/*
* Copyright (c) 2010 Jakub Jermar
* Copyright (c) 2018 Jiri Svoboda
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup kernel_generic_proc
* @{
*/
/**
* @file
* @brief Thread management functions.
*/
#include <assert.h>
#include <proc/scheduler.h>
#include <proc/thread.h>
#include <proc/task.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <arch/asm.h>
#include <arch/cycle.h>
#include <arch.h>
#include <synch/spinlock.h>
#include <synch/waitq.h>
#include <synch/syswaitq.h>
#include <cpu.h>
#include <str.h>
#include <context.h>
#include <adt/list.h>
#include <adt/odict.h>
#include <time/clock.h>
#include <time/timeout.h>
#include <time/delay.h>
#include <config.h>
#include <arch/interrupt.h>
#include <smp/ipi.h>
#include <atomic.h>
#include <memw.h>
#include <stdio.h>
#include <stdlib.h>
#include <main/uinit.h>
#include <syscall/copy.h>
#include <errno.h>
#include <debug.h>
#include <halt.h>
/** Thread states */
const char *thread_states[] = {
"Invalid",
"Running",
"Sleeping",
"Ready",
"Entering",
"Exiting",
"Lingering"
};
/** Lock protecting the @c threads ordered dictionary .
*
* For locking rules, see declaration thereof.
*/
IRQ_SPINLOCK_INITIALIZE(threads_lock);
/** Ordered dictionary of all threads by their address (i.e. pointer to
* the thread_t structure).
*
* When a thread is found in the @c threads ordered dictionary, it is
* guaranteed to exist as long as the @c threads_lock is held.
*
* Members are of type thread_t.
*
* This structure contains weak references. Any reference from it must not leave
* threads_lock critical section unless strengthened via thread_try_ref().
*/
odict_t threads;
IRQ_SPINLOCK_STATIC_INITIALIZE(tidlock);
static thread_id_t last_tid = 0;
static slab_cache_t *thread_cache;
static void *threads_getkey(odlink_t *);
static int threads_cmp(void *, void *);
/** Initialization and allocation for thread_t structure
*
*/
static errno_t thr_constructor(void *obj, unsigned int kmflags)
{
thread_t *thread = (thread_t *) obj;
link_initialize(&thread->rq_link);
link_initialize(&thread->wq_link);
link_initialize(&thread->th_link);
/* call the architecture-specific part of the constructor */
thr_constructor_arch(thread);
/*
* Allocate the kernel stack from the low-memory to prevent an infinite
* nesting of TLB-misses when accessing the stack from the part of the
* TLB-miss handler written in C.
*
* Note that low-memory is safe to be used for the stack as it will be
* covered by the kernel identity mapping, which guarantees not to
* nest TLB-misses infinitely (either via some hardware mechanism or
* by the construction of the assembly-language part of the TLB-miss
* handler).
*
* This restriction can be lifted once each architecture provides
* a similar guarantee, for example, by locking the kernel stack
* in the TLB whenever it is allocated from the high-memory and the
* thread is being scheduled to run.
*/
kmflags |= FRAME_LOWMEM;
kmflags &= ~FRAME_HIGHMEM;
/*
* NOTE: All kernel stacks must be aligned to STACK_SIZE,
* see CURRENT.
*/
uintptr_t stack_phys =
frame_alloc(STACK_FRAMES, kmflags, STACK_SIZE - 1);
if (!stack_phys)
return ENOMEM;
thread->kstack = (uint8_t *) PA2KA(stack_phys);
#ifdef CONFIG_UDEBUG
mutex_initialize(&thread->udebug.lock, MUTEX_PASSIVE);
#endif
return EOK;
}
/** Destruction of thread_t object */
static size_t thr_destructor(void *obj)
{
thread_t *thread = (thread_t *) obj;
/* call the architecture-specific part of the destructor */
thr_destructor_arch(thread);
frame_free(KA2PA(thread->kstack), STACK_FRAMES);
return STACK_FRAMES; /* number of frames freed */
}
/** Initialize threads
*
* Initialize kernel threads support.
