sched.h
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1 /*
2  * Copyright (C) 2014-2017 Freie Universität Berlin
3  *
4  * This file is subject to the terms and conditions of the GNU Lesser
5  * General Public License v2.1. See the file LICENSE in the top level
6  * directory for more details.
7  */
8 
9 #pragma once
10 
83 #include <stddef.h>
84 #include <inttypes.h>
85 
86 #include "kernel_defines.h"
87 #include "native_sched.h"
88 #include "clist.h"
89 
90 #ifdef __cplusplus
91 extern "C" {
92 #endif
93 
98 #ifndef MAXTHREADS
99 #if defined(MODULE_CORE_THREAD)
100 #define MAXTHREADS 32
101 #else
102 #define MAXTHREADS 0
103 #endif
104 #endif
105 
109 #define KERNEL_PID_UNDEF 0
110 
114 #define KERNEL_PID_FIRST (KERNEL_PID_UNDEF + 1)
115 
119 #define KERNEL_PID_LAST (KERNEL_PID_FIRST + MAXTHREADS - 1)
120 
124 #define PRIkernel_pid PRIi16
125 
126 #if defined(DEVELHELP) || defined(DOXYGEN)
130 #ifndef SCHED_TEST_STACK
131 #define SCHED_TEST_STACK 1
132 #endif /* SCHED_TEST_STACK */
133 #endif /* DEVELHELP */
134 
138 typedef int16_t kernel_pid_t;
139 
147 static inline int pid_is_valid(kernel_pid_t pid)
148 {
149  return ((KERNEL_PID_FIRST <= pid) && (pid <= KERNEL_PID_LAST));
150 }
154 typedef struct _thread thread_t;
155 
162 typedef enum {
176  STATUS_NUMOF
184 #define STATUS_ON_RUNQUEUE STATUS_RUNNING
186 #define STATUS_NOT_FOUND ((thread_status_t)~0)
192 #ifndef SCHED_PRIO_LEVELS
193 #define SCHED_PRIO_LEVELS 16
194 #endif
195 
204 
213 
226 void sched_switch(uint16_t other_prio);
227 
232 
237 extern volatile unsigned int sched_context_switch_request;
238 
242 extern volatile thread_t *sched_threads[KERNEL_PID_LAST + 1];
243 
247 extern volatile int sched_num_threads;
248 
253 
258 
270 void sched_change_priority(thread_t *thread, uint8_t priority);
271 
285 void sched_arch_idle(void);
286 
287 #if IS_USED(MODULE_SCHED_CB) || defined(DOXYGEN)
297 typedef void (*sched_callback_t)(kernel_pid_t active, kernel_pid_t next);
298 
305 #endif /* MODULE_SCHED_CB */
306 
322 static inline void sched_runq_advance(uint8_t prio)
323 {
325 }
326 
327 #if (IS_USED(MODULE_SCHED_RUNQ_CALLBACK)) || defined(DOXYGEN)
344 extern void sched_runq_callback(uint8_t prio);
345 #endif
346 
354 static inline int sched_runq_is_empty(uint8_t prio)
355 {
356  return clist_is_empty(&sched_runqueues[prio]);
357 }
358 
366 static inline int sched_runq_exactly_one(uint8_t prio)
367 {
368  return clist_exactly_one(&sched_runqueues[prio]);
369 }
370 
378 static inline int sched_runq_more_than_one(uint8_t prio)
379 {
380  return clist_more_than_one(&sched_runqueues[prio]);
381 }
382 
383 #ifdef __cplusplus
384 }
385 #endif
386 
Circular linked list.
static bool clist_more_than_one(clist_node_t *list)
Tells if a list has more than one element.
Definition: clist.h:493
static bool clist_is_empty(const clist_node_t *list)
Checks if *list is empty.
Definition: clist.h:117
static void clist_lpoprpush(clist_node_t *list)
Advances the circle list.
Definition: clist.h:202
static bool clist_exactly_one(clist_node_t *list)
Tells if a list has exactly one element.
Definition: clist.h:479
#define NORETURN
The NORETURN keyword tells the compiler to assume that the function cannot return.
