Support to multi-threading and pthread interface (POSIX.1-2008) (#23)

[lunaix-os.git] / lunaix-os / kernel / process / sched.c

diff --git a/lunaix-os/kernel/process/sched.c b/lunaix-os/kernel/process/sched.c
index bec2faef33af8cc4591949602359bc89d7bd0335..c92cde9efdb3a397042d8ed177ba09ad8f3a63b2 100644 (file)
--- a/lunaix-os/kernel/process/sched.c
+++ b/lunaix-os/kernel/process/sched.c
@@ -1,5 +1,4 @@
 #include <sys/abi.h>
 #include <sys/abi.h>

-#include <sys/interrupts.h>

 #include <sys/mm/mempart.h>
 
 #include <hal/intc.h>
 #include <sys/mm/mempart.h>
 
 #include <hal/intc.h>


@@ -11,6 +10,7 @@
 #include <lunaix/mm/pmm.h>
 #include <lunaix/mm/valloc.h>
 #include <lunaix/mm/vmm.h>
 #include <lunaix/mm/pmm.h>
 #include <lunaix/mm/valloc.h>
 #include <lunaix/mm/vmm.h>

+#include <lunaix/mm/procvm.h>

 #include <lunaix/process.h>
 #include <lunaix/sched.h>
 #include <lunaix/signal.h>
 #include <lunaix/process.h>
 #include <lunaix/sched.h>
 #include <lunaix/signal.h>


@@ -18,104 +18,125 @@
 #include <lunaix/status.h>
 #include <lunaix/syscall.h>
 #include <lunaix/syslog.h>
 #include <lunaix/status.h>
 #include <lunaix/syscall.h>
 #include <lunaix/syslog.h>

+#include <lunaix/pcontext.h>
+#include <lunaix/kpreempt.h>

 
 #include <klibc/string.h>
 
 volatile struct proc_info* __current;
 
 #include <klibc/string.h>
 
 volatile struct proc_info* __current;

-
-static struct proc_info dummy_proc;
-
-struct proc_info dummy;
+volatile struct thread* current_thread;

 
 struct scheduler sched_ctx;
 
 
 struct scheduler sched_ctx;
 

-struct cake_pile* proc_pile;
+struct cake_pile *proc_pile ,*thread_pile;

 
 LOG_MODULE("SCHED")
 
 
 LOG_MODULE("SCHED")
 

-void
-sched_init_dummy();
-

 void
 sched_init()
 {
     proc_pile = cake_new_pile("proc", sizeof(struct proc_info), 1, 0);
 void
 sched_init()
 {
     proc_pile = cake_new_pile("proc", sizeof(struct proc_info), 1, 0);

+    thread_pile = cake_new_pile("thread", sizeof(struct thread), 1, 0);

     cake_set_constructor(proc_pile, cake_ctor_zeroing);
     cake_set_constructor(proc_pile, cake_ctor_zeroing);

+    cake_set_constructor(thread_pile, cake_ctor_zeroing);

 
     sched_ctx = (struct scheduler){
 
     sched_ctx = (struct scheduler){

-        ._procs = vzalloc(PROC_TABLE_SIZE), .ptable_len = 0, .procs_index = 0};
-
-    // TODO initialize dummy_proc
-    sched_init_dummy();
+        .procs = vzalloc(PROC_TABLE_SIZE), .ptable_len = 0, .procs_index = 0};
+    
+    llist_init_head(&sched_ctx.sleepers);

 }
 
 }
 

-#define DUMMY_STACK_SIZE 2048
-

 void
 void

-sched_init_dummy()
+run(struct thread* thread)

 {
 {

-    // This surely need to be simplified or encapsulated!
-    // It is a living nightmare!
+    thread->state = PS_RUNNING;
+    thread->process->state = PS_RUNNING;
+    thread->process->th_active = thread;

 
 

-    extern void my_dummy();
-    static char dummy_stack[DUMMY_STACK_SIZE] __attribute__((aligned(16)));
+    set_current_executing(thread);

 
 

-    ptr_t stktop = (ptr_t)dummy_stack + DUMMY_STACK_SIZE;
+    switch_context();
+    fail("unexpected return from switching");
+}

 
 

-    dummy_proc = (struct proc_info){};
+/*
+    Currently, we do not allow self-destorying thread, doing
+    so will eliminate current kernel stack which is disaster.
+    A compromise solution is to perform a regular scan and 
+    clean-up on these thread, in the preemptible kernel thread.
+*/