*
*/
void thread_init(void)
{
THREAD = NULL;
atomic_store(&nrdy, 0);
thread_cache = slab_cache_create("thread_t", sizeof(thread_t), _Alignof(thread_t),
thr_constructor, thr_destructor, 0);
odict_initialize(&threads, threads_getkey, threads_cmp);
}
/** Wire thread to the given CPU
*
* @param cpu CPU to wire the thread to.
*
*/
void thread_wire(thread_t *thread, cpu_t *cpu)
{
ipl_t ipl = interrupts_disable();
atomic_set_unordered(&thread->cpu, cpu);
thread->nomigrate++;
interrupts_restore(ipl);
}
/** Start a thread that wasn't started yet since it was created.
*
* @param thread A reference to the newly created thread.
*/
void thread_start(thread_t *thread)
{
assert(atomic_get_unordered(&thread->state) == Entering);
thread_requeue_sleeping(thread_ref(thread));
}
/** Create new thread
*
* Create a new thread.
*
* @param func Thread's implementing function.
* @param arg Thread's implementing function argument.
* @param task Task to which the thread belongs. The caller must
* guarantee that the task won't cease to exist during the
* call. The task's lock may not be held.
* @param flags Thread flags.
* @param name Symbolic name (a copy is made).
*
* @return New thread's structure on success, NULL on failure.
*
*/
thread_t *thread_create(void (*func)(void *), void *arg, task_t *task,
thread_flags_t flags, const char *name)
{
thread_t *thread = (thread_t *) slab_alloc(thread_cache, FRAME_ATOMIC);
if (!thread)
return NULL;
refcount_init(&thread->refcount);
if (thread_create_arch(thread, flags) != EOK) {
slab_free(thread_cache, thread);
return NULL;
}
/* Not needed, but good for debugging */
memsetb(thread->kstack, STACK_SIZE, 0);
irq_spinlock_lock(&tidlock, true);
thread->tid = ++last_tid;
irq_spinlock_unlock(&tidlock, true);
context_create(&thread->saved_context, thread_main_func,
thread->kstack, STACK_SIZE);
current_initialize((current_t *) thread->kstack);
str_cpy(thread->name, THREAD_NAME_BUFLEN, name);
thread->thread_code = func;
thread->thread_arg = arg;
thread->ucycles = ATOMIC_TIME_INITIALIZER();
thread->kcycles = ATOMIC_TIME_INITIALIZER();
thread->uncounted =
((flags & THREAD_FLAG_UNCOUNTED) == THREAD_FLAG_UNCOUNTED);
atomic_init(&thread->priority, 0);
atomic_init(&thread->cpu, NULL);
thread->stolen = false;
thread->uspace =
((flags & THREAD_FLAG_USPACE) == THREAD_FLAG_USPACE);
thread->nomigrate = 0;
atomic_init(&thread->state, Entering);
atomic_init(&thread->sleep_queue, NULL);
thread->in_copy_from_uspace = false;
thread->in_copy_to_uspace = false;
thread->interrupted = false;
atomic_init(&thread->sleep_state, SLEEP_INITIAL);
waitq_initialize(&thread->join_wq);
thread->task = task;
thread->fpu_context_exists = false;
odlink_initialize(&thread->lthreads);
#ifdef CONFIG_UDEBUG
/* Initialize debugging stuff */
atomic_init(&thread->btrace, false);
udebug_thread_initialize(&thread->udebug);
#endif
if ((flags & THREAD_FLAG_NOATTACH) != THREAD_FLAG_NOATTACH)
thread_attach(thread, task);
return thread;
}
/** Destroy thread memory structure
*
* Detach thread from all queues, cpus etc. and destroy it.
*
* @param obj Thread to be destroyed.
