feat: support for SIGALRM

feat: alarm(2) syscall
refactor: better sleep(3).
chore: rename the process state for compactness.

diff --git a/lunaix-os/includes/lunaix/ds/llist.h b/lunaix-os/includes/lunaix/ds/llist.h
index 1a6ec9b5fc6a8377e84d7096bbdf149a8cbeff17..5afc36ad43b48ec822919a7dbb6a94008b130e44 100644 (file)
--- a/lunaix-os/includes/lunaix/ds/llist.h
+++ b/lunaix-os/includes/lunaix/ds/llist.h
@@ -64,7 +64,7 @@ llist_delete(struct llist_header* elem)
 static inline int
 llist_empty(struct llist_header* elem)
 {
-    return elem->next == elem;
+    return elem->next == elem && elem->prev == elem;
 }
 
 /**

diff --git a/lunaix-os/includes/lunaix/lunistd.h b/lunaix-os/includes/lunaix/lunistd.h
index 67f317478016bb0c7e424e2b3ee5710d1f3e879c..c16f2b09fc6d14c4c326dd7397805ba4fcbc09a0 100644 (file)
--- a/lunaix-os/includes/lunaix/lunistd.h
+++ b/lunaix-os/includes/lunaix/lunistd.h
@@ -22,4 +22,6 @@ __LXSYSCALL(int, pause)
 
 __LXSYSCALL2(int, kill, pid_t, pid, int, signum)
 
+__LXSYSCALL1(unsigned int, alarm, unsigned int, seconds)
+
 #endif /* __LUNAIX_UNISTD_H */

diff --git a/lunaix-os/includes/lunaix/process.h b/lunaix-os/includes/lunaix/process.h
index 589bfaa7348d529cae2a72972931ed86b4136563..d35bfe77c7cc9ddb41be6f1ae04997a029744668 100644 (file)
--- a/lunaix-os/includes/lunaix/process.h
+++ b/lunaix-os/includes/lunaix/process.h
@@ -12,17 +12,16 @@
 // 虽然内核不是进程，但为了区分，这里使用Pid=-1来指代内核。这主要是方便物理页所有权检查。
 #define KERNEL_PID -1
 
-#define PROC_STOPPED 0
-#define PROC_RUNNING 1
-#define PROC_TERMNAT 2
-#define PROC_DESTROY 4
-#define PROC_BLOCKED 8
-#define PROC_CREATED 16
+#define PS_STOPPED 0
+#define PS_RUNNING 1
+#define PS_TERMNAT 2
+#define PS_DESTROY 4
+#define PS_BLOCKED 8
+#define PS_CREATED 16
 
-#define PROC_TERMMASK 0x6
+#define PROC_TERMINATED(state) (state & 0x6)
 
 #define PROC_FINPAUSE 1
-#define PROC_FALRMSET (1 << 1)
 
 struct proc_mm
 {
@@ -60,6 +59,14 @@ struct proc_info
     struct llist_header siblings;
     struct llist_header children;
     struct llist_header grp_member;
+
+    struct
+    {
+        struct llist_header sleepers;
+        time_t wakeup_time;
+        time_t alarm_time;
+    } sleep;
+
     struct proc_mm mm;
     time_t created;
     uint8_t state;
@@ -71,7 +78,6 @@ struct proc_info
     int flags;
     void* sig_handler[_SIG_NUM];
     pid_t pgid;
-    struct lx_timer* timer;
 };
 
 extern volatile struct proc_info* __current;

diff --git a/lunaix-os/includes/lunaix/syscall.h b/lunaix-os/includes/lunaix/syscall.h
index e1d34030f71e39adf88084075055a4007ff2d368..b7b0d575f03130dfbcb0de799b234326c21a5373 100644 (file)
--- a/lunaix-os/includes/lunaix/syscall.h
+++ b/lunaix-os/includes/lunaix/syscall.h
@@ -18,6 +18,7 @@
 #define __SYSCALL_signal 13
 #define __SYSCALL_pause 14
 #define __SYSCALL_kill 15
+#define __SYSCALL_alarm 16
 
