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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/btree.h>
  55. #include <adt/list.h>
  56. #include <typedefs.h>
  57. #include <time/clock.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.  
  71.  
  72. /** Thread states */
  73. char *thread_states[] = {
  74.     "Invalid",
  75.     "Running",
  76.     "Sleeping",
  77.     "Ready",
  78.     "Entering",
  79.     "Exiting",
  80.     "Undead"
  81. };
  82.  
  83. /** Lock protecting the threads_btree B+tree. For locking rules, see declaration thereof. */
  84. SPINLOCK_INITIALIZE(threads_lock);
  85.  
  86. /** B+tree of all threads.
  87.  *
  88.  * When a thread is found in the threads_btree B+tree, it is guaranteed to exist as long
  89.  * as the threads_lock is held.
  90.  */
  91. btree_t threads_btree;     
  92.  
  93. SPINLOCK_INITIALIZE(tidlock);
  94. uint32_t last_tid = 0;
  95.  
  96. static slab_cache_t *thread_slab;
  97. #ifdef ARCH_HAS_FPU
  98. slab_cache_t *fpu_context_slab;
  99. #endif
  100.  
  101. /** Thread wrapper
  102.  *
  103.  * This wrapper is provided to ensure that every thread
  104.  * makes a call to thread_exit() when its implementing
  105.  * function returns.
  106.  *
  107.  * interrupts_disable() is assumed.
  108.  *
  109.  */
  110. static void cushion(void)
  111. {
  112.     void (*f)(void *) = THREAD->thread_code;
  113.     void *arg = THREAD->thread_arg;
  114.     THREAD->last_cycle = get_cycle();
  115.  
  116.     /* This is where each thread wakes up after its creation */
  117.     spinlock_unlock(&THREAD->lock);
  118.     interrupts_enable();
  119.  
  120.     f(arg);
  121.    
  122.     /* Accumulate accounting to the task */
  123.     ipl_t ipl = interrupts_disable();
  124.    
  125.     spinlock_lock(&THREAD->lock);
  126.     if (!THREAD->uncounted) {
  127.         thread_update_accounting();
  128.         uint64_t cycles = THREAD->cycles;
  129.         THREAD->cycles = 0;
  130.         spinlock_unlock(&THREAD->lock);
  131.        
  132.         spinlock_lock(&TASK->lock);
  133.         TASK->cycles += cycles;
  134.         spinlock_unlock(&TASK->lock);
  135.     } else
  136.         spinlock_unlock(&THREAD->lock);
  137.    
  138.     interrupts_restore(ipl);
  139.    
  140.     thread_exit();
  141.     /* not reached */
  142. }
  143.  
  144. /** Initialization and allocation for thread_t structure */
  145. static int thr_constructor(void *obj, int kmflags)
  146. {
  147.     thread_t *t = (thread_t *) obj;
  148.  
  149.     spinlock_initialize(&t->lock, "thread_t_lock");
  150.     link_initialize(&t->rq_link);
  151.     link_initialize(&t->wq_link);
  152.     link_initialize(&t->th_link);
  153.  
  154.     /* call the architecture-specific part of the constructor */
  155.     thr_constructor_arch(t);
  156.    
  157. #ifdef ARCH_HAS_FPU
  158. #  ifdef CONFIG_FPU_LAZY
  159.     t->saved_fpu_context = NULL;
  160. #  else
  161.     t->saved_fpu_context = slab_alloc(fpu_context_slab,kmflags);
  162.     if (!t->saved_fpu_context)
  163.         return -1;
  164. #  endif
  165. #endif 
  166.  
  167.     t->kstack = frame_alloc(STACK_FRAMES, FRAME_KA | kmflags);
  168.     if (! t->kstack) {
  169. #ifdef ARCH_HAS_FPU
  170.         if (t->saved_fpu_context)
  171.             slab_free(fpu_context_slab,t->saved_fpu_context);
  172. #endif
  173.         return -1;
  174.     }
  175.  
  176.     return 0;
  177. }
  178.  
  179. /** Destruction of thread_t object */
  180. static int thr_destructor(void *obj)
  181. {
  182.     thread_t *t = (thread_t *) obj;
  183.  
  184.     /* call the architecture-specific part of the destructor */
  185.     thr_destructor_arch(t);
  186.  
