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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.     return 0;
  180. }
  181.  
  182. /** Destruction of thread_t object */
  183. static int thr_destructor(void *obj)
  184. {
  185.     thread_t *t = (thread_t *) obj;
  186.  
  187.     /* call the architecture-specific part of the destructor */
  188.     thr_destructor_arch(t);
  189.  
  190.     frame_free(KA2PA(t->kstack));
  191. #ifdef ARCH_HAS_FPU
  192.     if (t->saved_fpu_context)
  193.         slab_free(fpu_context_slab, t->saved_fpu_context);
  194. #endif
  195.     return 1; /* One page freed */
  196. }
  197.  
  198. /** Initialize threads
  199.  *
  200.  * Initialize kernel threads support.
  201.  *
  202.  */
  203. void thread_init(void)
  204. {
  205.     THREAD = NULL;
  206.     atomic_set(&nrdy,0);
  207.     thread_slab = slab_cache_create("thread_slab", sizeof(thread_t), 0,
  208.         thr_constructor, thr_destructor, 0);
  209.  
  210. #ifdef ARCH_HAS_FPU
  211.     fpu_context_slab = slab_cache_create("fpu_slab", sizeof(fpu_context_t),
  212.         FPU_CONTEXT_ALIGN, NULL, NULL, 0);
  213. #endif
  214.  
  215.     avltree_create(&threads_tree);
  216. }
  217.  
  218. /** Make thread ready
  219.  *
  220.  * Switch thread t to the ready state.
  221.  *
  222.  * @param t Thread to make ready.
  223.  *
  224.  */
  225. void thread_ready(thread_t *t)
  226. {
  227.     cpu_t *cpu;
  228.     runq_t *r;
  229.     ipl_t ipl;
  230.     int i, avg;
  231.  
  232.     ipl = interrupts_disable();
  233.  
  234.     spinlock_lock(&t->lock);
  235.  
  236.     ASSERT(!(t->state == Ready));
  237.  
  238.     i = (t->priority < RQ_COUNT - 1) ? ++t->priority : t->priority;
  239.    
  240.     cpu = CPU;
  241.     if (t->flags & THREAD_FLAG_WIRED) {
  242.         ASSERT(t->cpu != NULL);
  243.         cpu = t->cpu;
  244.     }
  245.     t->state = Ready;
  246.     spinlock_unlock(&t->lock);
  247.    
  248.     /*
  249.      * Append t to respective ready queue on respective processor.
  250.      */
  251.     r = &cpu->rq[i];
  252.     spinlock_lock(&r->lock);
  253.     list_append(&t->rq_link, &r->rq_head);
  254.     r->n++;
  255.     spinlock_unlock(&r->lock);
  256.  
  257.     atomic_inc(&nrdy);
  258.     avg = atomic_get(&nrdy) / config.cpu_active;
  259.     atomic_inc(&cpu->nrdy);
  260.  
  261.     interrupts_restore(ipl);
  262. }
  263.  
  264. /** Create new thread
  265.  *
  266.  * Create a new thread.
  267.  *
  268.  * @param func      Thread's implementing function.
  269.  * @param arg       Thread's implementing function argument.
  270.  * @param task      Task to which the thread belongs.
  271.  * @param flags     Thread flags.
  272.  * @param name      Symbolic name.
  273.  * @param uncounted Thread's accounting doesn't affect accumulated task
  274.  *          accounting.
  275.  *
  276.  * @return New thread's structure on success, NULL on failure.
  277.  *
  278.  */
  279. thread_t *thread_create(void (* func)(void *), void *arg, task_t *task,
  280.     int flags, char *name, bool uncounted)
  281. {
  282.     thread_t *t;
  283.     ipl_t ipl;
  284.    
  285.     t = (thread_t *) slab_alloc(thread_slab, 0);
  286.     if (!t)
  287.         return NULL;
  288.    
  289.     /* Not needed, but good for debugging */
  290.     memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES,
  291.         0);
  292.    
