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Diffstat (limited to 'nuttx/sched/task_setup.c')
| -rw-r--r-- | nuttx/sched/task_setup.c | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/nuttx/sched/task_setup.c b/nuttx/sched/task_setup.c new file mode 100644 index 000000000..a37fb165a --- /dev/null +++ b/nuttx/sched/task_setup.c @@ -0,0 +1,347 @@ +/**************************************************************************** + * sched/task_setup.c + * + * Copyright (C) 2007-2012 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. 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. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "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 + * COPYRIGHT OWNER OR CONTRIBUTORS 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. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <sys/types.h> +#include <stdint.h> +#include <sched.h> +#include <string.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/arch.h> + +#include "os_internal.h" + +/**************************************************************************** + * Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/* This is the name for un-named tasks */ + +static const char g_noname[] = "<noname>"; + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +static int task_assignpid(FAR _TCB* tcb); + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: task_assignpid + * + * Description: + * This function assigns the next unique task ID to a task. + * + * Inputs: + * tcb - TCB of task + * + * Return: + * OK on success; ERROR on failure (errno is not set) + * + ****************************************************************************/ + +static int task_assignpid(FAR _TCB *tcb) +{ + pid_t next_pid; + int hash_ndx; + int tries; + + /* Disable pre-emption. This should provide sufficient protection + * for the following operation. + */ + + (void)sched_lock(); + + /* We'll try every allowable pid */ + + for (tries = 0; tries < CONFIG_MAX_TASKS; tries++) + { + /* Get the next process ID candidate */ + + next_pid = ++g_lastpid; + + /* Verify that the next_pid is in the valid range */ + + if (next_pid <= 0) + { + g_lastpid = 1; + next_pid = 1; + } + + /* Get the hash_ndx associated with the next_pid */ + + hash_ndx = PIDHASH(next_pid); + + /* Check if there is a (potential) duplicate of this pid */ + + if (!g_pidhash[hash_ndx].tcb) + { + g_pidhash[hash_ndx].tcb = tcb; + g_pidhash[hash_ndx].pid = next_pid; + tcb->pid = next_pid; + (void)sched_unlock(); + return OK; + } + } + + /* If we get here, then the g_pidhash[] table is completely full. + * We cannot allow another task to be started. + */ + + (void)sched_unlock(); + return ERROR; +} + +/**************************************************************************** + * Name: task_dupdspace + * + * Description: + * When a new task or thread is created from a PIC module, then that + * module (probably) intends the task or thread to execute in the same + * D-Space. This function will duplicate the D-Space for that purpose. + * + * Parameters: + * tcb - The TCB of the new task. + * + * Returned Value: + * None + * + * Assumptions: + * + ****************************************************************************/ + +#ifdef CONFIG_PIC +static inline void task_dupdspace(FAR _TCB *tcb) +{ + FAR _TCB *rtcb = (FAR _TCB*)g_readytorun.head; + if (rtcb->dspace != NULL) + { + /* Copy the D-Space structure reference and increment the reference + * count on the memory. The D-Space memory will persist until the + * last thread exits (see sched_releasetcb()). + */ + + tcb->dspace = rtcb->dspace; + tcb->dspace->crefs++; + } +} +#else +# define task_dupdspace(tcb) +#endif + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: task_schedsetup + * + * Description: + * This functions initializes a Task Control Block (TCB) in preparation + * for starting a new thread. + * + * task_schedsetup() is called from task_init(), task_start(), and + * pthread_create(); + * + * Input Parameters: + * tcb - Address of the new task's TCB + * priority - Priority of the new task + * entry - Entry point of a new task + * main - Application start point of the new task + * type - Type of the new thread: task, pthread, or kernel thread + * + * Return Value: + * OK on success; ERROR on failure. + * + * This function can only failure is it is unable to assign a new, unique + * task ID to the TCB (errno is not set). + * + ****************************************************************************/ + +int task_schedsetup(FAR _TCB *tcb, int priority, start_t start, main_t main) +{ + int ret; + + /* Assign a unique task ID to the task. */ + + ret = task_assignpid(tcb); + if (ret == OK) + { + /* Save task priority and entry point in the TCB */ + + tcb->init_priority = (uint8_t)priority; + tcb->sched_priority = (uint8_t)priority; +#ifdef CONFIG_PRIORITY_INHERITANCE + tcb->base_priority = (uint8_t)priority; +#endif + tcb->start = start; + tcb->entry.main = main; + + /* exec() and pthread_create() inherit the signal mask of the + * parent thread. I suppose that task_create() should as well. + */ + +#ifndef CONFIG_DISABLE_SIGNALS + (void)sigprocmask(SIG_SETMASK, NULL, &tcb->sigprocmask); +#endif + + /* Initialize the task state. It does not get a valid state + * until it is activated. + */ + + tcb->task_state = TSTATE_TASK_INVALID; + + /* Clone the parent tasks D-Space (if it was running PIC). This + * must be done before calling up_initial_state() so that the + * state setup will take the PIC address base into account. + */ + + task_dupdspace(tcb); + + /* Initialize the processor-specific portion of the TCB */ + + up_initial_state(tcb); + + /* Add the task to the inactive task list */ + + sched_lock(); + dq_addfirst((FAR dq_entry_t*)tcb, (dq_queue_t*)&g_inactivetasks); + tcb->task_state = TSTATE_TASK_INACTIVE; + sched_unlock(); + } + + return ret; +} + +/**************************************************************************** + * Name: task_argsetup + * + * Description: + * This functions sets up parameters in the Task Control + * Block (TCB) in preparation for starting a new thread. + * + * task_argsetup() is called only from task_init() and + * task_start() to create a new task. Argumens are + * cloned via strdup. + * + * Input Parameters: + * tcb - Address of the new task's TCB + * name - Name of the new task (not used) + * argv - A pointer to an array of input parameters. + * Up to CONFIG_MAX_TASK_ARG parameters may be + * provided. If fewer than CONFIG_MAX_TASK_ARG + * parameters are passed, the list should be + * terminated with a NULL argv[] value. + * If no parameters are required, argv may be NULL. + * + * Return Value: + * OK + * + ****************************************************************************/ + +int task_argsetup(FAR _TCB *tcb, const char *name, const char *argv[]) +{ + int i; + +#if CONFIG_TASK_NAME_SIZE > 0 + /* Give a name to the unnamed tasks */ + + if (!name) + { + name = (char *)g_noname; + } + + /* Copy the name into the TCB */ + + strncpy(tcb->name, name, CONFIG_TASK_NAME_SIZE); + + /* Save the name as the first argument */ + + tcb->argv[0] = tcb->name; +#else + /* Save the name as the first argument */ + + tcb->argv[0] = (char *)g_noname; +#endif /* CONFIG_TASK_NAME_SIZE */ + + /* For tasks, the life of the argument must be as long as + * the life of the task and the arguments must be strings. + * So for tasks, we have to to dup the strings. + * + * The first NULL argument terminates the list of + * arguments. The argv pointer may be NULL if no + * parameters are passed. + */ + + i = 1; + if (argv) + { + for (; i < CONFIG_MAX_TASK_ARGS+1 && argv[i-1]; i++) + { + tcb->argv[i] = strdup(argv[i-1]); + } + } + + /* Nullify any unused argument storage */ + + for (; i < CONFIG_MAX_TASK_ARGS+1; i++) + { + tcb->argv[i] = NULL; + } + + return OK; +} |