 
 

-    proc_init_transfer(&dummy_proc, stktop, (ptr_t)my_dummy, TRANSFER_IE);
+void _preemptible
+cleanup_detached_threads() {
+    ensure_preempt_caller();

 
 

-    dummy_proc.page_table = cpu_ldvmspace();
-    dummy_proc.state = PS_READY;
-    dummy_proc.parent = &dummy_proc;
-    dummy_proc.pid = KERNEL_PID;
+    // XXX may be a lock on sched_context will ben the most appropriate?
+    cpu_disable_interrupt();

 
 

-    __current = &dummy_proc;
-}
+    int i = 0;
+    struct thread *pos, *n;
+    llist_for_each(pos, n, sched_ctx.threads, sched_sibs) {
+        if (likely(!proc_terminated(pos) || !thread_detached(pos))) {
+            continue;
+        }

 
 

-void
-run(struct proc_info* proc)
-{
-    proc->state = PS_RUNNING;
+        vmm_mount_pd(VMS_MOUNT_1, vmroot(pos->process));
+        destory_thread(VMS_MOUNT_1, pos);
+        vmm_unmount_pd(VMS_MOUNT_1);
+        
+        i++;
+    }

 
 

-    intc_notify_eos(0);
-    switch_context(proc);
+    if (i) {
+        INFO("cleaned %d terminated detached thread(s)", i);
+    }
+
+    cpu_enable_interrupt();

 }
 
 int
 }
 
 int

-can_schedule(struct proc_info* proc)
+can_schedule(struct thread* thread)

 {
 {

-    if (!proc) {
+    if (!thread) {

         return 0;
     }
 
         return 0;
     }
 

-    struct sighail* sh = &proc->sigctx;
+    if (unlikely(kernel_process(thread->process))) {
+        // a kernel process is always runnable
+        return thread->state == PS_READY;
+    }
+
+    struct sigctx* sh = &thread->sigctx;

 
 

-    if ((proc->state & PS_PAUSED)) {
+    if ((thread->state & PS_PAUSED)) {

         return !!(sh->sig_pending & ~1);
     }
         return !!(sh->sig_pending & ~1);
     }

-    if ((proc->state & PS_BLOCKED)) {
+    if ((thread->state & PS_BLOCKED)) {

         return sigset_test(sh->sig_pending, _SIGINT);
     }
 
         return sigset_test(sh->sig_pending, _SIGINT);
     }
 

-    if (sigset_test(sh->sig_pending, _SIGCONT)) {
-        sigset_clear(sh->sig_pending, _SIGSTOP);
-    } else if (sigset_test(sh->sig_pending, _SIGSTOP)) {
-        // 如果进程受到SIGSTOP，则该进程不给予调度。
+    if (sigset_test(sh->sig_pending, _SIGSTOP)) {
+        // If one thread is experiencing SIGSTOP, then we know
+        // all other threads are also SIGSTOP (as per POSIX-2008.1)
+        // In which case, the entire process is stopped.
+        thread->state = PS_STOPPED;

         return 0;
     }
         return 0;
     }

+    if (sigset_test(sh->sig_pending, _SIGCONT)) {
+        thread->state = PS_READY;
+    }

 
 

-    return (proc->state == PS_READY);
+    return (thread->state == PS_READY) \
+            && proc_runnable(thread->process);

 }
 
 void
 check_sleepers()
 {
 }
 
 void
 check_sleepers()
 {

-    struct proc_info* leader = sched_ctx._procs[0];
-    struct proc_info *pos, *n;
+    struct thread *pos, *n;

     time_t now = clock_systime() / 1000;
     time_t now = clock_systime() / 1000;

-    llist_for_each(pos, n, &leader->sleep.sleepers, sleep.sleepers)
+
+    llist_for_each(pos, n, &sched_ctx.sleepers, sleep.sleepers)

     {
         if (proc_terminated(pos)) {
             goto del;
     {
         if (proc_terminated(pos)) {
             goto del;


@@ -131,7 +152,7 @@ check_sleepers()
 
         if (atime && now >= atime) {
             pos->sleep.alarm_time = 0;
 
         if (atime && now >= atime) {
             pos->sleep.alarm_time = 0;

-            proc_setsignal(pos, _SIGALRM);
+            thread_setsignal(pos, _SIGALRM);