  293.     ipl = interrupts_disable();
  294.     spinlock_lock(&tidlock);
  295.     t->tid = ++last_tid;
  296.     spinlock_unlock(&tidlock);
  297.     interrupts_restore(ipl);
  298.    
  299.     context_save(&t->saved_context);
  300.     context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack,
  301.         THREAD_STACK_SIZE);
  302.    
  303.     the_initialize((the_t *) t->kstack);
  304.    
  305.     ipl = interrupts_disable();
  306.     t->saved_context.ipl = interrupts_read();
  307.     interrupts_restore(ipl);
  308.    
  309.     memcpy(t->name, name, THREAD_NAME_BUFLEN);
  310.    
  311.     t->thread_code = func;
  312.     t->thread_arg = arg;
  313.     t->ticks = -1;
  314.     t->cycles = 0;
  315.     t->uncounted = uncounted;
  316.     t->priority = -1;       /* start in rq[0] */
  317.     t->cpu = NULL;
  318.     t->flags = flags;
  319.     t->state = Entering;
  320.     t->call_me = NULL;
  321.     t->call_me_with = NULL;
  322.    
  323.     timeout_initialize(&t->sleep_timeout);
  324.     t->sleep_interruptible = false;
  325.     t->sleep_queue = NULL;
  326.     t->timeout_pending = 0;
  327.  
  328.     t->in_copy_from_uspace = false;
  329.     t->in_copy_to_uspace = false;
  330.  
  331.     t->interrupted = false;
  332.     t->detached = false;
  333.     waitq_initialize(&t->join_wq);
  334.    
  335.     t->rwlock_holder_type = RWLOCK_NONE;
  336.        
  337.     t->task = task;
  338.    
  339.     t->fpu_context_exists = 0;
  340.     t->fpu_context_engaged = 0;
  341.  
  342.     avltree_node_initialize(&t->threads_tree_node);
  343.     t->threads_tree_node.key = (uintptr_t) t;
  344.    
  345.     /* Init debugging stuff */
  346.     waitq_initialize(&t->go_wq);
  347.     t->debug_go_call = NULL;
  348.     t->uspace_state = NULL;
  349.     t->debug_stop = true;
  350.     t->debug_active = false;
  351.  
  352.     /* might depend on previous initialization */
  353.     thread_create_arch(t); 
  354.  
  355.     if (!(flags & THREAD_FLAG_NOATTACH))
  356.         thread_attach(t, task);
  357.  
  358.     return t;
  359. }
  360.  
  361. /** Destroy thread structure of an unattached thread.
  362.  *
  363.  * Thread t must only have been created and never attached.
  364.  */
  365. void thread_unattached_free(thread_t *t)
  366. {
  367.     slab_free(thread_slab, t);
  368. }
  369.  
  370.  
  371. /** Destroy thread memory structure
  372.  *
  373.  * Detach thread from all queues, cpus etc. and destroy it.
  374.  *
  375.  * Assume thread->lock is held!!
  376.  */
  377. void thread_destroy(thread_t *t)
  378. {
  379.     ASSERT(t->state == Exiting || t->state == Lingering);
  380.     ASSERT(t->task);
  381.     ASSERT(t->cpu);
  382.  
  383.     spinlock_lock(&t->cpu->lock);
  384.     if (t->cpu->fpu_owner == t)
  385.         t->cpu->fpu_owner = NULL;
  386.     spinlock_unlock(&t->cpu->lock);
  387.  
  388.     spinlock_unlock(&t->lock);
  389.  
  390.     spinlock_lock(&threads_lock);
  391.     avltree_delete(&threads_tree, &t->threads_tree_node);
  392.     spinlock_unlock(&threads_lock);
  393.  
  394.     /*
  395.      * Detach from the containing task.
  396.      */
  397.     spinlock_lock(&t->task->lock);
  398.     list_remove(&t->th_link);
  399.     spinlock_unlock(&t->task->lock);   
  400.  
  401.     /*
  402.      * t is guaranteed to be the very last thread of its task.
