為增強(qiáng)實(shí)時(shí)操作系統(tǒng)的防危性，在分析現(xiàn)有調(diào)度機(jī)制的基礎(chǔ)上，探討了最大關(guān)鍵度優(yōu)先的調(diào)度算法，該算法是一種混合型的優(yōu)先級(jí)實(shí)時(shí)調(diào)度算法，由靜態(tài)優(yōu)先級(jí)、動(dòng)態(tài)子優(yōu)先級(jí)和靜態(tài)子優(yōu)先級(jí)3部分組成，綜合了固定優(yōu)先級(jí)調(diào)度算法和動(dòng)態(tài)優(yōu)先級(jí)調(diào)度算法的優(yōu)點(diǎn)，既可充分利用處理器資源，又能在發(fā)生瞬時(shí)過(guò)載時(shí)保證關(guān)鍵任務(wù)不受非關(guān)鍵任務(wù)的影響，從而增強(qiáng)了實(shí)時(shí)操作系統(tǒng)的防危性。

To buildup the safety of real time operating system, after status quo of existing scheduling mechanism analyzed, brought forward a kind of novel safety scheduling mechanism based on Maximum Criticality First (MCF). MCF is a hybrid priorities real time scheduling algorithm which consisting of three parts, the first two parts are the assignment of the importance and user priority, which is done statically, the second part is the assignment of the dynamic priority based on minimum laxity first scheduling algorithm. MCF synthesizes the strongpoint of the fixed priority scheduling algorithm and the dynamic priority scheduling algorithm. By this way, MCF not only takes full advantage of resources such as CPU, also make critical task not suffer from other non critical tasks at transient overload. The safety of real time operating system is improved with MCF.