/**************************************************************************** * sched/task/task_setup.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #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 Data ****************************************************************************/ /* This is the name for un-named tasks */ static const char g_noname[] = ""; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: nxtask_assign_pid * * Description: * This function assigns the next unique task ID to a task. * * Input Parameters: * tcb - TCB of task * * Returned Value: * OK on success; ERROR on failure (errno is not set) * ****************************************************************************/ static int nxtask_assign_pid(FAR struct tcb_s *tcb) { FAR struct tcb_s **pidhash; pid_t next_pid; int hash_ndx; int i; /* NOTE: * ERROR means that the g_pidhash[] table is completely full. * We cannot allow another task to be started. */ /* Protect the following operation with a critical section * because g_pidhash is accessed from an interrupt context */ irqstate_t flags = enter_critical_section(); /* We'll try every allowable pid */ retry: /* Get the next process ID candidate */ next_pid = g_lastpid + 1; for (i = 0; i < g_npidhash; i++) { /* Verify that the next_pid is in the valid range */ if (next_pid <= 0) { 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]) { /* Assign this PID to the task */ g_pidhash[hash_ndx] = tcb; tcb->pid = next_pid; g_lastpid = next_pid; leave_critical_section(flags); return OK; } next_pid++; } /* If we get here, then the g_pidhash[] table is completely full. * We will alloc new space and copy original g_pidhash to it to * expand space. */ pidhash = kmm_zalloc(g_npidhash * 2 * sizeof(*pidhash)); if (pidhash == NULL) { leave_critical_section(flags); return -ENOMEM; } g_npidhash *= 2; /* All original pid and hash_ndx are mismatch, * so we need to rebuild their relationship */ for (i = 0; i < g_npidhash / 2; i++) { hash_ndx = PIDHASH(g_pidhash[i]->pid); DEBUGASSERT(pidhash[hash_ndx] == NULL); pidhash[hash_ndx] = g_pidhash[i]; } /* Release resource for original g_pidhash, using new g_pidhash */ kmm_free(g_pidhash); g_pidhash = pidhash; /* Let's try every allowable pid again */ goto retry; } /**************************************************************************** * Name: nxtask_inherit_affinity * * Description: * exec(), task_create(), and vfork() all inherit the affinity mask from * the parent thread. This is the default for pthread_create() as well * but the affinity mask can be specified in the pthread attributes as * well. pthread_setup() will have to fix up the affinity mask in this * case. * * Input 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 assigned task * list for the current CPU. * ****************************************************************************/ #ifdef CONFIG_SMP static inline void nxtask_inherit_affinity(FAR struct tcb_s *tcb) { FAR struct tcb_s *rtcb = this_task(); tcb->affinity = rtcb->affinity; } #else # define nxtask_inherit_affinity(tcb) #endif /**************************************************************************** * Name: nxtask_save_parent * * Description: * Save the task ID of the parent task in the child task's group and * allocate a child status structure to catch the child task's exit * status. * * Input 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 nxtask_save_parent(FAR struct tcb_s *tcb, uint8_t ttype) { DEBUGASSERT(tcb != NULL && tcb->group != NULL); /* Only newly created tasks (and kernel threads) have parents. None of * this logic applies to pthreads with reside in the same group as the * parent and share that same child/parent relationships. */ #ifndef CONFIG_DISABLE_PTHREAD if ((tcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_PTHREAD) #endif { /* Get the TCB of the parent task. In this case, the calling task. */ FAR struct tcb_s *rtcb = this_task(); DEBUGASSERT(rtcb != NULL && rtcb->group != NULL); /* Save the PID of the parent tasks' task group in the child's task * group. Copy the ID from the parent's task group structure to * child's task group. */ tcb->group->tg_ppid = rtcb->group->tg_pid; #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_find_child(rtcb->group, tcb->pid); DEBUGASSERT(child == NULL); if (child == NULL) { /* Allocate a new status structure */ child = group_alloc_child(); } /* Did we successfully find/allocate the child status structure? */ DEBUGASSERT(child != NULL); if (child != NULL) { /* Yes.. Initialize the structure */ child->ch_flags = ttype; child->ch_pid = tcb->pid; child->ch_status = 0; /* Add the entry into the group's list of children */ group_add_child(rtcb->group, child); } } #else /* CONFIG_SCHED_CHILD_STATUS */ /* Child status is not retained. Simply keep track of the number * child tasks created. */ DEBUGASSERT(rtcb->group->tg_nchildren < UINT16_MAX); rtcb->group->tg_nchildren++; #endif /* CONFIG_SCHED_CHILD_STATUS */ } } #else # define nxtask_save_parent(tcb,ttype) #endif /**************************************************************************** * Name: nxtask_dup_dspace * * 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. * * Input 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 nxtask_dup_dspace(FAR struct tcb_s *tcb) { FAR struct tcb_s *rtcb = this_task(); 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 nxsched_release_tcb()). */ tcb->dspace = rtcb->dspace; tcb->dspace->crefs++; } } #else # define nxtask_dup_dspace(tcb) #endif /**************************************************************************** * Name: nxthread_setup_scheduler * * Description: * This functions initializes the common portions of the Task Control Block * (TCB) in preparation for starting a new thread. * * nxthread_setup_scheduler() is called from nxtask_setup_scheduler() and * pthread_setup_scheduler(). * * 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 * * Returned 