reorganize liblitmus to be more modular

9 files changed, 280 insertions, 233 deletions

diff --git a/Makefile b/Makefile
index ac463f3..5144f52 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,10 @@ CPPFLAGS=-Wall -g
 
 LIBS= ./liblitmus.a
 
-TARGETS = showsched iotest set_rt_mode  run timeout rt_launch edfhsb liblitmus.a wait_test np_test stdump mode_test
+LIB_OBJ=  litmus.o syscalls.o sched_trace.o adaptive.o edf-hsb.o task.o kernel_iface.o
+
+TARGETS = showsched iotest set_rt_mode  run timeout rt_launch edfhsb liblitmus.a \
+          wait_test np_test stdump mode_test
 
 vpath %.h include/
 vpath %.c src/
@@ -45,5 +48,6 @@ edfhsb: liblitmus.a edf-hsb.o litmus.h edf-hsb.h hrt.o
 stdump: liblitmus.a litmus.h sched_trace.h stdump.o
         cc -o stdump  stdump.o ${LIBS}
 
-liblitmus.a: litmus.o sched_trace.o adaptive.o adaptive.h litmus.h edf-hsb.o edf-hsb.h
-        ${AR} rcs liblitmus.a litmus.o adaptive.o edf-hsb.o sched_trace.o
+liblitmus.a:  ${LIB_OBJ} adaptive.h litmus.h edf-hsb.h
+        ${AR} rcs liblitmus.a ${LIB_OBJ}
+
diff --git a/include/internal.h b/include/internal.h
new file mode 100644
index 0000000..25e1573
--- /dev/null
+++ b/include/internal.h
@@ -0,0 +1,21 @@
+#ifndef INTERNAL_H
+#define INTERNAL_H
+
+/* low level operations, not intended for API use */
+
+/* prepare a real-time task */
+typedef int (*rt_setup_fn_t)(int pid, void* arg);
+int __launch_rt_task(rt_fn_t rt_prog, void *rt_arg, 
+                     rt_setup_fn_t setup, void* setup_arg);
+
+#define check(str)       \
+        if (ret == -1) { \
+                perror(str); \
+                fprintf(stderr, \
+                        "Warning: Could not initialize LITMUS^RT, " \
+                        "%s failed.\n", str                         \
+                        ); \
+        }
+
+
+#endif
diff --git a/include/litmus.h b/include/litmus.h
index 925cb44..ff21963 100644
--- a/include/litmus.h
+++ b/include/litmus.h
@@ -126,12 +126,8 @@ int reg_ics_cb(struct ics_cb* ics_cb);
 int start_wcs(int od);
 
 /*  library functions */
-void init_litmus(void);
-/* exit is currently unused, but was needed for syscall
- * tracing and may be needed in the future. Leave it in
- * for the purpose of source code compatability.
- */
-#define exit_litmus() {}
+int  init_litmus(void);
+void exit_litmus(void);
 
 int create_rt_task(rt_fn_t rt_prog, void *arg, int cpu, int wcet, int period);
 int __create_rt_task(rt_fn_t rt_prog, void *arg, int cpu, int wcet, 
@@ -157,12 +153,4 @@ void exit_np(void);
  */
 int litmus_task_active();
 
-
-/* low level operations, not intended for API use */
-
-/* prepare a real-time task */
-typedef int (*rt_setup_fn_t)(int pid, void* arg);
-int __launch_rt_task(rt_fn_t rt_prog, void *rt_arg, 
-                     rt_setup_fn_t setup, void* setup_arg);
-
 #endif
diff --git a/include/syscalls.h b/include/syscalls.h
new file mode 100644
index 0000000..28f1a39
--- /dev/null
+++ b/include/syscalls.h
@@ -0,0 +1,38 @@
+#ifndef SYSCALLS_H
+#define SYSCALLS_H
+
+/* this is missing in newer linux/unistd.h versions */
+
+#define _syscall0(type,name) \
+type name(void) \
+{\
+        return syscall(__NR_##name);\
+}
+
+#define _syscall1(type,name,type1,arg1) \
+type name(type1 arg1) \
+{\
+        return syscall(__NR_##name, arg1);\
+}
+
+
+#define _syscall2(type,name,type1,arg1,type2,arg2) \
+type name(type1 arg1,type2 arg2) \
+{\
+        return syscall(__NR_##name, arg1, arg2);\
+}
+
+#define _syscall3(type,name,type1,arg1,type2,arg2,type3,arg3)   \
+type name(type1 arg1,type2 arg2, type3 arg3)   \
+{\
+        return syscall(__NR_##name, arg1, arg2, arg3);  \
+}
+
+#define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4)\
+type name(type1 arg1,type2 arg2, type3 arg3, type4 arg4)                \
+{\
+        return syscall(__NR_##name, arg1, arg2, arg3, arg4);    \
+}
+
+
+#endif
diff --git a/src/adaptive.c b/src/adaptive.c
index ebf662d..6a7d7a2 100644
--- a/src/adaptive.c
+++ b/src/adaptive.c
@@ -2,6 +2,9 @@
 #include <unistd.h>
 
 #include "litmus.h"
+#include "internal.h"
+#include "syscalls.h"
+
 #include "adaptive.h"
 
 #define __NR_set_service_levels         346
diff --git a/src/kernel_iface.c b/src/kernel_iface.c
new file mode 100644
index 0000000..5751ca6
--- /dev/null
+++ b/src/kernel_iface.c
@@ -0,0 +1,61 @@
+#include <stdio.h>
+
+#include "litmus.h"
+#include "internal.h"
+
+struct np_flag {
+        #define RT_PREEMPTIVE           0x2050 /* = NP */
+        #define RT_NON_PREEMPTIVE       0x4e50 /* =  P */
+        unsigned short preemptivity;
+
+        #define RT_EXIT_NP_REQUESTED    0x5251 /* = RQ */
+        unsigned short request;
+
+        unsigned int ctr;
+};
+
+int register_np_flag(struct np_flag* flag);
+int signal_exit_np(void);
+
+
+
+static struct np_flag np_flag;
+
+
+int init_kernel_iface(void)
+{
+        int ret;
+        np_flag.preemptivity = RT_PREEMPTIVE;
+        np_flag.ctr = 0;
+        ret = register_np_flag(&np_flag);
+        check("register_np_flag()");  
+        return ret;
+}
+
+static inline void barrier(void)
+{
+        __asm__ __volatile__("sfence": : :"memory");
+}
+
+void enter_np(void)
+{
+        if (++np_flag.ctr == 1)
+        {
+                np_flag.request = 0;
+                barrier();
+                np_flag.preemptivity = RT_NON_PREEMPTIVE;
+        }
+}
+
+
+void exit_np(void)
+{
+        if (--np_flag.ctr == 0)
+        {
+                np_flag.preemptivity = RT_PREEMPTIVE;
+                barrier();
+                if (np_flag.request == RT_EXIT_NP_REQUESTED)
+                        signal_exit_np();
+        }
+}
+
diff --git a/src/litmus.c b/src/litmus.c
index 531f501..4005345 100644
--- a/src/litmus.c
+++ b/src/litmus.c
@@ -1,53 +1,12 @@
-/* To get syscall() we need to define _GNU_SOURCE 
- * in modern glibc versions.
- */
-#define _GNU_SOURCE
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-#include <sys/types.h>
-#include <errno.h>
 #include <signal.h>
 #include <sys/mman.h>
 
-
-