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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.     t->cur_event = 0;   /* none */
  354.  
  355.     /* might depend on previous initialization */
  356.     thread_create_arch(t); 
  357.  
  358.     if (!(flags & THREAD_FLAG_NOATTACH))
  359.         thread_attach(t, task);
  360.  
  361.     return t;
  362. }
  363.  
  364. /** Destroy thread structure of an unattached thread.
  365.  *
  366.  * Thread t must only have been created and never attached.
  367.  */
  368. void thread_unattached_free(thread_t *t)
  369. {
  370.     slab_free(thread_slab, t);
  371. }
  372.  
  373.  
  374. /** Destroy thread memory structure
  375.  *
  376.  * Detach thread from all queues, cpus etc. and destroy it.
  377.  *
  378.  * Assume thread->lock is held!!
  379.  */
  380. void thread_destroy(thread_t *t)
  381. {
  382.     ASSERT(t->state == Exiting || t->state == Lingering);
  383.     ASSERT(t->task);
  384.     ASSERT(t->cpu);
  385.  
  386.     spinlock_lock(&t->cpu->lock);
  387.     if (t->cpu->fpu_owner == t)
  388.         t->cpu->fpu_owner = NULL;
  389.     spinlock_unlock(&t->cpu->lock);
  390.  
  391.     spinlock_unlock(&t->lock);
  392.  
  393.     spinlock_lock(&threads_lock);
  394.     avltree_delete(&threads_tree, &t->threads_tree_node);
  395.     spinlock_unlock(&threads_lock);
  396.  
  397.     /*
  398.      * Detach from the containing task.
  399.      */
  400.     spinlock_lock(&t->task->lock);
  401.     list_remove(&t->th_link);
  402.     spinlock_unlock(&t->task->lock);   
  403.  
  404.     /*
  405.      * t is guaranteed to be the very last thread of its task.
  406.      * It is safe to destroy the task.
  407.      */
  408.     if (atomic_predec(&t->task->refcount) == 0)
  409.         task_destroy(t->task);
  410.    
  411.     slab_free(thread_slab, t);
  412. }
  413.  
  414. /** Attach thread to the given task.
  415.  *
  416.  * The task's lock must already be held and interrupts must be disabled.
  417.  *
  418.  * @param t Thread to be attached to the task.
  419.  * @param task  Task to which the thread is to be attached.
  420.  */
  421. static void _thread_attach_task(thread_t *t, task_t *task)
  422. {
  423.     atomic_inc(&task->refcount);
  424.     atomic_inc(&task->lifecount);
  425.  
  426.     list_append(&t->th_link, &task->th_head);
  427.  
  428.     /*
  429.      * Copy task debugging state to thread struct.
  430.      * The thread needs to know it is being debugged,
  431.      * otherwise it would neither stop nor respond to
  432.      * debug ops.
  433.      */
  434.     if (t->flags & THREAD_FLAG_USPACE) {
  435.         if (task->dt_state == UDEBUG_TS_BEGINNING ||
  436.             task->dt_state == UDEBUG_TS_ACTIVE) {
  437.             t->debug_active = true;
  438.         }
  439.     }
  440. }
  441.  
  442. /** Add thread to the threads tree.
  443.  *
  444.  * Interrupts must be already disabled.
  445.  *
  446.  * @param t Thread to be attached to the task.
  447.  * @param task  Task to which the thread is to be attached.
  448.  */
  449. static void _thread_attach_tree(thread_t *t)
  450. {
  451.     /*
  452.      * Register this thread in the system-wide list.
  453.      */
  454.     spinlock_lock(&threads_lock);
  455.     avltree_insert(&threads_tree, &t->threads_tree_node);
  456.     spinlock_unlock(&threads_lock);
  457. }
  458.  
  459.  
  460. /** Make the thread visible to the system.
  461.  *
  462.  * Attach the thread structure to the current task and make it visible in the
  463.  * threads_tree.
  464.  *
  465.  * @param t Thread to be attached to the task.
  466.  * @param task  Task to which the thread is to be attached.
  467.  */
  468. void thread_attach(thread_t *t, task_t *task)
  469. {
  470.     ipl_t ipl;
  471.  
  472.     ipl = interrupts_disable();
  473.  
  474.     /*
  475.      * Attach to the current task.
  476.      */
  477.     spinlock_lock(&task->lock);
  478.     _thread_attach_task(t, task);
  479.     spinlock_unlock(&task->lock);
  480.  
  481.     /*
  482.      * Register this thread in the system-wide list.
