-#include <lunaix/process.h>
-#include <lunaix/sched.h>
-#include <lunaix/mm/vmm.h>
-#include <hal/cpu.h>
#include <arch/x86/interrupts.h>
+#include <arch/x86/tss.h>
+
#include <hal/apic.h>
+#include <hal/cpu.h>
+#include <lunaix/mm/kalloc.h>
+#include <lunaix/mm/pmm.h>
+#include <lunaix/mm/valloc.h>
+#include <lunaix/mm/vmm.h>
+#include <lunaix/process.h>
+#include <lunaix/sched.h>
+#include <lunaix/signal.h>
#include <lunaix/spike.h>
#include <lunaix/status.h>
+#include <lunaix/syscall.h>
#include <lunaix/syslog.h>
#define MAX_PROCESS 512
-struct proc_info* __current;
-struct proc_info dummy;
+volatile struct proc_info* __current;
-extern void __proc_table;
+struct proc_info dummy;
struct scheduler sched_ctx;
LOG_MODULE("SCHED")
-void sched_init() {
+void
+sched_init()
+{
size_t pg_size = ROUNDUP(sizeof(struct proc_info) * MAX_PROCESS, 0x1000);
- assert_msg(
- vmm_alloc_pages(KERNEL_PID, &__proc_table, pg_size, PG_PREM_RW, PP_FGPERSIST),
- "Fail to allocate proc table"
- );
-
- sched_ctx = (struct scheduler) {
- ._procs = (struct proc_info*) &__proc_table,
- .ptable_len = 0,
- .procs_index = 0
- };
-}
-
-void schedule() {
+
+ for (size_t i = 0; i <= pg_size; i += 4096) {
+ uintptr_t pa = pmm_alloc_page(KERNEL_PID, PP_FGPERSIST);
+ vmm_set_mapping(
+ PD_REFERENCED, PROC_START + i, pa, PG_PREM_RW, VMAP_NULL);
+ }
+
+ sched_ctx = (struct scheduler){ ._procs = (struct proc_info*)PROC_START,
+ .ptable_len = 0,
+ .procs_index = 0 };
+}
+
+void
+run(struct proc_info* proc)
+{
+ proc->state = PS_RUNNING;
+
+ /*
+ 将tss.esp0设置为上次调度前的esp值。
+ 当处理信号时，上下文信息是不会恢复的，而是保存在用户栈中，然后直接跳转进位于用户空间的sig_wrapper进行
+ 信号的处理。当用户自定义的信号处理函数返回时，sigreturn的系统调用才开始进行上下文的恢复（或者说是进行
+ 另一次调度。
+ 由于这中间没有进行地址空间的交换，所以第二次跳转使用的是同一个内核栈，而之前默认tss.esp0的值是永远指向最顶部
+ 这样一来就有可能会覆盖更早的上下文信息（比如嵌套的信号捕获函数）
+ */
+ tss_update_esp(proc->intr_ctx.registers.esp);
+
+ apic_done_servicing();
+
+ asm volatile("pushl %0\n"
+ "jmp switch_to\n" ::"r"(proc)
+ : "memory"); // kernel/asm/x86/interrupt.S
+}
+
+int
+can_schedule(struct proc_info* proc)
+{
+ if (__SIGTEST(proc->sig_pending, _SIGCONT)) {
+ __SIGCLEAR(proc->sig_pending, _SIGSTOP);
+ } else if (__SIGTEST(proc->sig_pending, _SIGSTOP)) {
+ // 如果进程受到SIGSTOP，则该进程不给予调度。
+ return 0;
+ }
+
+ return 1;
+}
+
+void
+check_sleepers()
+{
+ struct proc_info* leader = &sched_ctx._procs[0];
+ struct proc_info *pos, *n;
+ time_t now = clock_systime();
+ llist_for_each(pos, n, &leader->sleep.sleepers, sleep.sleepers)
+ {
+ if (PROC_TERMINATED(pos->state)) {
+ goto del;
+ }
+
+ time_t wtime = pos->sleep.wakeup_time;
+ time_t atime = pos->sleep.alarm_time;
+
+ if (wtime && now >= wtime) {
+ pos->sleep.wakeup_time = 0;
+ pos->state = PS_STOPPED;
+ }
+
+ if (atime && now >= atime) {
+ pos->sleep.alarm_time = 0;
+ __SIGSET(pos->sig_pending, _SIGALRM);
+ }
+
+ if (!wtime && !atime) {
+ del:
+ llist_delete(&pos->sleep.sleepers);
+ }
+ }
+}
+
+void
+schedule()
+{
if (!sched_ctx.ptable_len) {
return;
}
+ // 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;
+
+ if (!(__current->state & ~PS_RUNNING)) {
+ __current->state = PS_STOPPED;
+ }
+
+ check_sleepers();
+
// round-robin scheduler
+redo:
do {
