4 * This file is part of BeRTOS.
6 * Bertos is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * As a special exception, you may use this file as part of a free software
21 * library without restriction. Specifically, if other files instantiate
22 * templates or use macros or inline functions from this file, or you compile
23 * this file and link it with other files to produce an executable, this
24 * file does not by itself cause the resulting executable to be covered by
25 * the GNU General Public License. This exception does not however
26 * invalidate any other reasons why the executable file might be covered by
27 * the GNU General Public License.
29 * Copyright 2001, 2004 Develer S.r.l. (http://www.develer.com/)
30 * Copyright 1999, 2000, 2001 Bernie Innocenti <bernie@codewiz.org>
34 * \brief Internal scheduler structures and definitions for processes.
37 * \author Bernie Innocenti <bernie@codewiz.org>
43 #include "cfg/cfg_proc.h"
44 #include "cfg/cfg_monitor.h"
46 #include <cfg/compiler.h>
48 #include <cpu/types.h> /* for cpu_stack_t */
49 #include <cpu/irq.h> // IRQ_ASSERT_DISABLED()
51 #include <kern/proc.h> // struct Process
53 #ifndef asm_switch_context
55 * CPU dependent context switching routines.
57 * Saving and restoring the context on the stack is done by a CPU-dependent
58 * support routine which usually needs to be written in assembly.
60 EXTERN_C void asm_switch_context(cpu_stack_t **new_sp, cpu_stack_t **save_sp);
64 * \name Flags for Process.flags.
67 #define PF_FREESTACK BV(0) /**< Free the stack when process dies */
71 /** Track running processes. */
72 extern REGISTER Process *current_process;
75 * Track ready processes.
77 * Access to this list must be performed with interrupts disabled
79 extern REGISTER List proc_ready_list;
82 #define prio_next() (LIST_EMPTY(&proc_ready_list) ? INT_MIN : \
83 ((PriNode *)LIST_HEAD(&proc_ready_list))->pri)
84 #define prio_proc(proc) (proc->link.pri)
85 #define prio_curr() prio_proc(current_process)
87 #define SCHED_ENQUEUE_INTERNAL(proc) \
88 LIST_ENQUEUE(&proc_ready_list, &(proc)->link)
89 #define SCHED_ENQUEUE_HEAD_INTERNAL(proc) \
90 LIST_ENQUEUE_HEAD(&proc_ready_list, &(proc)->link)
93 #define prio_proc(proc) 0
96 #define SCHED_ENQUEUE_INTERNAL(proc) ADDTAIL(&proc_ready_list, &(proc)->link)
97 #define SCHED_ENQUEUE_HEAD_INTERNAL(proc) ADDHEAD(&proc_ready_list, &(proc)->link)
101 * Enqueue a process in the ready list.
103 * Always use this macro to instert a process in the ready list, as its
104 * might vary to implement a different scheduling algorithms.
106 * \note Access to the scheduler ready list must be performed with
107 * interrupts disabled.
109 #define SCHED_ENQUEUE(proc) do { \
110 IRQ_ASSERT_DISABLED(); \
111 LIST_ASSERT_VALID(&proc_ready_list); \
112 SCHED_ENQUEUE_INTERNAL(proc); \
115 #define SCHED_ENQUEUE_HEAD(proc) do { \
116 IRQ_ASSERT_DISABLED(); \
117 LIST_ASSERT_VALID(&proc_ready_list); \
118 SCHED_ENQUEUE_HEAD_INTERNAL(proc); \
124 * Changes the priority of an already enqueued process.
126 * Searches and removes the process from the ready list, then uses LIST_ENQUEUE(()
127 * to insert again to fix priority.
129 * No action is performed for processes that aren't in the ready list, eg. in semaphore queues.
131 * \note Performance could be improved with a different implementation of priority list.
133 INLINE void sched_reenqueue(struct Process *proc)
135 IRQ_ASSERT_DISABLED();
136 LIST_ASSERT_VALID(&proc_ready_list);
139 FOREACH_NODE(n, &proc_ready_list)
141 if (n == &proc->link.link)
148 // only remove and enqueue again if process is already in the ready list
149 // otherwise leave it alone
152 REMOVE(&proc->link.link);
153 LIST_ENQUEUE(&proc_ready_list, &proc->link);
156 #endif //CONFIG_KERN_PRI
158 /* Process trampoline */
159 void proc_entry(void);
161 /* Schedule another process *without* adding the current one to the ready list. */
162 void proc_switch(void);
164 /* Immediately schedule a particular process bypassing the scheduler. */
165 void proc_wakeup(Process *proc);
167 /* Initialize a scheduler class. */
168 void proc_schedInit(void);
170 #if CONFIG_KERN_MONITOR
171 /** Initialize the monitor */
172 void monitor_init(void);
174 /** Register a process into the monitor */
175 void monitor_add(Process *proc, const char *name);
177 /** Unregister a process from the monitor */
178 void monitor_remove(Process *proc);
180 /** Rename a process */
181 void monitor_rename(Process *proc, const char *name);
182 #endif /* CONFIG_KERN_MONITOR */
185 * Quantum related macros are used in the
186 * timer module and must be empty when
187 * kernel is disabled.
189 #if (CONFIG_KERN && CONFIG_KERN_PREEMPT)
190 INLINE int preempt_quantum(void)
192 extern int _proc_quantum;
193 return _proc_quantum;
196 INLINE void proc_decQuantum(void)
198 extern int _proc_quantum;
199 if (_proc_quantum > 0)
203 INLINE void preempt_reset_quantum(void)
205 extern int _proc_quantum;
206 _proc_quantum = CONFIG_KERN_QUANTUM;
208 #else /* !(CONFIG_KERN && CONFIG_KERN_PREEMPT) */
209 INLINE int preempt_quantum(void)
214 INLINE void proc_decQuantum(void)
218 INLINE void preempt_reset_quantum(void)
221 #endif /* (CONFIG_KERN && CONFIG_KERN_PREEMPT) */
223 #endif /* KERN_PROC_P_H */