diff options
Diffstat (limited to 'nuttx/sched')
-rw-r--r-- | nuttx/sched/Kconfig | 77 | ||||
-rw-r--r-- | nuttx/sched/Makefile | 7 | ||||
-rw-r--r-- | nuttx/sched/clock_time2ticks.c | 42 | ||||
-rw-r--r-- | nuttx/sched/mq_initialize.c | 4 | ||||
-rw-r--r-- | nuttx/sched/os_bringup.c | 22 | ||||
-rw-r--r-- | nuttx/sched/os_internal.h | 6 | ||||
-rw-r--r-- | nuttx/sched/sched_addprioritized.c | 2 | ||||
-rw-r--r-- | nuttx/sched/sched_addreadytorun.c | 8 | ||||
-rw-r--r-- | nuttx/sched/sched_setuptaskfiles.c | 3 | ||||
-rw-r--r-- | nuttx/sched/sched_unlock.c | 1 | ||||
-rw-r--r-- | nuttx/sched/sched_wait.c | 90 | ||||
-rw-r--r-- | nuttx/sched/sched_waitid.c | 256 | ||||
-rw-r--r-- | nuttx/sched/sched_waitpid.c | 192 | ||||
-rw-r--r-- | nuttx/sched/sig_kill.c | 7 | ||||
-rw-r--r-- | nuttx/sched/sig_mqnotempty.c | 7 | ||||
-rw-r--r-- | nuttx/sched/sig_queue.c | 13 | ||||
-rw-r--r-- | nuttx/sched/sig_timedwait.c | 29 | ||||
-rw-r--r-- | nuttx/sched/task_create.c | 2 | ||||
-rw-r--r-- | nuttx/sched/task_deletecurrent.c | 20 | ||||
-rw-r--r-- | nuttx/sched/task_exithook.c | 71 | ||||
-rw-r--r-- | nuttx/sched/task_setup.c | 43 | ||||
-rw-r--r-- | nuttx/sched/task_vfork.c | 338 | ||||
-rw-r--r-- | nuttx/sched/timer_settime.c | 4 |
23 files changed, 1167 insertions, 77 deletions
diff --git a/nuttx/sched/Kconfig b/nuttx/sched/Kconfig index bfaec3b5d..6d53a03aa 100644 --- a/nuttx/sched/Kconfig +++ b/nuttx/sched/Kconfig @@ -38,6 +38,17 @@ config TASK_NAME_SIZE Useful if scheduler instrumentation is selected. Set to zero to disable. +config SCHED_HAVE_PARENT + bool "Remember Parent" + default n + ---help--- + Remember the ID of the parent thread when a new child thread is + created. This support enables some additional features (such as + SIGCHLD) and modifies the behavior of other interfaces. For + example, it makes waitpid() more standards complete by restricting + the waited-for tasks to the children of the caller. Default: + disabled. + config JULIAN_TIME bool "Enables Julian time conversions" default n @@ -127,6 +138,7 @@ config SDCLONE_DISABLE config SCHED_WORKQUEUE bool "Enable worker thread" default n + depends on !DISABLE_SIGNALS ---help--- Create a dedicated "worker" thread to handle delayed processing from interrupt handlers. This feature is required for some drivers but, if there are no @@ -158,14 +170,6 @@ config SCHED_WORKSTACKSIZE ---help--- The stack size allocated for the worker thread. Default: 2K. -config SIG_SIGWORK - int "Worker thread wakeup signal" - default 4 - depends on SCHED_WORKQUEUE - ---help--- - The signal number that will be used to wake-up the worker thread. - Default: 4 - config SCHED_LPWORK bool "Enable a lower priority worker thread" default n @@ -203,7 +207,12 @@ config SCHED_WAITPID bool "Enable waitpid() API" default n ---help--- - Enables the waitpid() API + Enables the waitpid() interface in a default, non-standard mode + (non-standard in the sense that the waited for PID need not be child + of the caller). If SCHED_HAVE_PARENT is also defined, then this + setting will modify the behavior or waitpid() (making more spec + compliant) and will enable the waitid() and wait() interfaces as + well. config SCHED_ATEXIT bool "Enable atexit() API" @@ -310,6 +319,56 @@ config DISABLE_POLL depends on DISABLE_OS_API default n +if !DISABLE_SIGNALS +comment "Signal Numbers" + +config SIG_SIGUSR1 + int "SIGUSR1" + default 1 + ---help--- + Value of standard user signal 1 (SIGUSR1). Default: 1 + +config SIG_SIGUSR2 + int "SIGUSR2" + default 2 + ---help--- + Value of standard user signal 2 (SIGUSR2). Default: 2 + +config SIG_SIGALARM + int "SIGALRM" + default 3 + ---help--- + Default the signal number used with POSIX timers (SIGALRM). + Default: 3 + +config SIG_SIGCHLD + int "SIGCHLD" + default 4 + depends on SCHED_HAVE_PARENT + ---help--- + The SIGCHLD signal is sent to the parent of a child process when it + exits, is interrupted (stopped), or resumes after being interrupted. + Default: 4 + +config SIG_SIGCONDTIMEDOUT + int "SIGCONDTIMEDOUT" + default 16 + depends on !DISABLE_PTHREAD + ---help--- + This non-standard signal number is used the implementation of + pthread_cond_timedwait(). Default 16. + +config SIG_SIGWORK + int "SIGWORK" + default 17 + depends on SCHED_WORKQUEUE + ---help--- + SIGWORK is a non-standard signal used to wake up the internal NuttX + worker thread. This setting specifies the signal number that will be + used for SIGWORK. Default: 17 + +endif + comment "Sizes of configurable things (0 disables)" config MAX_TASKS diff --git a/nuttx/sched/Makefile b/nuttx/sched/Makefile index 82f74fc3c..3d6b58bac 100644 --- a/nuttx/sched/Makefile +++ b/nuttx/sched/Makefile @@ -1,7 +1,7 @@ ############################################################################ # sched/Makefile # -# Copyright (C) 2007-2012 Gregory Nutt. All rights reserved. +# Copyright (C) 2007-2013 Gregory Nutt. All rights reserved. # Author: Gregory Nutt <gnutt@nuttx.org> # # Redistribution and use in source and binary forms, with or without @@ -45,7 +45,7 @@ MISC_SRCS = os_start.c os_bringup.c errno_getptr.c errno_get.c errno_set.c \ TSK_SRCS = prctl.c task_create.c task_init.c task_setup.c task_activate.c \ task_start.c task_delete.c task_deletecurrent.c task_exithook.c \ - task_restart.c exit.c getpid.c sched_addreadytorun.c \ + task_restart.c task_vfork.c exit.c getpid.c sched_addreadytorun.c \ sched_removereadytorun.c sched_addprioritized.c sched_mergepending.c \ sched_addblocked.c sched_removeblocked.c sched_free.c sched_gettcb.c \ sched_verifytcb.c sched_releasetcb.c @@ -69,6 +69,9 @@ endif ifeq ($(CONFIG_SCHED_WAITPID),y) SCHED_SRCS += sched_waitpid.c +ifeq ($(CONFIG_SCHED_HAVE_PARENT),y) +SCHED_SRCS += sched_waitid.c sched_wait.c +endif endif ENV_SRCS = env_getenvironptr.c env_dup.c env_share.c env_release.c \ diff --git a/nuttx/sched/clock_time2ticks.c b/nuttx/sched/clock_time2ticks.c index 9265872bb..012f4e4f1 100644 --- a/nuttx/sched/clock_time2ticks.c +++ b/nuttx/sched/clock_time2ticks.c @@ -89,14 +89,48 @@ int clock_time2ticks(FAR const struct timespec *reltime, FAR int *ticks) { +#ifdef CONFIG_HAVE_LONG_LONG + int64_t relnsec; + + /* Convert the relative time into nanoseconds. The range of the int64_t is + * sufficiently large that there is no real need for range checking. + */ + + relnsec = (int64_t)reltime->tv_sec * NSEC_PER_SEC + + (int64_t)reltime->tv_nsec; + + /* Convert nanoseconds to clock ticks, rounding up to the smallest integer + * that is greater than or equal to the exact number of tick. + */ + + *ticks = (int)((relnsec + NSEC_PER_TICK - 1) / NSEC_PER_TICK); + return OK; +#else int32_t relusec; - /* Convert the relative time into microseconds.