-/*!
+/**
* \file
* <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction. Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License. This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
* 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.
+ *
* -->
*
* \brief Simple realtime multitasking scheduler.
* \author Stefano Fedrigo <aleph@develer.com>
*/
-/*
- * $Log$
- * Revision 1.8 2004/08/14 19:37:57 rasky
- * Merge da SC: macros.h, pool.h, BIT_CHANGE, nome dei processi, etc.
- *
- * 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 "cpu.h"
#include "proc_p.h"
#include "proc.h"
-#include "event.h"
-#include "hw.h"
-#include <drv/kdebug.h>
+//#include "hw.h"
+#include <mware/event.h>
+#include <cpu/irq.h>
+#include <cpu/types.h>
+#include <cpu/attr.h>
+#include <cfg/debug.h>
+#include <cfg/module.h>
+#include <cfg/arch_config.h> /* ARCH_EMUL */
+#include <cfg/macros.h> /* ABS() */
#include <string.h> /* memset() */
-/*! CPU dependent context switching routines
- * \note This function *MUST* preserve also the status of the interrupts.
+/**
+ * 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);
+EXTERN_C void asm_switch_context(cpustack_t **new_sp, cpustack_t **save_sp);
+EXTERN_C int asm_switch_version(void);
/*
* The scheduer tracks ready and waiting processes
extern List StackFreeList;
#endif
-/* The main process (the one that executes main()) */
+/** The main process (the one that executes main()). */
struct Process MainProcess;
-#if CONFIG_KERN_MONITOR
-List MonitorProcs;
-
-static void monitor_init(void)
-{
- INITLIST(&MonitorProcs);
-}
-
-static void monitor_add(Process* proc, const char* name, cpustack_t* stack_base, size_t stack_size)
-{
- proc->monitor.name = name;
- proc->monitor.stack_base = stack_base;
- proc->monitor.stack_size = stack_size;
-
- ADDTAIL(&MonitorProcs, &proc->monitor.link);
-}
-
-static void monitor_remove(Process* proc)
+static void proc_init_struct(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;
- int i;
-
- if (ISLISTEMPTY(&MonitorProcs))
- {
- kprintf("No stacks registered in the monitor\n");
- return;
- }
-
- kprintf("%-24s %-6s%-8s%-8s%-8s\n", "Process name", "TCB", "SPbase", "SPsize", "SPfree");
- for (i=0;i<56;i++)
- kprintf("-");
- kprintf("\n");
-
- 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("%-24s %04x %04x %4x %4x\n", p->monitor.name, (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 */
+ /* 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
}
+MOD_DEFINE(proc);
void proc_init(void)
{
- INITLIST(&ProcReadyList);
+ LIST_INIT(&ProcReadyList);
#if CONFIG_KERN_MONITOR
monitor_init();
/* Make sure the assembly routine is up-to-date with us */
ASSERT(asm_switch_version() == 1);
+ MOD_INIT(proc);
}
-/*!
+/**
* Create a new process, starting at the provided entry point.
*
* \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_PROC_DEFSTACKSIZE;
#elif CONFIG_KERN_HEAP
/* Did the caller provide a stack for us? */
if (!stack_base)
{
/* Did the caller specify the desired stack size? */
if (!stacksize)
- stacksize = CONFIG_KERN_DEFSTACKSIZE + sizeof(Process);
+ stacksize = CONFIG_PROC_DEFSTACKSIZE + sizeof(Process);
/* Allocate stack dinamically */
if (!(stack_base = heap_alloc(stacksize)))
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 ready queue.
*
*/
void proc_schedule(void)
{
- /* This function must not have any "auto" variables, otherwise
- * the compiler might put them on the stack of the process
- * being switched out.
- */
- static Process *old_process;
- static cpuflags_t flags;
+ struct Process *old_process;
+ 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
+ * During idle-spinning, can occur an interrupt, it may be able to
+ * modify \p ProcReadyList. To ensure that compiler reload this
+ * variable every while cycle we call CPU_MEMORY_BARRIER.
+ * The memory barrier ensure that all variables used in this context
+ * are reloaded.
+ * \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;
+ MEMORY_BARRIER;
+ 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;
+ cpustack_t *dummy;
#if CONFIG_KERN_PREEMPTIVE
/* Reset quantum for this process */
}
-/*!
+/**
* Terminate the current 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_PROC_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 */
}
-/*!
+/**
* Co-operative context switch
*/
void proc_switch(void)
{
- /* Just like proc_schedule, this function must not have auto variables. */
- static cpuflags_t flags;
+ 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 current process
*/
struct Process *proc_current(void)
return CurrentProcess;
}
-/*!
+/**
* 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 0 /* Simple testcase for the scheduler */
-/*!
- * Proc scheduling test subthread 1
- */
-static void NORETURN proc_test_thread1(void)
-{
- for (;;)
- {
- kputs(">task 1\n");
- timer_delay(50);
- proc_switch();
- }
-}
+#if CONFIG_KERN_PREEMPTIVE
-/*!
- * Proc scheduling test subthread 2
+/**
+ * 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()
*/
-static void NORETURN proc_test_thread2(void)
+void proc_forbid(void)
{
- for (;;)
- {
- kputs(">task 2\n");
- timer_delay(75);
- proc_switch();
- }
+ /* No need to protect against interrupts here. */
+ ++CurrentProcess->forbid_cnt;
}
-static cpustack_t proc_test_stack1[CONFIG_KERN_DEFSTACKSIZE/sizeof(cpustack_t)];
-static cpustack_t proc_test_stack2[CONFIG_KERN_DEFSTACKSIZE/sizeof(cpustack_t)];
-
-/*!
- * Proc scheduling test
+/**
+ * Re-enable preemptive task switching.
+ *
+ * \sa proc_forbid()
*/
-void NORETURN proc_test(void)
+void proc_permit(void)
{
- proc_new(proc_test_thread1, NULL, sizeof(proc_test_stack1), proc_test_stack1);
- proc_new(proc_test_thread2, NULL, sizeof(proc_test_stack2), proc_test_stack2);
- kputs("Created tasks\n");
-
- kputs("stack1:\n");
- kdump(proc_test_stack1+sizeof(proc_test_stack1)-64, 64);
- kputs("stack2:\n");
- kdump(proc_test_stack2+sizeof(proc_test_stack1)-64, 64);
-
- for (;;)
- {
- kputs(">main task\n");
- timer_delay(93);
- proc_switch();
- }
-
- ASSERT(false);
+ /* No need to protect against interrupts here. */
+ --CurrentProcess->forbid_cnt;
}
-#endif
+
+#endif /* CONFIG_KERN_PREEMPTIVE */
projects / bertos.git / blobdiff