         }
 
         if (!wtime && !atime) {
         }
 
         if (!wtime && !atime) {


@@ -144,44 +165,49 @@ check_sleepers()
 void
 schedule()
 {
 void
 schedule()
 {

-    if (!sched_ctx.ptable_len) {
-        return;
-    }
+    assert(sched_ctx.ptable_len && sched_ctx.ttable_len);

 
     // 上下文切换相当的敏感！我们不希望任何的中断打乱栈的顺序……
     cpu_disable_interrupt();
 
     // 上下文切换相当的敏感！我们不希望任何的中断打乱栈的顺序……
     cpu_disable_interrupt();

-    struct proc_info* next;
-    int prev_ptr = sched_ctx.procs_index;
-    int ptr = prev_ptr;
-    int found = 0;

 
 

-    if (!(__current->state & ~PS_RUNNING)) {
+    if (!(current_thread->state & ~PS_RUNNING)) {
+        current_thread->state = PS_READY;

         __current->state = PS_READY;
     }
 
     check_sleepers();
 
     // round-robin scheduler
         __current->state = PS_READY;
     }
 
     check_sleepers();
 
     // round-robin scheduler

+    
+    struct thread* current = current_thread;
+    struct thread* to_check = current;
+    

     do {
     do {

-        ptr = (ptr + 1) % sched_ctx.ptable_len;
-        next = sched_ctx._procs[ptr];
+        to_check = list_next(to_check, struct thread, sched_sibs);

 
 

-        if (!(found = can_schedule(next))) {
-            if (ptr == prev_ptr) {
-                next = &dummy_proc;
-                goto done;
-            }
+        if (can_schedule(to_check)) {
+            break;
+        }
+
+        if (to_check == current) {
+            // FIXME do something less leathal here
+            fail("Ran out of threads!")
+            goto done;  

         }
         }

-    } while (!found);

 
 

-    sched_ctx.procs_index = ptr;
+    } while (1);
+
+    sched_ctx.procs_index = to_check->process->pid;

 
 done:
 
 done:

-    run(next);
+    intc_notify_eos(0);
+    run(to_check);
+
+    fail("unexpected return from scheduler");

 }
 
 void
 }
 
 void

-sched_yieldk()
+sched_pass()

 {
     cpu_enable_interrupt();
     cpu_trap_sched();
 {
     cpu_enable_interrupt();
     cpu_trap_sched();


@@ -194,21 +220,21 @@ __DEFINE_LXSYSCALL1(unsigned int, sleep, unsigned int, seconds)
     }
 
     time_t systime = clock_systime() / 1000;
     }
 
     time_t systime = clock_systime() / 1000;

+    struct haybed* bed = &current_thread->sleep;

 
 

-    if (__current->sleep.wakeup_time) {
-        return (__current->sleep.wakeup_time - systime);
+    if (bed->wakeup_time) {
+        return (bed->wakeup_time - systime);

     }
 
     }
 

-    struct proc_info* root_proc = sched_ctx._procs[0];
-    __current->sleep.wakeup_time = systime + seconds;
+    bed->wakeup_time = systime + seconds;

 
 

-    if (llist_empty(&__current->sleep.sleepers)) {
-        llist_append(&root_proc->sleep.sleepers, &__current->sleep.sleepers);
+    if (llist_empty(&bed->sleepers)) {
+        llist_append(&sched_ctx.sleepers, &bed->sleepers);

     }
 
     store_retval(seconds);
 
     }
 
     store_retval(seconds);
 

-    block_current();
+    block_current_thread();

     schedule();
 
     return 0;
     schedule();
 
     return 0;


@@ -216,14 +242,15 @@ __DEFINE_LXSYSCALL1(unsigned int, sleep, unsigned int, seconds)
 
 __DEFINE_LXSYSCALL1(unsigned int, alarm, unsigned int, seconds)
 {
 
 __DEFINE_LXSYSCALL1(unsigned int, alarm, unsigned int, seconds)
 {

-    time_t prev_ddl = __current->sleep.alarm_time;
+    struct haybed* bed = &current_thread->sleep;
+    time_t prev_ddl = bed->alarm_time;

     time_t now = clock_systime() / 1000;
 
     time_t now = clock_systime() / 1000;
 

-    __current->sleep.alarm_time = seconds ? now + seconds : 0;
+    bed->alarm_time = seconds ? now + seconds : 0;

 
 

