* <!--
* Copyright 2001,2004 Develer S.r.l. (http://www.develer.com/)
* Copyright 1999,2000,2001 Bernardo Innocenti <bernie@develer.com>
- * This file is part of DevLib - See devlib/README for information.
+ * This file is part of DevLib - See README.devlib for information.
* -->
*
* \brief Simple realtime multitasking scheduler.
/*#*
*#* $Log$
+ *#* Revision 1.30 2006/03/27 04:49:23 bernie
+ *#* CPU_IDLE(): Fix for new emulator.
+ *#*
+ *#* Revision 1.29 2006/02/24 01:17:05 bernie
+ *#* Update for new emulator.
+ *#*
+ *#* Revision 1.28 2006/02/21 16:06:55 bernie
+ *#* Cleanup/update process scheduling.
+ *#*
+ *#* Revision 1.27 2005/11/04 16:20:02 bernie
+ *#* Fix reference to README.devlib in header.
+ *#*
+ *#* Revision 1.26 2005/04/11 19:10:28 bernie
+ *#* Include top-level headers from cfg/ subdir.
+ *#*
+ *#* Revision 1.25 2005/03/15 00:20:54 bernie
+ *#* proc_schedule(): New sanity check.
+ *#*
+ *#* Revision 1.24 2005/01/08 09:20:54 bernie
+ *#* Remove unused variable.
+ *#*
+ *#* Revision 1.23 2004/12/13 12:07:06 bernie
+ *#* DISABLE_IRQSAVE/ENABLE_IRQRESTORE: Convert to IRQ_SAVE_DISABLE/IRQ_RESTORE.
+ *#*
+ *#* Revision 1.22 2004/12/13 11:51:08 bernie
+ *#* DISABLE_INTS/ENABLE_INTS: Convert to IRQ_DISABLE/IRQ_ENABLE.
+ *#*
+ *#* Revision 1.21 2004/11/28 23:20:25 bernie
+ *#* Remove obsolete INITLIST macro.
+ *#*
+ *#* Revision 1.20 2004/11/16 22:37:14 bernie
+ *#* Replace IPTR with iptr_t.
+ *#*
+ *#* Revision 1.19 2004/10/19 11:47:39 bernie
+ *#* Kill warnings when !CONFIG_PROC_MONITOR.
+ *#*
+ *#* Revision 1.18 2004/10/19 08:54:43 bernie
+ *#* Initialize forbid_cnt; Formatting/comments fixes.
+ *#*
+ *#* Revision 1.17 2004/10/19 08:47:13 bernie
+ *#* proc_rename(), proc_forbid(), proc_permit(): New functions.
+ *#*
*#* Revision 1.16 2004/10/03 20:39:28 bernie
*#* Import changes from sc/firmware.
*#*
#include "proc_p.h"
#include "proc.h"
-#include "cpu.h"
-#include "event.h"
-#include "hw.h"
-#include <debug.h>
-#include <arch_config.h> /* ARCH_EMUL */
-#include <macros.h> /* ABS() */
+//#include "hw.h"
+#include <mware/event.h>
+#include <cfg/cpu.h>
+#include <cfg/debug.h>
+#include <cfg/arch_config.h> /* ARCH_EMUL */
+#include <cfg/macros.h> /* ABS() */
#include <string.h> /* memset() */
extern List StackFreeList;
#endif
-/* The main process (the one that executes main()) */
+/*! The main process (the one that executes main()). */
struct Process MainProcess;
-static void proc_init_struct(Process* proc)
+static void proc_init_struct(Process *proc)
{
- /* Avoid warning for unused argument */
+ /* Avoid warning for unused argument. */
(void)proc;
#if CONFIG_KERN_SIGNALS
proc->sig_recv = 0;
#endif
+#if CONFIG_KERN_PREEMPTIVE
+ proc->forbid_cnt = 0;
+#endif
+
#if CONFIG_KERN_HEAP
proc->flags = 0;
#endif
void proc_init(void)
{
- INITLIST(&ProcReadyList);
+ LIST_INIT(&ProcReadyList);
#if CONFIG_KERN_MONITOR
monitor_init();
* \return Process structure of new created process
* if successful, NULL otherwise.
*/
-struct Process *proc_new_with_name(UNUSED(const char*, name), void (*entry)(void), IPTR data, size_t stacksize, cpustack_t *stack_base)
+struct Process *proc_new_with_name(UNUSED(const char *, name), void (*entry)(void), iptr_t data, size_t stacksize, cpustack_t *stack_base)
{
Process *proc;
- cpuflags_t flags;
size_t i;
size_t proc_size_words = ROUND2(sizeof(Process), sizeof(cpustack_t)) / sizeof(cpustack_t);
#if CONFIG_KERN_HEAP
#endif
#if (ARCH & ARCH_EMUL)
- /* Ignore stack provided by caller
- * and use the large enough default instead
- */
- stack_base = (cpustack_t *)StackFreeList.head;
- REMOVE((Node *)stack_base);
- stacksize = DEF_STACKSIZE;
+ /* Ignore stack provided by caller and use the large enough default instead. */
+ stack_base = (cpustack_t *)LIST_HEAD(&StackFreeList);
+ REMOVE(LIST_HEAD(&StackFreeList));
+ stacksize = CONFIG_KERN_DEFSTACKSIZE;
#elif CONFIG_KERN_HEAP
/* Did the caller provide a stack for us? */
if (!stack_base)
CPU_PUSH_WORD(proc->stack, CPU_REG_INIT_VALUE(i));
/* Add to ready list */
- DISABLE_IRQSAVE(flags);
- SCHED_ENQUEUE(proc);
- ENABLE_IRQRESTORE(flags);
+ ATOMIC(SCHED_ENQUEUE(proc));
#if CONFIG_KERN_MONITOR
monitor_add(proc, name, stack_base, stacksize);
return proc;
}
+/*! Rename a process */
+void proc_rename(struct Process *proc, const char *name)
+{
+#if CONFIG_KERN_MONITOR
+ monitor_rename(proc, name);
+#else
+ (void)proc; (void)name;
+#endif
+}
+
/*!
