/**************************************************************************** * sched/task/task_setup.c * * Copyright (C) 2007-2014 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 "sched/sched.h" #include "pthread/pthread.h" #include "group/group.h" #include "task/task.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* This is an artificial limit to detect error conditions where an argv[] * list is not properly terminated. */ #define MAX_STACK_ARGS 256 /**************************************************************************** * 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 struct tcb_s* 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 struct tcb_s *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) { /* Assign this PID to the task */ g_pidhash[hash_ndx].tcb = tcb; g_pidhash[hash_ndx].pid = next_pid; #ifdef CONFIG_SCHED_CPULOAD g_pidhash[hash_ndx].ticks = 0; #endif 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 and allocate * a child status structure to catch the child task's exit status. * * Parameters: * tcb - The TCB of the new, child task. * ttype - Type of the new thread: task, pthread, or kernel thread * * 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 struct tcb_s *tcb, uint8_t ttype) { FAR struct tcb_s *rtcb = (FAR struct tcb_s*)g_readytorun.head; #if defined(HAVE_GROUP_MEMBERS) || defined(CONFIG_SCHED_CHILD_STATUS) DEBUGASSERT(tcb && tcb->group && rtcb->group); #else #endif #ifdef HAVE_GROUP_MEMBERS /* Save the ID of the parent tasks' task group in the child's task group. * Do nothing for pthreads. The parent and the child are both members of * the same task group. */ #ifndef CONFIG_DISABLE_PTHREAD if ((tcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_PTHREAD) #endif { /* This is a new task in a new task group, we have to copy the ID from * the parent's task group structure to child's task group. */ tcb->group->tg_pgid = rtcb->group->tg_gid; } #else DEBUGASSERT(tcb); /* Save the parent task's ID in the child task's TCB. I am not sure if * this makes sense for the case of pthreads or not, but I don't think it * is harmful in any event. */ tcb->ppid = rtcb->pid; #endif #ifdef CONFIG_SCHED_CHILD_STATUS /* Tasks can also suppress retention of their child status by applying * the SA_NOCLDWAIT flag with sigaction(). */ if ((rtcb->group->tg_flags && GROUP_FLAG_NOCLDWAIT) == 0) { FAR struct child_status_s *child; /* Make sure that there is not already a structure for this PID in the * parent TCB. There should not be. */ child = group_findchild(rtcb->group, tcb->pid); DEBUGASSERT(!child); if (!child) { /* Allocate a new status structure */ child = group_allocchild(); } /* Did we successfully find/allocate the child status structure? */ DEBUGASSERT(child); if (child) { /* Yes.. Initialize the structure */ child->ch_flags = ttype; child->ch_pid = tcb->pid; child->ch_status = 0; /* Add the entry into the TCB list of children */ group_addchild(rtcb->group, child); } } #else DEBUGASSERT(rtcb->nchildren < UINT16_MAX); rtcb->nchildren++; #endif } #else # define task_saveparent(tcb,ttype) #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 struct tcb_s *tcb) { FAR struct tcb_s *rtcb = (FAR struct tcb_s*)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 /**************************************************************************** * Name: thread_schedsetup * * Description: * This functions initializes the common portions of the Task Control Block * (TCB) in preparation for starting a new thread. * * thread_schedsetup() is called from task_schedsetup() and * pthread_schedsetup(). * * Input Parameters: * tcb - Address of the new task's TCB * priority - Priority of the new task * start - Thread startup routine * entry - Thread user entry point * ttype - 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). * ****************************************************************************/ static int thread_schedsetup(FAR struct tcb_s *tcb, int priority, start_t start, CODE void *entry, uint8_t ttype) { 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->sched_priority = (uint8_t)priority; #ifdef CONFIG_PRIORITY_INHERITANCE tcb->base_priority = (uint8_t)priority; #endif tcb->start = start; tcb->entry.main = (main_t)entry; /* Save the thread type. This setting will be needed in * up_initial_state() is called. */ ttype &= TCB_FLAG_TTYPE_MASK; tcb->flags &= ~TCB_FLAG_TTYPE_MASK; tcb->flags |= ttype; /* Save the task ID of the parent task in the TCB and allocate * a child status structure. */ task_saveparent(tcb, ttype); /* 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_namesetup * * Description: * Assign the task name. * * Input Parameters: * tcb - Address of the new task's TCB * name - Name of the new task * * Return Value: * None * ****************************************************************************/ #if CONFIG_TASK_NAME_SIZE > 0 static void task_namesetup(FAR struct task_tcb_s *tcb, FAR const char *name) { /* Give a name to the unnamed tasks */ if (!name) { name = (FAR char *)g_noname; } /* Copy the name into the TCB */ strncpy(tcb->cmn.name, name, CONFIG_TASK_NAME_SIZE); } #else # define task_namesetup(t,n) #endif /* CONFIG_TASK_NAME_SIZE */ /**************************************************************************** * Name: task_stackargsetup * * Description: * This functions is called only from task_argsetup() It will allocate * space on the new task's stack and will copy the argv[] array and all * strings to the task's stack where it is readily accessible to the * task. Data on the