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[kernel] Store object ids instead of full koids

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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.
This commit is contained in:
Justin C. Miller
2022-10-20 22:41:16 -07:00
parent 6583744532
commit 372bc1d2e6
5 changed files with 44 additions and 37 deletions
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35
src/kernel/objects/kobject.cpp
View File

@@ -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()
{

26
src/kernel/objects/kobject.h
View File

@@ -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