  187.     frame_free(KA2PA(t->kstack));
  188. #ifdef ARCH_HAS_FPU
  189.     if (t->saved_fpu_context)
  190.         slab_free(fpu_context_slab,t->saved_fpu_context);
  191. #endif
  192.     return 1; /* One page freed */
  193. }
  194.  
  195. /** Initialize threads
  196.  *
  197.  * Initialize kernel threads support.
  198.  *
  199.  */
  200. void thread_init(void)
  201. {
  202.     THREAD = NULL;
  203.     atomic_set(&nrdy,0);
  204.     thread_slab = slab_cache_create("thread_slab",
  205.                     sizeof(thread_t),0,
  206.                     thr_constructor, thr_destructor, 0);
  207. #ifdef ARCH_HAS_FPU
  208.     fpu_context_slab = slab_cache_create("fpu_slab",
  209.                          sizeof(fpu_context_t),
  210.                          FPU_CONTEXT_ALIGN,
  211.                          NULL, NULL, 0);
  212. #endif
  213.  
  214.     btree_create(&threads_btree);
  215. }
  216.  
  217. /** Make thread ready
  218.  *
  219.  * Switch thread t to the ready state.
  220.  *
  221.  * @param t Thread to make ready.
  222.  *
  223.  */
  224. void thread_ready(thread_t *t)
  225. {
  226.     cpu_t *cpu;
  227.     runq_t *r;
  228.     ipl_t ipl;
  229.     int i, avg;
  230.  
  231.     ipl = interrupts_disable();
  232.  
  233.     spinlock_lock(&t->lock);
  234.  
  235.     ASSERT(! (t->state == Ready));
  236.  
  237.     i = (t->priority < RQ_COUNT -1) ? ++t->priority : t->priority;
  238.    
  239.     cpu = CPU;
  240.     if (t->flags & THREAD_FLAG_WIRED) {
  241.         cpu = t->cpu;
  242.     }
  243.     t->state = Ready;
  244.     spinlock_unlock(&t->lock);
  245.    
  246.     /*
  247.      * Append t to respective ready queue on respective processor.
  248.      */
  249.     r = &cpu->rq[i];
  250.     spinlock_lock(&r->lock);
  251.     list_append(&t->rq_link, &r->rq_head);
  252.     r->n++;
  253.     spinlock_unlock(&r->lock);
  254.  
  255.     atomic_inc(&nrdy);
  256.     avg = atomic_get(&nrdy) / config.cpu_active;
  257.     atomic_inc(&cpu->nrdy);
  258.  
  259.     interrupts_restore(ipl);
  260. }
  261.  
  262. /** Destroy thread memory structure
  263.  *
  264.  * Detach thread from all queues, cpus etc. and destroy it.
  265.  *
  266.  * Assume thread->lock is held!!
  267.  */
  268. void thread_destroy(thread_t *t)
  269. {
  270.     bool destroy_task = false; 
  271.  
  272.     ASSERT(t->state == Exiting || t->state == Undead);
  273.     ASSERT(t->task);
  274.     ASSERT(t->cpu);
  275.  
  276.     spinlock_lock(&t->cpu->lock);
  277.     if(t->cpu->fpu_owner==t)
  278.         t->cpu->fpu_owner=NULL;
  279.     spinlock_unlock(&t->cpu->lock);
  280.  
  281.     spinlock_unlock(&t->lock);
  282.  
  283.     spinlock_lock(&threads_lock);
  284.     btree_remove(&threads_btree, (btree_key_t) ((uintptr_t ) t), NULL);
  285.     spinlock_unlock(&threads_lock);
  286.  
  287.     /*
  288.      * Detach from the containing task.
  289.      */
  290.     spinlock_lock(&t->task->lock);
  291.     list_remove(&t->th_link);
  292.     if (--t->task->refcount == 0) {
  293.         t->task->accept_new_threads = false;
  294.         destroy_task = true;
  295.     }
  296.     spinlock_unlock(&t->task->lock);   
  297.    
  298.     if (destroy_task)
  299.         task_destroy(t->task);
  300.    
  301.     slab_free(thread_slab, t);
  302. }
  303.  
  304. /** Create new thread
  305.  *
  306.  * Create a new thread.
