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  1. /*
  2.  * Copyright (c) 2001-2004 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  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
  15.  *   derived from this software without specific prior written permission.
  16.  *
  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
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  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
  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
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genericproc
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Thread management functions.
  36.  */
  37.  
  38. #include <proc/scheduler.h>
  39. #include <proc/thread.h>
  40. #include <proc/task.h>
  41. #include <proc/uarg.h>
  42. #include <mm/frame.h>
  43. #include <mm/page.h>
  44. #include <arch/asm.h>
  45. #include <arch/cycle.h>
  46. #include <arch.h>
  47. #include <synch/synch.h>
  48. #include <synch/spinlock.h>
  49. #include <synch/waitq.h>
  50. #include <synch/rwlock.h>
  51. #include <cpu.h>
  52. #include <func.h>
  53. #include <context.h>
  54. #include <adt/avl.h>
  55. #include <adt/list.h>
  56. #include <time/clock.h>
  57. #include <time/timeout.h>
  58. #include <config.h>
  59. #include <arch/interrupt.h>
  60. #include <smp/ipi.h>
  61. #include <arch/faddr.h>
  62. #include <atomic.h>
  63. #include <memstr.h>
  64. #include <print.h>
  65. #include <mm/slab.h>
  66. #include <debug.h>
  67. #include <main/uinit.h>
  68. #include <syscall/copy.h>
  69. #include <errno.h>
  70. #include <console/klog.h>
  71.  
  72.  
  73. /** Thread states */
  74. char *thread_states[] = {
  75.     "Invalid",
  76.     "Running",
  77.     "Sleeping",
  78.     "Ready",
  79.     "Entering",
  80.     "Exiting",
  81.     "Lingering"
  82. };
  83.  
  84. /** Lock protecting the threads_tree AVL tree.
  85.  *
  86.  * For locking rules, see declaration thereof.
  87.  */
  88. SPINLOCK_INITIALIZE(threads_lock);
  89.  
  90. /** ALV tree of all threads.
  91.  *
  92.  * When a thread is found in the threads_tree AVL tree, it is guaranteed to
  93.  * exist as long as the threads_lock is held.
  94.  */
  95. avltree_t threads_tree;    
  96.  
  97. SPINLOCK_INITIALIZE(tidlock);
  98. thread_id_t last_tid = 0;
  99.  
  100. static slab_cache_t *thread_slab;
  101. #ifdef ARCH_HAS_FPU
  102. slab_cache_t *fpu_context_slab;
  103. #endif
  104.  
  105. /** Thread wrapper.
  106.  *
  107.  * This wrapper is provided to ensure that every thread makes a call to
  108.  * thread_exit() when its implementing function returns.
  109.  *
  110.  * interrupts_disable() is assumed.
  111.  *
  112.  */
  113. static void cushion(void)
  114. {
  115.     void (*f)(void *) = THREAD->thread_code;
  116.     void *arg = THREAD->thread_arg;
  117.     THREAD->last_cycle = get_cycle();
  118.  
  119.     /* This is where each thread wakes up after its creation */
  120.     spinlock_unlock(&THREAD->lock);
  121.     interrupts_enable();
  122.  
  123.     f(arg);
  124.    
  125.     /* Accumulate accounting to the task */
  126.     ipl_t ipl = interrupts_disable();
  127.    
  128.     spinlock_lock(&THREAD->lock);
  129.     if (!THREAD->uncounted) {
  130.         thread_update_accounting();
  131.         uint64_t cycles = THREAD->cycles;
  132.         THREAD->cycles = 0;
  133.         spinlock_unlock(&THREAD->lock);
  134.        
  135.         spinlock_lock(&TASK->lock);
  136.         TASK->cycles += cycles;
  137.         spinlock_unlock(&TASK->lock);
  138.     } else
  139.         spinlock_unlock(&THREAD->lock);
  140.    
  141.     interrupts_restore(ipl);
  142.    
  143.     thread_exit();
  144.     /* not reached */
  145. }
  146.  
  147. /** Initialization and allocation for thread_t structure */
  148. static int thr_constructor(void *obj, int kmflags)
  149. {
  150.     thread_t *t = (thread_t *) obj;
  151.  