  483.      */
  484.     _thread_attach_tree(t);
  485.    
  486.     interrupts_restore(ipl);
  487. }
  488.  
  489. /** Attach thread to a task given by its ID.
  490.  *
  491.  * Unlike thread_attach(), this function allows to attach a thread
  492.  * to an arbitrary task.
  493.  *
  494.  * @param t     Thread to be attached to the task.
  495.  * @param taskid    Task id to which the thread is to be attached.
  496.  * @return      An error code from errno.h
  497.  */
  498. int thread_attach_by_id(thread_t *t, task_id_t taskid)
  499. {
  500.     ipl_t ipl;
  501.     task_t *task;
  502.  
  503.     ipl = interrupts_disable();
  504.  
  505.     spinlock_lock(&tasks_lock);
  506.     task = task_find_by_id(taskid);
  507.     if (task == NULL) {
  508.         spinlock_unlock(&tasks_lock);
  509.         interrupts_restore(ipl);
  510.         return ENOENT;
  511.     }
  512.  
  513.     spinlock_lock(&task->lock);
  514.     spinlock_unlock(&tasks_lock);
  515.  
  516.     /*
  517.      * Attach to the current task.
  518.      */
  519.     _thread_attach_task(t, task);
  520.  
  521.     spinlock_unlock(&task->lock);
  522.  
  523.     /*
  524.      * Register this thread in the system-wide list.
  525.      */
  526.     _thread_attach_tree(t);
  527.    
  528.     interrupts_restore(ipl);
  529.  
  530.     return EOK;
  531. }
  532.  
  533.  
  534. /** Terminate thread.
  535.  *
  536.  * End current thread execution and switch it to the exiting state. All pending
  537.  * timeouts are executed.
  538.  */
  539. void thread_exit(void)
  540. {
  541.     ipl_t ipl;
  542.  
  543.     if (atomic_predec(&TASK->lifecount) == 0) {
  544.         /*
  545.          * We are the last thread in the task that still has not exited.
  546.          * With the exception of the moment the task was created, new
  547.          * threads can only be created by threads of the same task.
  548.          * We are safe to perform cleanup.
  549.          */
  550.         if (THREAD->flags & THREAD_FLAG_USPACE) {
  551.             ipc_cleanup();
  552.                 futex_cleanup();
  553.             klog_printf("Cleanup of task %llu completed.",
  554.                 TASK->taskid);
  555.         }
  556.     }
  557.  
  558. restart:
  559.     ipl = interrupts_disable();
  560.     spinlock_lock(&THREAD->lock);
  561.     if (THREAD->timeout_pending) {
  562.         /* busy waiting for timeouts in progress */
  563.         spinlock_unlock(&THREAD->lock);
  564.         interrupts_restore(ipl);
  565.         goto restart;
  566.     }
  567.    
  568.     THREAD->state = Exiting;
  569.     spinlock_unlock(&THREAD->lock);
  570.     scheduler();
  571.  
  572.     /* Not reached */
  573.     while (1)
  574.         ;
  575. }
  576.  
  577.  
  578. /** Thread sleep
  579.  *
  580.  * Suspend execution of the current thread.
  581.  *
  582.  * @param sec Number of seconds to sleep.
  583.  *
  584.  */
  585. void thread_sleep(uint32_t sec)
  586. {
  587.     thread_usleep(sec * 1000000);
  588. }
  589.  
  590. /** Wait for another thread to exit.
  591.  *
  592.  * @param t Thread to join on exit.
  593.  * @param usec Timeout in microseconds.
  594.  * @param flags Mode of operation.
  595.  *
  596.  * @return An error code from errno.h or an error code from synch.h.
  597.  */
  598. int thread_join_timeout(thread_t *t, uint32_t usec, int flags)
  599. {
  600.     ipl_t ipl;
  601.     int rc;
  602.  
  603.     if (t == THREAD)
  604.         return EINVAL;
  605.  
  606.     /*
  607.      * Since thread join can only be called once on an undetached thread,
  608.      * the thread pointer is guaranteed to be still valid.
  609.      */
  610.    
  611.     ipl = interrupts_disable();
  612.     spinlock_lock(&t->lock);
  613.     ASSERT(!t->detached);
  614.     spinlock_unlock(&t->lock);
  615.     interrupts_restore(ipl);
  616.    
  617.     rc = waitq_sleep_timeout(&t->join_wq, usec, flags);
  618.    
  619.     return rc; 
  620. }
  621.  
  622. /** Detach thread.
