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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.     thread_exit();
  122.     /* not reached */
  123. }
  124.  
  125. /** Initialization and allocation for thread_t structure */
  126. static int thr_constructor(void *obj, int kmflags)
  127. {
  128.     thread_t *t = (thread_t *) obj;
  129.  
  130.     spinlock_initialize(&t->lock, "thread_t_lock");
  131.     link_initialize(&t->rq_link);
  132.     link_initialize(&t->wq_link);
  133.     link_initialize(&t->th_link);
  134.  
  135.     /* call the architecture-specific part of the constructor */
  136.     thr_constructor_arch(t);
  137.    
  138. #ifdef ARCH_HAS_FPU
  139. #  ifdef CONFIG_FPU_LAZY
  140.     t->saved_fpu_context = NULL;
  141. #  else
  142.     t->saved_fpu_context = slab_alloc(fpu_context_slab,kmflags);
  143.     if (!t->saved_fpu_context)
  144.         return -1;
  145. #  endif
  146. #endif 
  147.  
  148.     t->kstack = frame_alloc(STACK_FRAMES, FRAME_KA | kmflags);
  149.     if (! t->kstack) {
  150. #ifdef ARCH_HAS_FPU
  151.         if (t->saved_fpu_context)
  152.             slab_free(fpu_context_slab,t->saved_fpu_context);
  153. #endif
  154.         return -1;
  155.     }
  156.  
  157.     return 0;
  158. }
  159.  
  160. /** Destruction of thread_t object */
  161. static int thr_destructor(void *obj)
  162. {
  163.     thread_t *t = (thread_t *) obj;
  164.  
  165.     /* call the architecture-specific part of the destructor */
  166.     thr_destructor_arch(t);
  167.  
  168.     frame_free(KA2PA(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; /* One page freed */
  174. }
  175.  
  176. /** Initialize threads
  177.  *
  178.  * Initialize kernel threads support.
  179.  *
  180.  */
  181. void thread_init(void)
  182. {
  183.     THREAD = NULL;
  184.     atomic_set(&nrdy,0);
  185.     thread_slab = slab_cache_create("thread_slab",
  186.                     sizeof(thread_t),0,
  187.                     thr_constructor, thr_destructor, 0);
  188. #ifdef ARCH_HAS_FPU
  189.     fpu_context_slab = slab_cache_create("fpu_slab",
  190.                          sizeof(fpu_context_t),
  191.                          FPU_CONTEXT_ALIGN,
  192.                          NULL, NULL, 0);
  193. #endif
  194.  
  195.     btree_create(&threads_btree);
  196. }
  197.  
  198. /** Make thread ready
  199.  *
  200.  * Switch thread t to the ready state.
  201.  *
  202.  * @param t Thread to make ready.
  203.  *
  204.  */
  205. void thread_ready(thread_t *t)
  206. {
  207.     cpu_t *cpu;
  208.     runq_t *r;
  209.     ipl_t ipl;
  210.     int i, avg;
  211.  
  212.     ipl = interrupts_disable();
  213.  
  214.     spinlock_lock(&t->lock);
  215.  
  216.     ASSERT(! (t->state == Ready));
  217.  
  218.     i = (t->priority < RQ_COUNT -1) ? ++t->priority : t->priority;
  219.    
  220.     cpu = CPU;
  221.     if (t->flags & THREAD_FLAG_WIRED) {
  222.         cpu = t->cpu;
  223.     }
  224.     t->state = Ready;
  225.     spinlock_unlock(&t->lock);
  226.    
  227.     /*
  228.      * Append t to respective ready queue on respective processor.
  229.      */
  230.     r = &cpu->rq[i];
  231.     spinlock_lock(&r->lock);
  232.     list_append(&t->rq_link, &r->rq_head);
  233.     r->n++;
  234.     spinlock_unlock(&r->lock);
  235.  
  236.     atomic_inc(&nrdy);
  237.     avg = atomic_get(&nrdy) / config.cpu_active;
  238.     atomic_inc(&cpu->nrdy);
  239.  
  240.     interrupts_restore(ipl);
  241. }
  242.  
  243. /** Destroy thread memory structure
  244.  *
  245.  * Detach thread from all queues, cpus etc. and destroy it.
  246.  *
  247.  * Assume thread->lock is held!!
  248.  */
  249. void thread_destroy(thread_t *t)
  250. {
  251.     bool destroy_task = false; 
  252.  
  253.     ASSERT(t->state == Exiting || t->state == Undead);
  254.     ASSERT(t->task);
  255.     ASSERT(t->cpu);
  256.  
  257.     spinlock_lock(&t->cpu->lock);
  258.     if(t->cpu->fpu_owner==t)
  259.         t->cpu->fpu_owner=NULL;
  260.     spinlock_unlock(&t->cpu->lock);
  261.  
