Add testcase for admission of suspended tasks

The kernel needs to be able to deal with tasks that do not make
themselves a real-time task, but get configured by some other task
instead.

3 files changed, 62 insertions, 1 deletions

diff --git a/include/litmus.h b/include/litmus.h
index 1009805..ef3fef3 100644
--- a/include/litmus.h
+++ b/include/litmus.h
@@ -18,6 +18,8 @@ extern "C" {
 
 #include "migration.h"
 
+#define SCHED_LITMUS 6
+
 void init_rt_task_param(struct rt_task* param);
 int set_rt_task_param(pid_t pid, struct rt_task* param);
 int get_rt_task_param(pid_t pid, struct rt_task* param);
diff --git a/src/task.c b/src/task.c
index 9121f0c..5f2fa26 100644
--- a/src/task.c
+++ b/src/task.c
@@ -66,7 +66,6 @@ int create_rt_task(rt_fn_t rt_prog, void *arg, int cluster, int cluster_size,
 
 
 #define SCHED_NORMAL 0
-#define SCHED_LITMUS 6
 
 int task_mode(int mode)
 {
diff --git a/tests/core_api.c b/tests/core_api.c
index fc4deb9..42529ce 100644
--- a/tests/core_api.c
+++ b/tests/core_api.c
@@ -1,6 +1,8 @@
 #include <sys/wait.h> /* for waitpid() */
 #include <unistd.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <sched.h>
 
 #include "tests.h"
 #include "litmus.h"
@@ -169,3 +171,61 @@ TESTCASE(ctrl_page_writable, ALL,
 
         ctrl_page[32] = 0x12345678;
 }
+
+
+TESTCASE(suspended_admission, LITMUS,
+         "admission control handles suspended tasks correctly")
+{
+        int child_rt,  status;
+        struct sched_param param;
+
+        int pipefd[2], err, token = 0;
+        struct rt_task params;
+
+        SYSCALL( pipe(pipefd) );
+
+        child_rt = FORK_TASK(
+                child_rt  = gettid();
+                /* make sure we are on the right CPU */
+                be_migrate_to_cpu(0);
+
+                /* carry out a blocking read to suspend */
+                err = read(pipefd[0], &token, sizeof(token));
+                ASSERT(err = sizeof(token));
+                ASSERT(token == 1234);
+
+                /* when we wake up, we should be a real-time task */
+                ASSERT( sched_getscheduler(child_rt) == SCHED_LITMUS );
+
+                SYSCALL( sleep_next_period() );
+                SYSCALL( sleep_next_period() );
+
+                exit(0);
+                );
+
+        /* give child some time to suspend */
+        SYSCALL( lt_sleep(ms2ns(100)) );
+
+        init_rt_task_param(&params);
+        params.cpu        = 0;
+        params.exec_cost  = ms2ns(10);
+        params.period     = ms2ns(100);
+
+        /* configure parameters of child */
+        SYSCALL( set_rt_task_param(child_rt, &params) );
+
+        /* make it a real-time task */
+        param.sched_priority = 0;
+        SYSCALL( sched_setscheduler(child_rt, SCHED_LITMUS, &param) );
+
+        /* should be a real-time task now */
+        ASSERT( sched_getscheduler(child_rt) == SCHED_LITMUS );
+
+        /* unblock it */
+        token = 1234;
+        ASSERT( write(pipefd[1], &token, sizeof(token)) == sizeof(token) );
+
+        /* wait for child to exit */
+        SYSCALL( waitpid(child_rt, &status, 0) );
+        ASSERT( status == 0 );
+}