ptr = (ptr + 1) % sched_ctx.ptable_len;
next = &sched_ctx._procs[ptr];
- } while((next->state != PROC_STOPPED && next->state != PROC_CREATED) && ptr != prev_ptr);
-
+ } while (next->state != PS_STOPPED && ptr != prev_ptr);
+
sched_ctx.procs_index = ptr;
-
- __current->state = PROC_STOPPED;
- next->state = PROC_RUNNING;
-
- __current = next;
- cpu_lcr3(__current->page_table);
+ if (!can_schedule(next)) {
+ // 如果该进程不给予调度，则尝试重新选择
+ goto redo;
+ }
- apic_done_servicing();
+ run(next);
+}
+
+__DEFINE_LXSYSCALL1(unsigned int, sleep, unsigned int, seconds)
+{
+ if (!seconds) {
+ return 0;
+ }
+
+ if (__current->sleep.wakeup_time) {
+ return (__current->sleep.wakeup_time - clock_systime()) / 1000U;
+ }
- asm volatile (
- "pushl %0\n"
- "jmp soft_iret\n"::"r"(&__current->intr_ctx): "memory");
+ __current->sleep.wakeup_time = clock_systime() + seconds * 1000;
+ llist_append(&sched_ctx._procs[0].sleep.sleepers,
+ &__current->sleep.sleepers);
+
+ __current->intr_ctx.registers.eax = seconds;
+ __current->state = PS_BLOCKED;
+ schedule();
}
-pid_t alloc_pid() {
+__DEFINE_LXSYSCALL1(unsigned int, alarm, unsigned int, seconds)
+{
+ time_t prev_ddl = __current->sleep.alarm_time;
+ time_t now = clock_systime();
+
+ __current->sleep.alarm_time = seconds ? now + seconds * 1000 : 0;
+
+ if (llist_empty(&__current->sleep.sleepers)) {
+ llist_append(&sched_ctx._procs[0].sleep.sleepers,
+ &__current->sleep.sleepers);
+ }
+
+ return prev_ddl ? (prev_ddl - now) / 1000 : 0;
+}
+
+__DEFINE_LXSYSCALL1(void, exit, int, status)
+{
+ terminate_proc(status);
+ schedule();
+}
+
+__DEFINE_LXSYSCALL(void, yield)
+{
+ schedule();
+}
+
+pid_t
+_wait(pid_t wpid, int* status, int options);
+
+__DEFINE_LXSYSCALL1(pid_t, wait, int*, status)
+{
+ return _wait(-1, status, 0);
+}
+
+__DEFINE_LXSYSCALL3(pid_t, waitpid, pid_t, pid, int*, status, int, options)
+{
+ return _wait(pid, status, options);
+}
+
+__DEFINE_LXSYSCALL(int, geterrno)
+{
+ return __current->k_status;
+}
+
+pid_t
+_wait(pid_t wpid, int* status, int options)
+{
+ pid_t cur = __current->pid;
+ int status_flags = 0;
+ struct proc_info *proc, *n;
+ if (llist_empty(&__current->children)) {
+ return -1;
+ }
+
+ wpid = wpid ? wpid : -__current->pgid;
+ cpu_enable_interrupt();
+repeat:
+ llist_for_each(proc, n, &__current->children, siblings)
+ {
+ if (!~wpid || proc->pid == wpid || proc->pgid == -wpid) {
+ if (proc->state == PS_TERMNAT && !options) {
+ status_flags |= PEXITTERM;
+ goto done;
+ }
+ if (proc->state == PS_STOPPED && (options & WUNTRACED)) {
+ status_flags |= PEXITSTOP;
+ goto done;
+ }
+ }
+ }
+ if ((options & WNOHANG)) {
+ return 0;
+ }
+ // 放弃当前的运行机会
+ sched_yield();
+ goto repeat;
+
+done:
+ cpu_disable_interrupt();
+ status_flags |= PEXITSIG * (proc->sig_inprogress != 0);
+ if (status) {
+ *status = proc->exit_code | status_flags;
+ }
+ return destroy_process(proc->pid);
+}
+
+struct proc_info*
+alloc_process()
+{
pid_t i = 0;
- for (; i < sched_ctx.ptable_len && sched_ctx._procs[i].state != PROC_DESTROY; i++);
+ for (; i < sched_ctx.ptable_len && sched_ctx._procs[i].state != PS_DESTROY;
+ i++)
+ ;
if (i == MAX_PROCESS) {
- __current->k_status = LXPROCFULL;