  152.     spinlock_initialize(&t->lock, "thread_t_lock");
  153.     link_initialize(&t->rq_link);
  154.     link_initialize(&t->wq_link);
  155.     link_initialize(&t->th_link);
  156.  
  157.     /* call the architecture-specific part of the constructor */
  158.     thr_constructor_arch(t);
  159.    
  160. #ifdef ARCH_HAS_FPU
  161. #ifdef CONFIG_FPU_LAZY
  162.     t->saved_fpu_context = NULL;
  163. #else
  164.     t->saved_fpu_context = slab_alloc(fpu_context_slab, kmflags);
  165.     if (!t->saved_fpu_context)
  166.         return -1;
  167. #endif
  168. #endif 
  169.  
  170.     t->kstack = (uint8_t *) frame_alloc(STACK_FRAMES, FRAME_KA | kmflags);
  171.     if (!t->kstack) {
  172. #ifdef ARCH_HAS_FPU
  173.         if (t->saved_fpu_context)
  174.             slab_free(fpu_context_slab, t->saved_fpu_context);
  175. #endif
  176.         return -1;
  177.     }
  178.  
  179.     spinlock_initialize(&t->debug_lock, "thread_debug_lock");
  180.  
  181.     return 0;
  182. }
  183.  
  184. /** Destruction of thread_t object */
  185. static int thr_destructor(void *obj)
  186. {
  187.     thread_t *t = (thread_t *) obj;
  188.  
  189.     /* call the architecture-specific part of the destructor */
  190.     thr_destructor_arch(t);
  191.  
  192.     frame_free(KA2PA(t->kstack));
  193. #ifdef ARCH_HAS_FPU
  194.     if (t->saved_fpu_context)
  195.         slab_free(fpu_context_slab, t->saved_fpu_context);
  196. #endif
  197.     return 1; /* One page freed */
  198. }
  199.  
  200. /** Initialize threads
  201.  *
  202.  * Initialize kernel threads support.
  203.  *
  204.  */
  205. void thread_init(void)
  206. {
  207.     THREAD = NULL;
  208.     atomic_set(&nrdy,0);
  209.     thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,
  210.         thr_constructor, thr_destructor, 0);
  211.  
  212. #ifdef ARCH_HAS_FPU
  213.     fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),
  214.         FPU_CONTEXT_ALIGN, NULL, NULL, 0);
  215. #endif
  216.  
  217.     avltree_create(&threads_tree);
  218. }
  219.  
  220. /** Make thread ready
  221.  *
  222.  * Switch thread t to the ready state.
  223.  *
  224.  * @param t Thread to make ready.
  225.  *
  226.  */
  227. void thread_ready(thread_t *t)
  228. {
  229.     cpu_t *cpu;
  230.     runq_t *r;
  231.     ipl_t ipl;
  232.     int i, avg;
  233.  
  234.     ipl = interrupts_disable();
  235.  
  236.     spinlock_lock(&t->lock);
  237.  
  238.     ASSERT(!(t->state == Ready));
  239.  
  240.     i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;
  241.    
  242.     cpu = CPU;
  243.     if (t->flags & THREAD_FLAG_WIRED) {
  244.         ASSERT(t->cpu != NULL);
  245.         cpu = t->cpu;
  246.     }
  247.     t->state = Ready;
  248.     spinlock_unlock(&t->lock);
  249.    
  250.     /*
  251.      * Append t to respective ready queue on respective processor.
  252.      */
  253.     r = &cpu->rq[i];
  254.     spinlock_lock(&r->lock);
  255.     list_append(&t->rq_link, &r->rq_head);
  256.     r->n++;
  257.     spinlock_unlock(&r->lock);
  258.  
  259.     atomic_inc(&nrdy);
  260.     avg = atomic_get(&nrdy) / config.cpu_active;
  261.     atomic_inc(&cpu->nrdy);
  262.  
  263.     interrupts_restore(ipl);
  264. }
  265.  
  266. /** Create new thread
  267.  *
  268.  * Create a new thread.
  269.  *
  270.  * @param func      Thread's implementing function.
  271.  * @param arg       Thread's implementing function argument.