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 nxthread_setup_scheduler(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 = nxtask_assign_pid(tcb); if (ret == OK) { /* Save task priority and entry point in the TCB */ tcb->sched_priority = (uint8_t)priority; tcb->init_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; /* Set the appropriate scheduling policy in the TCB */ tcb->flags &= ~TCB_FLAG_POLICY_MASK; #if CONFIG_RR_INTERVAL > 0 tcb->flags |= TCB_FLAG_SCHED_RR; tcb->timeslice = MSEC2TICK(CONFIG_RR_INTERVAL); #else tcb->flags |= TCB_FLAG_SCHED_FIFO; #endif #ifdef CONFIG_CANCELLATION_POINTS /* Set the deferred cancellation type */ tcb->flags |= TCB_FLAG_CANCEL_DEFERRED; #endif /* Save the task ID of the parent task in the TCB and allocate * a child status structure. */ nxtask_save_parent(tcb, ttype); #ifdef CONFIG_SMP /* exec(), task_create(), and vfork() all inherit the affinity mask * from the parent thread. This is the default for pthread_create() * as well but the affinity mask can be specified in the pthread * attributes as well. pthread_create() will have to fix up the * affinity mask in this case. */ nxtask_inherit_affinity(tcb); #endif /* exec(), pthread_create(), task_create(), and vfork() all * inherit the signal mask of the parent thread. */ nxsig_procmask(SIG_SETMASK, NULL, &tcb->sigprocmask); /* 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. */ nxtask_dup_dspace(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, (FAR dq_queue_t *)&g_inactivetasks); tcb->task_state = TSTATE_TASK_INACTIVE; sched_unlock(); } return ret; } /**************************************************************************** * Name: nxtask_setup_name * * Description: * Assign the task name. * * Input Parameters: * tcb - Address of the new task's TCB * name - Name of the new task * * Returned Value: * None * ****************************************************************************/ #if CONFIG_TASK_NAME_SIZE > 0 static void nxtask_setup_name(FAR struct task_tcb_s *tcb, FAR const char *name) { /* Copy the name into the TCB */ strncpy(tcb->cmn.name, name, CONFIG_TASK_NAME_SIZE); tcb->cmn.name[CONFIG_TASK_NAME_SIZE] = '\0'; } #else # define nxtask_setup_name(t,n) #endif /* CONFIG_TASK_NAME_SIZE */ /**************************************************************************** * Name: nxtask_setup_stackargs * * Description: * This functions is called only from nxtask_setup_arguments() 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. The arrau should be * terminated with a NULL argv[] value. If no parameters are * required, argv may be NULL. * * Returned Value: * Zero (OK) on success; a negated errno on failure. * ****************************************************************************/ static int nxtask_setup_stackargs(FAR struct task_tcb_s *tcb, FAR const char *name, FAR char * const argv[]) { FAR char **stackargv; FAR char *str; size_t strtablen; size_t argvlen; int nbytes; int argc; int i; /* 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 != NULL) { /* A NULL argument terminates the list */ while (argv[argc]) { /* Add the size of this argument (with NUL terminator). * Check each time if the accumulated size exceeds the * size of the allocated stack. */ strtablen += (strlen(argv[argc]) + 1); if (strtablen >= tcb->cmn.adj_stack_size) { return -ENAMETOOLONG; } /* 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[] array pointer in the TCB where it will be recovered later by * nxtask_start(). */ stackargv[argc + 1] = NULL; tcb->cmn.group->tg_info->argv = stackargv; return OK; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nxtask_setup_scheduler * * Description: * This functions initializes a Task Control Block (TCB) in preparation * for starting a new task. * * nxtask_setup_scheduler() is called from nxtask_init() and * nxtask_start(). * * Input Parameters: * tcb - Address of the new task's TCB * priority - Priority of the new task * start - Start-up function (probably nxtask_start()) * main - Application start point of the new task * ttype - Type of the new thread: task or kernel thread * * Returned 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 nxtask_setup_scheduler(FAR struct task_tcb_s *tcb, int priority, start_t start, main_t main, uint8_t ttype) { /* Perform common thread setup */ return nxthread_setup_scheduler((FAR struct tcb_s *)tcb, priority, start, (CODE void *)main, ttype); } /**************************************************************************** * Name: pthread_setup_scheduler * * Description: * This functions initializes a Task Control Block (TCB) in preparation * for starting a new pthread. * * pthread_setup_scheduler() 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 * * Returned 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_setup_scheduler(FAR struct pthread_tcb_s *tcb, int priority, start_t start, pthread_startroutine_t entry) { /* Perform common thread setup */ return nxthread_setup_scheduler((FAR struct tcb_s *)tcb, priority, start, (CODE void *)entry, TCB_FLAG_TTYPE_PTHREAD); } #endif /**************************************************************************** * Name: nxtask_setup_arguments * * Description: * This functions sets up parameters in the Task Control Block (TCB) in * preparation for starting a new thread. * * nxtask_setup_arguments() is called only from nxtask_init() and * nxtask_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. The array should be * terminated with a NULL argv[] value. If no parameters are * required, argv may be NULL. * * Returned Value: * OK * ****************************************************************************/ int nxtask_setup_arguments(FAR struct task_tcb_s *tcb, FAR const char *name, FAR char * const argv[]) { /* Give a name to the unnamed tasks */ if (!name) { name = (FAR char *)g_noname; } /* Setup the task name */ nxtask_setup_name(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 nxtask_setup_stackargs(tcb, name, argv); }