85 lines
4.6 KiB
Markdown
85 lines
4.6 KiB
Markdown
|
# scheduler.h
|
||
|
|
|
||
|
|
The scheduler is responsible for switching between threads and controlling processes.
|
||
|
|
|
||
|
|
#### `scheduler_processes_chunk_T` - struct
|
||
|
|
These chunks are a combination of static array and linked list.
|
||
|
|
They store the process_T pointer for each valid `pid_t`.
|
||
|
|
|
||
|
|
| Name | Type | Description |
|
||
|
|
|------------------|------------------------------|------------------------------------------------------------------------------------|
|
||
|
|
| processes | process_T** | The array of process pointers |
|
||
|
|
| processes_bitmap | bitmap_T(reference needed) | If a bit in this bitmap is set, the _processes_ entry with the same index is valid |
|
||
|
|
| num_free_pids | uint32_t | The amount of free slots in this chunk |
|
||
|
|
| prev | scheduler_processes_chunk_T* | The previous chunk |
|
||
|
|
| next | scheduler_processes_chunk_T* | The next chunk |
|
||
|
|
|
||
|
|
|
||
|
|
#### `scheduler_T` - struct
|
||
|
|
| Name | Type | Description |
|
||
|
|
|----------------|------------------------------|--------------------------------------------------------------------|
|
||
|
|
| num_threads | uint32_t | Total amount of currently spawned threads |
|
||
|
|
| num_processes | uint32_t | Total amount of currently spawned processes |
|
||
|
|
| running_thread | thread_T* | A pointer to the currently running thread. |
|
||
|
|
| processes | scheduler_processes_chunk_T* | The first processes store chunk |
|
||
|
|
| blocked | bool | Set to true, while switching the context. Thread safety mechanism. |
|
||
|
|
| initialized | bool | Set to true, if the scheduler is initialized and started. |
|
||
|
|
|
||
|
|
#### `scheduler_init(boot_info)` - function (void)
|
||
|
|
Initializes the scheduler and performs a `nx_scheduler_start` kernel syscall.
|
||
|
|
**_boot_info_** is needed in to spawn the kernels' main process.
|
||
|
|
After this function, the whole kernel is in scheduling mode.
|
||
|
|
|
||
|
|
#### `scheduler_start(state)` - function (cpu_state_T*)
|
||
|
|
Creates and starts a thread from **_state_**.
|
||
|
|
It returns the result of a context switch, I forgot, why I did it like that.
|
||
|
|
This is basically the backend for the `nx_scheduler_start` kernel syscall.
|
||
|
|
|
||
|
|
#### `scheduler_is_initialized()` - function (bool)
|
||
|
|
Returns if the scheduler is initialized (and running) or not.
|
||
|
|
|
||
|
|
#### `scheduler_dump_info(process, indent)` - function (void)
|
||
|
|
This recursively lists information(pid, name, threads) for all child processes of **_process_**.
|
||
|
|
**_indent_** is used intern for the recursive calls and should be set to 0 initially.
|
||
|
|
|
||
|
|
#### `scheduler_register_thread(thread)` - function (thread_T*)
|
||
|
|
Registers **_thread_** in the scheduler.
|
||
|
|
|
||
|
|
#### `scheduler_pause_thread(thread)` - function (void)
|
||
|
|
Pauses **_thread_**, by removing it from the scheduling queue.
|
||
|
|
|
||
|
|
**Potential Bug:** if **_thread_** was the currently running thread,
|
||
|
|
this could cause issues, because it's _prev_ and _next_ values are nulled.
|
||
|
|
|
||
|
|
#### `scheduler_start_thread(thread)` - function (void)
|
||
|
|
Starts **_thread_**, by linking it into the scheduling queue.
|
||
|
|
|
||
|
|
#### `scheduler_kill_thread(thread)` - function (void)
|
||
|
|
Pauses and unregisters **_thread_**.
|
||
|
|
|
||
|
|
#### `scheduler_register_process(process)` - function (pid_t)
|
||
|
|
Reqisters **_process_** and returns its pid.
|
||
|
|
|
||
|
|
#### `scheduler_pause_process(process)` - function (void)
|
||
|
|
Pauses **_process_** and its threads.
|
||
|
|
|
||
|
|
#### `scheduler_start_process(process)` - function (void)
|
||
|
|
Starts **_process_** and its threads.
|
||
|
|
|
||
|
|
#### `scheduler_kill_process(process)` - function (void)
|
||
|
|
Kills **_process_** and its threads and childs.
|
||
|
|
|
||
|
|
#### `scheduler_get_process(pid)` - function (process_T*)
|
||
|
|
Returns the `process_T` pointer that is associated with **_pid_**.
|
||
|
|
|
||
|
|
#### `scheduler_get_current_thread()` - function (thread_T*)
|
||
|
|
Returns a pointer to the currently running thread.
|
||
|
|
|
||
|
|
#### `scheduler_get_current_process()` - function (process_T*)
|
||
|
|
Returns a pointer to the currently running threads process.
|
||
|
|
|
||
|
|
#### `scheduler_switch_context(state)` - function (cpu_state_T*)
|
||
|
|
Saves **_state_** in the running threads _state_ value and increments their _cpu_time_ value.
|
||
|
|
Then it sets the next thread as the running thread and returns its _state_.
|
||
|
|
This needs to be called from an interrupt handler, for the returned state to be loaded.
|