1 use crate::{ 2 arch::CurrentIrqArch, 3 exception::InterruptArch, 4 process::ProcessManager, 5 smp::core::smp_get_processor_id, 6 syscall::{Syscall, SystemError}, 7 }; 8 9 use super::core::{do_sched, CPU_EXECUTING}; 10 11 impl Syscall { 12 /// @brief 让系统立即运行调度器的系统调用 13 /// 请注意，该系统调用不能由ring3的程序发起 14 #[inline(always)] 15 pub fn sched(from_user: bool) -> Result<usize, SystemError> { 16 let irq_guard = unsafe { CurrentIrqArch::save_and_disable_irq() }; 17 18 // 进行权限校验，拒绝用户态发起调度 19 if from_user { 20 return Err(SystemError::EPERM); 21 } 22 // 根据调度结果统一进行切换 23 let pcb = do_sched(); 24 25 if pcb.is_some() { 26 let next_pcb = pcb.unwrap(); 27 let current_pcb = ProcessManager::current_pcb(); 28 29 if current_pcb.pid() != next_pcb.pid() { 30 CPU_EXECUTING.set(smp_get_processor_id(), next_pcb.pid()); 31 unsafe { ProcessManager::switch_process(current_pcb, next_pcb) }; 32 } 33 } 34 drop(irq_guard); 35 return Ok(0); 36 } 37 } 38