  403.      * It is safe to destroy the task.
  404.      */
  405.     if (atomic_predec(&t->task->refcount) == 0)
  406.         task_destroy(t->task);
  407.    
  408.     slab_free(thread_slab, t);
  409. }
  410.  
  411. /** Attach thread to the given task.
  412.  *
  413.  * The task's lock must already be held and interrupts must be disabled.
  414.  *
  415.  * @param t Thread to be attached to the task.
  416.  * @param task  Task to which the thread is to be attached.
  417.  */
  418. static void _thread_attach_task(thread_t *t, task_t *task)
  419. {
  420.     atomic_inc(&task->refcount);
  421.     atomic_inc(&task->lifecount);
  422.  
  423.     /* FIXME: this must be done very carefully.. an unstoppable
  424.        thread cannot appear just-so, it must be possible to catch it. */
  425.     if (t->flags & THREAD_FLAG_USPACE)
  426.         ++task->not_stoppable_count;
  427.     list_append(&t->th_link, &task->th_head);
  428. }
  429.  
  430. /** Add thread to the threads tree.
  431.  *
  432.  * Interrupts must be already disabled.
  433.  *
  434.  * @param t Thread to be attached to the task.
  435.  * @param task  Task to which the thread is to be attached.
  436.  */
  437. static void _thread_attach_tree(thread_t *t)
  438. {
  439.     /*
  440.      * Register this thread in the system-wide list.
  441.      */
  442.     spinlock_lock(&threads_lock);
  443.     avltree_insert(&threads_tree, &t->threads_tree_node);
  444.     spinlock_unlock(&threads_lock);
  445. }
  446.  
  447.  
  448. /** Make the thread visible to the system.
  449.  *
  450.  * Attach the thread structure to the current task and make it visible in the
  451.  * threads_tree.
  452.  *
  453.  * @param t Thread to be attached to the task.
  454.  * @param task  Task to which the thread is to be attached.
  455.  */
  456. void thread_attach(thread_t *t, task_t *task)
  457. {
  458.     ipl_t ipl;
  459.  
  460.     ipl = interrupts_disable();
  461.  
  462.     /*
  463.      * Attach to the current task.
  464.      */
  465.     spinlock_lock(&task->lock);
  466.     _thread_attach_task(t, task);
  467.     spinlock_unlock(&task->lock);
  468.  
  469.     /*
  470.      * Register this thread in the system-wide list.
  471.      */
  472.     _thread_attach_tree(t);
  473.    
  474.     interrupts_restore(ipl);
  475. }
  476.  
  477. /** Attach thread to a task given by its ID.
  478.  *
  479.  * Unlike thread_attach(), this function allows to attach a thread
  480.  * to an arbitrary task.
  481.  *
  482.  * @param t     Thread to be attached to the task.
  483.  * @param taskid    Task id to which the thread is to be attached.
  484.  * @return      An error code from errno.h
  485.  */
  486. int thread_attach_by_id(thread_t *t, task_id_t taskid)
  487. {
  488.     ipl_t ipl;
  489.     task_t *task;
  490.  
  491.     ipl = interrupts_disable();
  492.  
  493.     spinlock_lock(&tasks_lock);
  494.     task = task_find_by_id(taskid);
  495.     if (task == NULL) {
  496.         spinlock_unlock(&tasks_lock);
  497.         interrupts_restore(ipl);
  498.         return ENOENT;
  499.     }
  500.  
  501.     spinlock_lock(&task->lock);
  502.     spinlock_unlock(&tasks_lock);
  503.  
  504.     /*
  505.      * Attach to the current task.
  506.      */
  507.     _thread_attach_task(t, task);
  508.  
  509.     spinlock_unlock(&task->lock);
  510.  
  511.     /*
  512.      * Register this thread in the system-wide list.
  513.      */
  514.     _thread_attach_tree(t);
  515.    
  516.     interrupts_restore(ipl);
  517.  
  518.     return EOK;
  519. }
  520.  
  521.  