-    struct proc_info* root_proc = sched_ctx._procs[0];
-    if (llist_empty(&__current->sleep.sleepers)) {
-        llist_append(&root_proc->sleep.sleepers, &__current->sleep.sleepers);
+    struct proc_info* root_proc = sched_ctx.procs[0];
+    if (llist_empty(&bed->sleepers)) {
+        llist_append(&sched_ctx.sleepers, &bed->sleepers);

     }
 
     return prev_ddl ? (prev_ddl - now) : 0;
     }
 
     return prev_ddl ? (prev_ddl - now) : 0;


@@ -231,7 +258,7 @@ __DEFINE_LXSYSCALL1(unsigned int, alarm, unsigned int, seconds)
 
 __DEFINE_LXSYSCALL1(void, exit, int, status)
 {
 
 __DEFINE_LXSYSCALL1(void, exit, int, status)
 {

-    terminate_proc(status);
+    terminate_current(status);

     schedule();
 }
 
     schedule();
 }
 


@@ -255,7 +282,7 @@ __DEFINE_LXSYSCALL3(pid_t, waitpid, pid_t, pid, int*, status, int, options)
 
 __DEFINE_LXSYSCALL(int, geterrno)
 {
 
 __DEFINE_LXSYSCALL(int, geterrno)
 {

-    return __current->k_status;
+    return current_thread->syscall_ret;

 }
 
 pid_t
 }
 
 pid_t


@@ -287,7 +314,7 @@ repeat:
         return 0;
     }
     // 放弃当前的运行机会
         return 0;
     }
     // 放弃当前的运行机会

-    sched_yieldk();
+    sched_pass();

     goto repeat;
 
 done:
     goto repeat;
 
 done:


@@ -297,87 +324,162 @@ done:
     return destroy_process(proc->pid);
 }
 
     return destroy_process(proc->pid);
 }
 

-struct proc_info*
-alloc_process()
-{
+static inline pid_t
+get_free_pid() {

     pid_t i = 0;
     pid_t i = 0;

-    for (; i < sched_ctx.ptable_len && sched_ctx._procs[i]; i++)
+    
+    for (; i < sched_ctx.ptable_len && sched_ctx.procs[i]; i++)

         ;
         ;

-
-    if (i == MAX_PROCESS) {
+    
+    if (unlikely(i == MAX_PROCESS)) {

         panick("Panic in Ponyville shimmer!");
     }
 
         panick("Panic in Ponyville shimmer!");
     }
 

+    return i;
+}
+
+struct thread*
+alloc_thread(struct proc_info* process) {
+    if (process->thread_count >= MAX_THREAD_PP) {
+        return NULL;
+    }
+    
+    struct thread* th = cake_grab(thread_pile);
+
+    th->process = process;
+    th->created = clock_systime();
+
+    // FIXME we need a better tid allocation method!
+    th->tid = th->created;
+    th->tid = (th->created ^ ((ptr_t)th)) % MAX_THREAD_PP;
+
+    th->state = PS_CREATED;
+    
+    llist_init_head(&th->sleep.sleepers);
+    llist_init_head(&th->sched_sibs);
+    llist_init_head(&th->proc_sibs);
+    waitq_init(&th->waitqueue);
+
+    return th;
+}
+
+struct proc_info*
+alloc_process()
+{
+    pid_t i = get_free_pid();
+

     if (i == sched_ctx.ptable_len) {
         sched_ctx.ptable_len++;
     }
 
     struct proc_info* proc = cake_grab(proc_pile);
     if (i == sched_ctx.ptable_len) {
         sched_ctx.ptable_len++;
     }
 
     struct proc_info* proc = cake_grab(proc_pile);

+    if (!proc) {
+        return NULL;
+    }

 
     proc->state = PS_CREATED;
     proc->pid = i;
 
     proc->state = PS_CREATED;
     proc->pid = i;

-    proc->mm.pid = i;

     proc->created = clock_systime();
     proc->pgid = proc->pid;
     proc->created = clock_systime();
     proc->pgid = proc->pid;

+
+    proc->sigreg = vzalloc(sizeof(struct sigregister));

     proc->fdtable = vzalloc(sizeof(struct v_fdtable));
 
     proc->fdtable = vzalloc(sizeof(struct v_fdtable));
 

-    llist_init_head(&proc->mm.regions);
+    proc->mm = procvm_create(proc);
+    

     llist_init_head(&proc->tasks);
     llist_init_head(&proc->children);
     llist_init_head(&proc->grp_member);
     llist_init_head(&proc->tasks);
     llist_init_head(&proc->children);
     llist_init_head(&proc->grp_member);

