From 3b1306078b57c5f6fa6141ecd3d80e4847c0b981 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Thu, 23 Jul 2015 15:08:41 -0600
Subject: [PATCH] Sporadic Scheduler: Ensure that the replenishment period is
greater than or equal to the budget period
---
sched/pthread/pthread_create.c | 46 +++++++++++++++++++------
sched/sched/sched_setparam.c | 59 ++++++++++++++++++++++----------
sched/sched/sched_setscheduler.c | 39 ++++++++++++---------
3 files changed, 100 insertions(+), 44 deletions(-)
diff --git a/sched/pthread/pthread_create.c b/sched/pthread/pthread_create.c
index 86e3dd8d8d..9cea2af0e8 100644
--- a/sched/pthread/pthread_create.c
+++ b/sched/pthread/pthread_create.c
@@ -227,9 +227,6 @@ int pthread_create(FAR pthread_t *thread, FAR const pthread_attr_t *attr,
{
FAR struct pthread_tcb_s *ptcb;
FAR struct join_s *pjoin;
-#ifdef CONFIG_SCHED_SPORADIC
- int ticks;
-#endif
int priority;
int policy;
int errcode;
@@ -308,6 +305,9 @@ int pthread_create(FAR pthread_t *thread, FAR const pthread_attr_t *attr,
if (attr->inheritsched == PTHREAD_INHERIT_SCHED)
{
struct sched_param param;
+#ifdef CONFIG_SCHED_SPORADIC
+ int ticks;
+#endif
/* Get the priority (and any other scheduling parameters) for this
* thread.
@@ -352,16 +352,42 @@ int pthread_create(FAR pthread_t *thread, FAR const pthread_attr_t *attr,
policy = attr->policy;
#ifdef CONFIG_SCHED_SPORADIC
- /* Save the sporadic scheduling parameters */
+ if (policy == SCHED_SPORADIC)
+ {
+ int repl_ticks;
+ int budget_ticks;
- ptcb->cmn.low_priority = attr->low_priority;
- ptcb->cmn.max_repl = attr->max_repl;
+ /* Convert timespec values to system clock ticks */
- (void)clock_time2ticks(&attr->repl_period, &ticks);
- ptcb->cmn.repl_period = ticks;
+ (void)clock_time2ticks(&attr->repl_period, &repl_ticks);
+ (void)clock_time2ticks(&attr->budget, &budget_ticks);
- (void)clock_time2ticks(&attr->budget, &ticks);
- ptcb->cmn.budget = ticks;
+ /* The replenishment period must be greater than or equal to the
+ * budget period.
+ */
+
+ if (repl_ticks < budget_ticks)
+ {
+ errcode = EINVAL;
+ goto errout_with_join;
+ }
+
+ /* Save the sporadic scheduling parameters */
+
+ ptcb->cmn.low_priority = attr->low_priority;
+ ptcb->cmn.max_repl = attr->max_repl;
+ ptcb->cmn.repl_period = repl_ticks;
+ ptcb->cmn.budget = budget_ticks;
+ }
+ else
+ {
+ /* Ignore sporadic scheduling parameters */
+
+ ptcb->cmn.low_priority = 0;
+ ptcb->cmn.max_repl = 0;
+ ptcb->cmn.repl_period = 0;
+ ptcb->cmn.budget = 0;
+ }
#endif
}
diff --git a/sched/sched/sched_setparam.c b/sched/sched/sched_setparam.c
index e75980c3b5..f7f193cdcf 100644
--- a/sched/sched/sched_setparam.c
+++ b/sched/sched/sched_setparam.c
@@ -86,14 +86,15 @@ int sched_setparam(pid_t pid, FAR const struct sched_param *param)
{
FAR struct tcb_s *rtcb;
FAR struct tcb_s *tcb;
+ int errcode;
int ret;
/* Verify that the requested priority is in the valid range */
if (!param)
{
- set_errno(EINVAL);
- return ERROR;
+ errcode = EINVAL;
+ goto errout_with_errcode;
}
/* Prohibit modifications to the head of the ready-to-run task
@@ -110,18 +111,17 @@ int sched_setparam(pid_t pid, FAR const struct sched_param *param)
tcb = rtcb;
}
- /* The pid is not the calling task, we will have to search for it */
+ /* The PID is not the calling task, we will have to search for it */
else
{
tcb = sched_gettcb(pid);
if (!tcb)
{
- /* No task with this pid was found */
+ /* No task with this PID was found */
- set_errno(ESRCH);
- sched_unlock();
- return ERROR;
+ errcode = ESRCH;
+ goto errout_with_lock;
}
}
@@ -130,20 +130,34 @@ int sched_setparam(pid_t pid, FAR const struct sched_param *param)
if ((rtcb->flags & TCB_FLAG_POLICY_MASK) == TCB_FLAG_SCHED_SPORADIC)
{
- int ticks;
+ int repl_ticks;
+ int budget_ticks;
DEBUGASSERT(param->sched_ss_max_repl <= UINT8_MAX);
+ /* Convert timespec values to system clock ticks */
+
+ (void)clock_time2ticks(¶m->sched_ss_repl_period, &repl_ticks);
+ (void)clock_time2ticks(¶m->sched_ss_init_budget, &budget_ticks);
+
+ /* The replenishment period must be greater than or equal to the
+ * budget period.
