X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fproc.c;h=84c5366370911c10e61c3a5f1b2c8dd5397dfd9c;hb=9740751dcd61ec99e1af95846d4c3b197a128d8a;hp=a9e956243a2677267449f74241541f87f0e55862;hpb=791e167e053bdd9250d34a9a5ccae6ccde4d6679;p=bertos.git diff --git a/bertos/kern/proc.c b/bertos/kern/proc.c index a9e95624..84c53663 100644 --- a/bertos/kern/proc.c +++ b/bertos/kern/proc.c @@ -27,7 +27,7 @@ * the GNU General Public License. * * Copyright 2001,2004 Develer S.r.l. (http://www.develer.com/) - * Copyright 1999,2000,2001 Bernardo Innocenti + * Copyright 1999,2000,2001 Bernie Innocenti * * --> * @@ -35,56 +35,68 @@ * Context switching is only done cooperatively. * * \version $Id$ - * - * \author Bernardo Innocenti + * \author Bernie Innocenti * \author Stefano Fedrigo */ - #include "proc_p.h" #include "proc.h" -//#include "hw.h" -#include + +#include "cfg/cfg_arch.h" /* ARCH_EMUL */ +#include +#include + +// Log settings for cfg/log.h. +#define LOG_LEVEL KERN_LOG_LEVEL +#define LOG_FORMAT KERN_LOG_FORMAT +#include + #include #include #include -#include -#include -#include /* ARCH_EMUL */ -#include /* ABS() */ -#include /* memset() */ +#include + +#include /* memset() */ /** * CPU dependent context switching routines. * - * \note This function *MUST* preserve also the status of the interrupts. + * Saving and restoring the context on the stack is done by a CPU-dependent + * support routine which usually needs to be written in assembly. */ 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 - * by enqueuing them in these lists. A pointer to the currently - * running process is stored in the CurrentProcess pointer. + * The scheduer tracks ready processes by enqueuing them in the + * ready list. * - * NOTE: these variables are protected by DI/EI locking + * \note Access to the list must occur while interrupts are disabled. */ -REGISTER Process *CurrentProcess; -REGISTER List ProcReadyList; +REGISTER List ProcReadyList; +/* + * Holds a pointer to the TCB of the currently running process. + * + * \note User applications should use proc_current() to retrieve this value. + */ +REGISTER Process *CurrentProcess; #if CONFIG_KERN_PREEMPTIVE /* - * The time sharing scheduler forces a task switch when - * the current process has consumed its quantum. + * The time sharing scheduler forces a task switch when the current + * process has exhausted its quantum. */ uint16_t Quantum; #endif -/* In Win32 we must emulate stack on the real process stack */ #if (ARCH & ARCH_EMUL) +/* + * In hosted environments, we must emulate the stack on the real process stack. + * + * Access to this list must be protected by PROC_ATOMIC(). + */ extern List StackFreeList; #endif @@ -116,19 +128,19 @@ void proc_init(void) { LIST_INIT(&ProcReadyList); -#if CONFIG_KERN_MONITOR - monitor_init(); -#endif - - /* We "promote" the current context into a real process. The only thing we have + /* + * 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. */ proc_init_struct(&MainProcess); CurrentProcess = &MainProcess; - /* Make sure the assembly routine is up-to-date with us */ - ASSERT(asm_switch_version() == 1); +#if CONFIG_KERN_MONITOR + monitor_init(); + monitor_add(CurrentProcess, "main"); +#endif + MOD_INIT(proc); } @@ -139,56 +151,58 @@ void proc_init(void) * \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_t 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 stack_size, cpustack_t *stack_base) { Process *proc; size_t i; - size_t proc_size_words = ROUND2(sizeof(Process), sizeof(cpustack_t)) / sizeof(cpustack_t); + const size_t PROC_SIZE_WORDS = ROUND2(sizeof(Process), sizeof(cpustack_t)) / sizeof(cpustack_t); #if CONFIG_KERN_HEAP bool free_stack = false; #endif + TRACEMSG("name=%s", name); #if (ARCH & ARCH_EMUL) /* 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; + PROC_ATOMIC(stack_base = (cpustack_t *)list_remHead(&StackFreeList)); + + stack_size = 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_PROC_DEFSTACKSIZE + sizeof(Process); + if (!stack_size) + stack_size = CONFIG_PROC_DEFSTACKSIZE + sizeof(Process); /* Allocate stack dinamically */ - if (!(stack_base = heap_alloc(stacksize))) + if (!