[kernel] Store object ids instead of full koids

In preparation for futexes, I wanted to make kobjects a bit lighter.
Storing 32 bits of object id, and 8 bits of type (and not ending the
class in a ushort for handle count, which meant all kobjects were likely
to have a bunch of pad bytes), the kobject class data is now just one 8
byte word.

Also from this, change logs that mention threads or processes from
printing the full koid to just 2 bytes of object id from both process
and thread, which makes following the logs much easier.

src/kernel/objects/kobject.cpp

@@ -7,30 +7,29 @@
 
 namespace obj {
 
-static j6_koid_t next_koids [static_cast<size_t>(kobject::type::max)] = { 0 };
+static constexpr unsigned types_count = static_cast<unsigned>(kobject::type::max);
+
+static uint32_t next_oids [types_count] = { 0 };
+
+static_assert(types_count <= (1 << kobject::koid_type_bits),
+        "kobject::koid_type_bits cannot represent all kobject types");
+
+static uint32_t
+oid_generate(kobject::type t)
+{
+    kassert(t < kobject::type::max, "Object type out of bounds");
+    unsigned type_int = static_cast<unsigned>(t);
+    return __atomic_fetch_add(&next_oids[type_int], 1, __ATOMIC_RELAXED);
+}
 
 kobject::kobject(type t) :
-    m_koid(koid_generate(t)),
+    m_handle_count {0},
-    m_handle_count(0)
+    m_type {t},
+    m_obj_id {oid_generate(t)}
 {}
 
 kobject::~kobject() {}
 
-j6_koid_t
-kobject::koid_generate(type t)
-{
-    kassert(t < type::max, "Object type out of bounds");
-    uint64_t type_int = static_cast<uint64_t>(t);
-    uint64_t id = __atomic_fetch_add(&next_koids[type_int], 1, __ATOMIC_SEQ_CST);
-    return (type_int << 48) | id;
-}
-
-kobject::type
-kobject::koid_type(j6_koid_t koid)
-{
-    return static_cast<type>((koid >> 48) & 0xffffull);
-}
-
 void
 kobject::on_no_handles()
 {

src/kernel/objects/kobject.h

@@ -23,24 +23,31 @@ public:
         max
     };
 
+    /// The koid's most significant bits represent the object's type
+    static constexpr unsigned koid_type_bits = 4;
+    static constexpr unsigned koid_type_mask = (1 << koid_type_bits) - 1;
+    static constexpr unsigned koid_type_shift = (8 * sizeof(j6_koid_t)) - koid_type_bits;
+
     kobject(type t);
     virtual ~kobject();
 
-    /// Generate a new koid for a given type
-    /// \arg t    The object type
-    /// \returns  A new unique koid
-    static j6_koid_t koid_generate(type t);
-
     /// Get the kobject type from a given koid
     /// \arg koid  An existing koid
     /// \returns   The object type for the koid
-    static type koid_type(j6_koid_t koid);
+    inline static type koid_type(j6_koid_t koid) {
+        return static_cast<type>((koid >> koid_type_shift) & koid_type_mask);
+    }
 
     /// Get this object's type
-    inline type get_type() const { return koid_type(m_koid); }
+    inline type get_type() const { return m_type; }
 
     /// Get this object's koid
-    inline j6_koid_t koid() const { return m_koid; }
+    inline j6_koid_t koid() const {
+        return (static_cast<j6_koid_t>(m_type) << koid_type_shift) | m_obj_id;
+    }
+
+    /// Get this object's type-relative object id
+    inline uint32_t obj_id() const { return m_obj_id; }
 
     /// Increment the handle refcount
     inline void handle_retain() { ++m_handle_count; }
@@ -63,8 +70,9 @@ private:
     kobject(const kobject &other) = delete;
     kobject(const kobject &&other) = delete;
 
-    j6_koid_t m_koid;
     uint16_t m_handle_count;
+    type m_type;
+    uint32_t m_obj_id;
 };
 