* System scheduler: pass CPU control to the next process in
* the compiler might put them on the stack of the process
* being switched out.
*/
- static Process *old_process;
+ static struct Process *old_process;
static cpuflags_t flags;
/* Remember old process to save its context later */
old_process = CurrentProcess;
+#ifdef IRQ_RUNNING
+ /* Scheduling in interrupts is a nono. */
+ ASSERT(!IRQ_RUNNING());
+#endif
+
/* Poll on the ready queue for the first ready process */
- DISABLE_IRQSAVE(flags);
- while (!(CurrentProcess = (struct Process*)REMHEAD(&ProcReadyList)))
+ IRQ_SAVE_DISABLE(flags);
+ while (!(CurrentProcess = (struct Process *)list_remHead(&ProcReadyList)))
{
/*
* Make sure we physically reenable interrupts here, no matter what
* are idle-spinning, we must allow interrupts, otherwise no
* process will ever wake up.
*
- * \todo If there was a way to code sig_wait so that it does not
+ * \todo If there was a way to write sig_wait() so that it does not
* disable interrupts while waiting, there would not be any
* reason to do this.
*/
- ENABLE_INTS;
- SCHEDULER_IDLE;
- DISABLE_INTS;
+ IRQ_ENABLE;
+ CPU_IDLE;
+ IRQ_DISABLE;
}
- ENABLE_IRQRESTORE(flags);
+ IRQ_RESTORE(flags);
- /* Optimization: don't switch contexts when the active
+ /*
+ * Optimization: don't switch contexts when the active
* process has not changed.
*/
if (CurrentProcess != old_process)
{
- static cpustack_t* dummy;
+ static cpustack_t *dummy;
#if CONFIG_KERN_PREEMPTIVE
/* Reset quantum for this process */
*/
void proc_exit(void)
{
+#if CONFIG_KERN_MONITOR
+ monitor_remove(CurrentProcess);
+#endif
+
#if CONFIG_KERN_HEAP
- /* The following code is BROKEN.
+ /*
+ * The following code is BROKEN.
* We are freeing our own stack before entering proc_schedule()
* BAJO: A correct fix would be to rearrange the scheduler with
* an additional parameter which frees the old stack/process
#endif
#if (ARCH & ARCH_EMUL)
-#error This is wrong
+#warning This is wrong
/* Reinsert process stack in free list */
ADDHEAD(&StackFreeList, (Node *)(CurrentProcess->stack
- - (DEF_STACKSIZE / sizeof(cpustack_t))));
+ - (CONFIG_KERN_DEFSTACKSIZE / sizeof(cpustack_t))));
- /* NOTE: At this point the first two words of what used
+ /*
+ * NOTE: At this point the first two words of what used
* to be our stack contain a list node. From now on, we
* rely on the compiler not reading/writing the stack.
*/
#endif /* ARCH_EMUL */
-#if CONFIG_KERN_MONITOR
- monitor_remove(CurrentProcess);
-#endif
-
CurrentProcess = NULL;
proc_schedule();
/* not reached */
/* Just like proc_schedule, this function must not have auto variables. */
static cpuflags_t flags;
- DISABLE_IRQSAVE(flags);
+ IRQ_SAVE_DISABLE(flags);
SCHED_ENQUEUE(CurrentProcess);
- ENABLE_IRQRESTORE(flags);
+ IRQ_RESTORE(flags);
proc_schedule();
}
/*!
* Get the pointer to the user data of the current process
*/
-IPTR proc_current_user_data(void)
+iptr_t proc_current_user_data(void)
{
return CurrentProcess->user_data;
}
+
+#if CONFIG_KERN_PREEMPTIVE
+
+/*!
+ * Disable preemptive task switching.
+ *
+ * The scheduler maintains a per-process nesting counter. Task switching is
+ * effectively re-enabled only when the number of calls to proc_permit()
+ * matches the number of calls to proc_forbid().
+ *
+ * Calling functions that could sleep while task switching is disabled
+ * is dangerous, although supported. Preemptive task switching is
+ * resumed while the process is sleeping and disabled again as soon as
+ * it wakes up again.
+ *
+ * \sa proc_permit()
+ */
+void proc_forbid(void)
+{
+ /* No need to protect against interrupts here. */
+ ++CurrentProcess->forbid_cnt;
+}
+
+/*!
+ * Re-enable preemptive task switching.
+ *
+ * \sa proc_forbid()
+ */
+void proc_permit(void)
+{
+ /* No need to protect against interrupts here. */
+ --CurrentProcess->forbid_cnt;
+}
+
+#endif /* CONFIG_KERN_PREEMPTIVE */
+
+
#if 0 /* Simple testcase for the scheduler */
#include <drv/timer.h>
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