Thread Group Based Multithreading; Deferred Task Disposal; Misc; Bugs Fixed.#79
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Thread Group Based Multithreading; Deferred Task Disposal; Misc; Bugs Fixed.#79
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Pull request overview
This PR restructures the kernel's task model around thread groups instead of per-task parent/child links, then threads that new topology through clone/exit/wait/accounting paths and scheduler/trap cleanup hooks. It fits into the kernel's core process-management layer by changing how processes, threads, exit state, and deferred destruction are represented and observed.
Changes:
- Split task topology into dedicated thread-group and parent/child modules, plus deferred task disposal support.
- Updated task syscalls and lifecycle flows (
clone,execve,exit,exit_group,wait4,getpid,getppid,gettid,times) to use thread-group semantics. - Added supporting ABI/kernel plumbing, scheduler/trap cleanup hooks, and a few platform/config updates.
Reviewed changes
Copilot reviewed 46 out of 47 changed files in this pull request and generated 8 comments.
Show a summary per file
| File | Description |
|---|---|
| conf/platforms/qemu-virt-rv64.toml | Adjusts example QEMU rootfs drive path for RV64. |
| conf/platforms/qemu-virt-la64.toml | Adjusts example QEMU rootfs drive path for LA64. |
| anemone-kernel/src/time/api/times.rs | Switches times(2) accounting to thread-group CPU usage. |
| anemone-kernel/src/task/topology/thread_group.rs | Adds thread-group/member APIs and dethreading logic. |
| anemone-kernel/src/task/topology/parent_child.rs | Adds inter-thread-group parent/child traversal and reaping helpers. |
| anemone-kernel/src/task/topology/mod.rs | Replaces old topology core with thread-group-aware publishing/lookup. |
| anemone-kernel/src/task/topology/deferred.rs | Introduces deferred task disposal queue and helpers. |
| anemone-kernel/src/task/topology.rs | Removes old monolithic topology implementation. |
| anemone-kernel/src/task/tid.rs | Adds typed accessor for TidHandle. |
| anemone-kernel/src/task/task.rs | Removes old standalone task definition file. |
| anemone-kernel/src/task/sig/mod.rs | Adds placeholder signal module. |
| anemone-kernel/src/task/mod.rs | Inlines/refactors task and thread-group core types and constructors. |
| anemone-kernel/src/task/fs.rs | Renames FS-state copy helper to fork. |
| anemone-kernel/src/task/files.rs | Renames file-table copy helper to fork. |
| anemone-kernel/src/task/cpu_usage.rs | Splits task vs thread-group CPU accounting. |
| anemone-kernel/src/task/api/wait4.rs | Reworks wait/reap semantics around child thread groups. |
| anemone-kernel/src/task/api/mod.rs | Registers new gettid syscall module. |
| anemone-kernel/src/task/api/gettid.rs | Adds gettid(2) syscall handler. |
| anemone-kernel/src/task/api/getppid.rs | Returns parent thread-group ID instead of old task parent. |
| anemone-kernel/src/task/api/getpid.rs | Returns TGID for getpid(2). |
| anemone-kernel/src/task/api/exit/mod.rs | Reworks thread/task exit, exit-group, reparenting, and cleanup. |
| anemone-kernel/src/task/api/exit/exit_group.rs | Wires syscall to new kernel_exit_group. |
| anemone-kernel/src/task/api/exit/exit.rs | Wires syscall to new ExitCode-based exit path. |
| anemone-kernel/src/task/api/execve/kernel.rs | Dethreads before exec and reorders address-space activation. |
| anemone-kernel/src/task/api/clone/mod.rs | Adds thread-group-aware clone validation, setup, and publish flow. |
| anemone-kernel/src/task/api/clone/clone.rs | Inlines syscall preparse tracing and logging tweaks. |
| anemone-kernel/src/syserror.rs | Adds Interrupted / EINTR. |
| anemone-kernel/src/sync/spinlock.rs | Adds SpinLock::into_inner. |
| anemone-kernel/src/sync/rwlock.rs | Adds RwLock::into_inner. |
| anemone-kernel/src/sched/mod.rs | Defers disposal from scheduler loop and adds notify. |
| anemone-kernel/src/sched/event.rs | Makes waits stop on killed tasks and documents lock expectations. |
| anemone-kernel/src/mm/uspace/fault.rs | Uses thread-group exit on fatal user page faults. |
| anemone-kernel/src/main.rs | Changes KUnit startup behavior in BSP init path. |
| anemone-kernel/src/exception/ipi.rs | Cleans now-unused task import. |
| anemone-kernel/src/arch/riscv64/sched.rs | Adapts kernel-thread exit call to ExitCode. |
| anemone-kernel/src/arch/riscv64/exception/trap/utrap.rs | Adds killed-task exit and deferred disposal on user trap return. |