*/ + /* This function uses an int32_t to only the relative time in microseconds. + * that means that the maximum supported relative time is 2,147,487.647 + * seconds + */ + +#if 0 // overkill + DEBUGASSERT(reltime->tv_sec < 2147487 || + reltime->tv_sec == 2147487 && + reltime->tv_nsec <= 647 * NSEC_PER_MSEC); +#endif + + /* Convert the relative time into microseconds, rounding up to the smallest + * value that is greater than or equal to the exact number of microseconds. + */ - relusec = reltime->tv_sec * USEC_PER_SEC + reltime->tv_nsec / NSEC_PER_USEC; + relusec = reltime->tv_sec * USEC_PER_SEC + + (reltime->tv_nsec + NSEC_PER_USEC - 1) / NSEC_PER_USEC; - /* Convert microseconds to clock ticks */ + /* Convert microseconds to clock ticks, rounding up to the smallest integer + * that is greater than or equal to the exact number of tick. + */ - *ticks = (relusec + USEC_PER_TICK - 1) / USEC_PER_TICK; + *ticks = (int)((relusec + USEC_PER_TICK - 1) / USEC_PER_TICK); return OK; +#endif } diff --git a/nuttx/sched/mq_initialize.c b/nuttx/sched/mq_initialize.c index 5b03a1120..dd7c7ed0f 100644 --- a/nuttx/sched/mq_initialize.c +++ b/nuttx/sched/mq_initialize.c @@ -217,11 +217,11 @@ void mq_initialize(void) void mq_desblockalloc(void) { - struct mq_des_block_s *mqdesblock; + FAR struct mq_des_block_s *mqdesblock; /* Allocate a block of message descriptors */ - mqdesblock = (struct mq_des_block_s *)kmalloc(sizeof(struct mq_des_block_s)); + mqdesblock = (FAR struct mq_des_block_s *)kmalloc(sizeof(struct mq_des_block_s)); if (mqdesblock) { int i; diff --git a/nuttx/sched/os_bringup.c b/nuttx/sched/os_bringup.c index e0a236bbe..610d8515a 100644 --- a/nuttx/sched/os_bringup.c +++ b/nuttx/sched/os_bringup.c @@ -57,9 +57,6 @@ #ifdef CONFIG_SCHED_WORKQUEUE # include "work_internal.h" #endif -#ifdef CONFIG_BUILTIN_APP_START -# include "apps/apps.h" -#endif #ifdef CONFIG_NUTTX_KERNEL # include "arch/board/user_map.h" #endif @@ -112,22 +109,15 @@ * function is to serve as the "bottom half" of device * drivers. * - * And the main application entry point. This may be one of two different + * And the main application entry point: * symbols: * - * - USER_ENTRYPOINT: This is the default entry point used for all of the - * example code in apps/examples. - * - CONFIG_BUILTIN_APP_START: The system can also be configured to start - * custom applications at however CONFIG_BUILTIN_APP_START - * is defined in the NuttX start-up file. + * - USER_ENTRYPOINT: This is the default user application entry point. * ****************************************************************************/ int os_bringup(void) { -#ifdef CONFIG_BUILTIN_APP_START - static const char *argv[3] = {NULL, "init", NULL}; -#endif int init_taskid; /* Setup up the initial environment for the idle task. At present, this @@ -188,19 +178,11 @@ int os_bringup(void) svdbg("Starting init thread\n"); -#ifdef CONFIG_BUILTIN_APP_START - /* Start the built-in named application, passing an "init" argument, so that - * application can distinguish different run-levels - */ - - init_taskid = exec_namedapp(CONFIG_BUILTIN_APP_START, argv); -#else /* Start the default application at CONFIG_USER_ENTRYPOINT() */ init_taskid = TASK_CREATE("init", SCHED_PRIORITY_DEFAULT, CONFIG_USERMAIN_STACKSIZE, (main_t)CONFIG_USER_ENTRYPOINT, (const char **)NULL); -#endif ASSERT(init_taskid != ERROR); /* We an save a few bytes by discarding the IDLE thread's environment. */ diff --git a/nuttx/sched/os_internal.h b/nuttx/sched/os_internal.h index 13b8083cf..32d9fb4ac 100644 --- a/nuttx/sched/os_internal.h +++ b/nuttx/sched/os_internal.h @@ -83,10 +83,10 @@ enum os_crash_codes_e OSERR_BADREPRIORITIZESTATE /* Attempt to reprioritize in bad state or priority */ }; -/* Special task IDS */ +/* Special task IDS. Any negative PID is invalid. */ -#define NULL_TASK_PROCESS_ID 0 -#define INVALID_PROCESS_ID 0 +#define NULL_TASK_PROCESS_ID (pid_t)0 +#define INVALID_PROCESS_ID (pid_t)-1 /* Although task IDs can take the (positive, non-zero) * range of pid_t, the number of tasks that will be supported diff --git a/nuttx/sched/sched_addprioritized.c b/nuttx/sched/sched_addprioritized.c index 8f19a4731..20178fb9c 100644 --- a/nuttx/sched/sched_addprioritized.c +++ b/nuttx/sched/sched_addprioritized.c @@ -114,7 +114,7 @@ bool sched_addprioritized(FAR _TCB *tcb, DSEG dq_queue_t *list) (next && sched_priority <= next->sched_priority); next = next->flink); - /* Add the tcb to the spot found in the list. Check if the tcb + /* Add the tcb to the spot found in the list. Check if the tcb * goes at the end of the list. NOTE: This could only happen if list * is the g_pendingtasks list! */ diff --git a/nuttx/sched/sched_addreadytorun.c b/nuttx/sched/sched_addreadytorun.c index f6117b6ff..1e1829343 100644 --- a/nuttx/sched/sched_addreadytorun.c +++ b/nuttx/sched/sched_addreadytorun.c @@ -84,8 +84,8 @@ * btcb - Points to the blocked TCB that is ready-to-run * * Return Value: - * true if the currently active task (the head of the - * g_readytorun list) has changed. + * true if the currently active task (the head of the g_readytorun list) + * has changed. * * Assumptions: * - The caller has established a critical section before @@ -104,7 +104,7 @@ bool sched_addreadytorun(FAR _TCB *btcb) bool ret; /* Check if pre-emption is disabled for the current running task and if - * the new ready-to-run task would cause the current running task to be + * the new ready-to-run task would cause the current running task to be * preempted. */ @@ -123,7 +123,7 @@ bool sched_addreadytorun(FAR _TCB *btcb) else if (sched_addprioritized(btcb, (FAR dq_queue_t*)&g_readytorun)) { - /* Information the instrumentation logic that we are switching tasks */ + /* Inform the instrumentation logic that we are switching tasks */ sched_note_switch(rtcb, btcb); diff --git a/nuttx/sched/sched_setuptaskfiles.c b/nuttx/sched/sched_setuptaskfiles.c index fe0b14143..d01b8d4cd 100644 --- a/nuttx/sched/sched_setuptaskfiles.c +++ b/nuttx/sched/sched_setuptaskfiles.c @@ -200,7 +200,8 @@ static inline void sched_dupsockets(FAR _TCB *tcb) * tcb - tcb of the new task. * * Return Value: - * None + * Zero (OK) is returned on success; A negated errno value is returned on + * failure. * * Assumptions: * diff --git a/nuttx/sched/sched_unlock.c b/nuttx/sched/sched_unlock.c index 9a52e8358..5eafcfc9e 100644 --- a/nuttx/sched/sched_unlock.c +++ b/nuttx/sched/sched_unlock.c @@ -126,5 +126,6 @@ int sched_unlock(void) irqrestore(flags); } + return OK; } diff --git a/nuttx/sched/sched_wait.c b/nuttx/sched/sched_wait.c new file mode 100644 index 000000000..813d4f842 --- /dev/null +++ b/nuttx/sched/sched_wait.c @@ -0,0 +1,90 @@ +/***************************************************************************** + * sched/sched_wait.c + * + * Copyright (C) 2013 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/wait.h> +#include <signal.h> +#include <errno.h> + +#include <nuttx/sched.h> + +#include "os_internal.h" + +#if defined(CONFIG_SCHED_WAITPID) && defined(CONFIG_SCHED_HAVE_PARENT) + +/***************************************************************************** + * Private Functions + *****************************************************************************/ + +/***************************************************************************** + * Public Functions + *****************************************************************************/ + +/***************************************************************************** + * Name: wait + * + * Description: + * The wait() function will suspend execution of the calling thread until + * status information for one of its terminated child processes is + * available, or until delivery of a signal whose action is either to + * execute a signal-catching function or to terminate the process. If more + * than one thread is suspended in wait() or waitpid() awaiting termination + * of the same process, exactly one thread will return the process status + * at the time of the target process termination. If status information is + * available prior to the call to wait(), return will be immediate. + * + * The waitpid() function will behave identically to wait(), if the pid + * argument is (pid_t)-1 and the options argument is 0. Otherwise, its + * behaviour will be modified by the values of the pid and options arguments. + * + * Input Parameters: + * stat_loc - The location to return the exit status + * + * Returned Value: + * See waitpid(); + * + *****************************************************************************/ + +pid_t wait(FAR int *stat_loc) +{ + return waitpid((pid_t)-1, stat_loc, 0); +} + +#endif /* CONFIG_SCHED_WAITPID && CONFIG_SCHED_HAVE_PARENT*/ diff --git a/nuttx/sched/sched_waitid.c b/nuttx/sched/sched_waitid.c new file mode 100644 index 000000000..eabc69afe --- /dev/null +++ b/nuttx/sched/sched_waitid.c @@ -0,0 +1,256 @@ +/***************************************************************************** + * sched/sched_waitid.c + * + * Copyright (C) 2013 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/wait.h> +#include <signal.h> +#include <errno.h> + +#include <nuttx/sched.h> + +#include "os_internal.h" + +#if defined(CONFIG_SCHED_WAITPID) && defined(CONFIG_SCHED_HAVE_PARENT) + +/***************************************************************************** + * Private Functions + *****************************************************************************/ + +/***************************************************************************** + * Public Functions + *****************************************************************************/ + +/***************************************************************************** + * Name: waitid + * + * Description: + * The waitid() function suspends the calling thread until one child of + * the process containing the calling thread changes state. It records the + * current state of a child in the structure pointed to by 'info'. If a + * child process changed state prior to the call to waitid(), waitid() + * returns immediately. If more than one thread is suspended in wait() or + * waitpid() waiting termination of the same process, exactly one thread + * will return the process status at the time of the target process + * termination + * + * The idtype and id arguments are used to specify which children waitid() + * will wait for. + * + * If idtype is P_PID, waitid() will wait for the child with a process + * ID equal to (pid_t)id. + * + * If idtype is P_PGID, waitid() will wait for any child with a process + * group ID equal to (pid_t)id. + * + * If idtype is P_ALL, waitid() will wait for any children and id is + * ignored. + * + * The options argument is used to specify which state changes waitid() + * will will wait for. It is formed by OR-ing together one or more of the + * following flags: + * + * WEXITED - Wait for processes that have exited. + * WSTOPPED - Status will be returned for any child that has stopped + * upon receipt of a signal. + * WCONTINUED - Status will be returned for any child that was stopped + * and has been continued. + * WNOHANG - Return immediately if there are no children to wait for. + * WNOWAIT - Keep the process whose status is returned in 'info' in a + * waitable state. This will not affect the state of the process; the + * process may be waited for again after this call completes. + * + * The 'info' argument must point to a siginfo_t structure. If waitid() + * returns because a child process was found that satisfied the conditions + * indicated by the arguments idtype and options, then the structure