X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fproc.c;h=bce8ac3e8a7fcadfd4eaf4d7073c659bf0813ff6;hb=8cfe12e5b95974d75b98ec964fc7edaf37919f0e;hp=5674038cae395e04fe2f6d677f96db0618c85c32;hpb=03eac0b24146fe73d585c998eca4c1c2873f1acb;p=bertos.git diff --git a/bertos/kern/proc.c b/bertos/kern/proc.c index 5674038c..bce8ac3e 100644 --- a/bertos/kern/proc.c +++ b/bertos/kern/proc.c @@ -26,9 +26,8 @@ * 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 Bernie Innocenti - * + * Copyright 2001, 2004 Develer S.r.l. (http://www.develer.com/) + * Copyright 1999, 2000, 2001, 2008 Bernie Innocenti * --> * * \brief Simple realtime multitasking scheduler. @@ -43,29 +42,19 @@ #include "proc.h" #include "cfg/cfg_arch.h" /* ARCH_EMUL */ -#include +#include "cfg/cfg_kern.h" #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 /* memset() */ -/** - * CPU dependent context switching routines. - * - * 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); +#if CONFIG_KERN_PREEMPT +#include "preempt.h" +#endif /* * The scheduer tracks ready processes by enqueuing them in the @@ -82,15 +71,6 @@ REGISTER List ProcReadyList; */ REGISTER Process *CurrentProcess; -#if CONFIG_KERN_PREEMPTIVE -/* - * The time sharing scheduler forces a task switch when the current - * process has exhausted its quantum. - */ -uint16_t Quantum; -#endif - - #if (ARCH & ARCH_EMUL) /* * In hosted environments, we must emulate the stack on the real process stack. @@ -141,6 +121,10 @@ void proc_init(void) monitor_add(CurrentProcess, "main"); #endif +#if CONFIG_KERN_PREEMPTIVE + preempt_init(); +#endif + MOD_INIT(proc); } @@ -188,8 +172,7 @@ struct Process *proc_new_with_name(UNUSED(const char *, name), void (*entry)(voi #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)); + memset(stack_base, CONFIG_KERN_STACKFILLCODE, stack_size); #endif /* Initialize the process control block */ @@ -221,8 +204,8 @@ 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++) @@ -250,81 +233,6 @@ void proc_rename(struct Process *proc, const char *name) } -/** - * System scheduler: pass CPU control to the next process in - * the ready queue. - */ -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; - - /* Poll on the ready queue for the first ready process */ - IRQ_SAVE_DISABLE(flags); - while (!(CurrentProcess = (struct Process *)list_remHead(&ProcReadyList))) - { - /* - * 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. - * - * 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 - * 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. - */ - IRQ_ENABLE; - CPU_IDLE; - MEMORY_BARRIER; - IRQ_DISABLE; - } - IRQ_RESTORE(flags); - - /* - * Optimization: don't switch contexts when the active - * process has not changed. - */ - if (CurrentProcess != old_process) - { - cpustack_t *dummy; - - #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 - * we ignore. In fact, this happens only when the old process has just - * exited. - * TODO: Instead of physically clearing the process at exit time, a zombie - * list should be created. - */ - asm_switch_context(&CurrentProcess->stack, old_process ? &old_process->stack : &dummy); - } - - /* This RET resumes the execution on the new process */ -} - - /** * Terminate the current process */ @@ -368,17 +276,6 @@ void proc_exit(void) } -/** - * Co-operative context switch - */ -void proc_switch(void) -{ - ATOMIC(SCHED_ENQUEUE(CurrentProcess)); - - proc_schedule(); -} - - /** * Get the pointer to the current process */ @@ -394,39 +291,3 @@ iptr_t proc_current_user_data(void) { return CurrentProcess->user_data; } - - -#if CONFIG_KERN_PREEMPTIVE - -/** - * 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() - */ -void proc_forbid(void) -{ - /* No need to protect against interrupts here. */ - ++CurrentProcess->forbid_cnt; -} - -/** - * Re-enable preemptive task switching. - * - * \sa proc_forbid() - */ -void proc_permit(void) -{ - /* No need to protect against interrupts here. */ - --CurrentProcess->forbid_cnt; -} - -#endif /* CONFIG_KERN_PREEMPTIVE */