Computers as Components, 2nd Edition

6.3 Priority-Based Scheduling 323

Deadline_tree

Activation_record

Data structure

Code

Activation_record

......

/* linked list, sorted by deadline */

Activation_record *processes;

/* data structure for sorting processes */

Deadline_tree *deadlines;

void expired_deadline(Activation_record *expired){

remove(expired); /* remove from the deadline-sorted list */

add(expired,expired->deadline); /* add at new deadline */

}

V

oid EDF(int current) { /* current ⫽ currently executing process */

int i;

/* turn off current process (may be turned back on) */

processes->state ⫽ READY_STATE;

/* find process to start executing */

for (alink = processes; alink !⫽ NULL; ...