  262.     spinlock_unlock(&t->lock);
  263.  
  264.     spinlock_lock(&threads_lock);
  265.     btree_remove(&threads_btree, (btree_key_t) ((uintptr_t ) t), NULL);
  266.     spinlock_unlock(&threads_lock);
  267.  
  268.     /*
  269.      * Detach from the containing task.
  270.      */
  271.     spinlock_lock(&t->task->lock);
  272.     list_remove(&t->th_link);
  273.     if (--t->task->refcount == 0) {
  274.         t->task->accept_new_threads = false;
  275.         destroy_task = true;
  276.     }
  277.     spinlock_unlock(&t->task->lock);   
  278.    
  279.     if (destroy_task)
  280.         task_destroy(t->task);
  281.    
  282.     slab_free(thread_slab, t);
  283. }
  284.  
  285. /** Create new thread
  286.  *
  287.  * Create a new thread.
  288.  *
  289.  * @param func  Thread's implementing function.
  290.  * @param arg   Thread's implementing function argument.
  291.  * @param task  Task to which the thread belongs.
  292.  * @param flags Thread flags.
  293.  * @param name  Symbolic name.
  294.  *
  295.  * @return New thread's structure on success, NULL on failure.
  296.  *
  297.  */
  298. thread_t *thread_create(void (* func)(void *), void *arg, task_t *task, int flags, char *name)
  299. {
  300.     thread_t *t;
  301.     ipl_t ipl;
  302.    
  303.     t = (thread_t *) slab_alloc(thread_slab, 0);
  304.     if (!t)
  305.         return NULL;
  306.    
  307.     /* Not needed, but good for debugging */
  308.     memsetb((uintptr_t) t->kstack, THREAD_STACK_SIZE * 1 << STACK_FRAMES, 0);
  309.    
  310.     ipl = interrupts_disable();
  311.     spinlock_lock(&tidlock);
  312.     t->tid = ++last_tid;
  313.     spinlock_unlock(&tidlock);
  314.     interrupts_restore(ipl);
  315.    
  316.     context_save(&t->saved_context);
  317.     context_set(&t->saved_context, FADDR(cushion), (uintptr_t) t->kstack, THREAD_STACK_SIZE);
  318.    
  319.     the_initialize((the_t *) t->kstack);
  320.    
  321.     ipl = interrupts_disable();
  322.     t->saved_context.ipl = interrupts_read();
  323.     interrupts_restore(ipl);
  324.    
  325.     memcpy(t->name, name, THREAD_NAME_BUFLEN);
  326.    
  327.     t->thread_code = func;
  328.     t->thread_arg = arg;
  329.     t->ticks = -1;
  330.     t->cycles = 0;
  331.     t->priority = -1;       /* start in rq[0] */
  332.     t->cpu = NULL;
  333.     t->flags = flags;
  334.     t->state = Entering;
  335.     t->call_me = NULL;
  336.     t->call_me_with = NULL;
  337.    
  338.     timeout_initialize(&t->sleep_timeout);
  339.     t->sleep_interruptible = false;
  340.     t->sleep_queue = NULL;
  341.     t->timeout_pending = 0;
  342.  
  343.     t->in_copy_from_uspace = false;
  344.     t->in_copy_to_uspace = false;
  345.  
  346.     t->interrupted = false;
  347.     t->join_type = None;
  348.     t->detached = false;
  349.     waitq_initialize(&t->join_wq);
  350.    
  351.     t->rwlock_holder_type = RWLOCK_NONE;
  352.        
  353.     t->task = task;
  354.    
  355.     t->fpu_context_exists = 0;
  356.     t->fpu_context_engaged = 0;
  357.  
  358.     thread_create_arch(t);      /* might depend on previous initialization */
  359.    
  360.     /*
  361.      * Attach to the containing task.
  362.      */
  363.     ipl = interrupts_disable();  
  364.     spinlock_lock(&task->lock);
  365.     if (!task->accept_new_threads) {
  366.         spinlock_unlock(&task->lock);
  367.         slab_free(thread_slab, t);
  368.         interrupts_restore(ipl);
  369.         return NULL;
  370.     }
  371.     list_append(&t->th_link, &task->th_head);
  372.     if (task->refcount++ == 0)
  373.         task->main_thread = t;
  374.     spinlock_unlock(&task->lock);
  375.  
  376.     /*
  377.      * Register this thread in the system-wide list.
  378.      */
  379.     spinlock_lock(&threads_lock);
  380.     btree_insert(&threads_btree, (btree_key_t) ((uintptr_t) t), (void *) t, NULL);
  381.     spinlock_unlock(&threads_lock);
  382.    
