X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=kern%2Fproc.c;h=a9e956243a2677267449f74241541f87f0e55862;hb=2535cb94ec2183791128f8bbd109ca69a960cf78;hp=975278b4b8192a430ef4c865e9d1c4c1d2a2e500;hpb=0d0eaf2e43aff60f23a662b9ea32525a1eb9fb79;p=bertos.git diff --git a/kern/proc.c b/kern/proc.c old mode 100755 new mode 100644 index 975278b4..a9e95624 --- a/kern/proc.c +++ b/kern/proc.c @@ -1,9 +1,34 @@ -/*! +/** * \file * * * \brief Simple realtime multitasking scheduler. @@ -15,68 +40,22 @@ * \author Stefano Fedrigo */ -/*#* - *#* $Log$ - *#* Revision 1.16 2004/10/03 20:39:28 bernie - *#* Import changes from sc/firmware. - *#* - *#* Revision 1.15 2004/09/20 03:29:39 bernie - *#* C++ fixes. - *#* - *#* Revision 1.14 2004/09/14 21:06:44 bernie - *#* Use debug.h instead of kdebug.h. - *#* - *#* Revision 1.13 2004/08/29 21:58:53 bernie - *#* Include macros.h explicityl. - *#* - *#* Revision 1.11 2004/08/24 16:09:08 bernie - *#* Add missing header. - *#* - *#* Revision 1.10 2004/08/24 16:07:01 bernie - *#* Use kputs()/kputchar() when possible. - *#* - *#* Revision 1.9 2004/08/24 14:26:57 bernie - *#* monitor_debug_stacks(): Conditionally compile on CONFIG_KERN_MONITOR. - *#* - *#* 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 è 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 "proc_p.h" #include "proc.h" -#include "cpu.h" -#include "event.h" -#include "hw.h" -#include -#include /* ARCH_EMUL */ -#include /* ABS() */ +//#include "hw.h" +#include +#include +#include +#include +#include +#include +#include /* ARCH_EMUL */ +#include /* ABS() */ #include /* memset() */ -/*! +/** * CPU dependent context switching routines. * * \note This function *MUST* preserve also the status of the interrupts. @@ -109,28 +88,33 @@ uint16_t Quantum; 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 } +MOD_DEFINE(proc); void proc_init(void) { - INITLIST(&ProcReadyList); + LIST_INIT(&ProcReadyList); #if CONFIG_KERN_MONITOR monitor_init(); @@ -145,19 +129,19 @@ void proc_init(void) /* 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 @@ -165,19 +149,17 @@ struct Process *proc_new_with_name(UNUSED(const char*, name), void (*entry)(void #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))) @@ -231,9 +213,7 @@ struct Process *proc_new_with_name(UNUSED(const char*, name), void (*entry)(void 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); @@ -242,8 +222,18 @@ struct Process *proc_new_with_name(UNUSED(const char*, name), void (*entry)(void 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. * @@ -253,19 +243,20 @@ struct Process *proc_new_with_name(UNUSED(const char*, name), void (*entry)(void */ 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 @@ -273,22 +264,29 @@ void proc_schedule(void) * 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 */ @@ -309,13 +307,18 @@ void proc_schedule(void) } -/*! +/** * 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 @@ -327,44 +330,40 @@ void proc_exit(void) #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) @@ -372,68 +371,46 @@ 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 */ -#include +#if CONFIG_KERN_PREEMPTIVE -/*! - * Proc scheduling test subthread 1 +/** + * 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_thread1(void) +void proc_forbid(void) { - for (;;) - { - kputs(">task 1\n"); - timer_delay(50); - proc_switch(); - } + /* No need to protect against interrupts here. */ + ++CurrentProcess->forbid_cnt; } -/*! - * Proc scheduling test subthread 2 +/** + * Re-enable preemptive task switching. + * + * \sa proc_forbid() */ -static void NORETURN proc_test_thread2(void) +void proc_permit(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 - */ -void NORETURN proc_test(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); -} -#endif +#endif /* CONFIG_KERN_PREEMPTIVE */