1 // -*- c-basic-offset: 4; related-file-name: "../../include/click/standard/scheduleinfo.hh" -*-
2 /*
3 * scheduleinfo.{cc,hh} -- element stores schedule parameters
4 * Benjie Chen, Eddie Kohler
5 *
6 * Copyright (c) 1999-2000 Massachusetts Institute of Technology
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, subject to the conditions
11 * listed in the Click LICENSE file. These conditions include: you must
12 * preserve this copyright notice, and you cannot mention the copyright
13 * holders in advertising related to the Software without their permission.
14 * The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
15 * notice is a summary of the Click LICENSE file; the license in that file is
16 * legally binding.
17 */
18
19 #include <click/config.h>
20 #include <click/standard/scheduleinfo.hh>
21 #include <click/nameinfo.hh>
22 #include <click/glue.hh>
23 #include <click/confparse.hh>
24 #include <click/router.hh>
25 #include <click/error.hh>
26 #include <click/nameinfo.hh>
27 CLICK_DECLS
28
ScheduleInfo()29 ScheduleInfo::ScheduleInfo()
30 {
31 #if HAVE_STRIDE_SCHED
32 static_assert((1 << FRAC_BITS) == Task::DEFAULT_TICKETS, "Stride scheduler constant issue.");
33 #endif
34 }
35
36 int
configure(Vector<String> & conf,ErrorHandler * errh)37 ScheduleInfo::configure(Vector<String> &conf, ErrorHandler *errh)
38 {
39 NameDB* db = NameInfo::getdb(NameInfo::T_SCHEDULEINFO, this, 4, true);
40
41 // compile scheduling info
42 for (int i = 0; i < conf.size(); i++) {
43 Vector<String> parts;
44 uint32_t mt;
45 cp_spacevec(conf[i], parts);
46 if (parts.size() == 0)
47 /* empty argument OK */;
48 else if (parts.size() != 2 || !FixedPointArg(FRAC_BITS).parse(parts[1], mt))
49 errh->error("expected %<ELEMENTNAME PARAM%>");
50 else
51 db->define(parts[0], &mt, 4);
52 }
53
54 return 0;
55 }
56
57 int
query(Element * e,ErrorHandler * errh)58 ScheduleInfo::query(Element *e, ErrorHandler *errh)
59 {
60 #if HAVE_STRIDE_SCHED
61 // check prefixes in order of increasing length
62 String id = e->name();
63
64 Vector<String> prefixes;
65 prefixes.push_back(String());
66 const char *slash = id.begin();
67 while ((slash = find(slash, id.end(), '/')) < id.end()) {
68 prefixes.push_back(id.substring(id.begin(), slash + 1));
69 slash++;
70 }
71 prefixes.push_back(id);
72
73 Vector<uint32_t> tickets(prefixes.size(), Task::DEFAULT_TICKETS);
74
75 NameDB *db = NameInfo::getdb(NameInfo::T_SCHEDULEINFO, e, 4, false);
76 while (db) {
77 bool frobbed = false;
78 for (int i = prefixes.size() - 1;
79 i >= 0 && prefixes[i].length() >= db->context().length();
80 i--)
81 if (db->query(prefixes[i].substring(db->context().length()), &tickets[i], 4))
82 frobbed = true;
83 else if (frobbed) // erase intermediate ticket settings
84 tickets[i] = Task::DEFAULT_TICKETS;
85 db = db->context_parent();
86 }
87
88 // multiply tickets
89 int tickets_out = tickets[0];
90 for (int i = 1; i < tickets.size(); i++)
91 if (tickets[i] != Task::DEFAULT_TICKETS)
92 #ifdef HAVE_INT64_TYPES
93 tickets_out = ((int64_t) tickets_out * tickets[i]) >> FRAC_BITS;
94 #else
95 tickets_out = (tickets_out * tickets[i]) >> FRAC_BITS;
96 #endif
97
98 // check for too many tickets
99 if (tickets_out > Task::MAX_TICKETS) {
100 tickets_out = Task::MAX_TICKETS;
101 String m = cp_unparse_real2(tickets_out, FRAC_BITS);
102 errh->warning("ScheduleInfo too high; reduced to %s", m.c_str());
103 }
104
105 // return the result you've got
106 return tickets_out;
107 #else
108 (void) e, (void) errh;
109 return 1;
110 #endif
111 }
112
113 void
initialize_task(Element * e,Task * task,bool schedule,ErrorHandler * errh)114 ScheduleInfo::initialize_task(Element *e, Task *task, bool schedule,
115 ErrorHandler *errh)
116 {
117 #if HAVE_STRIDE_SCHED
118 int tickets = query(e, errh);
119 if (tickets > 0) {
120 task->initialize(e, schedule);
121 task->set_tickets(tickets);
122 }
123 #else
124 (void) errh;
125 task->initialize(e, schedule);
126 #endif
127 }
128
129 CLICK_ENDDECLS
130 EXPORT_ELEMENT(ScheduleInfo)
131 ELEMENT_HEADER(<click/standard/scheduleinfo.hh>)
132