某計(jì)算機(jī)系統(tǒng)中有一個(gè)CPU、一臺(tái)掃描儀和一臺(tái)打印機(jī)?,F(xiàn)有3個(gè)圖像任務(wù),每個(gè)任務(wù)有3個(gè)程序段:掃描Si,圖像處理Ci和打印Pi(i=1,2,3)。如圖1-15所示為3個(gè)任務(wù)各程序段并發(fā)執(zhí)行的前驅(qū)圖,其中,(1)可并行執(zhí)行,(2)的直接制約,(3)的間接制約。
A."C1S2","P1C2S3","P2C3"
B."C1S1","S2C2P2","C3P3"
C."S1C1P1","S2C2P2","S3C3P3"
D."S1S2S3","C1C2C3","P1P2P3"