*
*/
static void thread_destroy(void *obj)
{
thread_t *thread = (thread_t *) obj;
assert_link_not_used(&thread->rq_link);
assert_link_not_used(&thread->wq_link);
assert(thread->task);
ipl_t ipl = interrupts_disable();
/* Remove thread from global list. */
irq_spinlock_lock(&threads_lock, false);
odict_remove(&thread->lthreads);
irq_spinlock_unlock(&threads_lock, false);
/* Remove thread from task's list and accumulate accounting. */
irq_spinlock_lock(&thread->task->lock, false);
list_remove(&thread->th_link);
/*
* No other CPU has access to this thread anymore, so we don't need
* thread->lock for accessing thread's fields after this point.
*/
if (!thread->uncounted) {
thread->task->ucycles += atomic_time_read(&thread->ucycles);
thread->task->kcycles += atomic_time_read(&thread->kcycles);
}
irq_spinlock_unlock(&thread->task->lock, false);
assert((atomic_get_unordered(&thread->state) == Exiting) || (atomic_get_unordered(&thread->state) == Lingering));
/* Clear cpu->fpu_owner if set to this thread. */
#ifdef CONFIG_FPU_LAZY
cpu_t *cpu = atomic_get_unordered(&thread->cpu);
if (cpu) {
/*
* We need to lock for this because the old CPU can concurrently try
* to dump this thread's FPU state, in which case we need to wait for
* it to finish. An atomic compare-and-swap wouldn't be enough.
*/
irq_spinlock_lock(&cpu->fpu_lock, false);
if (atomic_get_unordered(&cpu->fpu_owner) == thread)
atomic_set_unordered(&cpu->fpu_owner, NULL);
irq_spinlock_unlock(&cpu->fpu_lock, false);
}
#endif
interrupts_restore(ipl);
/*
* Drop the reference to the containing task.
*/
task_release(thread->task);
thread->task = NULL;
slab_free(thread_cache, thread);
}
void thread_put(thread_t *thread)
{
if (refcount_down(&thread->refcount)) {
thread_destroy(thread);
}
}
/** Make the thread visible to the system.
*
* Attach the thread structure to the current task and make it visible in the
* threads_tree.
*
* @param t Thread to be attached to the task.
* @param task Task to which the thread is to be attached.
*
*/
void thread_attach(thread_t *thread, task_t *task)
{
ipl_t ipl = interrupts_disable();
/*
* Attach to the specified task.
*/
irq_spinlock_lock(&task->lock, false);
/* Hold a reference to the task. */
task_hold(task);
/* Must not count kbox thread into lifecount */
if (thread->uspace)
atomic_inc(&task->lifecount);
list_append(&thread->th_link, &task->threads);
irq_spinlock_unlock(&task->lock, false);
/*
* Register this thread in the system-wide dictionary.
*/
irq_spinlock_lock(&threads_lock, false);
odict_insert(&thread->lthreads, &threads, NULL);
irq_spinlock_unlock(&threads_lock, false);
interrupts_restore(ipl);
}
/** Terminate thread.
*
* End current thread execution and switch it to the exiting state.
* All pending timeouts are executed.
*
*/
void thread_exit(void)
{
if (THREAD->uspace) {
#ifdef CONFIG_UDEBUG
/* Generate udebug THREAD_E event */
udebug_thread_e_event();
/*
* This thread will not execute any code or system calls from
* now on.
*/
udebug_stoppable_begin();
#endif
if (atomic_predec(&TASK->lifecount) == 0) {
/*
* We are the last userspace thread in the task that
* still has not exited. With the exception of the
* moment the task was created, new userspace threads
* can only be created by threads of the same task.
* We are safe to perform cleanup.
*
*/
ipc_cleanup();
sys_waitq_task_cleanup();
LOG("Cleanup of task %" PRIu64 " completed.", TASK->taskid);
}
}
scheduler_enter(Exiting);
unreachable();
}
/** Interrupts an existing thread so that it may exit as soon as possible.
