429	}
431		430
432	/** Terminate thread.	431	/** Terminate thread.
433	*	432	*
434	* End current thread execution and switch it to the exiting state. All pending	433	* End current thread execution and switch it to the exiting state. All pending
435	* timeouts are executed.	434	* timeouts are executed.
436	*/	435	*/
437	void thread_exit(void)	436	void thread_exit(void)
438	{	437	{
439	ipl_t ipl;	438	ipl_t ipl;
440		439
441	if (atomic_predec(&TASK->lifecount) == 0) {	440	if (atomic_predec(&TASK->lifecount) == 0) {
442	/*	441	/*
443	* We are the last thread in the task that still has not exited.	442	* We are the last thread in the task that still has not exited.
444	* With the exception of the moment the task was created, new	443	* With the exception of the moment the task was created, new
445	* threads can only be created by threads of the same task.	444	* threads can only be created by threads of the same task.
446	* We are safe to perform cleanup.	445	* We are safe to perform cleanup.
447	*/	446	*/
448	if (THREAD->flags & THREAD_FLAG_USPACE) {	447	if (THREAD->flags & THREAD_FLAG_USPACE) {
449	ipc_cleanup();	448	ipc_cleanup();
450	futex_cleanup();	449	futex_cleanup();
451	LOG("Cleanup of task %" PRIu64" completed.", TASK->taskid);	450	LOG("Cleanup of task %" PRIu64" completed.", TASK->taskid);
452	}	451	}
453	}	452	}
454		453
455	restart:	454	restart:
456	ipl = interrupts_disable();	455	ipl = interrupts_disable();
457	spinlock_lock(&THREAD->lock);	456	spinlock_lock(&THREAD->lock);
458	if (THREAD->timeout_pending) {	457	if (THREAD->timeout_pending) {
459	/* busy waiting for timeouts in progress */	458	/* busy waiting for timeouts in progress */
460	spinlock_unlock(&THREAD->lock);	459	spinlock_unlock(&THREAD->lock);
461	interrupts_restore(ipl);	460	interrupts_restore(ipl);
462	goto restart;	461	goto restart;
463	}	462	}
464		463
465	THREAD->state = Exiting;	464	THREAD->state = Exiting;
466	spinlock_unlock(&THREAD->lock);	465	spinlock_unlock(&THREAD->lock);
467	scheduler();	466	scheduler();
468		467
469	/* Not reached */	468	/* Not reached */
470	while (1)	469	while (1)
471	;	470	;
472	}	471	}
473		472
474		473
475	/** Thread sleep	474	/** Thread sleep
476	*	475	*
477	* Suspend execution of the current thread.	476	* Suspend execution of the current thread.
478	*	477	*
479	* @param sec Number of seconds to sleep.	478	* @param sec Number of seconds to sleep.
480	*	479	*
481	*/	480	*/
482	void thread_sleep(uint32_t sec)	481	void thread_sleep(uint32_t sec)
483	{	482	{
484	thread_usleep(sec * 1000000);	483	thread_usleep(sec * 1000000);
485	}	484	}
486		485
487	/** Wait for another thread to exit.	486	/** Wait for another thread to exit.
488	*	487	*
489	* @param t Thread to join on exit.	488	* @param t Thread to join on exit.
490	* @param usec Timeout in microseconds.	489	* @param usec Timeout in microseconds.
491	* @param flags Mode of operation.	490	* @param flags Mode of operation.
492	*	491	*
493	* @return An error code from errno.h or an error code from synch.h.	492	* @return An error code from errno.h or an error code from synch.h.
494	*/	493	*/
495	int thread_join_timeout(thread_t *t, uint32_t usec, int flags)	494	int thread_join_timeout(thread_t *t, uint32_t usec, int flags)
496	{	495	{
497	ipl_t ipl;	496	ipl_t ipl;
498	int rc;	497	int rc;
499		498
500	if (t == THREAD)	499	if (t == THREAD)

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/proc/thread.c – Rev 3063 → 3104