thread.h

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/*
 * Copyright (c) 2016, Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_INCLUDE_KERNEL_THREAD_H_
#define ZEPHYR_INCLUDE_KERNEL_THREAD_H_
 
#ifdef CONFIG_DEMAND_PAGING_THREAD_STATS
#include <zephyr/sys/mem_manage.h>
#endif
 
#include <zephyr/kernel/stats.h>
 
#ifdef CONFIG_THREAD_MONITOR
struct __thread_entry {
        k_thread_entry_t pEntry;
        void *parameter1;
        void *parameter2;
        void *parameter3;
};
#endif
 
struct k_thread;
 
/*
 * This _pipe_desc structure is used by the pipes kernel module when
 * CONFIG_PIPES has been selected.
 */
 
struct _pipe_desc {
        sys_dnode_t      node;
        unsigned char   *buffer;         /* Position in src/dest buffer */
        size_t           bytes_to_xfer;  /* # bytes left to transfer */
        struct k_thread *thread;         /* Back pointer to pended thread */
};
 
/* can be used for creating 'dummy' threads, e.g. for pending on objects */
struct _thread_base {
 
        /* this thread's entry in a ready/wait queue */
        union {
                sys_dnode_t qnode_dlist;
                struct rbnode qnode_rb;
        };
 
        /* wait queue on which the thread is pended (needed only for
         * trees, not dumb lists)
         */
        _wait_q_t *pended_on;
 
        /* user facing 'thread options'; values defined in include/kernel.h */
        uint8_t user_options;
 
        /* thread state */
        uint8_t thread_state;
 
        /*
         * scheduler lock count and thread priority
         *
         * These two fields control the preemptibility of a thread.
         *
         * When the scheduler is locked, sched_locked is decremented, which
         * means that the scheduler is locked for values from 0xff to 0x01. A
         * thread is coop if its prio is negative, thus 0x80 to 0xff when
         * looked at the value as unsigned.
         *
         * By putting them end-to-end, this means that a thread is
         * non-preemptible if the bundled value is greater than or equal to
         * 0x0080.
         */
        union {
                struct {
#ifdef CONFIG_BIG_ENDIAN
                        uint8_t sched_locked;
                        int8_t prio;
#else /* Little Endian */
                        int8_t prio;
                        uint8_t sched_locked;
#endif
                };
                uint16_t preempt;
        };
 
#ifdef CONFIG_SCHED_DEADLINE
        int prio_deadline;
#endif
 
        uint32_t order_key;
 
#ifdef CONFIG_SMP
        /* True for the per-CPU idle threads */
        uint8_t is_idle;
 
        /* CPU index on which thread was last run */
        uint8_t cpu;
 
        /* Recursive count of irq_lock() calls */
        uint8_t global_lock_count;
 
#endif
 
#ifdef CONFIG_SCHED_CPU_MASK
        /* "May run on" bits for each CPU */
        uint8_t cpu_mask;
#endif
 
        /* data returned by APIs */
        void *swap_data;
 
#ifdef CONFIG_SYS_CLOCK_EXISTS
        /* this thread's entry in a timeout queue */
        struct _timeout timeout;
#endif
 
#ifdef CONFIG_TIMESLICE_PER_THREAD
        int32_t slice_ticks;
        k_thread_timeslice_fn_t slice_expired;
        void *slice_data;
#endif
 
#ifdef CONFIG_SCHED_THREAD_USAGE
        struct k_cycle_stats  usage;   /* Track thread usage statistics */
#endif
};
 
typedef struct _thread_base _thread_base_t;
 
#if defined(CONFIG_THREAD_STACK_INFO)
/* Contains the stack information of a thread */
struct _thread_stack_info {
        /* Stack start - Represents the start address of the thread-writable
         * stack area.
         */
        uintptr_t start;
 
        /* Thread writable stack buffer size. Represents the size of the actual
         * buffer, starting from the 'start' member, that should be writable by
         * the thread. This comprises of the thread stack area, any area reserved
         * for local thread data storage, as well as any area left-out due to
         * random adjustments applied to the initial thread stack pointer during
         * thread initialization.
         */
        size_t size;
 
        /* Adjustment value to the size member, removing any storage
         * used for TLS or random stack base offsets. (start + size - delta)
         * is the initial stack pointer for a thread. May be 0.
         */
        size_t delta;
};
 
typedef struct _thread_stack_info _thread_stack_info_t;
#endif /* CONFIG_THREAD_STACK_INFO */
 
#if defined(CONFIG_USERSPACE)
struct _mem_domain_info {
        sys_dnode_t mem_domain_q_node;
        struct k_mem_domain *mem_domain;
};
 