  307.  *
  308.  * @param func      Thread's implementing function.
  309.  * @param arg       Thread's implementing function argument.
  310.  * @param task      Task to which the thread belongs.
  311.  * @param flags     Thread flags.
  312.  * @param name      Symbolic name.
  313.  * @param uncounted Thread's accounting doesn't affect accumulated task accounting.
  314.  *
  315.  * @return New thread's structure on success, NULL on failure.
  316.  *
  317.  */
  318. thread_t *thread_create(void (* func)(void *), void *arg, task_t *task, int flags, char *name, bool uncounted)
  319. {
  320.     thread_t *t;
  321.     ipl_t ipl;
  322.    
  323.     t = (thread_t *) slab_alloc(thread_slab, 0);
  324.     if (!t)
  325.         return NULL;
  326.    
  327.     /* Not needed, but good for debugging */
  328.     memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES, 0);
  329.    
  330.     ipl = interrupts_disable();
  331.     spinlock_lock(&tidlock);
  332.     t->tid = ++last_tid;
  333.     spinlock_unlock(&tidlock);
  334.     interrupts_restore(ipl);
  335.    
  336.     context_save(&t->saved_context);
  337.     context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack, THREAD_STACK_SIZE);
  338.    
  339.     the_initialize((the_t *) t->kstack);
  340.    
  341.     ipl = interrupts_disable();
  342.     t->saved_context.ipl = interrupts_read();
  343.     interrupts_restore(ipl);
  344.    
  345.     memcpy(t->name, name, THREAD_NAME_BUFLEN);
  346.    
  347.     t->thread_code = func;
  348.     t->thread_arg = arg;
  349.     t->ticks = -1;
  350.     t->cycles = 0;
  351.     t->uncounted = uncounted;
  352.     t->priority = -1;       /* start in rq[0] */
  353.     t->cpu = NULL;
  354.     t->flags = flags;
  355.     t->state = Entering;
  356.     t->call_me = NULL;
  357.     t->call_me_with = NULL;
  358.    
  359.     timeout_initialize(&t->sleep_timeout);
  360.     t->sleep_interruptible = false;
  361.     t->sleep_queue = NULL;
  362.     t->timeout_pending = 0;
  363.  
  364.     t->in_copy_from_uspace = false;
  365.     t->in_copy_to_uspace = false;
  366.  
  367.     t->interrupted = false;
  368.     t->join_type = None;
  369.     t->detached = false;
  370.     waitq_initialize(&t->join_wq);
  371.    
  372.     t->rwlock_holder_type = RWLOCK_NONE;
  373.        
  374.     t->task = task;
  375.    
  376.     t->fpu_context_exists = 0;
  377.     t->fpu_context_engaged = 0;
  378.  
  379.     thread_create_arch(t);      /* might depend on previous initialization */
  380.    
  381.     /*
  382.      * Attach to the containing task.
  383.      */
  384.     ipl = interrupts_disable();  
  385.     spinlock_lock(&task->lock);
  386.     if (!task->accept_new_threads) {
  387.         spinlock_unlock(&task->lock);
  388.         slab_free(thread_slab, t);
  389.         interrupts_restore(ipl);
  390.         return NULL;
  391.     }
  392.     list_append(&t->th_link, &task->th_head);
  393.     if (task->refcount++ == 0)
  394.         task->main_thread = t;
  395.     spinlock_unlock(&task->lock);
  396.  
  397.     /*
  398.      * Register this thread in the system-wide list.
  399.      */
  400.     spinlock_lock(&threads_lock);
  401.     btree_insert(&threads_btree, (btree_key_t) ((uintptr_t) t), (void *) t, NULL);
  402.     spinlock_unlock(&threads_lock);
  403.    
  404.     interrupts_restore(ipl);
  405.    
  406.     return t;
  407. }
  408.  
  409. /** Terminate thread.
  410.  *
  411.  * End current thread execution and switch it to the exiting
  412.  * state. All pending timeouts are executed.
  413.  *
  414.  */
  415. void thread_exit(void)
  416. {
  417.     ipl_t ipl;
  418.  