 #define __SYSCALL_MAX 0x100
 

diff --git a/lunaix-os/kernel/asm/x86/pfault.c b/lunaix-os/kernel/asm/x86/pfault.c
index 9e124445de45ce370e74afeb53748b1a1ee19c42..fcf373997f926dc58d73314e3df81ac02443c0dc 100644 (file)
--- a/lunaix-os/kernel/asm/x86/pfault.c
+++ b/lunaix-os/kernel/asm/x86/pfault.c
@@ -93,7 +93,7 @@ segv_term:
             ptr,
             param->cs,
             param->eip);
-    signal_send(__current->pid, _SIGSEGV);
+    __SIGSET(__current->sig_pending, _SIGSEGV);
     schedule();
     // should not reach
     while (1)

diff --git a/lunaix-os/kernel/asm/x86/syscall.S b/lunaix-os/kernel/asm/x86/syscall.S
index b323640f1cc26d056c1b36050d180bde9b7686b8..d69dd740401f823113b571587252e70ba52ccc8d 100644 (file)
--- a/lunaix-os/kernel/asm/x86/syscall.S
+++ b/lunaix-os/kernel/asm/x86/syscall.S
@@ -23,6 +23,7 @@
         .long __lxsys_signal
         .long __lxsys_pause
         .long __lxsys_kill          /* 15 */
+        .long __lxsys_alarm
         2:
         .rept __SYSCALL_MAX - (2b - 1b)/4
             .long 0

diff --git a/lunaix-os/kernel/k_init.c b/lunaix-os/kernel/k_init.c
index 447bff7feed8040ef49e087913faed4f3018c1a5..c173ad9621ae8c39002454daa6dacf2562cf08b7 100644 (file)
--- a/lunaix-os/kernel/k_init.c
+++ b/lunaix-os/kernel/k_init.c
@@ -162,7 +162,7 @@ spawn_proc0()
     commit_process(proc0);
 
     // 由于时钟中断与APIC未就绪，我们需要手动进行第一次调度。这里也会同时隐式地恢复我们的eflags.IF位
-    proc0->state = PROC_RUNNING;
+    proc0->state = PS_RUNNING;
     asm volatile("pushl %0\n"
                  "jmp switch_to\n" ::"r"(proc0));
 

diff --git a/lunaix-os/kernel/lxinit.c b/lunaix-os/kernel/lxinit.c
index fa5ce38783fc301b35e5fa0e452fcc9522acc933..91a4e504192401162709b8dafad6d11b266e8b38 100644 (file)
--- a/lunaix-os/kernel/lxinit.c
+++ b/lunaix-os/kernel/lxinit.c
@@ -33,6 +33,13 @@ sigsegv_handler(int signum)
     _exit(signum);
 }
 
+void __USER__
+sigalrm_handler(int signum)
+{
+    pid_t pid = getpid();
+    kprintf(KWARN "I, pid %d, have received an alarm!\n", pid);
+}
+
 void __USER__
 _lxinit_main()
 {
@@ -48,6 +55,9 @@ _lxinit_main()
 
     signal(_SIGCHLD, sigchild_handler);
     signal(_SIGSEGV, sigsegv_handler);
+    signal(_SIGALRM, sigalrm_handler);
+
+    alarm(5);
 
     int status;
 #ifdef WAIT_DEMO

diff --git a/lunaix-os/kernel/sched.c b/lunaix-os/kernel/sched.c
index f2ce4a28bb165d8d2907281636fe53e368f7c49d..12deb174e7c90cc3fe5b6bd07055075d21f6e3ad 100644 (file)
--- a/lunaix-os/kernel/sched.c
+++ b/lunaix-os/kernel/sched.c
@@ -44,7 +44,7 @@ sched_init()
 void
 run(struct proc_info* proc)
 {
-    proc->state = PROC_RUNNING;
+    proc->state = PS_RUNNING;
 
     /*
         将tss.esp0设置为上次调度前的esp值。
@@ -65,11 +65,7 @@ run(struct proc_info* proc)
 int
 can_schedule(struct proc_info* proc)
 {
-    if (__SIGTEST(proc->sig_pending, _SIGKILL)) {
-        // 如果进程受到SIGKILL，则直接终止，该进程不给予调度。
-        terminate_proc(PEXITNUM(PEXITSIG, _SIGKILL));
-        return 0;
-    } else if (__SIGTEST(proc->sig_pending, _SIGCONT)) {
+    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。
@@ -79,6 +75,38 @@ can_schedule(struct proc_info* proc)
     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()
 {
@@ -92,16 +120,18 @@ schedule()
     int prev_ptr = sched_ctx.procs_index;
     int ptr = prev_ptr;
 
-    if (!(__current->state & ~PROC_RUNNING)) {
-        __current->state = PROC_STOPPED;
+    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 && ptr != prev_ptr);
+    } while (next->state != PS_STOPPED && ptr != prev_ptr);
 
     sched_ctx.procs_index = ptr;
 
@@ -113,32 +143,40 @@ redo:
     run(next);
 }
 
-static void
-proc_timer_callback(struct proc_info* proc)
-{
-    proc->timer = NULL;
-    proc->state = PROC_STOPPED;
-}
-
 __DEFINE_LXSYSCALL1(unsigned int, sleep, unsigned int, seconds)
 {
-    // FIXME: sleep的实现或许需要改一下。专门绑一个计时器好像没有必要……
     if (!seconds) {
         return 0;
     }
 