  272.  * @param task      Task to which the thread belongs.
  273.  * @param flags     Thread flags.
  274.  * @param name      Symbolic name.
  275.  * @param uncounted Thread's accounting doesn't affect accumulated task
  276.  *          accounting.
  277.  *
  278.  * @return New thread's structure on success, NULL on failure.
  279.  *
  280.  */
  281. thread_t *thread_create(void (* func)(void *), void *arg, task_t *task,
  282.     int flags, char *name, bool uncounted)
  283. {
  284.     thread_t *t;
  285.     ipl_t ipl;
  286.    
  287.     t = (thread_t *) slab_alloc(thread_slab, 0);
  288.     if (!t)
  289.         return NULL;
  290.    
  291.     /* Not needed, but good for debugging */
  292.     memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES,
  293.         0);
  294.    
  295.     ipl = interrupts_disable();
  296.     spinlock_lock(&tidlock);
  297.     t->tid = ++last_tid;
  298.     spinlock_unlock(&tidlock);
  299.     interrupts_restore(ipl);
  300.    
  301.     context_save(&t->saved_context);
  302.     context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,
  303.         THREAD_STACK_SIZE);
  304.    
  305.     the_initialize((the_t *) t->kstack);
  306.    
  307.     ipl = interrupts_disable();
  308.     t->saved_context.ipl = interrupts_read();
  309.     interrupts_restore(ipl);
  310.    
  311.     memcpy(t->name, name, THREAD_NAME_BUFLEN);
  312.    
  313.     t->thread_code = func;
  314.     t->thread_arg = arg;
  315.     t->ticks = -1;
  316.     t->cycles = 0;
  317.     t->uncounted = uncounted;
  318.     t->priority = -1;       /* start in rq[0] */
  319.     t->cpu = NULL;
  320.     t->flags = flags;
  321.     t->state = Entering;
  322.     t->call_me = NULL;
  323.     t->call_me_with = NULL;
  324.    
  325.     timeout_initialize(&t->sleep_timeout);
  326.     t->sleep_interruptible = false;
  327.     t->sleep_queue = NULL;
  328.     t->timeout_pending = 0;
  329.  
  330.     t->in_copy_from_uspace = false;
  331.     t->in_copy_to_uspace = false;
  332.  
  333.     t->interrupted = false;
  334.     t->detached = false;
  335.     waitq_initialize(&t->join_wq);
  336.    
  337.     t->rwlock_holder_type = RWLOCK_NONE;
  338.        
  339.     t->task = task;
  340.    
  341.     t->fpu_context_exists = 0;
  342.     t->fpu_context_engaged = 0;
  343.  
  344.     avltree_node_initialize(&t->threads_tree_node);
  345.     t->threads_tree_node.key = (uintptr_t) t;
  346.    
  347.     /* Init debugging stuff */
  348.     waitq_initialize(&t->go_wq);
  349.     t->debug_go_call = NULL;
  350.     t->uspace_state = NULL;
  351.     t->debug_stop = true;
  352.     t->debug_active = false;
  353.  
  354.     /* might depend on previous initialization */
  355.     thread_create_arch(t); 
  356.  
  357.     if (!(flags & THREAD_FLAG_NOATTACH))
  358.         thread_attach(t, task);
  359.  
  360.     return t;
  361. }
  362.  
  363. /** Destroy thread structure of an unattached thread.
  364.  *
  365.  * Thread t must only have been created and never attached.
  366.  */
  367. void thread_unattached_free(thread_t *t)
  368. {
  369.     slab_free(thread_slab, t);
  370. }
  371.  
  372.  
  373. /** Destroy thread memory structure
  374.  *
  375.  * Detach thread from all queues, cpus etc. and destroy it.
  376.  *
  377.  * Assume thread->lock is held!!
  378.  */
  379. void thread_destroy(thread_t *t)
  380. {
  381.     ASSERT(t->state == Exiting || t->state == Lingering);
  382.     ASSERT(t->task);
  383.     ASSERT(t->cpu);
  384.  
  385.     spinlock_lock(&t->cpu->lock);
  386.     if (t->cpu->fpu_owner == t)
  387.         t->cpu->fpu_owner = NULL;
  388.     spinlock_unlock(&t->cpu->lock);
  389.  