  522. /** Terminate thread.
  523.  *
  524.  * End current thread execution and switch it to the exiting state. All pending
  525.  * timeouts are executed.
  526.  */
  527. void thread_exit(void)
  528. {
  529.     ipl_t ipl;
  530.  
  531.     if (atomic_predec(&TASK->lifecount) == 0) {
  532.         /*
  533.          * We are the last thread in the task that still has not exited.
  534.          * With the exception of the moment the task was created, new
  535.          * threads can only be created by threads of the same task.
  536.          * We are safe to perform cleanup.
  537.          */
  538.         if (THREAD->flags & THREAD_FLAG_USPACE) {
  539.             ipc_cleanup();
  540.                 futex_cleanup();
  541.             klog_printf("Cleanup of task %llu completed.",
  542.                 TASK->taskid);
  543.         }
  544.     }
  545.  
  546. restart:
  547.     ipl = interrupts_disable();
  548.     spinlock_lock(&THREAD->lock);
  549.     if (THREAD->timeout_pending) {
  550.         /* busy waiting for timeouts in progress */
  551.         spinlock_unlock(&THREAD->lock);
  552.         interrupts_restore(ipl);
  553.         goto restart;
  554.     }
  555.    
  556.     THREAD->state = Exiting;
  557.     spinlock_unlock(&THREAD->lock);
  558.     scheduler();
  559.  
  560.     /* Not reached */
  561.     while (1)
  562.         ;
  563. }
  564.  
  565.  
  566. /** Thread sleep
  567.  *
  568.  * Suspend execution of the current thread.
  569.  *
  570.  * @param sec Number of seconds to sleep.
  571.  *
  572.  */
  573. void thread_sleep(uint32_t sec)
  574. {
  575.     thread_usleep(sec * 1000000);
  576. }
  577.  
  578. /** Wait for another thread to exit.
  579.  *
  580.  * @param t Thread to join on exit.
  581.  * @param usec Timeout in microseconds.
  582.  * @param flags Mode of operation.
  583.  *
  584.  * @return An error code from errno.h or an error code from synch.h.
  585.  */
  586. int thread_join_timeout(thread_t *t, uint32_t usec, int flags)
  587. {
  588.     ipl_t ipl;
  589.     int rc;
  590.  
  591.     if (t == THREAD)
  592.         return EINVAL;
  593.  
  594.     /*
  595.      * Since thread join can only be called once on an undetached thread,
  596.      * the thread pointer is guaranteed to be still valid.
  597.      */
  598.    
  599.     ipl = interrupts_disable();
  600.     spinlock_lock(&t->lock);
  601.     ASSERT(!t->detached);
  602.     spinlock_unlock(&t->lock);
  603.     interrupts_restore(ipl);
  604.    
  605.     rc = waitq_sleep_timeout(&t->join_wq, usec, flags);
  606.    
  607.     return rc; 
  608. }
  609.  
  610. /** Detach thread.
  611.  *
  612.  * Mark the thread as detached, if the thread is already in the Lingering
  613.  * state, deallocate its resources.
  614.  *
  615.  * @param t Thread to be detached.
  616.  */
  617. void thread_detach(thread_t *t)
  618. {
  619.     ipl_t ipl;
  620.  
  621.     /*
  622.      * Since the thread is expected not to be already detached,
  623.      * pointer to it must be still valid.
  624.      */
  625.     ipl = interrupts_disable();
  626.     spinlock_lock(&t->lock);
  627.     ASSERT(!t->detached);
  628.     if (t->state == Lingering) {
  629.         thread_destroy(t);  /* unlocks &t->lock */
  630.         interrupts_restore(ipl);
  631.         return;
  632.     } else {
  633.         t->detached = true;
  634.     }
  635.     spinlock_unlock(&t->lock);
  636.     interrupts_restore(ipl);
  637. }
  638.  
  639. /** Thread usleep
  640.  *
  641.  * Suspend execution of the current thread.
  642.  *
  643.  * @param usec Number of microseconds to sleep.