  623.  *
  624.  * Mark the thread as detached, if the thread is already in the Lingering
  625.  * state, deallocate its resources.
  626.  *
  627.  * @param t Thread to be detached.
  628.  */
  629. void thread_detach(thread_t *t)
  630. {
  631.     ipl_t ipl;
  632.  
  633.     /*
  634.      * Since the thread is expected not to be already detached,
  635.      * pointer to it must be still valid.
  636.      */
  637.     ipl = interrupts_disable();
  638.     spinlock_lock(&t->lock);
  639.     ASSERT(!t->detached);
  640.     if (t->state == Lingering) {
  641.         thread_destroy(t);  /* unlocks &t->lock */
  642.         interrupts_restore(ipl);
  643.         return;
  644.     } else {
  645.         t->detached = true;
  646.     }
  647.     spinlock_unlock(&t->lock);
  648.     interrupts_restore(ipl);
  649. }
  650.  
  651. /** Thread usleep
  652.  *
  653.  * Suspend execution of the current thread.
  654.  *
  655.  * @param usec Number of microseconds to sleep.
  656.  *
  657.  */
  658. void thread_usleep(uint32_t usec)
  659. {
  660.     waitq_t wq;
  661.                  
  662.     waitq_initialize(&wq);
  663.  
  664.     (void) waitq_sleep_timeout(&wq, usec, SYNCH_FLAGS_NON_BLOCKING);
  665. }
  666.  
  667. /** Register thread out-of-context invocation
  668.  *
  669.  * Register a function and its argument to be executed
  670.  * on next context switch to the current thread.
  671.  *
  672.  * @param call_me      Out-of-context function.
  673.  * @param call_me_with Out-of-context function argument.
  674.  *
  675.  */
  676. void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
  677. {
  678.     ipl_t ipl;
  679.    
  680.     ipl = interrupts_disable();
  681.     spinlock_lock(&THREAD->lock);
  682.     THREAD->call_me = call_me;
  683.     THREAD->call_me_with = call_me_with;
  684.     spinlock_unlock(&THREAD->lock);
  685.     interrupts_restore(ipl);
  686. }
  687.  
  688. static bool thread_walker(avltree_node_t *node, void *arg)
  689. {
  690.     thread_t *t;
  691.        
  692.     t = avltree_get_instance(node, thread_t, threads_tree_node);
  693.  
  694.     uint64_t cycles;
  695.     char suffix;
  696.     order(t->cycles, &cycles, &suffix);
  697.    
  698.     if (sizeof(void *) == 4)
  699.         printf("%-6llu %-10s %#10zx %-8s %#10zx %-3ld %#10zx %#10zx %9llu%c ",
  700.             t->tid, t->name, t, thread_states[t->state], t->task,
  701.             t->task->context, t->thread_code, t->kstack, cycles, suffix);
  702.     else
  703.         printf("%-6llu %-10s %#18zx %-8s %#18zx %-3ld %#18zx %#18zx %9llu%c ",
  704.             t->tid, t->name, t, thread_states[t->state], t->task,
  705.             t->task->context, t->thread_code, t->kstack, cycles, suffix);
  706.            
  707.     if (t->cpu)
  708.         printf("%-4zd", t->cpu->id);
  709.     else
  710.         printf("none");
  711.            
  712.     if (t->state == Sleeping) {
  713.         if (sizeof(uintptr_t) == 4)
  714.             printf(" %#10zx", t->sleep_queue);
  715.         else
  716.             printf(" %#18zx", t->sleep_queue);
  717.     }
  718.            
  719.     printf("\n");
  720.  
  721.     return true;
  722. }
  723.  
  724. /** Print list of threads debug info */
  725. void thread_print_list(void)
  726. {
  727.     ipl_t ipl;
  728.    
  729.     /* Messing with thread structures, avoid deadlock */
  730.     ipl = interrupts_disable();
  731.     spinlock_lock(&threads_lock);
  732.    
  733.     if (sizeof(uintptr_t) == 4) {
  734.         printf("tid    name       address    state    task       "
  735.             "ctx code       stack      cycles     cpu  "
  736.             "waitqueue\n");
  737.         printf("------ ---------- ---------- -------- ---------- "
  738.             "--- ---------- ---------- ---------- ---- "
  739.             "----------\n");
  740.     } else {
  741.         printf("tid    name       address            state    task               "
  742.             "ctx code               stack              cycles     cpu  "
  743.             "waitqueue\n");
  744.         printf("------ ---------- ------------------ -------- ------------------ "
  745.             "--- ------------------ ------------------ ---------- ---- "
  746.             "------------------\n");
  747.     }
  748.  