(stack_base = heap_alloc(stack_size))) return NULL; free_stack = true; } #else /* Stack must have been provided by the user */ - ASSERT(stack_base); - ASSERT(stacksize); + ASSERT_VALID_PTR(stack_base); + ASSERT(stack_size); #endif #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)); +#warning size incorrect + memset(stack_base, CONFIG_KERN_STACKFILLCODE, stack_size / sizeof(cpustack_t)); #endif /* Initialize the process control block */ if (CPU_STACK_GROWS_UPWARD) { proc = (Process*)stack_base; - proc->stack = stack_base + proc_size_words; + proc->stack = stack_base + PROC_SIZE_WORDS; if (CPU_SP_ON_EMPTY_SLOT) proc->stack++; } else { - proc = (Process*)(stack_base + stacksize / sizeof(cpustack_t) - proc_size_words); + proc = (Process*)(stack_base + stack_size / sizeof(cpustack_t) - PROC_SIZE_WORDS); proc->stack = (cpustack_t*)proc; if (CPU_SP_ON_EMPTY_SLOT) proc->stack--; @@ -197,16 +211,18 @@ struct Process *proc_new_with_name(UNUSED(const char *, name), void (*entry)(voi proc_init_struct(proc); proc->user_data = data; -#if CONFIG_KERN_HEAP +#if CONFIG_KERN_HEAP | CONFIG_KERN_MONITOR | (ARCH & ARCH_EMUL) proc->stack_base = stack_base; proc->stack_size = stack_size; + #if CONFIG_KERN_HEAP if (free_stack) proc->flags |= PF_FREESTACK; + #endif #endif /* Initialize process stack frame */ - CPU_PUSH_CALL_CONTEXT(proc->stack, proc_exit); - CPU_PUSH_CALL_CONTEXT(proc->stack, entry); + CPU_PUSH_CALL_FRAME(proc->stack, proc_exit); + CPU_PUSH_CALL_FRAME(proc->stack, entry); /* Push a clean set of CPU registers for asm_switch_context() */ for (i = 0; i < CPU_SAVED_REGS_CNT; i++) @@ -214,9 +230,10 @@ struct Process *proc_new_with_name(UNUSED(const char *, name), void (*entry)(voi /* Add to ready list */ ATOMIC(SCHED_ENQUEUE(proc)); + ATOMIC(LIST_ASSERT_VALID(&ProcReadyList)); #if CONFIG_KERN_MONITOR - monitor_add(proc, name, stack_base, stacksize); + monitor_add(proc, name); #endif return proc; @@ -236,24 +253,19 @@ void proc_rename(struct Process *proc, const char *name) /** * System scheduler: pass CPU control to the next process in * the ready queue. - * - * Saving and restoring the context on the stack is done - * by a CPU-dependent support routine which must usually be - * written in assembly. */ void proc_schedule(void) { struct Process *old_process; cpuflags_t flags; + ATOMIC(LIST_ASSERT_VALID(&ProcReadyList)); + ASSERT_USER_CONTEXT(); + ASSERT_IRQ_ENABLED(); + /* 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 */ IRQ_SAVE_DISABLE(flags); while (!(CurrentProcess = (struct Process *)list_remHead(&ProcReadyList))) @@ -264,7 +276,7 @@ void proc_schedule(void) * are idle-spinning, we must allow interrupts, otherwise no * process will ever wake up. * - * During idle-spinning, can occur an interrupt, it may be able to + * During idle-spinning, an interrupt can occur and it may * 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 @@ -288,10 +300,16 @@ void proc_schedule(void) { cpustack_t *dummy; -#if CONFIG_KERN_PREEMPTIVE - /* Reset quantum for this process */ - Quantum = CONFIG_KERN_QUANTUM; -#endif + #if CONFIG_KERN_MONITOR + LOG_INFO("Switch from %p(%s) to %p(%s)\n", + old_process, old_process ? old_process->monitor.name : "NONE", + CurrentProcess, CurrentProcess->monitor.name); + #endif + + #if CONFIG_KERN_PREEMPTIVE + /* Reset quantum for this process */ + Quantum = CONFIG_KERN_QUANTUM; + #endif /* Save context of old process and switch to new process. If there is no * old process, we save the old stack pointer into a dummy variable that @@ -312,6 +330,8 @@ void proc_schedule(void) */ void proc_exit(void) { + TRACE; + #if CONFIG_KERN_MONITOR monitor_remove(CurrentProcess); #endif @@ -332,8 +352,8 @@ void proc_exit(void) #if (ARCH & ARCH_EMUL) #warning This is wrong /* Reinsert process stack in free list */ - ADDHEAD(&StackFreeList, (Node *)(CurrentProcess->stack - - (CONFIG_PROC_DEFSTACKSIZE / sizeof(cpustack_t)))); + PROC_ATOMIC(ADDHEAD(&StackFreeList, (Node *)(CurrentProcess->stack + - (CONFIG_PROC_DEFSTACKSIZE / sizeof(cpustack_t))))); /* * NOTE: At this point the first two words of what used @@ -353,11 +373,7 @@ void proc_exit(void) */ void proc_switch(void) { - cpuflags_t flags; - - IRQ_SAVE_DISABLE(flags); - SCHED_ENQUEUE(CurrentProcess); - IRQ_RESTORE(flags); + ATOMIC(SCHED_ENQUEUE(CurrentProcess)); proc_schedule(); }