X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fproc_p.h;h=85cb758f9ecfd7472ea540a3547bb2261fa5717b;hb=34a467fa89d01c8248fabc52bc5a4f5edf67570a;hp=7dad780d4fb03098ce3f388afcee3750acec50bb;hpb=dc9c2e09cf5e9837cdd3106c57db749301c5bf95;p=bertos.git diff --git a/bertos/kern/proc_p.h b/bertos/kern/proc_p.h index 7dad780d..85cb758f 100644 --- a/bertos/kern/proc_p.h +++ b/bertos/kern/proc_p.h @@ -34,75 +34,156 @@ * \brief Internal scheduler structures and definitions for processes. * * \version $Id$ - * * \author Bernie Innocenti */ #ifndef KERN_PROC_P_H #define KERN_PROC_P_H -#include "cfg/cfg_kern.h" +#include "cfg/cfg_proc.h" +#include "cfg/cfg_monitor.h" + #include #include /* for cpu_stack_t */ +#include // IRQ_ASSERT_DISABLED() + +#include // struct Process -#include +/** + * 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(cpu_stack_t **new_sp, cpu_stack_t **save_sp); -typedef struct Process +/* + * Save context of old process and switch to new process. + */ +INLINE void proc_switchTo(Process *next, Process *prev) { - Node link; /**< Link Process into scheduler lists */ - cpustack_t *stack; /**< Per-process SP */ - iptr_t user_data; /**< Custom data passed to the process */ + cpu_stack_t *dummy; + + if (UNLIKELY(next == prev)) + return; + /* + * 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. + */ + asm_switch_context(&next->stack, prev ? &prev->stack : &dummy); +} -#if CONFIG_KERN_SIGNALS - sigmask_t sig_wait; /**< Signals the process is waiting for */ - sigmask_t sig_recv; /**< Received signals */ -#endif +/** + * \name Flags for Process.flags. + * \{ + */ +#define PF_FREESTACK BV(0) /**< Free the stack when process dies */ +/*\}*/ -#if CONFIG_KERN_PREEMPTIVE - int forbid_cnt; /**< Nesting count for proc_forbid()/proc_permit(). */ -#endif -#if CONFIG_KERN_HEAP - uint16_t flags; /**< Flags */ -#endif +/** Track running processes. */ +extern REGISTER Process *current_process; -#if CONFIG_KERN_HEAP | CONFIG_KERN_MONITOR | (ARCH & ARCH_EMUL) - cpustack_t *stack_base; /**< Base of process stack */ - size_t stack_size; /**< Size of process stack */ +/** + * Track ready processes. + * + * Access to this list must be performed with interrupts disabled + */ +extern REGISTER List proc_ready_list; + +#if CONFIG_KERN_PRI + #define prio_next() (LIST_EMPTY(&proc_ready_list) ? INT_MIN : \ + ((PriNode *)LIST_HEAD(&proc_ready_list))->pri) + #define prio_proc(proc) (proc->link.pri) + #define prio_curr() prio_proc(current_process) + + #define SCHED_ENQUEUE_INTERNAL(proc) \ + LIST_ENQUEUE(&proc_ready_list, &(proc)->link) + #define SCHED_ENQUEUE_HEAD_INTERNAL(proc) \ + LIST_ENQUEUE_HEAD(&proc_ready_list, &(proc)->link) +#else + #define prio_next() 0 + #define prio_proc(proc) 0 + #define prio_curr() 0 + + #define SCHED_ENQUEUE_INTERNAL(proc) ADDTAIL(&proc_ready_list, &(proc)->link) + #define SCHED_ENQUEUE_HEAD_INTERNAL(proc) ADDHEAD(&proc_ready_list, &(proc)->link) #endif -#if CONFIG_KERN_MONITOR - struct ProcMonitor - { - Node link; - const char *name; - } monitor; -#endif +/** + * Enqueue a process in the ready list. + * + * Always use this macro to instert a process in the ready list, as its + * might vary to implement a different scheduling algorithms. + * + * \note Access to the scheduler ready list must be performed with + * interrupts disabled. + */ +#define SCHED_ENQUEUE(proc) do { \ + IRQ_ASSERT_DISABLED(); \ + LIST_ASSERT_VALID(&proc_ready_list); \ + SCHED_ENQUEUE_INTERNAL(proc); \ + } while (0) -} Process; +#define SCHED_ENQUEUE_HEAD(proc) do { \ + IRQ_ASSERT_DISABLED(); \ + LIST_ASSERT_VALID(&proc_ready_list); \ + SCHED_ENQUEUE_HEAD_INTERNAL(proc); \ + } while (0) +#if CONFIG_KERN_PRI /** - * \name Flags for Process.flags. - * \{ + * Changes the priority of an already enqueued process. + * + * Searches and removes the process from the ready list, then uses LIST_ENQUEUE(() + * to insert again to fix priority. + * + * No action is performed for processes that aren't in the ready list, eg. in semaphore queues. + * + * \note Performance could be improved with a different implementation of priority list. */ -#define PF_FREESTACK BV(0) /**< Free the stack when process dies */ -/*\}*/ - +INLINE void sched_reenqueue(struct Process *proc) +{ + IRQ_ASSERT_DISABLED(); + LIST_ASSERT_VALID(&proc_ready_list); + Node *n; + PriNode *pos = NULL; + FOREACH_NODE(n, &proc_ready_list) + { + if (n == &proc->link.link) + { + pos = (PriNode *)n; + break; + } + } + + // only remove and enqueue again if process is already in the ready list + // otherwise leave it alone + if (pos) + { + REMOVE(&proc->link.link); + LIST_ENQUEUE(&proc_ready_list, &proc->link); + } +} +#endif //CONFIG_KERN_PRI -/** Track running processes. */ -extern REGISTER Process *CurrentProcess; +/* Process trampoline */ +void proc_entry(void); -/** Track ready processes. */ -extern REGISTER List ProcReadyList; +/* Schedule another process *without* adding the current one to the ready list. */ +void proc_switch(void); +/* Low level scheduling routine. */ +void proc_schedule(void); -/** Enqueue a task in the ready list. */ -#define SCHED_ENQUEUE(proc) ADDTAIL(&ProcReadyList, &(proc)->link) +/* Low level context switch routine. */ +void proc_switchTo(Process *next, Process *prev); -/** Schedule to another process *without* adding the current to the ready list. */ -void proc_schedule(void); +/* Initialize a scheduler class. */ +void proc_schedInit(void); #if CONFIG_KERN_MONITOR /** Initialize the monitor */ @@ -119,4 +200,3 @@ void proc_schedule(void); #endif /* CONFIG_KERN_MONITOR */ #endif /* KERN_PROC_P_H */ -