aboutsummaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
authorChristian Cunningham <cc@localhost>2022-02-14 11:21:37 -0700
committerChristian Cunningham <cc@localhost>2022-02-14 11:21:37 -0700
commit30956118f25ae50e8427c75bb1776d9580a98cf7 (patch)
treef6786c244d24b467924fc6dea449b58460a60fdf /src
parentbbbe910a6cd7891e57e6e15ca0212f89ab230995 (diff)
Priority Inversion Protection
Diffstat (limited to 'src')
-rw-r--r--src/sys/schedule.c30
-rw-r--r--src/tests/test.c26
2 files changed, 50 insertions, 6 deletions
diff --git a/src/sys/schedule.c b/src/sys/schedule.c
index 1643670..913d66e 100644
--- a/src/sys/schedule.c
+++ b/src/sys/schedule.c
@@ -105,6 +105,10 @@ void add_thread(void* pc, void* arg, unsigned char priority)
}
trb->queue[trb->woffset++] = thread;
trb->woffset %= TQUEUE_MAX;
+ unsigned long mode = getmode() & 0x1F;
+ if (mode == 0x10) {
+ sys0(SYS_YIELD_HIGH);
+ }
}
void uart_scheduler(void)
@@ -187,6 +191,30 @@ void sched_mutex_yield(void* m)
trb->roffset %= TQUEUE_MAX;
trbm->queue[trbm->woffset++] = rthread;
trbm->woffset %= TQUEUE_MAX;
+ for (int p = 0; p < PRIORITIES; p++) {
+ struct ThreadRotBuffer* trbm = &scheduler.thread_queues[p].mwait;
+ unsigned long roffset = trbm->roffset;
+ while (roffset != trbm->woffset) {
+ if (trbm->queue[roffset]->mptr == m && trbm->queue[roffset] != rthread) {
+ trb->queue[trb->woffset++] = trbm->queue[roffset];
+ trb->woffset %= TQUEUE_MAX;
+ // Copy all next backward to fill space
+ unsigned long coffset = roffset;
+ while (coffset != trbm->woffset) {
+ trbm->queue[coffset] = trbm->queue[(coffset+1)%TQUEUE_MAX];
+ coffset++;
+ coffset %= TQUEUE_MAX;
+ }
+ if(trbm->woffset == 0)
+ trbm->woffset = TQUEUE_MAX-1;
+ else
+ trbm->woffset--;
+ return;
+ }
+ roffset++;
+ roffset %= TQUEUE_MAX;
+ }
+ }
}
void sched_mutex_resurrect(void* m)
@@ -197,7 +225,7 @@ void sched_mutex_resurrect(void* m)
while (roffset != trbm->woffset) {
if (trbm->queue[roffset]->mptr == m) {
trbm->queue[roffset]->mptr = 0;
- struct ThreadRotBuffer* trb = &scheduler.thread_queues[p].ready;
+ struct ThreadRotBuffer* trb = &scheduler.thread_queues[trbm->queue[roffset]->priority].ready;
trb->queue[trb->woffset++] = trbm->queue[roffset];
trb->woffset %= TQUEUE_MAX;
// Copy all next backward to fill space
diff --git a/src/tests/test.c b/src/tests/test.c
index 612c3e0..d828163 100644
--- a/src/tests/test.c
+++ b/src/tests/test.c
@@ -36,31 +36,47 @@ void test_entry(void)
//static struct Mutex testm = {.addr = 0, .pid = 0};
static struct Lock testm = {.pid = 0};
+void ctest1(void);
+void ctest2(void);
+void ctest3(void);
+void ctest4(void);
+
void ctest1(void)
{
uart_string("1 Started\n");
+ uart_string("1 Locking\n");
lock(&testm);
+ add_thread(ctest3, 0, 3);
+ add_thread(ctest2, 0, 2);
+ uart_string("1 Unlocking\n");
+ unlock(&testm);
uart_string("1 Finished\n");
}
void ctest2(void)
{
uart_string("2 Started\n");
+ add_thread(ctest4, 0, 3);
+ uart_string("2 Locking\n");
lock(&testm);
- uart_string("2 Finished\n");
+ uart_string("2 Unlocking\n");
unlock(&testm);
+ uart_string("2 Finished\n");
}
void ctest3(void)
{
uart_string("3 Started\n");
- unlock(&testm);
uart_string("3 Finished\n");
}
+void ctest4(void)
+{
+ uart_string("4 Started\n");
+ uart_string("4 Finished\n");
+}
+
void btest(void)
{
- add_thread(ctest1, 0, 1);
- add_thread(ctest2, 0, 2);
- add_thread(ctest3, 0, 3);
+ add_thread(ctest1, 0, 3);
}