  749.     avltree_walk(&threads_tree, thread_walker, NULL);
  750.  
  751.     spinlock_unlock(&threads_lock);
  752.     interrupts_restore(ipl);
  753. }
  754.  
  755. /** Check whether thread exists.
  756.  *
  757.  * Note that threads_lock must be already held and
  758.  * interrupts must be already disabled.
  759.  *
  760.  * @param t Pointer to thread.
  761.  *
  762.  * @return True if thread t is known to the system, false otherwise.
  763.  */
  764. bool thread_exists(thread_t *t)
  765. {
  766.     avltree_node_t *node;
  767.  
  768.     node = avltree_search(&threads_tree, (avltree_key_t) ((uintptr_t) t));
  769.    
  770.     return node != NULL;
  771. }
  772.  
  773.  
  774. /** Update accounting of current thread.
  775.  *
  776.  * Note that thread_lock on THREAD must be already held and
  777.  * interrupts must be already disabled.
  778.  *
  779.  */
  780. void thread_update_accounting(void)
  781. {
  782.     uint64_t time = get_cycle();
  783.     THREAD->cycles += time - THREAD->last_cycle;
  784.     THREAD->last_cycle = time;
  785. }
  786.  
  787. /** Process syscall to create new thread.
  788.  *
  789.  */
  790. unative_t sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name,
  791.     thread_id_t *uspace_thread_id)
  792. {
  793.     thread_t *t;
  794.     char namebuf[THREAD_NAME_BUFLEN];
  795.     uspace_arg_t *kernel_uarg;
  796.     int rc;
  797.  
  798.     rc = copy_from_uspace(namebuf, uspace_name, THREAD_NAME_BUFLEN);
  799.     if (rc != 0)
  800.         return (unative_t) rc;
  801.  
  802.     /*
  803.      * In case of failure, kernel_uarg will be deallocated in this function.
  804.      * In case of success, kernel_uarg will be freed in uinit().
  805.      */
  806.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  807.    
  808.     rc = copy_from_uspace(kernel_uarg, uspace_uarg, sizeof(uspace_arg_t));
  809.     if (rc != 0) {
  810.         free(kernel_uarg);
  811.         return (unative_t) rc;
  812.     }
  813.  
  814.     t = thread_create(uinit, kernel_uarg, TASK,
  815.         THREAD_FLAG_USPACE | THREAD_FLAG_NOATTACH, namebuf, false);
  816.     if (t) {
  817.         if (uspace_thread_id != NULL) {
  818.             int rc;
  819.  
  820.             rc = copy_to_uspace(uspace_thread_id, &t->tid,
  821.                 sizeof(t->tid));
  822.             if (rc != 0) {
  823.                 /*
  824.                  * We have encountered a failure, but the thread
  825.                  * has already been created. We need to undo its
  826.                  * creation now.
  827.                  */
  828.  
  829.                 /*
  830.                  * The new thread structure is initialized, but
  831.                  * is still not visible to the system.
  832.                  * We can safely deallocate it.
  833.                  */
  834.                 slab_free(thread_slab, t);
  835.                 free(kernel_uarg);
  836.  
  837.                 return (unative_t) rc;
  838.              }
  839.         }
  840.         thread_attach(t, TASK);
  841.         thread_ready(t);
  842.  
  843.         udebug_new_thread_event(t);
  844.  
  845.         return 0;
  846.     } else
  847.         free(kernel_uarg);
  848.  
  849.     return (unative_t) ENOMEM;
  850. }
  851.  
  852. /** Process syscall to terminate thread.
  853.  *
  854.  */
  855. unative_t sys_thread_exit(int uspace_status)
  856. {
  857.     thread_exit();
  858.     /* Unreachable */
  859.     return 0;
  860. }
  861.  
  862. /** Syscall for getting TID.
  863.  *
  864.  * @param uspace_thread_id Userspace address of 8-byte buffer where to store
  865.  * current thread ID.
  866.  *
  867.  * @return 0 on success or an error code from @ref errno.h.
  868.  */
  869. unative_t sys_thread_get_id(thread_id_t *uspace_thread_id)
  870. {
  871.     /*
  872.      * No need to acquire lock on THREAD because tid
  873.      * remains constant for the lifespan of the thread.
  874.      */
  875.     return (unative_t) copy_to_uspace(uspace_thread_id, &THREAD->tid,
  876.         sizeof(THREAD->tid));
  877. }
  878.  
  879. /** @}
  880.  */
  881.