*
* Threads that are blocked waiting for a synchronization primitive
* are woken up with a return code of EINTR if the
* blocking call was interruptable. See waitq_sleep_timeout().
*
* Interrupted threads automatically exit when returning back to user space.
*
* @param thread A valid thread object.
*/
void thread_interrupt(thread_t *thread)
{
assert(thread != NULL);
thread->interrupted = true;
thread_wakeup(thread);
}
/** Prepare for putting the thread to sleep.
*
* @returns whether the thread is currently terminating. If THREAD_OK
* is returned, the thread is guaranteed to be woken up instantly if the thread
* is terminated at any time between this function's return and
* thread_wait_finish(). If THREAD_TERMINATING is returned, the thread can still
* go to sleep, but doing so will delay termination.
*/
thread_termination_state_t thread_wait_start(void)
{
assert(THREAD != NULL);
/*
* This is an exchange rather than a store so that we can use the acquire
* semantics, which is needed to ensure that code after this operation sees
* memory ops made before thread_wakeup() in other thread, if that wakeup
* was reset by this operation.
*
* In particular, we need this to ensure we can't miss the thread being
* terminated concurrently with a synchronization primitive preparing to
* sleep.
*/
(void) atomic_exchange_explicit(&THREAD->sleep_state, SLEEP_INITIAL,
memory_order_acquire);
return THREAD->interrupted ? THREAD_TERMINATING : THREAD_OK;
}
static void thread_wait_timeout_callback(void *arg)
{
thread_wakeup(arg);
}
/**
* Suspends this thread's execution until thread_wakeup() is called on it,
* or deadline is reached.
*
* The way this would normally be used is that the current thread call
* thread_wait_start(), and if interruption has not been signaled, stores
* a reference to itself in a synchronized structure (such as waitq).
* After that, it releases any spinlocks it might hold and calls this function.
*
* The thread doing the wakeup will acquire the thread's reference from said
* synchronized structure and calls thread_wakeup() on it.
*
* Notably, there can be more than one thread performing wakeup.
* The number of performed calls to thread_wakeup(), or their relative
* ordering with thread_wait_finish(), does not matter. However, calls to
* thread_wakeup() are expected to be synchronized with thread_wait_start()
* with which they are associated, otherwise wakeups may be missed.
* However, the operation of thread_wakeup() is defined at any time,
* synchronization notwithstanding (in the sense of C un/defined behavior),
* and is in fact used to interrupt waiting threads by external events.
* The waiting thread must operate correctly in face of spurious wakeups,
* and clean up its reference in the synchronization structure if necessary.
*
* Returns THREAD_WAIT_TIMEOUT if timeout fired, which is a necessary condition
* for it to have been waken up by the timeout, but the caller must assume
* that proper wakeups, timeouts and interrupts may occur concurrently, so
* the fact timeout has been registered does not necessarily mean the thread
* has not been woken up or interrupted.
*/
thread_wait_result_t thread_wait_finish(deadline_t deadline)
{
assert(THREAD != NULL);
timeout_t timeout;
/* Extra check to avoid going to scheduler if we don't need to. */
if (atomic_load_explicit(&THREAD->sleep_state, memory_order_acquire) !=
SLEEP_INITIAL)
return THREAD_WAIT_SUCCESS;
if (deadline != DEADLINE_NEVER) {
timeout_initialize(&timeout);
timeout_register_deadline(&timeout, deadline,
thread_wait_timeout_callback, THREAD);
}
scheduler_enter(Sleeping);
if (deadline != DEADLINE_NEVER && !timeout_unregister(&timeout)) {
return THREAD_WAIT_TIMEOUT;
} else {
return THREAD_WAIT_SUCCESS;
}
}
void thread_wakeup(thread_t *thread)
{
assert(thread != NULL);
int state = atomic_exchange_explicit(&thread->sleep_state, SLEEP_WOKE,
memory_order_acq_rel);
if (state == SLEEP_ASLEEP) {
/*
* Only one thread gets to do this.
