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, 2008 Develer S.r.l. (http://www.develer.com/)
30 * Copyright 1999, 2000, 2001, 2008 Bernie Innocenti <bernie@codewiz.org>
33 * \brief Simple cooperative multitasking scheduler.
36 * \author Bernie Innocenti <bernie@codewiz.org>
37 * \author Stefano Fedrigo <aleph@develer.com>
43 // Log settings for cfg/log.h.
44 #define LOG_LEVEL KERN_LOG_LEVEL
45 #define LOG_FORMAT KERN_LOG_FORMAT
49 #include <cpu/types.h>
51 #include <cpu/frame.h>
54 * Define function prototypes exported outside.
56 * Required to silent gcc "no previous prototype" warnings.
58 void coop_yield(void);
59 void coop_switch(void);
60 void coop_wakeup(Process *proc);
63 * Give the control of the CPU to another process.
65 * \note Assume the current process has been already added to a wait queue.
67 * \warning This should be considered an internal kernel function, even if it
68 * is allowed, usage from application code is strongly discouraged.
70 void coop_switch(void)
72 ATOMIC(proc_schedule());
76 * Immediately wakeup a process, dispatching it to the CPU.
78 void coop_wakeup(Process *proc)
80 ASSERT(proc_preemptAllowed());
81 ASSERT(current_process);
82 IRQ_ASSERT_DISABLED();
84 if (prio_proc(proc) >= prio_curr())
86 Process *old_process = current_process;
88 SCHED_ENQUEUE(current_process);
89 current_process = proc;
90 proc_switchTo(current_process, old_process);
93 SCHED_ENQUEUE_HEAD(proc);
97 * Co-operative context switch
101 ATOMIC(SCHED_ENQUEUE(current_process));