- return -1;
+ panick("Panic in Ponyville shimmer!");
}
- return i + 1;
+
+ if (i == sched_ctx.ptable_len) {
+ sched_ctx.ptable_len++;
+ }
+
+ struct proc_info* proc = &sched_ctx._procs[i];
+ memset(proc, 0, sizeof(*proc));
+
+ proc->state = PS_CREATED;
+ proc->pid = i;
+ proc->created = clock_systime();
+ proc->pgid = proc->pid;
+ proc->fdtable = vzalloc(sizeof(struct v_fdtable));
+
+ llist_init_head(&proc->mm.regions);
+ llist_init_head(&proc->children);
+ llist_init_head(&proc->grp_member);
+ llist_init_head(&proc->sleep.sleepers);
+
+ return proc;
}
-void push_process(struct proc_info* process) {
- int index = process->pid - 1;
- if (index < 0 || index > sched_ctx.ptable_len) {
- __current->k_status = LXINVLDPID;
+void
+commit_process(struct proc_info* process)
+{
+ assert(process == &sched_ctx._procs[process->pid]);
+
+ if (process->state != PS_CREATED) {
+ __current->k_status = EINVAL;
return;
}
-
- if (index == sched_ctx.ptable_len) {
- sched_ctx.ptable_len++;
+
+ // every process is the child of first process (pid=1)
+ if (!process->parent) {
+ process->parent = &sched_ctx._procs[1];
}
-
- process->parent = __current->pid;
- process->state = PROC_CREATED;
- sched_ctx._procs[index] = *process;
+ llist_append(&process->parent->children, &process->siblings);
+
+ process->state = PS_STOPPED;
}
-void destroy_process(pid_t pid) {
- int index = pid - 1;
- if (index < 0 || index > sched_ctx.ptable_len) {
- __current->k_status = LXINVLDPID;
+// from <kernel/process.c>
+extern void
+__del_pagetable(pid_t pid, uintptr_t mount_point);
+
+pid_t
+destroy_process(pid_t pid)
+{
+ int index = pid;
+ if (index <= 0 || index > sched_ctx.ptable_len) {
+ __current->k_status = EINVAL;
return;
}
+ struct proc_info* proc = &sched_ctx._procs[index];
+ proc->state = PS_DESTROY;
+ llist_delete(&proc->siblings);
+
+ for (size_t i = 0; i < VFS_MAX_FD; i++) {
+ struct v_fd* fd = proc->fdtable->fds[i];
+ if (fd)
+ vfs_close(fd->file);
+ }
+
+ vfree(proc->fdtable);
+
+ struct mm_region *pos, *n;
+ llist_for_each(pos, n, &proc->mm.regions.head, head)
+ {
+ lxfree(pos);
+ }
- sched_ctx._procs[index].state = PROC_DESTROY;
+ vmm_mount_pd(PD_MOUNT_1, proc->page_table);
- // TODO: recycle the physical pages used by page tables
+ __del_pagetable(pid, PD_MOUNT_1);
+
+ vmm_unmount_pd(PD_MOUNT_1);
+
+ return pid;
}
-void terminate_process(int exit_code) {
- __current->state = PROC_TERMNAT;
+void
+terminate_proc(int exit_code)
+{
+ __current->state = PS_TERMNAT;
__current->exit_code = exit_code;
- schedule();
+ __SIGSET(__current->parent->sig_pending, _SIGCHLD);
}
-struct proc_info* get_process(pid_t pid) {
- int index = pid - 1;
+struct proc_info*
+get_process(pid_t pid)
+{
+ int index = pid;
if (index < 0 || index > sched_ctx.ptable_len) {
return NULL;
}
return &sched_ctx._procs[index];
+}
+
+int
+orphaned_proc(pid_t pid)
+{
+ if (!pid)
+ return 0;
+ if (pid >= sched_ctx.ptable_len)
+ return 0;
+ 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
+ // 或者其父进程是在该进程之后创建的，那么该进程为孤儿进程
+ return PROC_TERMINATED(parent->state) || parent->created > proc->created;
}
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / blobdiff