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| // Copyright 2016 The Fuchsia Authors
// Copyright (c) 2008-2015 Travis Geiselbrecht
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT
/**
* @file
* @brief Kernel threading
*
* This file is the core kernel threading interface.
*
* @defgroup thread Threads
* @{
*/
#include <kernel/thread.h>
#include <arch/exception.h>
#include <assert.h>
#include <debug.h>
#include <err.h>
#include <inttypes.h>
#include <kernel/atomic.h>
#include <kernel/dpc.h>
#include <kernel/mp.h>
#include <kernel/percpu.h>
#include <kernel/sched.h>
#include <kernel/stats.h>
#include <kernel/thread.h>
#include <kernel/timer.h>
#include <lib/counters.h>
#include <lib/heap.h>
#include <lib/ktrace.h>
#include <list.h>
#include <malloc.h>
#include <object/c_user_thread.h>
#include <platform.h>
#include <printf.h>
#include <string.h>
#include <target.h>
#include <vm/vm.h>
#include <zircon/types.h>
// kernel counters. TODO(cpu): remove LK-era counters
// The counters below never decrease.
//
// counts the number of thread_t succesfully created.
KCOUNTER(thread_create_count, "kernel.thread.create");
// counts the number of thread_t joined. Never decreases.
KCOUNTER(thread_join_count, "kernel.thread.join");
// counts the number of calls to suspend() that succeeded.
KCOUNTER(thread_suspend_count, "kernel.thread.suspend");
// counts the number of calls to resume() that succeeded.
KCOUNTER(thread_resume_count, "kernel.thread.resume");
/* global thread list */
static struct list_node thread_list = LIST_INITIAL_VALUE(thread_list);
/* master thread spinlock */
spin_lock_t thread_lock = SPIN_LOCK_INITIAL_VALUE;
/* local routines */
static void thread_exit_locked(thread_t* current_thread, int retcode) __NO_RETURN;
static void thread_do_suspend(void);
static void init_thread_struct(thread_t* t, const char* name) {
memset(t, 0, sizeof(thread_t));
t->magic = THREAD_MAGIC;
strlcpy(t->name, name, sizeof(t->name));
wait_queue_init(&t->retcode_wait_queue);
}
static void initial_thread_func(void) TA_REQ(thread_lock) __NO_RETURN;
static void initial_thread_func(void) {
int ret;
/* release the thread lock that was implicitly held across the reschedule */
spin_unlock(&thread_lock);
arch_enable_ints();
thread_t* ct = get_current_thread();
ret = ct->entry(ct->arg);
thread_exit(ret);
}
/**
* @brief Create a new thread
*
* This function creates a new thread. The thread is initially suspended, so you
* need to call thread_resume() to execute it.
*
* @param name Name of thread
* @param entry Entry point of thread
* @param arg Arbitrary argument passed to entry()
* @param priority Execution priority for the thread.
* @param stack_size Stack size for the thread.
* @param alt_trampoline If not NULL, an alternate trampoline for the thread
* to start on.
*
* Thread priority is an integer from 0 (lowest) to 31 (highest). Some standard
* prioritys are defined in <kernel/thread.h>:
*
* HIGHEST_PRIORITY
* DPC_PRIORITY
* HIGH_PRIORITY
* DEFAULT_PRIORITY
* LOW_PRIORITY
* IDLE_PRIORITY
* LOWEST_PRIORITY
*
* Stack size is typically set to DEFAULT_STACK_SIZE
*
* @return Pointer to thread object, or NULL on failure.
*/
thread_t* thread_create_etc(
thread_t* t,
const char* name,
thread_start_routine entry, void* arg,
int priority,
void* stack, void* unsafe_stack, size_t stack_size,
thread_trampoline_routine alt_trampoline) {
unsigned int flags = 0;
if (!t) {
<span style="font-family: monospace; padding: 2px; background: #ddd; display: inline-block">t = malloc(sizeof(thread_t)); // allocation dynamique …</span> if (!t)
return NULL;
flags |= THREAD_FLAG_FREE_STRUCT;
}
init_thread_struct(t, name);
t->entry = entry;
t->arg = arg;
t->state = THREAD_INITIAL;
t->signals = 0;
t->blocking_wait_queue = NULL;
t->blocked_status = ZX_OK;
t->interruptable = false;
t->curr_cpu = INVALID_CPU;
t->last_cpu = INVALID_CPU;
t->cpu_affinity = CPU_MASK_ALL;
t->retcode = 0;
wait_queue_init(&t->retcode_wait_queue);
sched_init_thread(t, priority);
/* create the stack */
if (!stack) {
if (THREAD_STACK_BOUNDS_CHECK) {
stack_size += THREAD_STACK_PADDING_SIZE;
flags |= THREAD_FLAG_DEBUG_STACK_BOUNDS_CHECK;
}
t->stack = malloc(stack_size);
if (!t->stack) {
if (flags & THREAD_FLAG_FREE_STRUCT)
free(t);
return NULL;
}
flags |= THREAD_FLAG_FREE_STACK;
if (THREAD_STACK_BOUNDS_CHECK) {
memset(t->stack, STACK_DEBUG_BYTE, THREAD_STACK_PADDING_SIZE);
}
} else {
t->stack = stack;
}
#if __has_feature(safe_stack)
if (!unsafe_stack) {
DEBUG_ASSERT(!stack);
DEBUG_ASSERT(flags & THREAD_FLAG_FREE_STACK);
t->unsafe_stack = malloc(stack_size);
if (!t->unsafe_stack) {
free(t->stack);
if (flags & THREAD_FLAG_FREE_STRUCT)
free(t);
return NULL;
}
if (THREAD_STACK_BOUNDS_CHECK) {
memset(t->unsafe_stack, STACK_DEBUG_BYTE, THREAD_STACK_PADDING_SIZE);
}
} else {
DEBUG_ASSERT(stack);
t->unsafe_stack = unsafe_stack;
}
#else
DEBUG_ASSERT(!unsafe_stack);
#endif
t->stack_size = stack_size;
/* save whether or not we need to free the thread struct and/or stack */
t->flags = flags;
if (likely(alt_trampoline == NULL)) {
alt_trampoline = initial_thread_func;
}
/* set up the initial stack frame */
arch_thread_initialize(t, (vaddr_t)alt_trampoline);
/* add it to the global thread list */
THREAD_LOCK(state);
list_add_head(&thread_list, &t->thread_list_node);
THREAD_UNLOCK(state);
kcounter_add(thread_create_count, 1u);
return t;
} |