  644.  *
  645.  */
  646. void thread_usleep(uint32_t usec)
  647. {
  648.     waitq_t wq;
  649.                  
  650.     waitq_initialize(&wq);
  651.  
  652.     (void) waitq_sleep_timeout(&wq, usec, SYNCH_FLAGS_NON_BLOCKING);
  653. }
  654.  
  655. /** Register thread out-of-context invocation
  656.  *
  657.  * Register a function and its argument to be executed
  658.  * on next context switch to the current thread.
  659.  *
  660.  * @param call_me      Out-of-context function.
  661.  * @param call_me_with Out-of-context function argument.
  662.  *
  663.  */
  664. void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
  665. {
  666.     ipl_t ipl;
  667.    
  668.     ipl = interrupts_disable();
  669.     spinlock_lock(&THREAD->lock);
  670.     THREAD->call_me = call_me;
  671.     THREAD->call_me_with = call_me_with;
  672.     spinlock_unlock(&THREAD->lock);
  673.     interrupts_restore(ipl);
  674. }
  675.  
  676. static bool thread_walker(avltree_node_t *node, void *arg)
  677. {
  678.     thread_t *t;
  679.        
  680.     t = avltree_get_instance(node, thread_t, threads_tree_node);
  681.  
  682.     uint64_t cycles;
  683.     char suffix;
  684.     order(t->cycles, &cycles, &suffix);
  685.    
  686.     if (sizeof(void *) == 4)
  687.         printf("%-6llu %-10s %#10zx %-8s %#10zx %-3ld %#10zx %#10zx %9llu%c ",
  688.             t->tid, t->name, t, thread_states[t->state], t->task,
  689.             t->task->context, t->thread_code, t->kstack, cycles, suffix);
  690.     else
  691.         printf("%-6llu %-10s %#18zx %-8s %#18zx %-3ld %#18zx %#18zx %9llu%c ",
  692.             t->tid, t->name, t, thread_states[t->state], t->task,
  693.             t->task->context, t->thread_code, t->kstack, cycles, suffix);
  694.            
  695.     if (t->cpu)
  696.         printf("%-4zd", t->cpu->id);
  697.     else
  698.         printf("none");
  699.            
  700.     if (t->state == Sleeping) {
  701.         if (sizeof(uintptr_t) == 4)
  702.             printf(" %#10zx", t->sleep_queue);
  703.         else
  704.             printf(" %#18zx", t->sleep_queue);
  705.     }
  706.            
  707.     printf("\n");
  708.  
  709.     return true;
  710. }
  711.  
  712. /** Print list of threads debug info */
  713. void thread_print_list(void)
  714. {
  715.     ipl_t ipl;
  716.    
  717.     /* Messing with thread structures, avoid deadlock */
  718.     ipl = interrupts_disable();
  719.     spinlock_lock(&threads_lock);
  720.    
  721.     if (sizeof(uintptr_t) == 4) {
  722.         printf("tid    name       address    state    task       "
  723.             "ctx code       stack      cycles     cpu  "
  724.             "waitqueue\n");
  725.         printf("------ ---------- ---------- -------- ---------- "
  726.             "--- ---------- ---------- ---------- ---- "
  727.             "----------\n");
  728.     } else {
  729.         printf("tid    name       address            state    task               "
  730.             "ctx code               stack              cycles     cpu  "
  731.             "waitqueue\n");
  732.         printf("------ ---------- ------------------ -------- ------------------ "
  733.             "--- ------------------ ------------------ ---------- ---- "
  734.             "------------------\n");
  735.     }
  736.  
  737.     avltree_walk(&threads_tree, thread_walker, NULL);
  738.  
  739.     spinlock_unlock(&threads_lock);
  740.     interrupts_restore(ipl);
  741. }
  742.  
  743. /** Check whether thread exists.
  744.  *
  745.  * Note that threads_lock must be already held and
  746.  * interrupts must be already disabled.
  747.  *
  748.  * @param t Pointer to thread.