  419. restart:
  420.     ipl = interrupts_disable();
  421.     spinlock_lock(&THREAD->lock);
  422.     if (THREAD->timeout_pending) { /* busy waiting for timeouts in progress */
  423.         spinlock_unlock(&THREAD->lock);
  424.         interrupts_restore(ipl);
  425.         goto restart;
  426.     }
  427.     THREAD->state = Exiting;
  428.     spinlock_unlock(&THREAD->lock);
  429.     scheduler();
  430.  
  431.     /* Not reached */
  432.     while (1)
  433.         ;
  434. }
  435.  
  436.  
  437. /** Thread sleep
  438.  *
  439.  * Suspend execution of the current thread.
  440.  *
  441.  * @param sec Number of seconds to sleep.
  442.  *
  443.  */
  444. void thread_sleep(uint32_t sec)
  445. {
  446.     thread_usleep(sec*1000000);
  447. }
  448.  
  449. /** Wait for another thread to exit.
  450.  *
  451.  * @param t Thread to join on exit.
  452.  * @param usec Timeout in microseconds.
  453.  * @param flags Mode of operation.
  454.  *
  455.  * @return An error code from errno.h or an error code from synch.h.
  456.  */
  457. int thread_join_timeout(thread_t *t, uint32_t usec, int flags)
  458. {
  459.     ipl_t ipl;
  460.     int rc;
  461.  
  462.     if (t == THREAD)
  463.         return EINVAL;
  464.  
  465.     /*
  466.      * Since thread join can only be called once on an undetached thread,
  467.      * the thread pointer is guaranteed to be still valid.
  468.      */
  469.    
  470.     ipl = interrupts_disable();
  471.     spinlock_lock(&t->lock);
  472.     ASSERT(!t->detached);
  473.     spinlock_unlock(&t->lock);
  474.     interrupts_restore(ipl);
  475.    
  476.     rc = waitq_sleep_timeout(&t->join_wq, usec, flags);
  477.    
  478.     return rc; 
  479. }
  480.  
  481. /** Detach thread.
  482.  *
  483.  * Mark the thread as detached, if the thread is already in the Undead state,
  484.  * deallocate its resources.
  485.  *
  486.  * @param t Thread to be detached.
  487.  */
  488. void thread_detach(thread_t *t)
  489. {
  490.     ipl_t ipl;
  491.  
  492.     /*
  493.      * Since the thread is expected to not be already detached,
  494.      * pointer to it must be still valid.
  495.      */
  496.     ipl = interrupts_disable();
  497.     spinlock_lock(&t->lock);
  498.     ASSERT(!t->detached);
  499.     if (t->state == Undead) {
  500.         thread_destroy(t);  /* unlocks &t->lock */
  501.         interrupts_restore(ipl);
  502.         return;
  503.     } else {
  504.         t->detached = true;
  505.     }
  506.     spinlock_unlock(&t->lock);
  507.     interrupts_restore(ipl);
  508. }
  509.  
  510. /** Thread usleep
  511.  *
  512.  * Suspend execution of the current thread.
  513.  *
  514.  * @param usec Number of microseconds to sleep.
  515.  *
  516.  */
  517. void thread_usleep(uint32_t usec)
  518. {
  519.     waitq_t wq;
  520.                  
  521.     waitq_initialize(&wq);
  522.  
  523.     (void) waitq_sleep_timeout(&wq, usec, SYNCH_FLAGS_NON_BLOCKING);
  524. }
  525.  
  526. /** Register thread out-of-context invocation
  527.  *
  528.  * Register a function and its argument to be executed
  529.  * on next context switch to the current thread.
  530.  *
  531.  * @param call_me      Out-of-context function.
  532.  * @param call_me_with Out-of-context function argument.
  533.  *
  534.  */
  535. void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
  536. {
  537.     ipl_t ipl;
  538.    
  539.     ipl = interrupts_disable();
  540.     spinlock_lock(&THREAD->lock);
  541.     THREAD->call_me = call_me;
  542.     THREAD->call_me_with = call_me_with;
  543.     spinlock_unlock(&THREAD->lock);
  544.     interrupts_restore(ipl);
  545. }
  546.  
  547. /** Print list of threads debug info */
  548. void thread_print_list(void)
  549. {
  550.     link_t *cur;
  551.     ipl_t ipl;
  552.    