* The reference consumed here is the reference implicitly passed to
* the waking thread by the sleeper in thread_wait_finish().
*/
thread_requeue_sleeping(thread);
}
}
/** Prevent the current thread from being migrated to another processor. */
void thread_migration_disable(void)
{
ipl_t ipl = interrupts_disable();
assert(THREAD);
THREAD->nomigrate++;
interrupts_restore(ipl);
}
/** Allow the current thread to be migrated to another processor. */
void thread_migration_enable(void)
{
ipl_t ipl = interrupts_disable();
assert(THREAD);
assert(THREAD->nomigrate > 0);
if (THREAD->nomigrate > 0)
THREAD->nomigrate--;
interrupts_restore(ipl);
}
/** Thread sleep
*
* Suspend execution of the current thread.
*
* @param sec Number of seconds to sleep.
*
*/
void thread_sleep(uint32_t sec)
{
/*
* Sleep in 1000 second steps to support
* full argument range
*/
while (sec > 0) {
uint32_t period = (sec > 1000) ? 1000 : sec;
thread_usleep(period * 1000000);
sec -= period;
}
}
errno_t thread_join(thread_t *thread)
{
return thread_join_timeout(thread, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE);
}
/** Wait for another thread to exit.
* After successful wait, the thread reference is destroyed.
*
* @param thread Thread to join on exit.
* @param usec Timeout in microseconds.
* @param flags Mode of operation.
*
* @return An error code from errno.h or an error code from synch.h.
*
*/
errno_t thread_join_timeout(thread_t *thread, uint32_t usec, unsigned int flags)
{
assert(thread != NULL);
if (thread == THREAD)
return EINVAL;
errno_t rc = _waitq_sleep_timeout(&thread->join_wq, usec, flags);
if (rc == EOK)
thread_put(thread);
return rc;
}
void thread_detach(thread_t *thread)
{
thread_put(thread);
}
/** Thread usleep
*
* Suspend execution of the current thread.
*
* @param usec Number of microseconds to sleep.
*
*/
void thread_usleep(uint32_t usec)
{
waitq_t wq;
waitq_initialize(&wq);
(void) waitq_sleep_timeout(&wq, usec);
}
/** Allow other threads to run. */
void thread_yield(void)
{
assert(THREAD != NULL);
scheduler_enter(Running);
}
static void thread_print(thread_t *thread, bool additional)
{
uint64_t ucycles, kcycles;
char usuffix, ksuffix;
order_suffix(atomic_time_read(&thread->ucycles), &ucycles, &usuffix);
order_suffix(atomic_time_read(&thread->kcycles), &kcycles, &ksuffix);
state_t state = atomic_get_unordered(&thread->state);
char *name;
if (str_cmp(thread->name, "uinit") == 0)
name = thread->task->name;
else
name = thread->name;
if (additional)
printf("%-8" PRIu64 " %p %p %9" PRIu64 "%c %9" PRIu64 "%c ",
thread->tid, thread->thread_code, thread->kstack,
ucycles, usuffix, kcycles, ksuffix);
else
printf("%-8" PRIu64 " %-14s %p %-8s %p %-5" PRIu32 "\n",
thread->tid, name, thread, thread_states[state],
thread->task, thread->task->container);
if (additional) {
cpu_t *cpu = atomic_get_unordered(&thread->cpu);
if (cpu)
printf("%-5u", cpu->id);
else
printf("none ");
if (state == Sleeping) {
printf(" %p", thread->sleep_queue);
}
printf("\n");
}
}
/** Print list of threads debug info
*
* @param additional Print additional information.