pointed + * to by 'info' will be filled in by the system with the status of the + * process. The si_signo member will always be equal to SIGCHLD. + * + * Input Parameters: + * See description. + * + * Returned Value: + * If waitid() returns due to the change of state of one of its children, + * 0 is returned. Otherwise, -1 is returned and errno is set to indicate + * the error. + * + * The waitid() function will fail if: + * + * ECHILD - The calling process has no existing unwaited-for child + * processes. + * EINTR - The waitid() function was interrupted by a signal. + * EINVAL - An invalid value was specified for options, or idtype and id + * specify an invalid set of processes. + * + *****************************************************************************/ + +int waitid(idtype_t idtype, id_t id, siginfo_t *info, int options) +{ + FAR _TCB *rtcb = (FAR _TCB *)g_readytorun.head; + sigset_t sigset; + int err; + int ret; + + /* MISSING LOGIC: If WNOHANG is provided in the options, then this function + * should returned immediately. However, there is no mechanism available now + * know if the thread has child: The children remember their parents (if + * CONFIG_SCHED_HAVE_PARENT) but the parents do not remember their children. + */ + + /* None of the options are supported except for WEXITED (which must be + * provided. Currently SIGCHILD always reports CLD_EXITED so we cannot + * distinguish any other events. + */ + +#ifdef CONFIG_DEBUG + if (options != WEXITED) + { + set_errno(ENOSYS); + return ERROR; + } +#endif + + /* Create a signal set that contains only SIGCHLD */ + + (void)sigemptyset(&sigset); + (void)sigaddset(&sigset, SIGCHLD); + + /* Disable pre-emption so that nothing changes while the loop executes */ + + sched_lock(); + + /* Verify that this task actually has children and that the the requeste + * TCB is actually a child of this task. + */ + + if (rtcb->nchildren == 0) + { + err = ECHILD; + goto errout_with_errno; + } + else if (idtype == P_PID) + { + /* Get the TCB corresponding to this PID and make sure it is our child. */ + + FAR _TCB *ctcb = sched_gettcb((pid_t)id); + if (!ctcb || ctcb->parent != rtcb->pid) + { + err = ECHILD; + goto errout_with_errno; + } + } + + /* Loop until the child that we are waiting for dies */ + + for (;;) + { + /* Check if the task has already died. Signals are not queued in + * NuttX. So a possibility is that the child has died and we + * missed the death of child signal (we got some other signal + * instead). + */ + + if (rtcb->nchildren == 0 || + (idtype == P_PID && (ret = kill((pid_t)id, 0)) < 0)) + { + /* We know that the child task was running okay we stared, + * so we must have lost the signal. What can we do? + * Let's claim we were interrupted by a signal. + */ + + err = EINTR; + goto errout_with_errno; + } + + /* Wait for any death-of-child signal */ + + ret = sigwaitinfo(&sigset, info); + if (ret < 0) + { + goto errout; + } + + /* Make there this was SIGCHLD */ + + if (info->si_signo == SIGCHLD) + { + /* Yes.. Are we waiting for the death of a specific child? */ + + if (idtype == P_PID) + { + /* Was this the death of the thread we were waiting for? */ + + if (info->si_pid == (pid_t)id) + { + /* Yes... return success */ + + break; + } + } + + /* Are we waiting for any child to change state? */ + + else if (idtype == P_ALL) + { + /* Return success */ + + break; + } + + /* Other ID types are not supported */ + + else /* if (idtype == P_PGID) */ + { + set_errno(ENOSYS); + goto errout; + } + } + } + + sched_unlock(); + return OK; + +errout_with_errno: + set_errno(err); +errout: + sched_unlock(); + return ERROR; +} + +#endif /* CONFIG_SCHED_WAITPID && CONFIG_SCHED_HAVE_PARENT*/ diff --git a/nuttx/sched/sched_waitpid.c b/nuttx/sched/sched_waitpid.c index 692ef6410..dc715b2e9 100644 --- a/nuttx/sched/sched_waitpid.c +++ b/nuttx/sched/sched_waitpid.c @@ -1,7 +1,7 @@ /***************************************************************************** * sched/sched_waitpid.c * - * Copyright (C) 2011-2012 Gregory Nutt. All rights reserved. + * Copyright (C) 2011-2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt <gnutt@nuttx.org> * * Redistribution and use in source and binary forms, with or without @@ -41,13 +41,14 @@ #include <sys/wait.h> #include <semaphore.h> +#include <signal.h> #include <errno.h> #include <nuttx/sched.h> #include "os_internal.h" -#ifdef CONFIG_SCHED_WAITPID /* Experimental */ +#ifdef CONFIG_SCHED_WAITPID /***************************************************************************** * Private Functions @@ -58,7 +59,7 @@ *****************************************************************************/ /***************************************************************************** - * Name: sched_waitpid + * Name: waitpid * * Description: * @@ -172,10 +173,16 @@ * *****************************************************************************/ -/***************************************************************************/ -/* NOTE: This is a partially functional, experimental version of waitpid() */ -/***************************************************************************/ +/*************************************************************************** + * NOTE: This is a partially functional, experimental version of waitpid() + * + * If there is no SIGCHLD signal supported (CONFIG_SCHED_HAVE_PARENT not + * defined), then waitpid() is still available, but does not obey the + * restriction that the pid be a child of the caller. + * + ***************************************************************************/ +#ifndef CONFIG_SCHED_HAVE_PARENT pid_t waitpid(pid_t pid, int *stat_loc, int options) { _TCB *tcb; @@ -183,9 +190,24 @@ pid_t waitpid(pid_t pid, int *stat_loc, int options) int err; int ret; + DEBUGASSERT(stat_loc); + + /* None of the options are supported */ + +#ifdef CONFIG_DEBUG + if (options != 0) + { + set_errno(ENOSYS); + return ERROR; + } +#endif + /* Disable pre-emption so that nothing changes in the following tests */ sched_lock(); + + /* Get the TCB corresponding to this PID */ + tcb = sched_gettcb(pid); if (!tcb) { @@ -193,16 +215,6 @@ pid_t waitpid(pid_t pid, int *stat_loc, int options) goto errout_with_errno; } - /* None of the options are supported */ - -#ifdef CONFIG_DEBUG - if (options != 0) - { - err = ENOSYS; - goto errout_with_errno; - } -#endif - /* "If more than one thread is suspended in waitpid() awaiting termination of * the same process, exactly one thread will return the process status at the * time of the target process termination." Hmmm.. what do we return to the @@ -245,4 +257,152 @@ errout: return ERROR; } +/*************************************************************************** + * + * If CONFIG_SCHED_HAVE_PARENT is defined, then waitpid will use the SIGHCLD + * signal. It can also handle the pid == (pid_t)-1 arguement. This is + * slightly more spec-compliant. + * + * But then I have to be concerned about the fact that NuttX does not queue + * signals. This means that a flurry of signals can cause signals to be + * lost (or to have the data in the struct siginfo to be overwritten by + * the next signal). + * + ***************************************************************************/ + +#else +pid_t waitpid(pid_t pid, int *stat_loc, int options) +{ + FAR _TCB *rtcb = (FAR _TCB *)g_readytorun.head; + FAR struct siginfo info; + sigset_t sigset; + int err; + int ret; + + DEBUGASSERT(stat_loc); + + /* None of the options are supported */ + +#ifdef CONFIG_DEBUG + if (options != 0) + { + set_errno(ENOSYS); + return ERROR; + } +#endif + + /* Create a signal set that contains only SIGCHLD */ + + (void)sigemptyset(&sigset); + (void)sigaddset(&sigset, SIGCHLD); + + /* Disable pre-emption so that nothing changes while the loop executes */ + + sched_lock(); + + /* Verify that this task actually has children and that the the requeste + * TCB is actually a child of this task. + */ + + if (rtcb->nchildren == 0) + { + err = ECHILD; + goto errout_with_errno; + } + else if (pid != (pid_t)-1) + { + /* Get the TCB corresponding to this PID and make sure it is our child. */ + + FAR _TCB *ctcb = sched_gettcb(pid); + if (!ctcb || ctcb->parent != rtcb->pid) + { + err = ECHILD; + goto errout_with_errno; + } + } + + /* Loop until the child that we are waiting for dies */ + + for (;;) + { + /* Check if the task has already died. Signals are not queued in + * NuttX. So a possibility is that the child has died and we + * missed the death of child signal (we got some other signal + * instead). + */ + + if (pid == (pid_t)-1) + { + /* We are waiting for any child, check if there are still + * chilren. + */ + + if (rtcb->nchildren == 0) + { + /* There were one or more children when we started so they + * must have exit'ed. There are just no bread crumbs left + * behind to tell us the PID(s) of the existed children. + * Reporting ECHLD is about all we can do in this case. + */ + + err = ECHILD; + goto errout_with_errno; + } + } + else + { + /* We are waiting for a specific PID. We can use kill() with + * signal number 0 to determine if that task is still alive. + */ + + ret = kill(pid, 0); + if (ret < 0) + { + /* It is no longer running. We know that the child task was + * running okay when we started, so we must have lost the + * signal. In this case, we know that the task exit'ed, but + * we do not know its exit status. It would be better to + * reported ECHILD that bogus status. + */ + + err = ECHILD; + goto errout_with_errno; + } + } + + /* Wait for any death-of-child signal */ + + ret = sigwaitinfo(&sigset, &info); + if (ret < 0) + { + goto errout_with_lock; + } + + /* Was this the death of the thread we were waiting for? In the of + * pid == (pid_t)-1, we are waiting for any child thread. + */ + + if (info.si_signo == SIGCHLD && + (pid == (pid_t)-1 || info.si_pid == pid)) + { + /* Yes... return the status and PID (in the event it was -1) */ + + *stat_loc = info.si_status; + pid = info.si_pid; + break; + } + } + + sched_unlock(); + return (int)pid; + +errout_with_errno: + set_errno(err); + +errout_with_lock: + sched_unlock(); + return ERROR; +} +#endif /* CONFIG_SCHED_HAVE_PARENT */ + #endif /* CONFIG_SCHED_WAITPID */ diff --git a/nuttx/sched/sig_kill.c b/nuttx/sched/sig_kill.c index 17921015f..b3d74d8a1 100644 --- a/nuttx/sched/sig_kill.c +++ b/nuttx/sched/sig_kill.c @@ -84,6 +84,9 @@ int kill(pid_t pid, int signo) { +#ifdef CONFIG_SCHED_HAVE_PARENT + FAR _TCB *rtcb = (FAR _TCB *)g_readytorun.head; +#endif FAR _TCB *stcb; siginfo_t info; int ret = ERROR; @@ -124,6 +127,10 @@ int kill(pid_t pid, int signo) info.si_signo = signo; info.si_code = SI_USER; info.si_value.sival_ptr = NULL; +#ifdef CONFIG_SCHED_HAVE_PARENT + info.si_pid = rtcb->pid; + info.si_status = OK; +#endif /* Send the signal */ diff --git a/nuttx/sched/sig_mqnotempty.c b/nuttx/sched/sig_mqnotempty.c index 9a1fd7243..f7ae6fd0d 100644 --- a/nuttx/sched/sig_mqnotempty.c +++ b/nuttx/sched/sig_mqnotempty.c @@ -88,6 +88,9 @@ int sig_mqnotempty (int pid, int signo, union sigval value) int sig_mqnotempty (int pid, int signo, void *sival_ptr) #endif { +#ifdef CONFIG_SCHED_HAVE_PARENT + FAR _TCB *rtcb = (FAR _TCB *)g_readytorun.head; +#endif FAR _TCB *stcb; siginfo_t info; int ret = ERROR; @@ -113,6 +116,10 @@ int sig_mqnotempty (int pid, int signo, void *sival_ptr) #else info.si_value.sival_ptr = sival_ptr; #endif +#ifdef CONFIG_SCHED_HAVE_PARENT + info.si_pid = rtcb->pid; + info.si_status = OK; +#endif /* Verify that we can perform the signalling operation */ diff --git a/nuttx/sched/sig_queue.c b/nuttx/sched/sig_queue.c index dee1c798a..db404238e 100644 --- a/nuttx/sched/sig_queue.c +++ b/nuttx/sched/sig_queue.c @@ -111,6 +111,9 @@ int sigqueue (int pid, int signo, union sigval value) int sigqueue(int pid, int signo, void *sival_ptr) #endif { +#ifdef CONFIG_SCHED_HAVE_PARENT + FAR _TCB *rtcb = (FAR _TCB *)g_readytorun.head; +#endif FAR _TCB *stcb; siginfo_t info; int ret = ERROR; @@ -142,13 +145,17 @@ int sigqueue(int pid, int signo, void *sival_ptr) /* Create the siginfo structure */ - info.si_signo = signo; - info.si_code = SI_QUEUE; + info.si_signo = signo; + info.si_code = SI_QUEUE; #ifdef