#endif /* CONFIG_USERSPACE */
 
#ifdef CONFIG_THREAD_USERSPACE_LOCAL_DATA
struct _thread_userspace_local_data {
#if defined(CONFIG_ERRNO) && !defined(CONFIG_ERRNO_IN_TLS) && !defined(CONFIG_LIBC_ERRNO)
        int errno_var;
#endif
};
#endif
 
typedef struct k_thread_runtime_stats {
#ifdef CONFIG_SCHED_THREAD_USAGE
        uint64_t execution_cycles;
        uint64_t total_cycles;        /* total # of non-idle cycles */
        /*
         * In the context of thread statistics, [execution_cycles] is the same
         * as the total # of non-idle cycles. In the context of CPU statistics,
         * it refers to the sum of non-idle + idle cycles.
         */
#endif
 
#ifdef CONFIG_SCHED_THREAD_USAGE_ANALYSIS
        /*
         * For threads, the following fields refer to the time spent executing
         * as bounded by when the thread was scheduled in and scheduled out.
         * For CPUs, the same fields refer to the time spent executing
         * non-idle threads as bounded by the idle thread(s).
         */
 
        uint64_t current_cycles;      /* current # of non-idle cycles */
        uint64_t peak_cycles;         /* peak # of non-idle cycles */
        uint64_t average_cycles;      /* average # of non-idle cycles */
#endif
 
#ifdef CONFIG_SCHED_THREAD_USAGE_ALL
        /*
         * This field is always zero for individual threads. It only comes
         * into play when gathering statistics for the CPU. In that case it
         * represents the total number of cycles spent idling.
         */
 
        uint64_t idle_cycles;
#endif
 
#if defined(__cplusplus) && !defined(CONFIG_SCHED_THREAD_USAGE) &&                                 \
        !defined(CONFIG_SCHED_THREAD_USAGE_ANALYSIS) && !defined(CONFIG_SCHED_THREAD_USAGE_ALL)
        /* If none of the above Kconfig values are defined, this struct will have a size 0 in C
         * which is not allowed in C++ (it'll have a size 1). To prevent this, we add a 1 byte dummy
         * variable when the struct would otherwise be empty.
         */
        uint8_t dummy;
#endif
}  k_thread_runtime_stats_t;
 
struct z_poller {
        bool is_polling;
        uint8_t mode;
};
 
struct k_thread {
 
        struct _thread_base base;
 
        struct _callee_saved callee_saved;
 
        void *init_data;
 
        _wait_q_t join_queue;
 
#if defined(CONFIG_POLL)
        struct z_poller poller;
#endif
 
#if defined(CONFIG_EVENTS)
        struct k_thread *next_event_link;
 
        uint32_t   events;
        uint32_t   event_options;
 
        bool no_wake_on_timeout;
#endif
 
#if defined(CONFIG_THREAD_MONITOR)
        struct __thread_entry entry;
 
        struct k_thread *next_thread;
#endif
 
#if defined(CONFIG_THREAD_NAME)
        char name[CONFIG_THREAD_MAX_NAME_LEN];
#endif
 
#ifdef CONFIG_THREAD_CUSTOM_DATA
        void *custom_data;
#endif
 
#ifdef CONFIG_THREAD_USERSPACE_LOCAL_DATA
        struct _thread_userspace_local_data *userspace_local_data;
#endif
 
#if defined(CONFIG_ERRNO) && !defined(CONFIG_ERRNO_IN_TLS) && !defined(CONFIG_LIBC_ERRNO)
#ifndef CONFIG_USERSPACE
        int errno_var;
#endif
#endif
 
#if defined(CONFIG_THREAD_STACK_INFO)
        struct _thread_stack_info stack_info;
#endif /* CONFIG_THREAD_STACK_INFO */
 
#if defined(CONFIG_USERSPACE)
        struct _mem_domain_info mem_domain_info;
        k_thread_stack_t *stack_obj;
        void *syscall_frame;
#endif /* CONFIG_USERSPACE */
 
 
#if defined(CONFIG_USE_SWITCH)
        /* When using __switch() a few previously arch-specific items
         * become part of the core OS
         */
 
        int swap_retval;
 
        void *switch_handle;
#endif
        struct k_heap *resource_pool;
 
#if defined(CONFIG_THREAD_LOCAL_STORAGE)
        /* Pointer to arch-specific TLS area */
        uintptr_t tls;
#endif /* CONFIG_THREAD_LOCAL_STORAGE */
 
#ifdef CONFIG_DEMAND_PAGING_THREAD_STATS
        struct k_mem_paging_stats_t paging_stats;
#endif
 
#ifdef CONFIG_PIPES
        struct _pipe_desc pipe_desc;
#endif
 
        struct _thread_arch arch;
};
 
typedef struct k_thread _thread_t;
typedef struct k_thread *k_tid_t;
 
void z_init_cpu(int id);
void z_sched_ipi(void);
void z_smp_start_cpu(int id);
 
#endif