  390.     spinlock_unlock(&t->lock);
  391.  
  392.     spinlock_lock(&threads_lock);
  393.     avltree_delete(&threads_tree, &t->threads_tree_node);
  394.     spinlock_unlock(&threads_lock);
  395.  
  396.     /*
  397.      * Detach from the containing task.
  398.      */
  399.     spinlock_lock(&t->task->lock);
  400.     list_remove(&t->th_link);
  401.     spinlock_unlock(&t->task->lock);   
  402.  
  403.     /*
  404.      * t is guaranteed to be the very last thread of its task.
  405.      * It is safe to destroy the task.
  406.      */
  407.     if (atomic_predec(&t->task->refcount) == 0)
  408.         task_destroy(t->task);
  409.    
  410.     slab_free(thread_slab, t);
  411. }
  412.  
  413. /** Attach thread to the given task.
  414.  *
  415.  * The task's lock must already be held and interrupts must be disabled.
  416.  *
  417.  * @param t Thread to be attached to the task.
  418.  * @param task  Task to which the thread is to be attached.
  419.  */
  420. static void _thread_attach_task(thread_t *t, task_t *task)
  421. {
  422.     atomic_inc(&task->refcount);
  423.     atomic_inc(&task->lifecount);
  424.  
  425.     /* FIXME: this must be done very carefully.. an unstoppable
  426.        thread cannot appear just-so, it must be possible to catch it. */
  427.     if (t->flags & THREAD_FLAG_USPACE)
  428.         ++task->not_stoppable_count;
  429.     list_append(&t->th_link, &task->th_head);
  430. }
  431.  
  432. /** Add thread to the threads tree.
  433.  *
  434.  * Interrupts must be already disabled.
  435.  *
  436.  * @param t Thread to be attached to the task.
  437.  * @param task  Task to which the thread is to be attached.
  438.  */
  439. static void _thread_attach_tree(thread_t *t)
  440. {
  441.     /*
  442.      * Register this thread in the system-wide list.
  443.      */
  444.     spinlock_lock(&threads_lock);
  445.     avltree_insert(&threads_tree, &t->threads_tree_node);
  446.     spinlock_unlock(&threads_lock);
  447. }
  448.  
  449.  
  450. /** Make the thread visible to the system.
  451.  *
  452.  * Attach the thread structure to the current task and make it visible in the
  453.  * threads_tree.
  454.  *
  455.  * @param t Thread to be attached to the task.
  456.  * @param task  Task to which the thread is to be attached.
  457.  */
  458. void thread_attach(thread_t *t, task_t *task)
  459. {
  460.     ipl_t ipl;
  461.  
  462.     ipl = interrupts_disable();
  463.  
  464.     /*
  465.      * Attach to the current task.
  466.      */
  467.     spinlock_lock(&task->lock);
  468.     _thread_attach_task(t, task);
  469.     spinlock_unlock(&task->lock);
  470.  
  471.     /*
  472.      * Register this thread in the system-wide list.
  473.      */
  474.     _thread_attach_tree(t);
  475.    
  476.     interrupts_restore(ipl);
  477. }
  478.  
  479. /** Attach thread to a task given by its ID.
  480.  *
  481.  * Unlike thread_attach(), this function allows to attach a thread
  482.  * to an arbitrary task.
  483.  *
  484.  * @param t     Thread to be attached to the task.
  485.  * @param taskid    Task id to which the thread is to be attached.
  486.  * @return      An error code from errno.h
  487.  */
  488. int thread_attach_by_id(thread_t *t, task_id_t taskid)
  489. {
  490.     ipl_t ipl;
  491.     task_t *task;
  492.  
  493.     ipl = interrupts_disable();
  494.  
  495.     spinlock_lock(&tasks_lock);
  496.     task = task_find_by_id(taskid);
  497.     if (task == NULL) {
  498.         spinlock_unlock(&tasks_lock);
  499.         interrupts_restore(ipl);
  500.         return ENOENT;
  501.     }
  502.  
  503.     spinlock_lock(&task->lock);
  504.     spinlock_unlock(&tasks_lock);
  505.  