| anemone-kernel/src/arch/riscv64/exception/trap/ktrap.rs | Adds killed-task exit and deferred disposal on kernel trap return. |
| anemone-kernel/src/arch/riscv64/bootstrap.rs | Publishes init/AP tasks with new thread-group-aware API. |
| anemone-kernel/src/arch/loongarch64/sched.rs | Adapts kernel-thread exit call to ExitCode. |
| anemone-kernel/src/arch/loongarch64/exception/trap/utrap.rs | Adds killed-task exit and deferred disposal on user trap return. |
| anemone-kernel/src/arch/loongarch64/exception/trap/ktrap.rs | Adds killed-task exit and deferred disposal on kernel trap return. |
| anemone-kernel/src/arch/loongarch64/bootstrap.rs | Publishes init/AP tasks with new thread-group-aware API. |
| anemone-abi/src/syscall/riscv.rs | Adds RISC-V syscall number for gettid. |
| anemone-abi/src/syscall/loongarch.rs | Adds LoongArch syscall number for gettid. |
| anemone-abi/src/process.rs | Adds newer clone flag constants to ABI. |
| .vscode/settings.json | Switches default rust-analyzer target selection. |
| .gitignore | Broadens ignored rootfs config file pattern. |
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| pub fn cpu_usage_snapshot(&self) -> ThreadGroupCpuUsage { | ||
| let mut snapshot = self.inner.read_irqsave().cpu_usage; | ||
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| pub fn on_reap_child(&self, child: &Task) { | ||
| self.for_each_member(|member| { | ||
| let member_cpu_usage = member.cpu_usage_snapshot(); | ||
| snapshot.accumulate_member_usage(&member_cpu_usage); | ||
| }); | ||
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| snapshot |
| #[cfg(feature = "kunit")] | ||
| { | ||
| crate::debug::kunit::kunit_runner(); | ||
| // crate::debug::kunit::kunit_runner(); |
| # "-no-reboot", | ||
| # "-drive", | ||
| # "file=build/rootfs/minimal/rootfs.img,format=raw,if=none,id=x1", | ||
| # "file=build/rootfs/minimal-rv/rootfs.img,format=raw,if=none,id=x1", |
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| # "-drive", | ||
| # "file=build/rootfs/minimal/rootfs.img,format=raw,if=none,id=x1", | ||
| # "file=build/rootfs/minimal-la/rootfs.img,format=raw,if=none,id=x1", |
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| /// This function is unsafe because: | ||
| /// * The parent task of the created task is set to [None] by default. | ||
| /// However, according to the task tree structure, there could be only | ||
| /// one root task whose `parent` is [None]. Casually creating multiple | ||
| /// root tasks will break the task hierarchy and cause undefined | ||
| /// behavior. |
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| if flags.contains(CloneFlags::PARENT_SETTID) { | ||
| if let Some(parent_tid) = parent_tid { | ||
| // again, map_err cannot be used here. | ||
| if let Err(e) = parent_tid.safe_write(new_tid) { | ||
| let _ = unsafe { Box::from_raw(frame_ptr) }; | ||
| unsafe { guard.forget() }; | ||
| defer_to_dispose(Arc::new(new_task)); | ||
| return Err(e); | ||
| } | ||
| } else { | ||
| // this is valid. it's user's responsibility to provide a valid pointer if they | ||
| // set the flag. | ||
| kdebugln!( | ||
| "clone: PARENT_SETTID flag is set, but parent_tid pointer is null. ignoring..." | ||
| ); | ||
| } | ||
| } | ||
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| match guard.publish(new_task, binding) { |
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| if tg.ntasks() == 0 { | ||
| // this may happen, even though above exists a check for matched_any. | ||
| // consider following scenario: | ||
| // - thread A and B are waiting for the only child C. | ||
| // - C exits, A and B are both woken up. | ||
| // - A gets the lock first, reaps C successfully and returns. | ||
| // - B gets the lock later, fails to find C. now there are no children, but B | ||
| // did match C. -ECHILD should be returned in this case, since 0 is for "no | ||
| // child reaped but there are still matching children". | ||
| return Err(SysError::ChildNotFound); |
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| let mut topology = TOPOLOGY.inner.write_irqsave(); | ||
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| let child_tg = topology.thread_groups.remove(&child_tgid)?; | ||
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| assert!( | ||
| matches!( | ||
| child_tg.status().life_cycle(), | ||
| ThreadGroupLifeCycle::Exited(_) | ||
| ), | ||
| "task topology: child thread group {} is not exited yet when reaping", | ||
| child_tgid | ||
| ); | ||
| assert!( | ||
| child_tg.parent_tgid() == Some(self.tgid()), |
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