+ */
+
+ if (repl_ticks < budget_ticks)
+ {
+ errcode = EINVAL;
+ goto errout_with_lock;
+ }
+
+ /* Save the sporadic scheduling parameters */
+
tcb->flags |= TCB_FLAG_SCHED_SPORADIC;
tcb->timeslice = MSEC2TICK(CONFIG_RR_INTERVAL);
tcb->low_priority = param->sched_ss_low_priority;
tcb->max_repl = param->sched_ss_max_repl;
-
- (void)clock_time2ticks(¶m->sched_ss_repl_period, &ticks);
- tcb->repl_period = ticks;
-
- (void)clock_time2ticks(¶m->sched_ss_init_budget, &ticks);
- tcb->budget = ticks;
+ tcb->repl_period = repl_ticks;
+ tcb->budget = budget_ticks;
}
else
{
@@ -154,9 +168,18 @@ int sched_setparam(pid_t pid, FAR const struct sched_param *param)
}
#endif
- /* Then perform the reprioritization */
+ /* Then perform the reprioritization */
+
+ ret = sched_reprioritize(tcb, param->sched_priority);
+ sched_unlock();
+ return ret;
+
+errout_with_lock:
+ set_errno(errcode);
+ sched_unlock();
+ return ERROR;
- ret = sched_reprioritize(tcb, param->sched_priority);
- sched_unlock();
- return ret;
+errout_with_errcode:
+ set_errno(errcode);
+ return ERROR;
}
diff --git a/sched/sched/sched_setscheduler.c b/sched/sched/sched_setscheduler.c
index f05fb39bc7..0c3c6a6f94 100644
--- a/sched/sched/sched_setscheduler.c
+++ b/sched/sched/sched_setscheduler.c
@@ -166,20 +166,35 @@ int sched_setscheduler(pid_t pid, int policy,
#ifdef CONFIG_SCHED_SPORADIC
case SCHED_SPORADIC:
{
- int ticks;
+ int repl_ticks;
+ int budget_ticks;
DEBUGASSERT(param->sched_ss_max_repl <= UINT8_MAX);
+ /* Convert timespec values to system clock ticks */
+
+ (void)clock_time2ticks(¶m->sched_ss_repl_period, &repl_ticks);
+ (void)clock_time2ticks(¶m->sched_ss_init_budget, &budget_ticks);
+
+ /* The replenishment period must be greater than or equal to the
+ * budget period.
+ */
+
+ if (repl_ticks < budget_ticks)
+ {
+ set_errno(EINVAL);
+ sched_unlock();
+ return ERROR;
+ }
+
+ /* Save the sporadic scheduling parameters */
+
tcb->flags |= TCB_FLAG_SCHED_SPORADIC;
tcb->timeslice = MSEC2TICK(CONFIG_RR_INTERVAL);
tcb->low_priority = param->sched_ss_low_priority;
tcb->max_repl = param->sched_ss_max_repl;
-
- (void)clock_time2ticks(¶m->sched_ss_repl_period, &ticks);
- tcb->repl_period = ticks;
-
- (void)clock_time2ticks(¶m->sched_ss_init_budget, &ticks);
- tcb->budget = ticks;
+ tcb->repl_period = repl_ticks;
+ tcb->budget = budget_ticks;
}
break;
#endif
@@ -197,13 +212,5 @@ int sched_setscheduler(pid_t pid, int policy,
ret = sched_reprioritize(tcb, param->sched_priority);
sched_unlock();
-
- if (ret != OK)
- {
- return ERROR;
- }
- else
- {
- return OK;
- }
+ return (ret >= 0) ? OK : ERROR;
}
--
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