-    llist_init_head(&proc->sleep.sleepers);
+    llist_init_head(&proc->threads);

 
     iopoll_init(&proc->pollctx);
 
     iopoll_init(&proc->pollctx);

-    waitq_init(&proc->waitqueue);

 
 

-    sched_ctx._procs[i] = proc;
+    sched_ctx.procs[i] = proc;

 
     return proc;
 }
 
 void
 
     return proc;
 }
 
 void

-commit_process(struct proc_info* process)
-{
-    assert(process == sched_ctx._procs[process->pid]);
+commit_thread(struct thread* thread) {
+    struct proc_info* process = thread->process;

 
 

-    if (process->state != PS_CREATED) {
-        __current->k_status = EINVAL;
-        return;
+    assert(process && !proc_terminated(process));
+
+    llist_append(&process->threads, &thread->proc_sibs);
+    
+    if (sched_ctx.threads) {
+        llist_append(sched_ctx.threads, &thread->sched_sibs);
+    } else {
+        sched_ctx.threads = &thread->sched_sibs;

     }
 
     }
 

+    sched_ctx.ttable_len++;
+    process->thread_count++;
+    thread->state = PS_READY;
+}
+
+void
+commit_process(struct proc_info* process)
+{
+    assert(process == sched_ctx.procs[process->pid]);
+    assert(process->state == PS_CREATED);
+

     // every process is the child of first process (pid=1)
     if (!process->parent) {
     // every process is the child of first process (pid=1)
     if (!process->parent) {

-        process->parent = sched_ctx._procs[1];
+        if (likely(!kernel_process(process))) {
+            process->parent = sched_ctx.procs[1];
+        } else {
+            process->parent = process;
+        }
+    } else {
+        assert(!proc_terminated(process->parent));
+    }
+
+    if (sched_ctx.proc_list) {
+        llist_append(sched_ctx.proc_list, &process->tasks);
+    } else {
+        sched_ctx.proc_list = &process->tasks;

     }
 
     llist_append(&process->parent->children, &process->siblings);
     }
 
     llist_append(&process->parent->children, &process->siblings);

-    llist_append(&sched_ctx._procs[0]->tasks, &process->tasks);

 
     process->state = PS_READY;
 }
 
 
     process->state = PS_READY;
 }
 

-// from <kernel/process.c>
-extern void
-__del_pagetable(pid_t pid, ptr_t mount_point);
+void
+destory_thread(ptr_t vm_mnt, struct thread* thread) 
+{
+    cake_ensure_valid(thread);
+    
+    struct proc_info* proc = thread->process;

 
 

-pid_t
-destroy_process(pid_t pid)
+    llist_delete(&thread->sched_sibs);
+    llist_delete(&thread->proc_sibs);
+    llist_delete(&thread->sleep.sleepers);
+    waitq_cancel_wait(&thread->waitqueue);
+
+    thread_release_mem(thread, vm_mnt);
+
+    proc->thread_count--;
+    sched_ctx.ttable_len--;
+
+    cake_release(thread_pile, thread);
+}
+
+void 
+delete_process(struct proc_info* proc)

 {
 {

-    int index = pid;
-    if (index <= 0 || index > sched_ctx.ptable_len) {
-        __current->k_status = EINVAL;
-        return -1;
-    }
+    pid_t pid = proc->pid;

 
 

-    struct proc_info* proc = sched_ctx._procs[index];
-    sched_ctx._procs[index] = 0;
+    assert(pid);    // long live the pid0 !!
+
+    sched_ctx.procs[pid] = NULL;

 
     llist_delete(&proc->siblings);
     llist_delete(&proc->grp_member);
     llist_delete(&proc->tasks);
 
     llist_delete(&proc->siblings);
     llist_delete(&proc->grp_member);
     llist_delete(&proc->tasks);

-    llist_delete(&proc->sleep.sleepers);

 
 

-    iopoll_free(pid, &proc->pollctx);
+    iopoll_free(proc);

 
     taskfs_invalidate(pid);
 
 
     taskfs_invalidate(pid);
 


@@ -385,6 +487,10 @@ destroy_process(pid_t pid)
         vfs_unref_dnode(proc->cwd);
     }
 
         vfs_unref_dnode(proc->cwd);
     }
 

+    if (proc->cmd) {
+        vfree(proc->cmd);
+    }
+

     for (size_t i = 0; i < VFS_MAX_FD; i++) {
         struct v_fd* fd = proc->fdtable->fds[i];
         if (fd) {
     for (size_t i = 0; i < VFS_MAX_FD; i++) {
         struct v_fd* fd = proc->fdtable->fds[i];
         if (fd) {