  383.     interrupts_restore(ipl);
  384.    
  385.     return t;
  386. }
  387.  
  388. /** Terminate thread.
  389.  *
  390.  * End current thread execution and switch it to the exiting
  391.  * state. All pending timeouts are executed.
  392.  *
  393.  */
  394. void thread_exit(void)
  395. {
  396.     ipl_t ipl;
  397.  
  398. restart:
  399.     ipl = interrupts_disable();
  400.     spinlock_lock(&THREAD->lock);
  401.     if (THREAD->timeout_pending) { /* busy waiting for timeouts in progress */
  402.         spinlock_unlock(&THREAD->lock);
  403.         interrupts_restore(ipl);
  404.         goto restart;
  405.     }
  406.     THREAD->state = Exiting;
  407.     spinlock_unlock(&THREAD->lock);
  408.     scheduler();
  409.  
  410.     /* Not reached */
  411.     while (1)
  412.         ;
  413. }
  414.  
  415.  
  416. /** Thread sleep
  417.  *
  418.  * Suspend execution of the current thread.
  419.  *
  420.  * @param sec Number of seconds to sleep.
  421.  *
  422.  */
  423. void thread_sleep(uint32_t sec)
  424. {
  425.     thread_usleep(sec*1000000);
  426. }
  427.  
  428. /** Wait for another thread to exit.
  429.  *
  430.  * @param t Thread to join on exit.
  431.  * @param usec Timeout in microseconds.
  432.  * @param flags Mode of operation.
  433.  *
  434.  * @return An error code from errno.h or an error code from synch.h.
  435.  */
  436. int thread_join_timeout(thread_t *t, uint32_t usec, int flags)
  437. {
  438.     ipl_t ipl;
  439.     int rc;
  440.  
  441.     if (t == THREAD)
  442.         return EINVAL;
  443.  
  444.     /*
  445.      * Since thread join can only be called once on an undetached thread,
  446.      * the thread pointer is guaranteed to be still valid.
  447.      */
  448.    
  449.     ipl = interrupts_disable();
  450.     spinlock_lock(&t->lock);
  451.     ASSERT(!t->detached);
  452.     spinlock_unlock(&t->lock);
  453.     interrupts_restore(ipl);
  454.    
  455.     rc = waitq_sleep_timeout(&t->join_wq, usec, flags);
  456.    
  457.     return rc; 
  458. }
  459.  
  460. /** Detach thread.
  461.  *
  462.  * Mark the thread as detached, if the thread is already in the Undead state,
  463.  * deallocate its resources.
  464.  *
  465.  * @param t Thread to be detached.
  466.  */
  467. void thread_detach(thread_t *t)
  468. {
  469.     ipl_t ipl;
  470.  
  471.     /*
  472.      * Since the thread is expected to not be already detached,
  473.      * pointer to it must be still valid.
  474.      */
  475.     ipl = interrupts_disable();
  476.     spinlock_lock(&t->lock);
  477.     ASSERT(!t->detached);
  478.     if (t->state == Undead) {
  479.         thread_destroy(t);  /* unlocks &t->lock */
  480.         interrupts_restore(ipl);
  481.         return;
  482.     } else {
  483.         t->detached = true;
  484.     }
  485.     spinlock_unlock(&t->lock);
  486.     interrupts_restore(ipl);
  487. }
  488.  
  489. /** Thread usleep
  490.  *
  491.  * Suspend execution of the current thread.
  492.  *
  493.  * @param usec Number of microseconds to sleep.
  494.  *
  495.  */
  496. void thread_usleep(uint32_t usec)
  497. {
  498.     waitq_t wq;
  499.                  
  500.     waitq_initialize(&wq);
  501.  
  502.     (void) waitq_sleep_timeout(&wq, usec, SYNCH_FLAGS_NON_BLOCKING);
  503. }
  504.  
  505. /** Register thread out-of-context invocation
  506.  *
  507.  * Register a function and its argument to be executed
  508.  * on next context switch to the current thread.
  509.  *
  510.  * @param call_me      Out-of-context function.
  511.  * @param call_me_with Out-of-context function argument.
  512.  *
  513.  */
  514. void thread_register_call_me(void (* call_me)(void *), void *call_me_with)
  515. {
  516.     ipl_t ipl;
  517.    
  518.     ipl = interrupts_disable();
  519.     spinlock_lock(&THREAD->lock);
  520.     THREAD->call_me = call_me;
  521.     THREAD->call_me_with = call_me_with;
  522.     spinlock_unlock(&THREAD->lock);
  523.     interrupts_restore(ipl);
  524. }
  525.  
  526. /** Print list of threads debug info */
  527. void thread_print_list(void)
  528. {
  529.     link_t *cur;
  530.     ipl_t ipl;
  531.    