-    if (__current->timer) {
-        return __current->timer->counter / timer_context()->running_frequency;
+    if (__current->sleep.wakeup_time) {
+        return (__current->sleep.wakeup_time - clock_systime()) / 1000U;
     }
 
-    struct lx_timer* timer =
-      timer_run_second(seconds, proc_timer_callback, __current, 0);
-    __current->timer = timer;
+    __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 = PROC_BLOCKED;
+    __current->state = PS_BLOCKED;
     schedule();
 }
 
+__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);
@@ -179,11 +217,11 @@ repeat:
     llist_for_each(proc, n, &__current->children, siblings)
     {
         if (!~wpid || proc->pid == wpid || proc->pgid == -wpid) {
-            if (proc->state == PROC_TERMNAT && !options) {
+            if (proc->state == PS_TERMNAT && !options) {
                 status_flags |= PEXITTERM;
                 goto done;
             }
-            if (proc->state == PROC_STOPPED && (options & WUNTRACED)) {
+            if (proc->state == PS_STOPPED && (options & WUNTRACED)) {
                 status_flags |= PEXITSTOP;
                 goto done;
             }
@@ -207,8 +245,7 @@ struct proc_info*
 alloc_process()
 {
     pid_t i = 0;
-    for (;
-         i < sched_ctx.ptable_len && sched_ctx._procs[i].state != PROC_DESTROY;
+    for (; i < sched_ctx.ptable_len && sched_ctx._procs[i].state != PS_DESTROY;
          i++)
         ;
 
@@ -223,7 +260,7 @@ alloc_process()
     struct proc_info* proc = &sched_ctx._procs[i];
     memset(proc, 0, sizeof(*proc));
 
-    proc->state = PROC_CREATED;
+    proc->state = PS_CREATED;
     proc->pid = i;
     proc->created = clock_systime();
     proc->pgid = proc->pid;
@@ -231,6 +268,7 @@ alloc_process()
     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;
 }
@@ -240,7 +278,7 @@ commit_process(struct proc_info* process)
 {
     assert(process == &sched_ctx._procs[process->pid]);
 
-    if (process->state != PROC_CREATED) {
+    if (process->state != PS_CREATED) {
         __current->k_status = LXINVL;
         return;
     }
@@ -252,7 +290,7 @@ commit_process(struct proc_info* process)
 
     llist_append(&process->parent->children, &process->siblings);
 
-    process->state = PROC_STOPPED;
+    process->state = PS_STOPPED;
 }
 
 // from <kernel/process.c>
@@ -268,7 +306,7 @@ destroy_process(pid_t pid)
         return;
     }
     struct proc_info* proc = &sched_ctx._procs[index];
-    proc->state = PROC_DESTROY;
+    proc->state = PS_DESTROY;
     llist_delete(&proc->siblings);
 
     struct mm_region *pos, *n;
@@ -289,7 +327,7 @@ destroy_process(pid_t pid)
 void
 terminate_proc(int exit_code)
 {
-    __current->state = PROC_TERMNAT;
+    __current->state = PS_TERMNAT;
     __current->exit_code = exit_code;
 
     __SIGSET(__current->parent->sig_pending, _SIGCHLD);
@@ -317,5 +355,5 @@ orphaned_proc(pid_t pid)
 
     // 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 (parent->state & PROC_TERMMASK) || parent->created > proc->created;
+    return PROC_TERMINATED(parent->state) || parent->created > proc->created;
 }
\ No newline at end of file

diff --git a/lunaix-os/kernel/signal.c b/lunaix-os/kernel/signal.c
index c3a6c07ffa89982bce3932a31652b32096dcb79e..19deff29802ba83713a6d1d2b173dc3ca9e1b256 100644 (file)
--- a/lunaix-os/kernel/signal.c
+++ b/lunaix-os/kernel/signal.c
@@ -19,6 +19,7 @@ void* default_handlers[_SIG_NUM] = {
     // TODO: 添加默认handler
     [_SIGINT] = default_sighandler_term,
     [_SIGTERM] = default_sighandler_term,
+    [_SIGKILL] = default_sighandler_term,
 };
 
 // Referenced in kernel/asm/x86/interrupt.S
@@ -105,7 +106,7 @@ send_grp:
     return 0;
 
 send_single:
-    if ((proc->state & PROC_TERMMASK)) {
+    if (PROC_TERMINATED(proc->state)) {
         __current->k_status = LXINVL;
         return -1;
     }