-/**
+/*!
* \file
* <!--
* Copyright 2001,2004 Develer S.r.l. (http://www.develer.com/)
* Copyright 1999,2000,2001 Bernardo Innocenti <bernie@develer.com>
- * All Rights Reserved.
+ * This file is part of DevLib - See devlib/README for information.
* -->
*
* \brief Simple realtime multitasking scheduler.
/*
* $Log$
+ * Revision 1.7 2004/08/02 20:20:29 aleph
+ * Merge from project_ks
+ *
+ * Revision 1.6 2004/07/30 14:24:16 rasky
+ * Task switching con salvataggio perfetto stato di interrupt (SR)
+ * Kernel monitor per dump informazioni su stack dei processi
+ *
+ * Revision 1.5 2004/07/14 14:18:09 rasky
+ * Merge da SC: Rimosso timer dentro il task, che รจ uno spreco di memoria per troppi task
+ *
+ * Revision 1.4 2004/07/13 19:21:28 aleph
+ * Avoid warning for unused arg when compiled without some CONFIG_KERN_xx options
+ *
+ * Revision 1.3 2004/06/06 18:37:57 bernie
+ * Rename event macros to look like regular functions.
+ *
+ * Revision 1.2 2004/06/03 11:27:09 bernie
+ * Add dual-license information.
+ *
* Revision 1.1 2004/05/23 17:27:00 bernie
* Import kern/ subdirectory.
*
#include <string.h> /* memset() */
-/* CPU dependent context switching routines */
+/*! CPU dependent context switching routines
+ * \note This function *MUST* preserve also the status of the interrupts.
+ */
extern void asm_switch_context(cpustack_t **new_sp, cpustack_t **save_sp);
+extern int asm_switch_version(void);
/*
* The scheduer tracks ready and waiting processes
REGISTER Process *CurrentProcess;
REGISTER List ProcReadyList;
+
#if CONFIG_KERN_PREEMPTIVE
/*
* The time sharing scheduler forces a task switch when
/* The main process (the one that executes main()) */
struct Process MainProcess;
-static void proc_init_struct(Process* proc)
+
+#if CONFIG_KERN_MONITOR
+List MonitorProcs;
+
+static void monitor_init(void)
+{
+ INITLIST(&MonitorProcs);
+}
+
+static void monitor_add(Process* proc, cpustack_t* stack_base, size_t stack_size)
{
-#if CONFIG_KERN_TIMER
- INITEVENT_SIG(&proc->proc_timer.expire, proc, SIG_SINGLE);
+ proc->monitor.stack_base = stack_base;
+ proc->monitor.stack_size = stack_size;
+
+ ADDTAIL(&MonitorProcs, &proc->monitor.link);
+}
+
+static void monitor_remove(Process* proc)
+{
+ REMOVE(&proc->monitor.link);
+}
+
+#define MONITOR_NODE_TO_PROCESS(node) \
+ (struct Process*)((char*)(node) - offsetof(struct Process, monitor.link))
+
+size_t monitor_check_stack(cpustack_t* stack_base, size_t stack_size)
+{
+ cpustack_t* beg;
+ cpustack_t* cur;
+ cpustack_t* end;
+ size_t sp_free;
+
+ beg = stack_base;
+ end = stack_base + stack_size / sizeof(cpustack_t) - 1;
+
+ if (CPU_STACK_GROWS_UPWARD)
+ {
+ cur = beg;
+ beg = end;
+ end = cur;
+ }
+
+ cur = beg;
+ while (cur != end)
+ {
+ if (*cur != CONFIG_KERN_STACKFILLCODE)
+ break;
+
+ if (CPU_STACK_GROWS_UPWARD)
+ cur--;
+ else
+ cur++;
+ }
+
+ sp_free = ABS(cur - beg) * sizeof(cpustack_t);
+ return sp_free;
+}
+
+void monitor_debug_stacks(void)
+{
+ struct Process* p;
+
+ for (p = MONITOR_NODE_TO_PROCESS(MonitorProcs.head);
+ p->monitor.link.succ;
+ p = MONITOR_NODE_TO_PROCESS(p->monitor.link.succ))
+ {
+ size_t free = monitor_check_stack(p->monitor.stack_base, p->monitor.stack_size);
+ kprintf("TCB: %x sp_base: %x sp_size: %x sp_free: %x\n", (uint16_t)p, (uint16_t)p->monitor.stack_base, (uint16_t)p->monitor.stack_size, (uint16_t)free);
+ }
+}
+
#endif
+
+static void proc_init_struct(Process* proc)
+{
+ /* Avoid warning for unused argument */
+ (void)proc;
+
#if CONFIG_KERN_SIGNALS
proc->sig_recv = 0;
#endif
#endif
}
+
void proc_init(void)
{
INITLIST(&ProcReadyList);
+#if CONFIG_KERN_MONITOR
+ monitor_init();
+#endif
+
/* We "promote" the current context into a real process. The only thing we have
- to do is create a PCB and make it current. We don't need to setup the stack
- pointer because it will be written the first time we switch to another process. */
+ * to do is create a PCB and make it current. We don't need to setup the stack
+ * pointer because it will be written the first time we switch to another process.
