X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fproc.h;h=390099da4b771789c5aa55741526f25284163330;hb=d9d931610bca1df6ceb9227eacc9ff2c7f89b77a;hp=693cd72c76aaf4780397d389a201db4831acaa20;hpb=a66622f826a7ee317cb0459735cbb70bbd27e6da;p=bertos.git diff --git a/bertos/kern/proc.h b/bertos/kern/proc.h index 693cd72c..390099da 100644 --- a/bertos/kern/proc.h +++ b/bertos/kern/proc.h @@ -30,51 +30,167 @@ * Copyright 1999, 2000, 2001, 2008 Bernie Innocenti * --> * - * \brief Bertos Kernel core (Process scheduler). + * \brief BeRTOS Kernel core (Process scheduler). * * \version $Id$ * \author Bernie Innocenti * - * $WIZARD_MODULE = { - * "name" : "kernel", - * "depends" : [], - * "configuration" : "bertos/cfg/cfg_kern.h" - * } + * $WIZ$ module_name = "kernel" + * $WIZ$ module_configuration = "bertos/cfg/cfg_proc.h" + * $WIZ$ module_depends = "switch_ctx", "coop", "preempt" + * $WIZ$ module_supports = "not atmega103" */ #ifndef KERN_PROC_H #define KERN_PROC_H -#include "cfg/cfg_kern.h" +#include "cfg/cfg_proc.h" +#include "cfg/cfg_signal.h" +#include "cfg/cfg_monitor.h" + +#include // Node, PriNode + #include #if CONFIG_KERN_PREEMPT #include // ASSERT() + #include #endif #include // cpu_stack_t #include // CPU_SAVED_REGS_CNT /* - * Forward declaration. The definition of struct Process is private to the - * scheduler and hidden in proc_p.h. + * WARNING: struct Process is considered private, so its definition can change any time + * without notice. DO NOT RELY on any field defined here, use only the interface + * functions below. + * + * You have been warned. */ -struct Process; +typedef struct Process +{ +#if CONFIG_KERN_PRI + PriNode link; /**< Link Process into scheduler lists */ +#else + Node link; /**< Link Process into scheduler lists */ +#endif + cpu_stack_t *stack; /**< Per-process SP */ + iptr_t user_data; /**< Custom data passed to the process */ + +#if CONFIG_KERN_SIGNALS + sigmask_t sig_wait; /**< Signals the process is waiting for */ + sigmask_t sig_recv; /**< Received signals */ +#endif + +#if CONFIG_KERN_HEAP + uint16_t flags; /**< Flags */ +#endif + +#if CONFIG_KERN_HEAP | CONFIG_KERN_MONITOR + cpu_stack_t *stack_base; /**< Base of process stack */ + size_t stack_size; /**< Size of process stack */ +#endif + /* The actual process entry point */ + void (*user_entry)(void); + +#if CONFIG_KERN_MONITOR + struct ProcMonitor + { + Node link; + const char *name; + } monitor; +#endif + +} Process; + +/** + * Initialize the process subsystem (kernel). + * It must be called before using any process related function. + */ void proc_init(void); + struct Process *proc_new_with_name(const char *name, void (*entry)(void), iptr_t data, size_t stacksize, cpu_stack_t *stack); #if !CONFIG_KERN_MONITOR + /** + * Create a new named process and schedules it for execution. + * + * When defining the stacksize take into account that you may want at least: + * \li save all the registers for each nested function call; + * \li have memory for the struct Process, which is positioned at the bottom + * of the stack; + * \li have some memory for temporary variables inside called functions. + * + * The value given by KERN_MINSTACKSIZE is rather safe to use in the first place. + * + * \param entry Function that the process will execute. + * \param data Pointer to user data. + * \param size Length of the stack. + * \param stack Pointer to the memory area to be used as a stack. + * + * \return Process structure of new created process + * if successful, NULL otherwise. + */ #define proc_new(entry,data,size,stack) proc_new_with_name(NULL,(entry),(data),(size),(stack)) #else #define proc_new(entry,data,size,stack) proc_new_with_name(#entry,(entry),(data),(size),(stack)) #endif +/** + * Terminate the execution of the current process. + */ void proc_exit(void); + +/** + * Public scheduling class methods. + */ void proc_yield(void); +void proc_preempt(void); +int proc_needPreempt(void); + +/** + * Dummy function that defines unimplemented scheduler class methods. + */ +INLINE void __proc_noop(void) +{ +} + +#if CONFIG_KERN_PREEMPT + /** + * Preemptive scheduler public methods. + */ + #define preempt_yield proc_yield + #define preempt_needPreempt proc_needPreempt + #define preempt_preempt proc_preempt + /** + * Preemptive scheduler: private methods. + */ + #define preempt_switch proc_switch +#else + /** + * Co-operative scheduler: public methods. + */ + #define coop_yield proc_yield + #define proc_needPreempt __proc_noop + #define proc_preempt __proc_noop + /** + * Co-operative scheduler: private methods. + */ + #define coop_switch proc_switch +#endif + void proc_rename(struct Process *proc, const char *name); const char *proc_name(struct Process *proc); const char *proc_currentName(void); + +/** + * Return a pointer to the user data of the current process. + * + * To obtain user data, just call this function inside the process. Remember to cast + * the returned pointer to the correct type. + * \return Pointer to the user data of the current process. + */ iptr_t proc_currentUserData(void); int proc_testSetup(void); @@ -90,8 +206,8 @@ int proc_testTearDown(void); */ INLINE struct Process *proc_current(void) { - extern struct Process *CurrentProcess; - return CurrentProcess; + extern struct Process *current_process; + return current_process; } #if CONFIG_KERN_PRI @@ -102,30 +218,28 @@ INLINE struct Process *proc_current(void) } #endif -/** - * Disable preemptive task switching. - * - * The scheduler maintains a global 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(). - * - * \note Calling functions that could sleep while task switching is disabled - * is dangerous and unsupported. - * - * \note calling proc_forbid() from within an interrupt is illegal and - * meaningless. - * - * \note proc_permit() expands inline to 1-2 asm instructions, so it's a - * very efficient locking primitive in simple but performance-critical - * situations. In all other cases, semaphores offer a more flexible and - * fine-grained locking primitive. - * - * \sa proc_permit() - */ -INLINE void proc_forbid(void) -{ - #if CONFIG_KERN_PREEMPT - extern cpu_atomic_t _preempt_forbid_cnt; +#if CONFIG_KERN_PREEMPT + + /** + * Disable preemptive task switching. + * + * The scheduler maintains a global 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(). + * + * \note Calling functions that could sleep while task switching is disabled + * is dangerous and unsupported. + * + * \note proc_permit() expands inline to 1-2 asm instructions, so it's a + * very efficient locking primitive in simple but performance-critical + * situations. In all other cases, semaphores offer a more flexible and + * fine-grained locking primitive. + * + * \sa proc_permit() + */ + INLINE void proc_forbid(void) + { + extern cpu_atomic_t preempt_count; /* * We don't need to protect the counter against other processes. * The reason why is a bit subtle. @@ -149,58 +263,57 @@ INLINE void proc_forbid(void) * "preempt_forbid_cnt != 0" means that no task switching is * possible. */ - ++_preempt_forbid_cnt; + ++preempt_count; /* - * Make sure _preempt_forbid_cnt is flushed to memory so the - * preemption softirq will see the correct value from now on. + * Make sure preempt_count is flushed to memory so the preemption + * softirq will see the correct value from now on. */ MEMORY_BARRIER; - #endif -} + } -/** - * Re-enable preemptive task switching. - * - * \sa proc_forbid() - */ -INLINE void proc_permit(void) -{ - #if CONFIG_KERN_PREEMPT + /** + * Re-enable preemptive task switching. + * + * \sa proc_forbid() + */ + INLINE void proc_permit(void) + { + extern cpu_atomic_t preempt_count; /* * This is to ensure any global state changed by the process gets * flushed to memory before task switching is re-enabled. */ MEMORY_BARRIER; - extern cpu_atomic_t _preempt_forbid_cnt; /* No need to protect against interrupts here. */ - ASSERT(_preempt_forbid_cnt != 0); - --_preempt_forbid_cnt; - + ASSERT(preempt_count > 0); + --preempt_count; /* - * This ensures _preempt_forbid_cnt is flushed to memory immediately - * so the preemption interrupt sees the correct value. + * This ensures preempt_count is flushed to memory immediately so the + * preemption interrupt sees the correct value. */ MEMORY_BARRIER; + } - #endif -} + /** + * \return true if preemptive task switching is allowed. + * \note This accessor is needed because preempt_count + * must be absoultely private. + */ + INLINE bool proc_preemptAllowed(void) + { + extern cpu_atomic_t preempt_count; + return (preempt_count == 0); + } +#else /* CONFIG_KERN_PREEMPT */ + #define proc_forbid() /* NOP */ + #define proc_permit() /* NOP */ + #define proc_preemptAllowed() (true) +#endif /* CONFIG_KERN_PREEMPT */ -/** - * \return true if preemptive task switching is allowed. - * \note This accessor is needed because _preempt_forbid_cnt - * must be absoultely private. - */ -INLINE bool proc_allowed(void) -{ - #if CONFIG_KERN_PREEMPT - extern cpu_atomic_t _preempt_forbid_cnt; - return (_preempt_forbid_cnt == 0); - #else - return true; - #endif -} +/** Deprecated, use the proc_preemptAllowed() macro. */ +#define proc_allowed() proc_preemptAllowed() /** * Execute a block of \a CODE atomically with respect to task scheduling. @@ -212,37 +325,74 @@ INLINE bool proc_allowed(void) proc_permit(); \ } while(0) -#ifndef CONFIG_KERN_MINSTACKSIZE +/** + * Default stack size for each thread, in bytes. + * + * The goal here is to allow a minimal task to save all of its + * registers twice, plus push a maximum of 32 variables on the + * stack. We add also struct Process size since we save it into the process' + * stack. + * + * The actual size computed by the default formula greatly depends on what + * options are active and on the architecture. + * + * Note that on most 16bit architectures, interrupts will also + * run on the stack of the currently running process. Nested + * interrupts will greatly increases the amount of stack space + * required per process. Use irqmanager to minimize stack + * usage. + */ - #if (ARCH & ARCH_EMUL) - /* We need a large stack because system libraries are bloated */ - #define CONFIG_KERN_MINSTACKSIZE 65536 - #else - /** - * Default stack size for each thread, in bytes. - * - * The goal here is to allow a minimal task to save all of its - * registers twice, plus push a maximum of 32 variables on the - * stack. - * - * The actual size computed by the default formula is: - * AVR: 102 - * i386: 156 - * ARM: 164 - * x86_64: 184 +#if (ARCH & ARCH_EMUL) + /* We need a large stack because system libraries are bloated */ + #define KERN_MINSTACKSIZE 65536 +#else + #if CONFIG_KERN_PREEMPT + /* + * A preemptible kernel needs a larger stack compared to the + * cooperative case. A task can be interrupted anytime in each + * node of the call graph, at any level of depth. This may + * result in a higher stack consumption, to call the ISR, save + * the current user context and to execute the kernel + * preemption routines implemented as ISR prologue and + * epilogue. All these calls are nested into the process stack. * - * Note that on most 16bit architectures, interrupts will also - * run on the stack of the currently running process. Nested - * interrupts will greatly increases the amount of stack space - * required per process. Use irqmanager to minimize stack - * usage. + * So, to reduce the risk of stack overflow/underflow problems + * add a x2 to the portion stack reserved to the user process. */ - #define CONFIG_KERN_MINSTACKSIZE \ - (CPU_SAVED_REGS_CNT * 2 * sizeof(cpu_stack_t) \ - + 48 * sizeof(int)) - #endif + #define KERN_MINSTACKSIZE \ + (sizeof(Process) + CPU_SAVED_REGS_CNT * 2 * sizeof(cpu_stack_t) \ + + 32 * sizeof(int) * 2) + #else + #define KERN_MINSTACKSIZE \ + (sizeof(Process) + CPU_SAVED_REGS_CNT * 2 * sizeof(cpu_stack_t) \ + + 32 * sizeof(int)) + #endif /* CONFIG_KERN_PREEMPT */ + +#endif + +#ifndef CONFIG_KERN_MINSTACKSIZE + /* For backward compatibility */ + #define CONFIG_KERN_MINSTACKSIZE KERN_MINSTACKSIZE +#else + #warning FIXME: This macro is deprecated, use KERN_MINSTACKSIZE instead #endif +/** + * Utility macro to allocate a stack of size \a size. + * + * This macro define a static stack for one process and do + * check if given stack size is enough to run process. + * \note If you plan to use kprintf() and similar functions, you will need + * at least KERN_MINSTACKSIZE * 2 bytes. + * + * \param name Variable name for the stack. + * \param size Stack size in bytes. It must be at least KERN_MINSTACKSIZE. + */ +#define PROC_DEFINE_STACK(name, size) \ + cpu_stack_t name[((size) + sizeof(cpu_stack_t) - 1) / sizeof(cpu_stack_t)]; \ + STATIC_ASSERT((size) >= KERN_MINSTACKSIZE); + /* Memory fill codes to help debugging */ #if CONFIG_KERN_MONITOR #include