X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;ds=sidebyside;f=bertos%2Fkern%2Fproc.c;h=84c5366370911c10e61c3a5f1b2c8dd5397dfd9c;hb=9740751dcd61ec99e1af95846d4c3b197a128d8a;hp=32e3afe8a2f50b317af65291fa9f0d86fcc3f7b2;hpb=dc9c2e09cf5e9837cdd3106c57db749301c5bf95;p=bertos.git diff --git a/bertos/kern/proc.c b/bertos/kern/proc.c index 32e3afe8..84c53663 100644 --- a/bertos/kern/proc.c +++ b/bertos/kern/proc.c @@ -35,19 +35,21 @@ * Context switching is only done cooperatively. * * \version $Id$ - * * \author Bernie Innocenti * \author Stefano Fedrigo */ - #include "proc_p.h" #include "proc.h" #include "cfg/cfg_arch.h" /* ARCH_EMUL */ #include #include -#include /* ABS() */ + +// Log settings for cfg/log.h. +#define LOG_LEVEL KERN_LOG_LEVEL +#define LOG_FORMAT KERN_LOG_FORMAT +#include #include #include @@ -60,33 +62,41 @@ /** * 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 @@ -118,19 +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); } @@ -149,10 +159,11 @@ struct Process *proc_new_with_name(UNUSED(const char *, name), void (*entry)(voi #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_remHead(&StackFreeList); + PROC_ATOMIC(stack_base = (cpustack_t *)list_remHead(&StackFreeList)); stack_size = CONFIG_PROC_DEFSTACKSIZE; #elif CONFIG_KERN_HEAP @@ -171,12 +182,13 @@ struct Process *proc_new_with_name(UNUSED(const char *, name), void (*entry)(voi } #else /* Stack must have been provided by the user */ - ASSERT(stack_base); + ASSERT_VALID_PTR(stack_base); ASSERT(stack_size); #endif #if CONFIG_KERN_MONITOR /* Fill-in the stack with a special marker to help debugging */ +#warning size incorrect memset(stack_base, CONFIG_KERN_STACKFILLCODE, stack_size / sizeof(cpustack_t)); #endif @@ -209,8 +221,8 @@ struct Process *proc_new_with_name(UNUSED(const char *, name), void (*entry)(voi #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++) @@ -218,6 +230,7 @@ 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); @@ -240,24 +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))) @@ -292,10 +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 @@ -316,6 +330,8 @@ void proc_schedule(void) */ void proc_exit(void) { + TRACE; + #if CONFIG_KERN_MONITOR monitor_remove(CurrentProcess); #endif @@ -336,8 +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 @@ -357,11 +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(); }