  553.     /* Messing with thread structures, avoid deadlock */
  554.     ipl = interrupts_disable();
  555.     spinlock_lock(&threads_lock);
  556.    
  557.     printf("tid    name       address    state    task       ctx code       stack      cycles     cpu  kstack     waitqueue\n");
  558.     printf("------ ---------- ---------- -------- ---------- --- ---------- ---------- ---------- ---- ---------- ----------\n");
  559.  
  560.     for (cur = threads_btree.leaf_head.next; cur != &threads_btree.leaf_head; cur = cur->next) {
  561.         btree_node_t *node;
  562.         int i;
  563.  
  564.         node = list_get_instance(cur, btree_node_t, leaf_link);
  565.         for (i = 0; i < node->keys; i++) {
  566.             thread_t *t;
  567.        
  568.             t = (thread_t *) node->value[i];
  569.            
  570.             uint64_t cycles;
  571.             char suffix;
  572.             order(t->cycles, &cycles, &suffix);
  573.            
  574.             printf("%-6zd %-10s %#10zx %-8s %#10zx %-3ld %#10zx %#10zx %9llu%c ", t->tid, t->name, t, thread_states[t->state], t->task, t->task->context, t->thread_code, t->kstack, cycles, suffix);
  575.            
  576.             if (t->cpu)
  577.                 printf("%-4zd", t->cpu->id);
  578.             else
  579.                 printf("none");
  580.            
  581.             if (t->state == Sleeping)
  582.                 printf(" %#10zx %#10zx", t->kstack, t->sleep_queue);
  583.            
  584.             printf("\n");
  585.         }
  586.     }
  587.  
  588.     spinlock_unlock(&threads_lock);
  589.     interrupts_restore(ipl);
  590. }
  591.  
  592. /** Check whether thread exists.
  593.  *
  594.  * Note that threads_lock must be already held and
  595.  * interrupts must be already disabled.
  596.  *
  597.  * @param t Pointer to thread.
  598.  *
  599.  * @return True if thread t is known to the system, false otherwise.
  600.  */
  601. bool thread_exists(thread_t *t)
  602. {
  603.     btree_node_t *leaf;
  604.    
  605.     return btree_search(&threads_btree, (btree_key_t) ((uintptr_t) t), &leaf) != NULL;
  606. }
  607.  
  608.  
  609. /** Update accounting of current thread.
  610.  *
  611.  * Note that thread_lock on THREAD must be already held and
  612.  * interrupts must be already disabled.
  613.  *
  614.  */
  615. void thread_update_accounting(void)
  616. {
  617.     uint64_t time = get_cycle();
  618.     THREAD->cycles += time - THREAD->last_cycle;
  619.     THREAD->last_cycle = time;
  620. }
  621.  
  622. /** Process syscall to create new thread.
  623.  *
  624.  */
  625. unative_t sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name)
  626. {
  627.     thread_t *t;
  628.     char namebuf[THREAD_NAME_BUFLEN];
  629.     uspace_arg_t *kernel_uarg;
  630.     uint32_t tid;
  631.     int rc;
  632.  
  633.     rc = copy_from_uspace(namebuf, uspace_name, THREAD_NAME_BUFLEN);
  634.     if (rc != 0)
  635.         return (unative_t) rc;
  636.  
  637.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  638.     rc = copy_from_uspace(kernel_uarg, uspace_uarg, sizeof(uspace_arg_t));
  639.     if (rc != 0) {
  640.         free(kernel_uarg);
  641.         return (unative_t) rc;
  642.     }
  643.  
  644.     if ((t = thread_create(uinit, kernel_uarg, TASK, THREAD_FLAG_USPACE, namebuf, false))) {
  645.         tid = t->tid;
  646.         thread_ready(t);
  647.         return (unative_t) tid;
  648.     } else {
  649.         free(kernel_uarg);
  650.     }
  651.  
  652.     return (unative_t) ENOMEM;
  653. }
  654.  
  655. /** Process syscall to terminate thread.
  656.  *
  657.  */
  658. unative_t sys_thread_exit(int uspace_status)
  659. {
  660.     thread_exit();
  661.     /* Unreachable */
  662.     return 0;
  663. }
  664.  
  665. /** @}
  666.  */
  667.