CONFIG_CAN_PASS_STRUCTS - info.si_value = value; + info.si_value = value; #else info.si_value.sival_ptr = sival_ptr; #endif +#ifdef CONFIG_SCHED_HAVE_PARENT + info.si_pid = rtcb->pid; + info.si_status = OK; +#endif /* Send the signal */ diff --git a/nuttx/sched/sig_timedwait.c b/nuttx/sched/sig_timedwait.c index 1b8dfd162..f8c619b21 100644 --- a/nuttx/sched/sig_timedwait.c +++ b/nuttx/sched/sig_timedwait.c @@ -38,6 +38,7 @@ ****************************************************************************/ #include <nuttx/config.h> +#include <nuttx/compiler.h> #include <stdint.h> #include <string.h> @@ -119,6 +120,10 @@ static void sig_timeout(int argc, uint32_t itcb) u.wtcb->sigunbinfo.si_signo = SIG_WAIT_TIMEOUT; u.wtcb->sigunbinfo.si_code = SI_TIMER; u.wtcb->sigunbinfo.si_value.sival_int = 0; +#ifdef CONFIG_SCHED_HAVE_PARENT + u.wtcb->sigunbinfo.si_pid = 0; /* Not applicable */ + u.wtcb->sigunbinfo.si_status = OK; +#endif up_unblock_task(u.wtcb); } } @@ -223,7 +228,7 @@ int sigtimedwait(FAR const sigset_t *set, FAR struct siginfo *info, /* The return value is the number of the signal that awakened us */ - ret = info->si_signo; + ret = sigpend->info.si_signo; } /* We will have to wait for a signal to be posted to this task. */ @@ -238,10 +243,25 @@ int sigtimedwait(FAR const sigset_t *set, FAR struct siginfo *info, if (timeout) { - /* Convert the timespec to milliseconds */ + /* Convert the timespec to system clock ticks, making sure that + * the resultint delay is greater than or equal to the requested + * time in nanoseconds. + */ - waitticks = MSEC2TICK(timeout->tv_sec * MSEC_PER_SEC - + timeout->tv_nsec / NSEC_PER_MSEC); +#ifdef CONFIG_HAVE_LONG_LONG + uint64_t waitticks64 = ((uint64_t)timeout->tv_sec * NSEC_PER_SEC + + (uint64_t)timeout->tv_nsec + NSEC_PER_TICK - 1) / + NSEC_PER_TICK; + DEBUGASSERT(waitticks64 <= UINT32_MAX); + waitticks = (uint32_t)waitticks64; +#else + uint32_t waitmsec; + + DEBUGASSERT(timeout->tv_sec < UINT32_MAX / MSEC_PER_SEC); + waitmsec = timeout->tv_sec * MSEC_PER_SEC + + (timeout->tv_nsec + NSEC_PER_MSEC - 1) / NSEC_PER_MSEC; + waitticks = (waitmsec + MSEC_PER_TICK - 1) / MSEC_PER_TICK; +#endif /* Create a watchdog */ @@ -326,6 +346,7 @@ int sigtimedwait(FAR const sigset_t *set, FAR struct siginfo *info, { memcpy(info, &rtcb->sigunbinfo, sizeof(struct siginfo)); } + irqrestore(saved_state); } diff --git a/nuttx/sched/task_create.c b/nuttx/sched/task_create.c index 4d92c9bb0..801706cbf 100644 --- a/nuttx/sched/task_create.c +++ b/nuttx/sched/task_create.c @@ -169,6 +169,8 @@ static int thread_create(const char *name, uint8_t type, int priority, ret = task_activate(tcb); if (ret != OK) { + /* The TCB was added to the active task list by task_schedsetup() */ + dq_rem((FAR dq_entry_t*)tcb, (dq_queue_t*)&g_inactivetasks); goto errout_with_tcb; } diff --git a/nuttx/sched/task_deletecurrent.c b/nuttx/sched/task_deletecurrent.c index 77025f5e0..e1e06acf6 100644 --- a/nuttx/sched/task_deletecurrent.c +++ b/nuttx/sched/task_deletecurrent.c @@ -90,6 +90,9 @@ * Return Value: * OK on success; or ERROR on failure * + * Assumeptions: + * Interrupts are disabled. + * ****************************************************************************/ int task_deletecurrent(void) @@ -108,13 +111,16 @@ int task_deletecurrent(void) (void)sched_removereadytorun(dtcb); rtcb = (FAR _TCB*)g_readytorun.head; - /* We are not in a bad state -- the head of the ready to run task list + /* We are now in a bad state -- the head of the ready to run task list * does not correspond to the thread that is running. Disabling pre- * emption on this TCB and marking the new ready-to-run task as not * running (see, for example, get_errno_ptr()). + * + * We disable pre-emption here by directly incrementing the lockcount + * (vs. calling sched_lock()). */ - sched_lock(); + rtcb->lockcount++; rtcb->task_state = TSTATE_TASK_READYTORUN; /* Move the TCB to the specified blocked task list and delete it */ @@ -132,9 +138,15 @@ int task_deletecurrent(void) (void)sched_mergepending(); } - /* Now calling sched_unlock() should have no effect */ + /* We can't use sched_unlock() to decrement the lock count because the + * sched_mergepending() call above might have changed the task at the + * head of the ready-to-run list. Furthermore, we should not need to + * perform the unlock action anyway because we know that the pending + * task list is empty. So all we really need to do is to decrement + * the lockcount on rctb. + */ - sched_unlock(); + rtcb->lockcount--; return OK; } diff --git a/nuttx/sched/task_exithook.c b/nuttx/sched/task_exithook.c index 3bde8fb7a..1106f2885 100644 --- a/nuttx/sched/task_exithook.c +++ b/nuttx/sched/task_exithook.c @@ -41,6 +41,7 @@ #include <stdlib.h> #include <unistd.h> +#include <signal.h> #include <debug.h> #include <errno.h> @@ -188,6 +189,70 @@ static inline void task_onexit(FAR _TCB *tcb, int status) #endif /**************************************************************************** + * Name: task_sigchild + * + * Description: + * Send the SIGCHILD signal to the parent thread + * + ****************************************************************************/ + +#ifdef CONFIG_SCHED_HAVE_PARENT +static inline void task_sigchild(FAR _TCB *tcb, int status) +{ + FAR _TCB *ptcb; + siginfo_t info; + + /* Keep things stationary through the following */ + + sched_lock(); + + /* Get the TCB of the receiving task */ + + ptcb = sched_gettcb(tcb->parent); + if (!ptcb) + { + /* The parent no longer exists... bail */ + + sched_unlock(); + return; + } + + /* Decrement the number of children from this parent */ + + DEBUGASSERT(ptcb->nchildren > 0); + ptcb->nchildren--; + + /* Set the parent to an impossible PID. We do this because under certain + * conditions, task_exithook() can be called multiple times. If this + * function is called again, sched_gettcb() will fail on the invalid + * parent PID above, nchildren will be decremented once and all will be + * well. + */ + + tcb->parent = INVALID_PROCESS_ID; + + /* Create the siginfo structure. We don't actually know the cause. That + * is a