source: src/libcfa/concurrency/alarm.c@ 70c2df8

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr new-env no_list persistent-indexer pthread-emulation qualifiedEnum resolv-new with_gc
Last change on this file since 70c2df8 was 82ff5845, checked in by Thierry Delisle <tdelisle@…>, 8 years ago

First implementation of preemption, does not appear to work with scheduling

  • Property mode set to 100644
File size: 4.2 KB
Line 
1// -*- Mode: CFA -*-
2//
3// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
4//
5// The contents of this file are covered under the licence agreement in the
6// file "LICENCE" distributed with Cforall.
7//
8// alarm.c --
9//
10// Author : Thierry Delisle
11// Created On : Fri Jun 2 11:31:25 2017
12// Last Modified By : Thierry Delisle
13// Last Modified On : --
14// Update Count : 0
15//
16
17extern "C" {
18#include <errno.h>
19#include <stdio.h>
20#include <string.h>
21#include <time.h>
22#include <unistd.h>
23#include <sys/time.h>
24}
25
26#include "alarm.h"
27#include "kernel_private.h"
28#include "libhdr.h"
29#include "preemption.h"
30
31//=============================================================================================
32// Clock logic
33//=============================================================================================
34
35__cfa_time_t __kernel_get_time() {
36 timespec curr;
37 clock_gettime( CLOCK_REALTIME, &curr );
38 __cfa_time_t curr_time = ((__cfa_time_t)curr.tv_sec * TIMEGRAN) + curr.tv_nsec;
39 LIB_DEBUG_DO(
40 char text[256];
41 __attribute__((unused)) int len = snprintf( text, 256, "Kernel : current time is %lu\n", curr_time );
42 LIB_DEBUG_WRITE( STDERR_FILENO, text, len );
43 );
44 return curr_time;
45}
46
47void __kernel_set_timer( __cfa_time_t alarm ) {
48
49 LIB_DEBUG_DO(
50 char text[256];
51 __attribute__((unused)) int len = snprintf( text, 256, "Kernel : set timer to %lu\n", (__cfa_time_t)alarm );
52 LIB_DEBUG_WRITE( STDERR_FILENO, text, len );
53 );
54
55 itimerval val;
56 val.it_value.tv_sec = alarm / TIMEGRAN; // seconds
57 val.it_value.tv_usec = (alarm % TIMEGRAN) / ( TIMEGRAN / 1_000_000L ); // microseconds
58 val.it_interval.tv_sec = 0;
59 val.it_interval.tv_usec = 0;
60 setitimer( ITIMER_REAL, &val, NULL );
61}
62
63//=============================================================================================
64// Alarm logic
65//=============================================================================================
66
67void ?{}( alarm_node_t * this, thread_desc * thrd, __cfa_time_t alarm = 0, __cfa_time_t period = 0 ) {
68 this->thrd = thrd;
69 this->alarm = alarm;
70 this->period = period;
71 this->next = 0;
72 this->set = false;
73 this->kernel_alarm = false;
74}
75
76void ?{}( alarm_node_t * this, processor * proc, __cfa_time_t alarm = 0, __cfa_time_t period = 0 ) {
77 this->proc = proc;
78 this->alarm = alarm;
79 this->period = period;
80 this->next = 0;
81 this->set = false;
82 this->kernel_alarm = true;
83}
84
85void ^?{}( alarm_node_t * this ) {
86 if( this->set ) {
87 unregister_self( this );
88 }
89}
90
91static inline void insert_at( alarm_list_t * this, alarm_node_t * n, __alarm_it_t p ) {
92 assert( !n->next );
93 if( p == this->tail ) {
94 this->tail = &n->next;
95 }
96 else {
97 n->next = *p;
98 }
99 *p = n;
100}
101
102void insert( alarm_list_t * this, alarm_node_t * n ) {
103 alarm_node_t ** it = &this->head;
104 while( (*it) && (n->alarm > (*it)->alarm) ) {
105 it = &(*it)->next;
106 }
107
108 insert_at( this, n, it );
109}
110
111alarm_node_t * pop( alarm_list_t * this ) {
112 alarm_node_t * head = this->head;
113 if( head ) {
114 this->head = head->next;
115 if( !head->next ) {
116 this->tail = &this->head;
117 }
118 head->next = NULL;
119 }
120 return head;
121}
122
123static inline void remove_at( alarm_list_t * this, alarm_node_t * n, __alarm_it_t it ) {
124 assert( it );
125 assert( (*it)->next == n );
126
127 (*it)->next = n->next;
128 if( !n-> next ) {
129 this->tail = it;
130 }
131 n->next = NULL;
132}
133
134static inline void remove( alarm_list_t * this, alarm_node_t * n ) {
135 alarm_node_t ** it = &this->head;
136 while( (*it) && (*it)->next != n ) {
137 it = &(*it)->next;
138 }
139
140 if( *it ) { remove_at( this, n, it ); }
141}
142
143void register_self( alarm_node_t * this ) {
144 disable_interrupts();
145 assert( !systemProcessor->pending_alarm );
146 lock( &systemProcessor->alarm_lock );
147 {
148 bool first = !systemProcessor->alarms.head;
149
150 insert( &systemProcessor->alarms, this );
151 if( systemProcessor->pending_alarm ) {
152 tick_preemption();
153 }
154 if( first ) {
155 __kernel_set_timer( systemProcessor->alarms.head->alarm - __kernel_get_time() );
156 }
157 }
158 unlock( &systemProcessor->alarm_lock );
159 this->set = true;
160 enable_interrupts();
161}
162
163void unregister_self( alarm_node_t * this ) {
164 disable_interrupts();
165 lock( &systemProcessor->alarm_lock );
166 remove( &systemProcessor->alarms, this );
167 unlock( &systemProcessor->alarm_lock );
168 disable_interrupts();
169 this->set = false;
170}
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