 } // namespace obj

src/kernel/syscalls/process.cpp

@@ -13,7 +13,7 @@ j6_status_t
 process_create(j6_handle_t *self)
 {
     process *p = construct_handle<process>(self);
-    log::info(logs::task, "Process %llx created", p->koid());
+    log::info(logs::task, "Process <%02lx> created", p->obj_id());
     return j6_status_ok;
 }
 
@@ -22,7 +22,7 @@ process_kill(process *self)
 {
     process &p = process::current();
 
-    log::info(logs::task, "Process %llx killed by process %llx", self->koid(), p.koid());
+    log::info(logs::task, "Process <%02lx> killed by process <%02lx>", self->obj_id(), p.obj_id());
     self->exit(-1u);
 
     return j6_status_ok;
@@ -32,7 +32,7 @@ j6_status_t
 process_exit(int32_t status)
 {
     process &p = process::current();
-    log::info(logs::task, "Process %llx exiting with code %d", p.koid(), status);
+    log::info(logs::task, "Process <%02lx> exiting with code %d", p.obj_id(), status);
 
     p.exit(status);
 

src/kernel/syscalls/system.cpp

@@ -24,7 +24,7 @@ j6_status_t
 log(const char *message)
 {
     thread &th = thread::current();
-    log::info(logs::syscall, "Message[%llx]: %s", th.koid(), message);
+    log::info(logs::syscall, "Message <%02lx:%02lx>: %s", th.parent().obj_id(), th.obj_id(), message);
     return j6_status_ok;
 }
 
@@ -32,7 +32,7 @@ j6_status_t
 noop()
 {
     thread &th = thread::current();
-    log::verbose(logs::syscall, "Thread %llx called noop syscall.", th.koid());
+    log::verbose(logs::syscall, "Thread <%02lx:%02lx> called noop syscall.", th.parent().obj_id(), th.koid());
     return j6_status_ok;
 }
 

src/kernel/syscalls/thread.cpp

@@ -22,8 +22,8 @@ thread_create(j6_handle_t *self, process *proc, uintptr_t stack_top, uintptr_t e
     *self = child->self_handle();
     child->set_state(thread::state::ready);
 
-    log::verbose(logs::task, "Thread %llx:%llx spawned new thread %llx:%llx",
+    log::verbose(logs::task, "Thread <%02lx:%02lx> spawned new thread <%02lx:%02lx>",
-        parent_pr.koid(), parent_th.koid(), proc->koid(), child->koid());
+        parent_pr.obj_id(), parent_th.obj_id(), proc->obj_id(), child->obj_id());
 
     return j6_status_ok;
 }
@@ -31,7 +31,7 @@ thread_create(j6_handle_t *self, process *proc, uintptr_t stack_top, uintptr_t e
 j6_status_t
 thread_kill(thread *self)
 {
-    log::verbose(logs::task, "Killing thread %llx", self->koid());
+    log::verbose(logs::task, "Killing thread <%02lx:%02lx>", self->parent().obj_id(), self->obj_id());
     self->exit();
     return j6_status_ok;
 }
@@ -46,7 +46,7 @@ j6_status_t
 thread_exit()
 {
     thread &th = thread::current();
-    log::verbose(logs::task, "Thread %llx exiting", th.koid());
+    log::verbose(logs::task, "Thread <%02lx:%02lx> exiting", th.parent().obj_id(), th.obj_id());
     th.exit();
 
     log::error(logs::task, "returned to exit syscall");
@@ -60,7 +60,7 @@ thread_sleep(uint64_t duration)
 
     uint64_t til = clock::get().value() + duration;
 
-    log::verbose(logs::task, "Thread %llx sleeping until %llu", th.koid(), til);
+    log::verbose(logs::task, "Thread <%02lx:%02lx> sleeping until %llu", th.parent().obj_id(), th.obj_id(), til);
     th.set_wake_timeout(til);
     th.block();
     return j6_status_ok;