Add initial pass of syscall API kobjects

src/kernel/objects/kobject.cpp

@@ -0,0 +1,98 @@
+#include "j6/errors.h"
+#include "j6/signals.h"
+#include "j6/types.h"
+#include "kutil/heap_allocator.h"
+#include "objects/kobject.h"
+
+extern kutil::heap_allocator g_kernel_heap;
+
+// TODO: per-cpu this?
+static j6_koid_t next_koid;
+
+kobject::kobject(type t, j6_signal_t signals) :
+	m_koid(koid_generate(t)),
+	m_signals(signals),
+	m_observers(g_kernel_heap),
+	m_handle_count(0)
+{}
+
+kobject::~kobject()
+{
+	notify_signal_observers(0, j6_status_destroyed);
+}
+
+j6_koid_t
+kobject::koid_generate(type t)
+{
+	return (static_cast<uint64_t>(t) << 48) | next_koid++;
+}
+
+kobject::type
+kobject::koid_type(j6_koid_t koid)
+{
+	return static_cast<type>((koid >> 48) & 0xffffull);
+}
+
+void
+kobject::assert_signal(j6_signal_t s)
+{
+	m_signals |= s;
+	notify_signal_observers(s);
+}
+
+void
+kobject::deassert_signal(j6_signal_t s)
+{
+	m_signals &= ~s;
+	notify_signal_observers(s);
+}
+
+void
+kobject::register_signal_observer(observer *object, j6_signal_t s)
+{
+	m_observers.emplace(object, s);
+}
+
+void
+kobject::deregister_signal_observer(observer *object)
+{
+	for (size_t i = 0; i < m_observers.count(); ++i) {
+		auto &reg = m_observers[i];
+		if (reg.object != object) continue;
+
+		reg = m_observers[m_observers.count() - 1];
+		m_observers.remove();
+		break;
+	}
+}
+
+void
+kobject::notify_signal_observers(j6_signal_t mask, j6_status_t result)
+{
+	for (auto &reg : m_observers) {
+		if (mask == 0 || (reg.signals & mask) != 0) {
+			if (!reg.object->on_signals_changed(this, m_signals, mask, result))
+				reg.object = nullptr;
+		}
+	}
+
+	// Compact the observer list
+	long last = m_observers.count() - 1;
+	while (m_observers[last].object == nullptr && last >= 0) last--;
+
+	for (long i = 0; i < long(m_observers.count()) && i < last; ++i) {
+		auto &reg = m_observers[i];
+		if (reg.object != nullptr) continue;
+		reg = m_observers[last--];
+
+		while (m_observers[last].object == nullptr && last >= i) last--;
+	}
+
+	m_observers.set_size(last + 1);
+}
+
+void
+kobject::on_no_handles()
+{
+	assert_signal(j6_signal_no_handles);
+}