  506.     /*
  507.      * Attach to the current task.
  508.      */
  509.     _thread_attach_task(t, task);
  510.  
  511.     spinlock_unlock(&task->lock);
  512.  
  513.     /*
  514.      * Register this thread in the system-wide list.
  515.      */
  516.     _thread_attach_tree(t);
  517.    
  518.     interrupts_restore(ipl);
  519.  
  520.     return EOK;
  521. }
  522.  
  523.  
  524. /** Terminate thread.
  525.  *
  526.  * End current thread execution and switch it to the exiting state. All pending
  527.  * timeouts are executed.
  528.  */
  529. void thread_exit(void)
  530. {
  531.     ipl_t ipl;
  532.  
  533.     if (atomic_predec(&TASK->lifecount) == 0) {
  534.         /*
  535.          * We are the last thread in the task that still has not exited.
  536.          * With the exception of the moment the task was created, new
  537.          * threads can only be created by threads of the same task.
  538.          * We are safe to perform cleanup.
  539.          */
  540.         if (THREAD->flags & THREAD_FLAG_USPACE) {
  541.             ipc_cleanup();
  542.                 futex_cleanup();
  543.             klog_printf("Cleanup of task %llu completed.",
  544.                 TASK->taskid);
  545.         }
  546.     }
  547.  
  548. restart:
  549.     ipl = interrupts_disable();
  550.     spinlock_lock(&THREAD->lock);
  551.     if (THREAD->timeout_pending) {
  552.         /* busy waiting for timeouts in progress */
  553.         spinlock_unlock(&THREAD->lock);
  554.         interrupts_restore(ipl);
  555.         goto restart;
  556.     }
  557.    
  558.     THREAD->state = Exiting;
  559.     spinlock_unlock(&THREAD->lock);
  560.     scheduler();
  561.  
  562.     /* Not reached */
  563.     while (1)
  564.         ;
  565. }
  566.  
  567.  
  568. /** Thread sleep
  569.  *
  570.  * Suspend execution of the current thread.
  571.  *
  572.  * @param sec Number of seconds to sleep.
  573.  *
  574.  */
  575. void thread_sleep(uint32_t sec)
  576. {
  577.     thread_usleep(sec * 1000000);
  578. }
  579.  
  580. /** Wait for another thread to exit.
  581.  *
  582.  * @param t Thread to join on exit.
  583.  * @param usec Timeout in microseconds.
  584.  * @param flags Mode of operation.
  585.  *
  586.  * @return An error code from errno.h or an error code from synch.h.
  587.  */
  588. int thread_join_timeout(thread_t *t, uint32_t usec, int flags)
  589. {
  590.     ipl_t ipl;
  591.     int rc;
  592.  
  593.     if (t == THREAD)
  594.         return EINVAL;
  595.  
  596.     /*
  597.      * Since thread join can only be called once on an undetached thread,
  598.      * the thread pointer is guaranteed to be still valid.
  599.      */
  600.    
  601.     ipl = interrupts_disable();
  602.     spinlock_lock(&t->lock);
  603.     ASSERT(!t->detached);
  604.     spinlock_unlock(&t->lock);
  605.     interrupts_restore(ipl);
  606.    
  607.     rc = waitq_sleep_timeout(&t->join_wq, usec, flags);
  608.    
  609.     return rc; 
  610. }
  611.  
  612. /** Detach thread.
  613.  *
  614.  * Mark the thread as detached, if the thread is already in the Lingering
  615.  * state, deallocate its resources.
  616.  *
  617.  * @param t Thread to be detached.
  618.  */
  619. void thread_detach(thread_t *t)
  620. {
  621.     ipl_t ipl;
  622.  
  623.     /*
  624.      * Since the thread is expected not to be already detached,
  625.      * pointer to it must be still valid.
  626.      */
  627.     ipl = interrupts_disable();
  628.     spinlock_lock(&t->lock);
  629.     ASSERT(!t->detached);
  630.     if (t->state == Lingering) {
  631.         thread_destroy(t);  /* unlocks &t->lock */
  632.         interrupts_restore(ipl);
  633.         return;
  634.     } else {
  635.         t->detached = true;
  636.     }
  637.     spinlock_unlock(&t->lock);
  638.     interrupts_restore(ipl);
  639. }
  640.  
