sched.h
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1 /*
2  * SPDX-FileCopyrightText: 2014-2017 Freie Universität Berlin
3  * SPDX-License-Identifier: LGPL-2.1-only
4  */
5 
6 #pragma once
7 
80 #include <stddef.h>
81 #include <inttypes.h>
82 
83 #include "kernel_defines.h"
84 #include "native_sched.h"
85 #include "clist.h"
86 
87 #ifdef __cplusplus
88 extern "C" {
89 #endif
90 
95 #ifndef MAXTHREADS
96 #if defined(MODULE_CORE_THREAD)
97 #define MAXTHREADS 32
98 #else
99 #define MAXTHREADS 0
100 #endif
101 #endif
102 
106 #define KERNEL_PID_UNDEF 0
107 
111 #define KERNEL_PID_FIRST (KERNEL_PID_UNDEF + 1)
112 
116 #define KERNEL_PID_LAST (KERNEL_PID_FIRST + MAXTHREADS - 1)
117 
121 #define PRIkernel_pid PRIi16
122 
123 #if defined(DEVELHELP) || defined(DOXYGEN)
127 #ifndef SCHED_TEST_STACK
128 #define SCHED_TEST_STACK 1
129 #endif /* SCHED_TEST_STACK */
130 #endif /* DEVELHELP */
131 
135 typedef int16_t kernel_pid_t;
136 
144 static inline int pid_is_valid(kernel_pid_t pid)
145 {
146  return ((KERNEL_PID_FIRST <= pid) && (pid <= KERNEL_PID_LAST));
147 }
151 typedef struct _thread thread_t;
152 
159 typedef enum {
173  STATUS_NUMOF
181 #define STATUS_ON_RUNQUEUE STATUS_RUNNING
183 #define STATUS_NOT_FOUND ((thread_status_t)~0)
189 #ifndef SCHED_PRIO_LEVELS
190 #define SCHED_PRIO_LEVELS 16
191 #endif
192 
201 
210 
223 void sched_switch(uint16_t other_prio);
224 
229 
234 extern volatile unsigned int sched_context_switch_request;
235 
239 extern volatile thread_t *sched_threads[KERNEL_PID_LAST + 1];
240 
244 extern volatile int sched_num_threads;
245 
250 
255 
267 void sched_change_priority(thread_t *thread, uint8_t priority);
268 
282 void sched_arch_idle(void);
283 
284 #if IS_USED(MODULE_SCHED_CB) || defined(DOXYGEN)
294 typedef void (*sched_callback_t)(kernel_pid_t active, kernel_pid_t next);
295 
302 #endif /* MODULE_SCHED_CB */
303 
319 static inline void sched_runq_advance(uint8_t prio)
320 {
322 }
323 
324 #if (IS_USED(MODULE_SCHED_RUNQ_CALLBACK)) || defined(DOXYGEN)
341 extern void sched_runq_callback(uint8_t prio);
342 #endif
343 
351 static inline int sched_runq_is_empty(uint8_t prio)
352 {
353  return clist_is_empty(&sched_runqueues[prio]);
354 }
355 
363 static inline int sched_runq_exactly_one(uint8_t prio)
364 {
365  return clist_exactly_one(&sched_runqueues[prio]);
366 }
367 
375 static inline int sched_runq_more_than_one(uint8_t prio)
376 {
377  return clist_more_than_one(&sched_runqueues[prio]);
378 }
379 
380 #ifdef __cplusplus
381 }
382 #endif
383 
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:491
static bool clist_is_empty(const clist_node_t *list)
Checks if *list is empty.
Definition: clist.h:115
static void clist_lpoprpush(clist_node_t *list)
Advances the circle list.
Definition: clist.h:200
static bool clist_exactly_one(clist_node_t *list)
Tells if a list has exactly one element.
Definition: clist.h:477
#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:190
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:375
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:144
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:363
void(* sched_callback_t)(kernel_pid_t active, kernel_pid_t next)
Scheduler run callback.
Definition: sched.h:294
#define KERNEL_PID_LAST
The last valid PID (inclusive).
Definition: sched.h:116
int16_t kernel_pid_t
Unique process identifier.
Definition: sched.h:135
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:159
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:351
static void sched_runq_advance(uint8_t prio)
Advance a runqueue.
Definition: sched.h:319
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:111
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:170
@ STATUS_RUNNING
currently running
Definition: sched.h:171
@ STATUS_MUTEX_BLOCKED
waiting for a locked mutex
Definition: sched.h:163
@ STATUS_STOPPED
has terminated
Definition: sched.h:160
@ STATUS_SLEEPING
sleeping
Definition: sched.h:162
@ STATUS_FLAG_BLOCKED_ANY
waiting for any flag from flag_mask
Definition: sched.h:167
@ STATUS_SEND_BLOCKED
waiting for message to be delivered
Definition: sched.h:165
@ STATUS_MBOX_BLOCKED
waiting for get/put on mbox
Definition: sched.h:169
@ STATUS_PENDING
waiting to be scheduled to run
Definition: sched.h:172
@ STATUS_NUMOF
number of supported thread states
Definition: sched.h:173
@ STATUS_REPLY_BLOCKED
waiting for a message response
Definition: sched.h:166
@ STATUS_ZOMBIE
has terminated & keeps thread's thread_t
Definition: sched.h:161
@ STATUS_FLAG_BLOCKED_ALL
waiting for all flags in flag_mask
Definition: sched.h:168
@ STATUS_RECEIVE_BLOCKED
waiting for a message
Definition: sched.h:164
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:36