*
*/
void thread_print_list(bool additional)
{
thread_t *thread;
/* Accessing system-wide threads list through thread_first()/thread_next(). */
irq_spinlock_lock(&threads_lock, true);
if (sizeof(void *) <= 4) {
if (additional)
printf("[id ] [code ] [stack ] [ucycles ] [kcycles ]"
" [cpu] [waitqueue]\n");
else
printf("[id ] [name ] [address ] [state ] [task ]"
" [ctn]\n");
} else {
if (additional) {
printf("[id ] [code ] [stack ] [ucycles ] [kcycles ]"
" [cpu] [waitqueue ]\n");
} else
printf("[id ] [name ] [address ] [state ]"
" [task ] [ctn]\n");
}
thread = thread_first();
while (thread != NULL) {
thread_print(thread, additional);
thread = thread_next(thread);
}
irq_spinlock_unlock(&threads_lock, true);
}
static bool thread_exists(thread_t *thread)
{
odlink_t *odlink = odict_find_eq(&threads, thread, NULL);
return odlink != NULL;
}
/** Check whether the thread exists, and if so, return a reference to it.
*/
thread_t *thread_try_get(thread_t *thread)
{
irq_spinlock_lock(&threads_lock, true);
if (thread_exists(thread)) {
/* Try to strengthen the reference. */
thread = thread_try_ref(thread);
} else {
thread = NULL;
}
irq_spinlock_unlock(&threads_lock, true);
return thread;
}
/** Update accounting of current thread.
*
* Note that thread_lock on THREAD must be already held and
* interrupts must be already disabled.
*
* @param user True to update user accounting, false for kernel.
*
*/
void thread_update_accounting(bool user)
{
assert(interrupts_disabled());
uint64_t time = get_cycle();
if (user)
atomic_time_increment(&THREAD->ucycles, time - THREAD->last_cycle);
else
atomic_time_increment(&THREAD->kcycles, time - THREAD->last_cycle);
THREAD->last_cycle = time;
}
/** Find thread structure corresponding to thread ID.
*
* The threads_lock must be already held by the caller of this function and
* interrupts must be disabled.
*
* The returned reference is weak.
* If the caller needs to keep it, thread_try_ref() must be used to upgrade
* to a strong reference _before_ threads_lock is released.
*
* @param id Thread ID.
*
* @return Thread structure address or NULL if there is no such thread ID.
*
*/
thread_t *thread_find_by_id(thread_id_t thread_id)
{
thread_t *thread;
assert(interrupts_disabled());
assert(irq_spinlock_locked(&threads_lock));
thread = thread_first();
while (thread != NULL) {
if (thread->tid == thread_id)
return thread;
thread = thread_next(thread);
}
return NULL;
}
/** Get count of threads.
*
* @return Number of threads in the system
*/
size_t thread_count(void)
{
assert(interrupts_disabled());
assert(irq_spinlock_locked(&threads_lock));
return odict_count(&threads);
}
/** Get first thread.
*
* @return Pointer to first thread or @c NULL if there are none.
*/
thread_t *thread_first(void)
{
odlink_t *odlink;
assert(interrupts_disabled());
assert(irq_spinlock_locked(&threads_lock));
odlink = odict_first(&threads);
if (odlink == NULL)
return NULL;
return odict_get_instance(odlink, thread_t, lthreads);
}
/** Get next thread.
*
* @param cur Current thread
* @return Pointer to next thread or @c NULL if there are no more threads.
*/
thread_t *thread_next(thread_t *cur)
{
odlink_t *odlink;
assert(interrupts_disabled());
assert(irq_spinlock_locked(&threads_lock));
odlink = odict_next(&cur->lthreads, &threads);
if (odlink == NULL)
return NULL;
return odict_get_instance(odlink, thread_t, lthreads);
}
#ifdef CONFIG_UDEBUG
void thread_stack_trace(thread_id_t thread_id)
{
irq_spinlock_lock(&threads_lock, true);
thread_t *thread = thread_try_ref(thread_find_by_id(thread_id));
irq_spinlock_unlock(&threads_lock, true);
if (thread == NULL) {
printf("No such thread.\n");
return;
}
/*
* Schedule a stack trace to be printed
* just before the thread is scheduled next.
*
* If the thread is sleeping then try to interrupt
* the sleep. Any request for printing an uspace stack
* trace from within the kernel should be always
* considered a last resort debugging means, therefore
* forcing the thread's sleep to be interrupted
* is probably justifiable.