bug. Let's just say that the child task just exit-ted for now. + */ + + info.si_signo = SIGCHLD; + info.si_code = CLD_EXITED; + info.si_value.sival_ptr = NULL; + info.si_pid = tcb->pid; + info.si_status = status; + + /* Send the signal. We need to use this internal interface so that we can + * provide the correct si_code value with the signal. + */ + + (void)sig_received(ptcb, &info); + sched_unlock(); +} +#else +# define task_sigchild(tcb,status) +#endif + +/**************************************************************************** * Name: task_exitwakeup * * Description: @@ -195,7 +260,7 @@ static inline void task_onexit(FAR _TCB *tcb, int status) * ****************************************************************************/ -#ifdef CONFIG_SCHED_WAITPID +#if defined(CONFIG_SCHED_WAITPID) && !defined(CONFIG_SCHED_HAVE_PARENT) static inline void task_exitwakeup(FAR _TCB *tcb, int status) { /* Wakeup any tasks waiting for this task to exit */ @@ -263,6 +328,10 @@ void task_exithook(FAR _TCB *tcb, int status) task_onexit(tcb, status); + /* Send SIGCHLD to the parent of the exit-ing task */ + + task_sigchild(tcb, status); + /* Wakeup any tasks waiting for this task to exit */ task_exitwakeup(tcb, status); diff --git a/nuttx/sched/task_setup.c b/nuttx/sched/task_setup.c index a37fb165a..92897f0ae 100644 --- a/nuttx/sched/task_setup.c +++ b/nuttx/sched/task_setup.c @@ -147,6 +147,37 @@ static int task_assignpid(FAR _TCB *tcb) } /**************************************************************************** + * 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; + + DEBUGASSERT(rtcb->nchildren < UINT16_MAX); + tcb->parent = rtcb->pid; + rtcb->nchildren++; +} +#else +# define task_saveparent(tcb) +#endif + +/**************************************************************************** * Name: task_dupdspace * * Description: @@ -161,6 +192,8 @@ static int task_assignpid(FAR _TCB *tcb) * None * * Assumptions: + * The parent of the new task is the task at the head of the ready-to-run + * list. * ****************************************************************************/ @@ -231,8 +264,12 @@ int task_schedsetup(FAR _TCB *tcb, int priority, start_t start, main_t main) 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. + /* 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 @@ -243,7 +280,7 @@ int task_schedsetup(FAR _TCB *tcb, int priority, start_t start, main_t main) * until it is activated. */ - tcb->task_state = TSTATE_TASK_INVALID; + 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 diff --git a/nuttx/sched/task_vfork.c b/nuttx/sched/task_vfork.c new file mode 100644 index 000000000..46b2d8e9f --- /dev/null +++ b/nuttx/sched/task_vfork.c @@ -0,0 +1,338 @@ +/**************************************************************************** + * sched/task_vfork + * + * Copyright (C) 2013 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 <stdint.h> +#include <assert.h> +#include <queue.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/sched.h> + +#include "os_internal.h" +#include "env_internal.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: task_vforksetup + * + * Description: + * The vfork() function has the same effect as fork(), except that the + * behavior is undefined if the process created by vfork() either modifies + * any data other than a variable of type pid_t used to store the return + * value from vfork(), or returns from the function in which vfork() was + * called, or calls any other function before successfully calling _exit() + * or one of the exec family of functions. + * + * This functin provides one step in the overall vfork() sequence: It + * Allocates and initializes the child task's TCB. The overall sequence is: + * + * 1) User code calls vfork(). vfork() is provided in architecture-specific + * code. + * 2) vfork()and calls task_vforksetup(). + * 3) task_vforksetup() allocates and configures the child task's TCB. This + * consists of: + * - Allocation of the child task's TCB. + * - Initialization of file descriptors and streams + * - Configuration of environment variables + * - Setup the intput parameters for the task. + * - Initialization of the TCB (including call to up_initial_state() + * 4) up_vfork() provides any additional operating context. up_vfork must: + * - Allocate and initialize the stack + * - Initialize special values in any CPU registers that were not + * already configured by up_initial_state() + * 5) up_vfork() then calls task_vforkstart() + * 6) task_vforkstart() then executes the child thread. + * + * Input Paremeters: + * retaddr - The return address from vfork() where the child task + * will be started. + * + * Returned Value: + * Upon successful completion, task_vforksetup() returns a pointer to + * newly allocated and initalized child task's TCB. NULL is returned + * on any failure and the errno is set appropriately. + * + ****************************************************************************/ + +FAR _TCB *task_vforksetup(start_t retaddr) +{ + _TCB *parent = (FAR _TCB *)g_readytorun.head; + _TCB *child; + int priority; + int ret; + + DEBUGASSERT(retaddr); + + /* Allocate a TCB for the child task. */ + + child = (FAR _TCB*)kzalloc(sizeof(_TCB)); + if (!child) + { + set_errno(ENOMEM); + return NULL; + } + + /* Associate file descriptors with the new task */ + +#if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0 + ret = sched_setuptaskfiles(child); + if (ret != OK) + { + goto errout_with_tcb; + } +#endif + + /* Clone the parent's task environment */ + + (void)env_dup(child); + + /* Mark the type of this thread (this setting will be needed in + * task_schedsetup() when up_initial_state() is called. + */ + + child->flags |= TCB_FLAG_TTYPE_TASK; + + /* Get the priority of the parent task */ + +#ifdef CONFIG_PRIORITY_INHERITANCE + priority = parent->base_priority; /* "Normal," unboosted priority */ +#else + priority = parent->sched_priority; /* Current priority */ +#endif + + /* Initialize the task control block. This calls up_initial_state() */ + + svdbg("Child priority=%d start=%p\n", priority, retaddr); + ret = task_schedsetup(child, priority, retaddr, parent->entry.main); + if (ret != OK) + { + goto errout_with_tcb; + } + + svdbg("parent=%p, returning child=%p\n", parent, child); + return child; + +errout_with_tcb: + sched_releasetcb(child); + set_errno(-ret); + return NULL; +} + +/**************************************************************************** + * Name: task_vforkstart + * + * Description: + * The vfork() function has the same effect as fork(), except that the + * behavior is undefined if the process created by vfork() either modifies + * any data other than a variable of type pid_t used to store the return + * value from vfork(), or returns from the function in which vfork() was + * called, or calls any other function before successfully calling _exit() + * or one of the exec family of functions. + * + * This functin provides one step in the overall vfork() sequence: It + * starts execution of the previously initialized TCB. The overall + * sequence is: + * + * 1) User code calls vfork() + * 2) Architecture-specific code provides vfork()and calls task_vforksetup(). + * 3) task_vforksetup() allocates and configures the child task's TCB. This + * consists of: + * - Allocation of the child task's TCB. + * - Initialization of file descriptors and streams + * - Configuration of environment variables + * - Setup the intput parameters for the task. + * - Initialization of the TCB (including call to up_initial_state() + * 4) vfork() provides any additional operating context. vfork must: + * - Allocate and initialize the stack + * - Initialize special values in any CPU registers that were not + * already configured by up_initial_state() + * 5) vfork() then calls task_vforkstart() + * 6) task_vforkstart() then executes the child thread. + * + * Input Paremeters: + * retaddr - The return address from vfork() where the child task + * will be started. + * + * Returned Value: + * Upon successful completion, vfork() returns 0 to the child process and + * returns the process ID of the child process to the parent process. + * Otherwise, -1 is returned to the parent, no child process is created, + * and errno is set to indicate the error. + * + ****************************************************************************/ + +pid_t task_vforkstart(FAR _TCB *child) +{ +#if CONFIG_TASK_NAME_SIZE > 0 + _TCB *parent = (FAR _TCB *)g_readytorun.head; +#endif + FAR const char *name; + pid_t pid; +#ifdef CONFIG_SCHED_WAITPID + int rc; +#endif + int ret; + + svdbg("Starting Child TCB=%p, parent=%p\n", child, g_readytorun.head); + DEBUGASSERT(child); + + /* Setup to pass parameters to the new task */ + +#if CONFIG_TASK_NAME_SIZE > 0 + name = parent->name; +#else + name = NULL; +#endif + + (void)task_argsetup(child, name, (const char **)NULL); + + /* Get the assigned pid before we start the task */ + + pid = (int)child->pid; + + /* Activate the task */ + + ret = task_activate(child); + if (ret != OK) + { + task_vforkabort(child, -ret); + return ERROR; + } + + /* Since the child task has the same priority as the parent task, it is + * now ready to run, but has not yet ran. It is a requirement that + * the parent enivornment be stable while vfork runs; the child thread + * is still dependent on things in the parent thread... like the pointers + * into parent thread's stack which will still appear in the child's + * registers and environment. + * + * We do not have SIG_CHILD, so we have to do some silly things here. + * The simplest way to make sure that the child thread runs to completion + * is simply to yield here. Since the child can only do exit() or + * execv/l(), that should be all that is needed. + * + * Hmmm.. this is probably not sufficient. What if we are running + * SCHED_RR? What if the child thread is suspeneded and rescheduled + * after the parent thread again? + */ + +#ifdef CONFIG_SCHED_WAITPID + + /* We can also exploit a bug in the execv() implementation: The PID + * of the task exec'ed by the child will not be the same as the PID of + * the child task. Therefore, waitpid() on the child task's PID will + * accomplish what we need to do. + */ + + rc = 0; + +#ifdef CONFIG_DEBUG + ret = waitpid(pid, &rc, 0); + if (ret < 0) + { + sdbg("ERROR: waitpid failed: %d\n", errno); + } +#else + (void)waitpid(pid, &rc, 0); +#endif + +#else + /* The following logic does not appear to work... It gets stuff in an + * infinite kill() loop and hogs the processor. Therefore, it looks + * as though CONFIG_SCHED_WAITPID may be a requirement to used vfork(). + * + * Again exploiting that execv() bug: Check if the child thread is + * still running. + */ + + while (kill(pid, 0) == OK) + { + /* Yes.. then we can yield to it -- assuming that it has not lowered + * its priority. sleep(0) might be a safer thing to do since it does + * not depend on prioirities: It will halt the parent thread for one + * system clock tick. This will delay the return to the parent thread. + */ + +#ifndef CONFIG_DISABLE_SIGNALS + sleep(0); +#else + sched_yield(); +#endif + } +#endif + + return pid; +} + +/**************************************************************************** + * Name: task_vforkabort + * + * Description: + * Recover from any errors after task_vforksetup() was called. + * + * Returned Value: + * None + * + ****************************************************************************/ + +void task_vforkabort(FAR _TCB *child, int errcode) +{ + /* The TCB was added to the active task list by task_schedsetup() */ + + dq_rem((FAR dq_entry_t*)child, (dq_queue_t*)&g_inactivetasks); + + /* Release the TCB */ + + sched_releasetcb(child); + set_errno(errcode); +} diff --git a/nuttx/sched/timer_settime.c b/nuttx/sched/timer_settime.c index 1814ba898..f09842ad4 100644 --- a/nuttx/sched/timer_settime.c +++ b/nuttx/sched/timer_settime.c @@ -113,6 +113,10 @@ static void inline timer_sigqueue(FAR struct posix_timer_s *timer) #else info.si_value.sival_ptr = timer->pt_value.sival_ptr; #endif +#ifdef CONFIG_SCHED_HAVE_PARENT + info.si_pid = 0; /* Not applicable */ + info.si_status = OK; +#endif /* Send the signal */ |