+ */
proc_init_struct(&MainProcess);
CurrentProcess = &MainProcess;
+
+ /* Make sure the assembly routine is up-to-date with us */
+ ASSERT(asm_switch_version() == 1);
}
Process *proc_new(void (*entry)(void), 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
ASSERT(stacksize);
#endif
-#ifdef _DEBUG
+#if CONFIG_KERN_MONITOR
/* Fill-in the stack with a special marker to help debugging */
memset(stack_base, CONFIG_KERN_STACKFILLCODE, stacksize / sizeof(cpustack_t));
-#endif /* _DEBUG */
+#endif
/* Initialize the process control block */
if (CPU_STACK_GROWS_UPWARD)
CPU_PUSH_WORD(proc->stack, CPU_REG_INIT_VALUE(i));
/* Add to ready list */
- DISABLE_INTS;
+ DISABLE_IRQSAVE(flags);
SCHED_ENQUEUE(proc);
- ENABLE_INTS;
+ ENABLE_IRQRESTORE(flags);
+
+#if CONFIG_KERN_MONITOR
+ monitor_add(proc, stack_base, stacksize);
+#endif
return proc;
}
* being switched out.
*/
static Process *old_process;
+ static cpuflags_t flags;
/* Remember old process to save its context later */
old_process = CurrentProcess;
- CurrentProcess = NULL;
- /* Poll on the ready queue for the first ready process
- */
- for(;;) /* forever */
+ /* Poll on the ready queue for the first ready process */
+ DISABLE_IRQSAVE(flags);
+ while (!(CurrentProcess = (struct Process*)REMHEAD(&ProcReadyList)))
{
- /* Do CPU specific idle processing (ARGH, should be moved to the end of the loop!) */
+ /*
+ * Make sure we physically reenable interrupts here, no matter what
+ * the current task status is. This is important because if we
+ * 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
+ * disable interrupts while waiting, there would not be any
+ * reason to do this.
+ */
+ ENABLE_INTS;
SCHEDULER_IDLE;
-
DISABLE_INTS;
- if (!ISLISTEMPTY(&ProcReadyList))
- {
- /* Get process from ready list */
- CurrentProcess = (Process *)ProcReadyList.head;
- REMOVE((Node *)CurrentProcess);
- ENABLE_INTS;
- break;
- }
- ENABLE_INTS;
}
+ ENABLE_IRQRESTORE(flags);
/* Optimization: don't switch contexts when the active
* process has not changed.
*/
#endif /* ARCH_EMUL */
+#if CONFIG_KERN_MONITOR
+ monitor_remove(CurrentProcess);
+#endif
+
CurrentProcess = NULL;
proc_schedule();
/* not reached */
*/
void proc_switch(void)
{
- DISABLE_INTS;
+ /* Just like proc_schedule, this function must not have auto variables. */
+ static cpuflags_t flags;
+
+ DISABLE_IRQSAVE(flags);
SCHED_ENQUEUE(CurrentProcess);
- ENABLE_INTS;
+ ENABLE_IRQRESTORE(flags);
+
proc_schedule();
}
projects / bertos.git / blobdiff