/**************************************************************************** * sched/task_setup.c * * Copyright (C) 2007-2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include #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[] = ""; /**************************************************************************** * 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_saveparent * * Description: * Save the task ID of the parent task in the child task's TCB. * * Parameters: * tcb - The TCB of the new, child task. * * Returned Value: * None * * Assumptions: * The parent of the new task is the task at the head of the ready-to-run * list. * ****************************************************************************/ #ifdef CONFIG_SCHED_HAVE_PARENT static inline void task_saveparent(FAR _TCB *tcb) { FAR _TCB *rtcb = (FAR _TCB*)g_readytorun.head; tcb->parent = rtcb->pid; } #else # define task_saveparent(tcb) #endif /**************************************************************************** * 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: * The parent of the new task is the task at the head of the ready-to-run * list. * ****************************************************************************/ #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; /* Save the task ID of the parent task in the TCB */ task_saveparent(tcb); /* exec(), pthread_create(), task_create(), and vfork() all * inherit the signal mask of the parent thread. */ #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; }