stack, on the other hand, is guaranteed to be * accessible no matter what privilege mode the task runs in. * * Input Parameters: * tcb - Address of the new task's TCB * 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: * Zero (OK) on success; a negated errno on failure. * ****************************************************************************/ static inline int task_stackargsetup(FAR struct task_tcb_s *tcb, FAR char * const argv[]) { FAR char **stackargv; FAR const char *name; FAR char *str; size_t strtablen; size_t argvlen; int nbytes; int argc; int i; /* Get the name string that we will use as the first argument */ #if CONFIG_TASK_NAME_SIZE > 0 name = tcb->cmn.name; #else name = (FAR const char *)g_noname; #endif /* CONFIG_TASK_NAME_SIZE */ /* Get the size of the task name (including the NUL terminator) */ strtablen = (strlen(name) + 1); /* Count the number of arguments and get the accumulated size of the * argument strings (including the null terminators). The argument count * does not include the task name in that will be in argv[0]. */ argc = 0; if (argv) { /* A NULL argument terminates the list */ while (argv[argc]) { /* Add the size of this argument (with NUL terminator) */ strtablen += (strlen(argv[argc]) + 1); /* Increment the number of args. Here is a sanity check to * prevent running away with an unterminated argv[] list. * MAX_STACK_ARGS should be sufficiently large that this never * happens in normal usage. */ if (++argc > MAX_STACK_ARGS) { return -E2BIG; } } } /* Allocate a stack frame to hold argv[] array and the strings. NOTE * that argc + 2 entries are needed: The number of arguments plus the * task name plus a NULL argv[] entry to terminate the list. */ argvlen = (argc + 2)*sizeof(FAR char*); stackargv = (FAR char **)up_stack_frame(&tcb->cmn, argvlen + strtablen); DEBUGASSERT(stackargv != NULL); if (stackargv == NULL) { return -ENOMEM; } /* Get the address of the string table that will lie immediately after * the argv[] array and mark it as a null string. */ str = (FAR char *)stackargv + argvlen; /* Copy the task name. Increment str to skip over the task name and its * NUL terminator in the string buffer. */ stackargv[0] = str; nbytes = strlen(name) + 1; strcpy(str, name); str += nbytes; /* Copy each argument */ for (i = 0; i < argc; i++) { /* Save the pointer to the location in the string buffer and copy * the argument into the buffer. Increment str to skip over the * argument and its NUL terminator in the string buffer. */ stackargv[i+1] = str; nbytes = strlen(argv[i]) + 1; strcpy(str, argv[i]); str += nbytes; } /* Put a terminator entry at the end of the argv[] array. Then save the * argv[] arry pointer in the TCB where it will be recovered later by * task_start(). */ stackargv[argc + 1] = NULL; tcb->argv = stackargv; return OK; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: task_schedsetup * * Description: * This functions initializes a Task Control Block (TCB) in preparation * for starting a new task. * * task_schedsetup() is called from task_init() and task_start(). * * Input Parameters: * tcb - Address of the new task's TCB * priority - Priority of the new task * start - Start-up function (probably task_start()) * main - Application start point of the new task * ttype - Type of the new thread: task 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 struct task_tcb_s *tcb, int priority, start_t start, main_t main, uint8_t ttype) { int ret; /* Perform common thread setup */ ret = thread_schedsetup((FAR struct tcb_s *)tcb, priority, start, (CODE void *)main, ttype); if (ret == OK) { /* Save task restart priority */ tcb->init_priority = (uint8_t)priority; } return ret; } /**************************************************************************** * Name: pthread_schedsetup * * Description: * This functions initializes a Task Control Block (TCB) in preparation * for starting a new pthread. * * pthread_schedsetup() is called from pthread_create(), * * Input Parameters: * tcb - Address of the new task's TCB * priority - Priority of the new task * start - Start-up function (probably pthread_start()) * entry - Entry point of the new pthread * ttype - 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). * ****************************************************************************/ #ifndef CONFIG_DISABLE_PTHREAD int pthread_schedsetup(FAR struct pthread_tcb_s *tcb, int priority, start_t start, pthread_startroutine_t entry) { /* Perform common thread setup */ return thread_schedsetup((FAR struct tcb_s *)tcb, priority, start, (CODE void *)entry, TCB_FLAG_TTYPE_PTHREAD); } #endif /**************************************************************************** * 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. In the "normal" case, the argv[] array is a * structure in the TCB, the arguments are cloned via strdup. * * In the kernel build case, the argv[] array and all strings are copied * to the task's stack. This is done because the TCB (and kernel allocated * strings) are only accessible in kernel-mode. Data on the stack, on the * other hand, is guaranteed to be accessible no matter what mode the * task runs in. * * 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 struct task_tcb_s *tcb, FAR const char *name, FAR char * const argv[]) { /* Setup the task name */ task_namesetup(tcb, name); /* Copy the argv[] array and all strings are to the task's stack. Data on * the stack is guaranteed to be accessible by the ask no matter what * privilege mode the task runs in. */ return task_stackargsetup(tcb, argv); }