#define SCHED_PRIO_LEVELS
The number of thread priority levels.
Definition: sched.h:193
static int sched_runq_more_than_one(uint8_t prio)
Tell if the number of threads in a runqueue greater than 1.
Definition: sched.h:378
void sched_register_cb(sched_callback_t callback)
Register a callback that will be called on every scheduler run.
void sched_arch_idle(void)
Set CPU to idle mode (CPU dependent)
static int pid_is_valid(kernel_pid_t pid)
Determine if the given pid is valid.
Definition: sched.h:147
volatile int sched_num_threads
Number of running (non-terminated) threads.
void sched_runq_callback(uint8_t prio)
Scheduler runqueue (change) callback.
static int sched_runq_exactly_one(uint8_t prio)
Tell if the number of threads in a runqueue is 1.
Definition: sched.h:366
void(* sched_callback_t)(kernel_pid_t active, kernel_pid_t next)
Scheduler run callback.
Definition: sched.h:297
#define KERNEL_PID_LAST
The last valid PID (inclusive).
Definition: sched.h:119
int16_t kernel_pid_t
Unique process identifier.
Definition: sched.h:138
volatile unsigned int sched_context_switch_request
Flag indicating whether a context switch is necessary after handling an interrupt.
void sched_switch(uint16_t other_prio)
Yield if appropriate.
void sched_set_status(thread_t *process, thread_status_t status)
Set the status of the specified process.
NORETURN void sched_task_exit(void)
Removes thread from scheduler and set status to STATUS_STOPPED.
void sched_change_priority(thread_t *thread, uint8_t priority)
Change the priority of the given thread.
volatile thread_t * sched_threads[KERNEL_PID_LAST+1]
Thread table.
thread_status_t
Definition: sched.h:162
thread_t * sched_run(void)
Triggers the scheduler to schedule the next thread.
static int sched_runq_is_empty(uint8_t prio)
Tell if the number of threads in a runqueue is 0.
Definition: sched.h:354
static void sched_runq_advance(uint8_t prio)
Advance a runqueue.
Definition: sched.h:322
NORETURN void cpu_switch_context_exit(void)
Call context switching at thread exit.
#define KERNEL_PID_FIRST
The first valid PID (inclusive).
Definition: sched.h:114
clist_node_t sched_runqueues[SCHED_PRIO_LEVELS]
List of runqueues per priority level.
@ STATUS_COND_BLOCKED
waiting for a condition variable
Definition: sched.h:173
@ STATUS_RUNNING
currently running
Definition: sched.h:174
@ STATUS_MUTEX_BLOCKED
waiting for a locked mutex
Definition: sched.h:166
@ STATUS_STOPPED
has terminated
Definition: sched.h:163
@ STATUS_SLEEPING
sleeping
Definition: sched.h:165
@ STATUS_FLAG_BLOCKED_ANY
waiting for any flag from flag_mask
Definition: sched.h:170
@ STATUS_SEND_BLOCKED
waiting for message to be delivered
Definition: sched.h:168
@ STATUS_MBOX_BLOCKED
waiting for get/put on mbox
Definition: sched.h:172
@ STATUS_PENDING
waiting to be scheduled to run
Definition: sched.h:175
@ STATUS_NUMOF
number of supported thread states
Definition: sched.h:176
@ STATUS_REPLY_BLOCKED
waiting for a message response
Definition: sched.h:169
@ STATUS_ZOMBIE
has terminated & keeps thread's thread_t
Definition: sched.h:164
@ STATUS_FLAG_BLOCKED_ALL
waiting for all flags in flag_mask
Definition: sched.h:171
@ STATUS_RECEIVE_BLOCKED
waiting for a message
Definition: sched.h:167
Adds include for missing inttype definitions.
Common macros and compiler attributes/pragmas configuration.
Add definitions required on the native board.
thread_t holds thread's context data.
Definition: thread.h:167
thread_status_t status
thread's status
Definition: thread.h:169
uint8_t priority
thread's priority
Definition: thread.h:170
List node structure.
Definition: list.h:39