<util/tls.h>

Per-thread control block (TCB): identity, priority and message box.

Every thread has one TCB slot in its space; the kernel fills the header and IPC copies messages through buf. GetTls() finds the current thread's slot.

#include <util/tls.h>

Constants

Name	Value	Description
PAGE_SIZE	4096	Page size in bytes.
TCB_HDR_SIZE	64	Bytes of TCB header before the message box.
MSG_BUF_SIZE	512	Size of a thread's message box: the most one Call() or Reply() can carry.
TCB_SLOT_SIZE	(TCB_HDR_SIZE + MSG_BUF_SIZE)	Bytes per TCB slot (576).
SLOTS_PER_PAGE	(PAGE_SIZE / TCB_SLOT_SIZE)	TCB slots per page (7).
TCB_MAX_SLOTS	255	Most threads per space; 0xFF is reserved to mean "no slot".
MAX_TCB_PAGES		Pages reserved for TCB slots in every space (37).

Structures

ThreadLocalData

One thread's TCB slot. The header is written by the kernel; treat it as read-only.

Field	Type	Description
msg_buf	void *	Address of buf, set by the kernel.
tid	Tid	Thread ID.
spid	Spid	ID of the owning space.
prio	uint8_t	Base priority.
max_prio	uint8_t	Highest priority the thread may set.
padding	uint8_t	Pads the header to TCB_HDR_SIZE.
buf	uint8_t	Message box used by Call(), Reply() and receives.