  532.     /* Messing with thread structures, avoid deadlock */
  533.     ipl = interrupts_disable();
  534.     spinlock_lock(&threads_lock);
  535.    
  536.     printf("tid    name       address    state    task       ctx code       stack      cycles     cpu  kst        wq\n");
  537.     printf("------ ---------- ---------- -------- ---------- --- ---------- ---------- ---------- ---- ---------- ----------\n");
  538.  
  539.     for (cur = threads_btree.leaf_head.next; cur != &threads_btree.leaf_head; cur = cur->next) {
  540.         btree_node_t *node;
  541.         int i;
  542.  
  543.         node = list_get_instance(cur, btree_node_t, leaf_link);
  544.         for (i = 0; i < node->keys; i++) {
  545.             thread_t *t;
  546.        
  547.             t = (thread_t *) node->value[i];
  548.            
  549.             uint64_t cycles;
  550.             char suffix;
  551.            
  552.             if (t->cycles > 1000000000000000000LL) {
  553.                 cycles = t->cycles / 1000000000000000000LL;
  554.                 suffix = 'E';
  555.             } else if (t->cycles > 1000000000000LL) {
  556.                 cycles = t->cycles / 1000000000000LL;
  557.                 suffix = 'T';
  558.             } else if (t->cycles > 1000000LL) {
  559.                 cycles = t->cycles / 1000000LL;
  560.                 suffix = 'M';
  561.             } else {
  562.                 cycles = t->cycles;
  563.                 suffix = ' ';
  564.             }
  565.            
  566.             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);
  567.            
  568.             if (t->cpu)
  569.                 printf("%-4zd", t->cpu->id);
  570.             else
  571.                 printf("none");
  572.            
  573.             if (t->state == Sleeping)
  574.                 printf(" %#10zx %#10zx", t->kstack, t->sleep_queue);
  575.            
  576.             printf("\n");
  577.         }
  578.     }
  579.  
  580.     spinlock_unlock(&threads_lock);
  581.     interrupts_restore(ipl);
  582. }
  583.  
  584. /** Check whether thread exists.
  585.  *
  586.  * Note that threads_lock must be already held and
  587.  * interrupts must be already disabled.
  588.  *
  589.  * @param t Pointer to thread.
  590.  *
  591.  * @return True if thread t is known to the system, false otherwise.
  592.  */
  593. bool thread_exists(thread_t *t)
  594. {
  595.     btree_node_t *leaf;
  596.    
  597.     return btree_search(&threads_btree, (btree_key_t) ((uintptr_t) t), &leaf) != NULL;
  598. }
  599.  
  600.  
  601. /** Update accounting of current thread.
  602.  *
  603.  * Note that thread_lock on THREAD must be already held and
  604.  * interrupts must be already disabled.
  605.  *
  606.  * @param t Pointer to thread.
  607.  *
  608.  */
  609. void thread_update_accounting(void)
  610. {
  611.     uint64_t time = get_cycle();
  612.     THREAD->cycles += time - THREAD->last_cycle;
  613.     THREAD->last_cycle = time;
  614. }
  615.  
  616. /** Process syscall to create new thread.
  617.  *
  618.  */
  619. unative_t sys_thread_create(uspace_arg_t *uspace_uarg, char *uspace_name)
  620. {
  621.     thread_t *t;
  622.     char namebuf[THREAD_NAME_BUFLEN];
  623.     uspace_arg_t *kernel_uarg;
  624.     uint32_t tid;
  625.     int rc;
  626.  
  627.     rc = copy_from_uspace(namebuf, uspace_name, THREAD_NAME_BUFLEN);
  628.     if (rc != 0)
  629.         return (unative_t) rc;
  630.  
  631.     kernel_uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t), 0);
  632.     rc = copy_from_uspace(kernel_uarg, uspace_uarg, sizeof(uspace_arg_t));
  633.     if (rc != 0) {
  634.         free(kernel_uarg);
  635.         return (unative_t) rc;
  636.     }
  637.  
  638.     if ((t = thread_create(uinit, kernel_uarg, TASK, THREAD_FLAG_USPACE, namebuf))) {
  639.         tid = t->tid;
  640.         thread_ready(t);
  641.         return (unative_t) tid;
  642.     } else {
  643.         free(kernel_uarg);
  644.     }
  645.  
  646.     return (unative_t) ENOMEM;
  647. }
  648.  
  649. /** Process syscall to terminate thread.
  650.  *
  651.  */
  652. unative_t sys_thread_exit(int uspace_status)
  653. {
  654.     thread_exit();
  655.     /* Unreachable */
  656.     return 0;
  657. }
  658.  
  659. /** @}
  660.  */
  661.