Module thread_ops 

Thread lifecycle operations shared by the syscall layer and /thread VFS scheme.

Extracted from syscall/process.rs so that both SYS_THREAD_CREATE/JOIN/EXIT and the Plan 9 style /thread/* scheme forward to the exact same internal implementation (no duplicated WaitQueue, no duplicated validation).

Also owns the kernel-owned user stack bookkeeping: threads created via /thread/create get their user stack allocated and mapped by the kernel, which reclaims it deterministically when the thread dies. Threads created through raw SYS_THREAD_CREATE keep providing their own stack and leave the field untouched.

Structs

ThreadUserContext 🔒

UserEntryContext

Caller’s userspace segment/flag state used to seed the child iret frame.

Constants

THREAD_DEFAULT_STACK_BYTES

Default size when the caller passes stack_size == 0.

THREAD_MAX_STACK_BYTES

THREAD_MIN_STACK_BYTES

Bounds of a kernel-owned user stack request.

THREAD_OFF_ARG0 🔒

THREAD_OFF_ENTRY 🔒

THREAD_OFF_STACK_TOP 🔒

THREAD_OFF_USER_CS 🔒

THREAD_OFF_USER_RFLAGS 🔒

THREAD_OFF_USER_SS 🔒

USER_TOP_EXCLUSIVE 🔒

Statics

KERNEL_USER_STACKS_ACTIVE 🔒

Number of kernel-owned user stacks currently alive (allocated - reclaimed).

KERNEL_USER_STACKS_ALLOCATED 🔒

Total number of kernel-owned user stacks ever allocated.

Functions

alloc_kernel_user_stack 🔒

Allocate and lazily map a user stack in the parent process address space.

build_user_thread_task 🔒

Performs the build user thread task operation.

create_user_thread

Core of SYS_THREAD_CREATE and /thread/create.

create_user_thread_inner 🔒

create_user_thread_with_kernel_stack

/thread/create variant: the kernel allocates and owns the user stack.

current_thread_tid

Current TID of the calling task (scheme /thread/current fast path).

exit_current_thread

Core of SYS_THREAD_EXIT and /thread/exit.

join_task

Core of SYS_THREAD_JOIN and /thread/join/<tid>.

kernel_user_stack_stats

Snapshot of kernel-owned user stack counters (allocated_total, active).

kill_thread

Kill a thread by TID, restricted to threads of the caller’s own process.

page_align_up 🔒

reclaim_kernel_user_stack

Reclaim the kernel-owned user stack of task, if any.

thread_child_start 🔒

Performs the thread child start operation.

thread_iret_from_ctx 🔒 ^⚠

Performs the thread iret from ctx operation.