  641. /** Thread usleep
  642.  *
  643.  * Suspend execution of the current thread.
  644.  *
  645.  * @param usec Number of microseconds to sleep.
  646.  *
  647.  */
  648. void thread_usleep(uint32_t usec)
  649. {
  650.     waitq_t wq;
  651.                  
  652.     waitq_initialize(&wq);
  653.  
  654.     (void) waitq_sleep_timeout(&wq, usec, SYNCH_FLAGS_NON_BLOCKING);
  655. }
  656.  
  657. /** Register thread out-of-context invocation
  658.  *
  659.  * Register a function and its argument to be executed
  660.  * on next context switch to the current thread.
  661.  *
  662.  * @param call_me      Out-of-context function.
  663.  * @param call_me_with Out-of-context function argument.
  664.  *
  665.  */
  666. void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
  667. {
  668.     ipl_t ipl;
  669.    
  670.     ipl = interrupts_disable();
  671.     spinlock_lock(&THREAD->lock);
  672.     THREAD->call_me = call_me;
  673.     THREAD->call_me_with = call_me_with;
  674.     spinlock_unlock(&THREAD->lock);
  675.     interrupts_restore(ipl);
  676. }
  677.  
  678. static bool thread_walker(avltree_node_t *node, void *arg)
  679. {
  680.     thread_t *t;
  681.        
  682.     t = avltree_get_instance(node, thread_t, threads_tree_node);
  683.  
  684.     uint64_t cycles;
  685.     char suffix;
  686.     order(t->cycles, &cycles, &suffix);
  687.    
  688.     if (sizeof(void *) == 4)
  689.         printf("%-6llu %-10s %#10zx %-8s %#10zx %-3ld %#10zx %#10zx %9llu%c ",
  690.             t->tid, t->name, t, thread_states[t->state], t->task,
  691.             t->task->context, t->thread_code, t->kstack, cycles, suffix);
  692.     else
  693.         printf("%-6llu %-10s %#18zx %-8s %#18zx %-3ld %#18zx %#18zx %9llu%c ",
  694.             t->tid, t->name, t, thread_states[t->state], t->task,
  695.             t->task->context, t->thread_code, t->kstack, cycles, suffix);
  696.            
  697.     if (t->cpu)
  698.         printf("%-4zd", t->cpu->id);
  699.     else
  700.         printf("none");
  701.            
  702.     if (t->state == Sleeping) {
  703.         if (sizeof(uintptr_t) == 4)
  704.             printf(" %#10zx", t->sleep_queue);
  705.         else
  706.             printf(" %#18zx", t->sleep_queue);
  707.     }
  708.            
  709.     printf("\n");
  710.  
  711.     return true;
  712. }
  713.  
  714. /** Print list of threads debug info */
  715. void thread_print_list(void)
  716. {
  717.     ipl_t ipl;
  718.    
  719.     /* Messing with thread structures, avoid deadlock */
  720.     ipl = interrupts_disable();
  721.     spinlock_lock(&threads_lock);
  722.    
  723.     if (sizeof(uintptr_t) == 4) {
  724.         printf("tid    name       address    state    task       "
  725.             "ctx code       stack      cycles     cpu  "
  726.             "waitqueue\n");
  727.         printf("------ ---------- ---------- -------- ---------- "
  728.             "--- ---------- ---------- ---------- ---- "
  729.             "----------\n");
  730.     } else {
  731.         printf("tid    name       address            state    task               "
  732.             "ctx code               stack              cycles     cpu  "
  733.             "waitqueue\n");
  734.         printf("------ ---------- ------------------ -------- ------------------ "
  735.             "--- ------------------ ------------------ ---------- ---- "
  736.             "------------------\n");
  737.     }
  738.  
  739.     avltree_walk(&threads_tree, thread_walker, NULL);
  740.  
  741.     spinlock_unlock(&threads_lock);
  742.     interrupts_restore(ipl);
  743. }
  744.  
  745. /** Check whether thread exists.
