Kernel: Convert BlockedSignal and BlockedLurking to the new Blocker mechanism

The last two of the old block states gone :)

Kernel/Process.cpp

@@ -869,7 +869,7 @@ ssize_t Process::sys$writev(int fd, const struct iovec* iov, int iov_count)
     }
 
     if (current->has_unmasked_pending_signals()) {
-        current->block(Thread::State::BlockedSignal);
+        current->block(*new Thread::SemiPermanentBlocker(Thread::SemiPermanentBlocker::Reason::Signal));
         if (nwritten == 0)
             return -EINTR;
     }
@@ -914,7 +914,7 @@ ssize_t Process::do_write(FileDescription& description, const u8* data, int data
         if (rc == 0)
             break;
         if (current->has_unmasked_pending_signals()) {
-            current->block(Thread::State::BlockedSignal);
+            current->block(*new Thread::SemiPermanentBlocker(Thread::SemiPermanentBlocker::Reason::Signal));
             if (nwritten == 0)
                 return -EINTR;
         }
@@ -939,7 +939,7 @@ ssize_t Process::sys$write(int fd, const u8* data, ssize_t size)
         return -EBADF;
     auto nwritten = do_write(*description, data, size);
     if (current->has_unmasked_pending_signals()) {
-        current->block(Thread::State::BlockedSignal);
+        current->block(*new Thread::SemiPermanentBlocker(Thread::SemiPermanentBlocker::Reason::Signal));
         if (nwritten == 0)
             return -EINTR;
     }
@@ -1265,7 +1265,7 @@ int Process::sys$kill(pid_t pid, int signal)
     }
     if (pid == m_pid) {
         current->send_signal(signal, this);
-        current->block(Thread::State::BlockedSignal);
+        current->block(*new Thread::SemiPermanentBlocker(Thread::SemiPermanentBlocker::Reason::Signal));
         return 0;
     }
     InterruptDisabler disabler;

Kernel/Scheduler.cpp

@@ -201,6 +201,16 @@ bool Thread::WaitBlocker::should_unblock(Thread& thread, time_t, long)
     return should_unblock;
 }
 
+Thread::SemiPermanentBlocker::SemiPermanentBlocker(Reason reason)
+    : m_reason(reason)
+{}
+
+bool Thread::SemiPermanentBlocker::should_unblock(Thread&, time_t, long)
+{
+    // someone else has to unblock us
+    return false;
+}
+
 // Called by the scheduler on threads that are blocked for some reason.
 // Make a decision as to whether to unblock them or not.
 void Thread::consider_unblock(time_t now_sec, long now_usec)
@@ -215,8 +225,6 @@ void Thread::consider_unblock(time_t now_sec, long now_usec)
     case Thread::Running:
     case Thread::Dead:
     case Thread::Stopped:
-    case Thread::BlockedLurking:
-    case Thread::BlockedSignal:
         /* don't know, don't care */
         return;
     case Thread::BlockedCondition:
@@ -234,7 +242,7 @@ void Thread::consider_unblock(time_t now_sec, long now_usec)
         return;
     case Thread::Dying:
         ASSERT(g_finalizer);
-        if (g_finalizer->state() == Thread::BlockedLurking)
+        if (g_finalizer->is_blocked())
             g_finalizer->unblock();
         return;
     }

Kernel/Thread.cpp

@@ -162,10 +162,6 @@ const char* to_string(Thread::State state)
         return "Skip1";
     case Thread::Skip0SchedulerPasses:
         return "Skip0";
-    case Thread::BlockedSignal:
-        return "Signal";
-    case Thread::BlockedLurking:
-        return "Lurking";
     case Thread::BlockedCondition:
         return "Condition";
     case Thread::__Begin_Blocked_States__:
@@ -349,9 +345,7 @@ ShouldUnblockThread Thread::dispatch_signal(u8 signal)
             m_process.terminate_due_to_signal(signal);
             return ShouldUnblockThread::No;
         case DefaultSignalAction::Ignore:
-            if (state() == BlockedSignal)
-                set_state(Runnable);
-            return ShouldUnblockThread::No;
+            ASSERT_NOT_REACHED();
         case DefaultSignalAction::Continue:
             return ShouldUnblockThread::Yes;
         }

Kernel/Thread.h

@@ -65,8 +65,6 @@ public:
         Stopped,
 
         __Begin_Blocked_States__,
-        BlockedLurking,
-        BlockedSignal,
         BlockedCondition,
         __End_Blocked_States__
     };
@@ -158,6 +156,20 @@ public:
         pid_t& m_waitee_pid;
     };
 
+    class SemiPermanentBlocker : public Blocker {
+    public:
+        enum class Reason {
+            Lurking,
+            Signal,
+        };
+
+        SemiPermanentBlocker(Reason reason);
+        virtual bool should_unblock(Thread&, time_t, long) override;
+
+    private:
+        Reason m_reason;
+    };
+
     void did_schedule() { ++m_times_scheduled; }
     u32 times_scheduled() const { return m_times_scheduled; }
 

Kernel/init.cpp

@@ -242,7 +242,7 @@ extern "C" [[noreturn]] void init()
         current->process().set_priority(Process::LowPriority);
         for (;;) {
             Thread::finalize_dying_threads();
-            current->block(Thread::BlockedLurking);
+            current->block(*new Thread::SemiPermanentBlocker(Thread::SemiPermanentBlocker::Reason::Lurking));
             Scheduler::yield();
         }
     });