  749.  *
  750.  * @return True if thread t is known to the system, false otherwise.
  751.  */
  752. bool thread_exists(thread_t *t)
  753. {
  754.     avltree_node_t *node;
  755.  
  756.     node = avltree_search(&threads_tree, (avltree_key_t) ((uintptr_t) t));
  757.    
  758.     return node != NULL;
  759. }
  760.  
  761.  
  762. /** Update accounting of current thread.
  763.  *
  764.  * Note that thread_lock on THREAD must be already held and
  765.  * interrupts must be already disabled.
  766.  *
  767.  */
  768. void thread_update_accounting(void)
  769. {
  770.     uint64_t time = get_cycle();
  771.     THREAD->cycles += time - THREAD->last_cycle;
  772.     THREAD->last_cycle = time;
  773. }
  774.  
  775. /** Process syscall to create new thread.
  776.  *
  777.  */
  778. unative_t sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name,
  779.     thread_id_t *uspace_thread_id)
  780. {
  781.     thread_t *t;
  782.     char namebuf[THREAD_NAME_BUFLEN];
  783.     uspace_arg_t *kernel_uarg;
  784.     int rc;
  785.  
  786.     rc = copy_from_uspace(namebuf, uspace_name, THREAD_NAME_BUFLEN);
  787.     if (rc != 0)
  788.         return (unative_t) rc;
  789.  
  790.     /*
  791.      * In case of failure, kernel_uarg will be deallocated in this function.
  792.      * In case of success, kernel_uarg will be freed in uinit().
  793.      */
  794.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  795.    
  796.     rc = copy_from_uspace(kernel_uarg, uspace_uarg, sizeof(uspace_arg_t));
  797.     if (rc != 0) {
  798.         free(kernel_uarg);
  799.         return (unative_t) rc;
  800.     }
  801.  
  802.     t = thread_create(uinit, kernel_uarg, TASK,
  803.         THREAD_FLAG_USPACE | THREAD_FLAG_NOATTACH, namebuf, false);
  804.     if (t) {
  805.         if (uspace_thread_id != NULL) {
  806.             int rc;
  807.  
  808.             rc = copy_to_uspace(uspace_thread_id, &t->tid,
  809.                 sizeof(t->tid));
  810.             if (rc != 0) {
  811.                 /*
  812.                  * We have encountered a failure, but the thread
  813.                  * has already been created. We need to undo its
  814.                  * creation now.
  815.                  */
  816.  
  817.                 /*
  818.                  * The new thread structure is initialized, but
  819.                  * is still not visible to the system.
  820.                  * We can safely deallocate it.
  821.                  */
  822.                 slab_free(thread_slab, t);
  823.                 free(kernel_uarg);
  824.  
  825.                 return (unative_t) rc;
  826.              }
  827.         }
  828.         thread_attach(t, TASK);
  829.         thread_ready(t);
  830.  
  831.         return 0;
  832.     } else
  833.         free(kernel_uarg);
  834.  
  835.     return (unative_t) ENOMEM;
  836. }
  837.  
  838. /** Process syscall to terminate thread.
  839.  *
  840.  */
  841. unative_t sys_thread_exit(int uspace_status)
  842. {
  843.     thread_exit();
  844.     /* Unreachable */
  845.     return 0;
  846. }
  847.  
  848. /** Syscall for getting TID.
  849.  *
  850.  * @param uspace_thread_id Userspace address of 8-byte buffer where to store
  851.  * current thread ID.
  852.  *
  853.  * @return 0 on success or an error code from @ref errno.h.
  854.  */
  855. unative_t sys_thread_get_id(thread_id_t *uspace_thread_id)
  856. {
  857.     /*
  858.      * No need to acquire lock on THREAD because tid
  859.      * remains constant for the lifespan of the thread.
  860.      */
  861.     return (unative_t) copy_to_uspace(uspace_thread_id, &THREAD->tid,
  862.         sizeof(THREAD->tid));
  863. }
  864.  
  865. /** @}
  866.  */
  867.