  746.  *
  747.  * Note that threads_lock must be already held and
  748.  * interrupts must be already disabled.
  749.  *
  750.  * @param t Pointer to thread.
  751.  *
  752.  * @return True if thread t is known to the system, false otherwise.
  753.  */
  754. bool thread_exists(thread_t *t)
  755. {
  756.     avltree_node_t *node;
  757.  
  758.     node = avltree_search(&threads_tree, (avltree_key_t) ((uintptr_t) t));
  759.    
  760.     return node != NULL;
  761. }
  762.  
  763.  
  764. /** Update accounting of current thread.
  765.  *
  766.  * Note that thread_lock on THREAD must be already held and
  767.  * interrupts must be already disabled.
  768.  *
  769.  */
  770. void thread_update_accounting(void)
  771. {
  772.     uint64_t time = get_cycle();
  773.     THREAD->cycles += time - THREAD->last_cycle;
  774.     THREAD->last_cycle = time;
  775. }
  776.  
  777. /** Process syscall to create new thread.
  778.  *
  779.  */
  780. unative_t sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name,
  781.     thread_id_t *uspace_thread_id)
  782. {
  783.     thread_t *t;
  784.     char namebuf[THREAD_NAME_BUFLEN];
  785.     uspace_arg_t *kernel_uarg;
  786.     int rc;
  787.  
  788.     rc = copy_from_uspace(namebuf, uspace_name, THREAD_NAME_BUFLEN);
  789.     if (rc != 0)
  790.         return (unative_t) rc;
  791.  
  792.     /*
  793.      * In case of failure, kernel_uarg will be deallocated in this function.
  794.      * In case of success, kernel_uarg will be freed in uinit().
  795.      */
  796.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  797.    
  798.     rc = copy_from_uspace(kernel_uarg, uspace_uarg, sizeof(uspace_arg_t));
  799.     if (rc != 0) {
  800.         free(kernel_uarg);
  801.         return (unative_t) rc;
  802.     }
  803.  
  804.     t = thread_create(uinit, kernel_uarg, TASK,
  805.         THREAD_FLAG_USPACE | THREAD_FLAG_NOATTACH, namebuf, false);
  806.     if (t) {
  807.         if (uspace_thread_id != NULL) {
  808.             int rc;
  809.  
  810.             rc = copy_to_uspace(uspace_thread_id, &t->tid,
  811.                 sizeof(t->tid));
  812.             if (rc != 0) {
  813.                 /*
  814.                  * We have encountered a failure, but the thread
  815.                  * has already been created. We need to undo its
  816.                  * creation now.
  817.                  */
  818.  
  819.                 /*
  820.                  * The new thread structure is initialized, but
  821.                  * is still not visible to the system.
  822.                  * We can safely deallocate it.
  823.                  */
  824.                 slab_free(thread_slab, t);
  825.                 free(kernel_uarg);
  826.  
  827.                 return (unative_t) rc;
  828.              }
  829.         }
  830.         thread_attach(t, TASK);
  831.         thread_ready(t);
  832.  
  833.         return 0;
  834.     } else
  835.         free(kernel_uarg);
  836.  
  837.     return (unative_t) ENOMEM;
  838. }
  839.  
  840. /** Process syscall to terminate thread.
  841.  *
  842.  */
  843. unative_t sys_thread_exit(int uspace_status)
  844. {
  845.     thread_exit();
  846.     /* Unreachable */
  847.     return 0;
  848. }
  849.  
  850. /** Syscall for getting TID.
  851.  *
  852.  * @param uspace_thread_id Userspace address of 8-byte buffer where to store
  853.  * current thread ID.
  854.  *
  855.  * @return 0 on success or an error code from @ref errno.h.
  856.  */
  857. unative_t sys_thread_get_id(thread_id_t *uspace_thread_id)
  858. {
  859.     /*
  860.      * No need to acquire lock on THREAD because tid
  861.      * remains constant for the lifespan of the thread.
  862.      */
  863.     return (unative_t) copy_to_uspace(uspace_thread_id, &THREAD->tid,
  864.         sizeof(THREAD->tid));
  865. }
  866.  
  867. /** @}
  868.  */
  869.