*/
printf("Scheduling thread stack trace.\n");
atomic_set_unordered(&thread->btrace, true);
thread_wakeup(thread);
thread_put(thread);
}
#endif /* CONFIG_UDEBUG */
/** Get key function for the @c threads ordered dictionary.
*
* @param odlink Link
* @return Pointer to thread structure cast as 'void *'
*/
static void *threads_getkey(odlink_t *odlink)
{
thread_t *thread = odict_get_instance(odlink, thread_t, lthreads);
return (void *) thread;
}
/** Key comparison function for the @c threads ordered dictionary.
*
* @param a Pointer to thread A
* @param b Pointer to thread B
* @return -1, 0, 1 iff pointer to A is less than, equal to, greater than B
*/
static int threads_cmp(void *a, void *b)
{
if (a > b)
return -1;
else if (a == b)
return 0;
else
return +1;
}
/** Process syscall to create new thread.
* The started thread will have initial pc and sp set to the exact values passed
* to the syscall. The kernel will not touch any stack data below the stack
* pointer, but some architectures may require some space to be available
* for use above it. See userspace() in kernel, and <libarch/thread.h> in libc.
*
*/
sys_errno_t sys_thread_create(sysarg_t pc, sysarg_t sp,
uspace_ptr_char uspace_name, size_t name_len)
{
if (name_len > THREAD_NAME_BUFLEN - 1)
name_len = THREAD_NAME_BUFLEN - 1;
char namebuf[THREAD_NAME_BUFLEN];
errno_t rc = copy_from_uspace(namebuf, uspace_name, name_len);
if (rc != EOK)
return (sys_errno_t) rc;
namebuf[name_len] = 0;
/*
* In case of failure, kernel_uarg will be deallocated in this function.
* In case of success, kernel_uarg will be freed in uinit().
*/
uinit_arg_t *kernel_uarg = malloc(sizeof(uinit_arg_t));
if (!kernel_uarg)
return (sys_errno_t) ENOMEM;
kernel_uarg->pc = pc;
kernel_uarg->sp = sp;
// TODO: fix some unnecessary inconsistencies between architectures
thread_t *thread = thread_create(uinit, kernel_uarg, TASK,
THREAD_FLAG_USPACE | THREAD_FLAG_NOATTACH, namebuf);
if (!thread) {
free(kernel_uarg);
return (sys_errno_t) ENOMEM;
}
#ifdef CONFIG_UDEBUG
/*
* Generate udebug THREAD_B event and attach the thread.
* This must be done atomically (with the debug locks held),
* otherwise we would either miss some thread or receive
* THREAD_B events for threads that already existed
* and could be detected with THREAD_READ before.
*/
udebug_thread_b_event_attach(thread, TASK);
#else
thread_attach(thread, TASK);
#endif
thread_start(thread);
thread_put(thread);
return (sys_errno_t) EOK;
}
/** Process syscall to terminate thread.
*
*/
sys_errno_t sys_thread_exit(int uspace_status)
{
thread_exit();
}
/** Syscall for getting TID.
*
* @param uspace_thread_id Userspace address of 8-byte buffer where to store
* current thread ID.
*
* @return 0 on success or an error code from @ref errno.h.
*
*/
sys_errno_t sys_thread_get_id(uspace_ptr_thread_id_t uspace_thread_id)
{
/*
* No need to acquire lock on THREAD because tid
* remains constant for the lifespan of the thread.
*
*/
return (sys_errno_t) copy_to_uspace(uspace_thread_id, &THREAD->tid,
sizeof(THREAD->tid));
}
/** Syscall wrapper for sleeping. */
sys_errno_t sys_thread_usleep(uint32_t usec)
{
thread_usleep(usec);
return 0;
}
sys_errno_t sys_thread_udelay(uint32_t usec)
{
delay(usec);
return 0;
}
/** @}
*/