@@ -395,31 +501,82 @@ destroy_process(pid_t pid)
 
     vfree(proc->fdtable);
 
 
     vfree(proc->fdtable);
 

-    vmm_mount_pd(VMS_MOUNT_1, proc->page_table);
+    signal_free_registers(proc->sigreg);

 
 

-    struct mm_region *pos, *n;
-    llist_for_each(pos, n, &proc->mm.regions, head)
-    {
-        mem_sync_pages(VMS_MOUNT_1, pos, pos->start, pos->end - pos->start, 0);
-        region_release(pos);
+    vmm_mount_pd(VMS_MOUNT_1, vmroot(proc));
+    
+    struct thread *pos, *n;
+    llist_for_each(pos, n, &proc->threads, proc_sibs) {
+        // terminate and destory all thread unconditionally
+        destory_thread(VMS_MOUNT_1, pos);

     }
 
     }
 

-    __del_pagetable(pid, VMS_MOUNT_1);
+    procvm_cleanup(VMS_MOUNT_1, proc);

 
     vmm_unmount_pd(VMS_MOUNT_1);
 
     cake_release(proc_pile, proc);
 
     vmm_unmount_pd(VMS_MOUNT_1);
 
     cake_release(proc_pile, proc);

+}
+
+pid_t
+destroy_process(pid_t pid)
+{
+    int index = pid;
+    if (index <= 0 || index > sched_ctx.ptable_len) {
+        syscall_result(EINVAL);
+        return -1;
+    }
+
+    struct proc_info* proc = sched_ctx.procs[index];
+    delete_process(proc);

 
     return pid;
 }
 
 
     return pid;
 }
 

+static void 
+terminate_proc_only(struct proc_info* proc, int exit_code) {
+    proc->state = PS_TERMNAT;
+    proc->exit_code = exit_code;
+
+    proc_setsignal(proc->parent, _SIGCHLD);
+}
+

 void
 void

-terminate_proc(int exit_code)
-{
-    __current->state = PS_TERMNAT;
-    __current->exit_code = exit_code;
+terminate_thread(struct thread* thread, ptr_t val) {
+    thread->exit_val = val;
+    thread->state = PS_TERMNAT;
+
+    struct proc_info* proc = thread->process;
+    if (proc->thread_count == 1) {
+        terminate_proc_only(thread->process, 0);
+    }
+}
+
+void
+terminate_current_thread(ptr_t val) {
+    terminate_thread(current_thread, val);
+}
+
+void 
+terminate_proccess(struct proc_info* proc, int exit_code) {
+    assert(!kernel_process(proc));
+
+    if (proc->pid == 1) {
+        panick("Attempt to kill init");
+    }
+
+    terminate_proc_only(proc, exit_code);

 
 

-    proc_setsignal(__current->parent, _SIGCHLD);
+    struct thread *pos, *n;
+    llist_for_each(pos, n, &__current->threads, proc_sibs) {
+        pos->state = PS_TERMNAT;
+    }
+}
+
+void
+terminate_current(int exit_code)
+{
+    terminate_proccess(__current, exit_code);

 }
 
 struct proc_info*
 }
 
 struct proc_info*


@@ -429,7 +586,7 @@ get_process(pid_t pid)
     if (index < 0 || index > sched_ctx.ptable_len) {
         return NULL;
     }
     if (index < 0 || index > sched_ctx.ptable_len) {
         return NULL;
     }

-    return sched_ctx._procs[index];
+    return sched_ctx.procs[index];

 }
 
 int
 }
 
 int


@@ -439,7 +596,7 @@ orphaned_proc(pid_t pid)
         return 0;
     if (pid >= sched_ctx.ptable_len)
         return 0;
         return 0;
     if (pid >= sched_ctx.ptable_len)
         return 0;

-    struct proc_info* proc = sched_ctx._procs[pid];
+    struct proc_info* proc = sched_ctx.procs[pid];

     struct proc_info* parent = proc->parent;
 
     // 如果其父进程的状态是terminated 或 destroy中的一种
     struct proc_info* parent = proc->parent;
 
     // 如果其父进程的状态是terminated 或 destroy中的一种