core: add gettid() system call

We need the system call to enable multi-threaded real-time applications,
and libc doesn't provide it.

2 files changed, 8 insertions, 0 deletions

diff --git a/include/litmus.h b/include/litmus.h
index 6a1de21..c3cd51d 100644
--- a/include/litmus.h
+++ b/include/litmus.h
@@ -45,6 +45,9 @@ typedef struct rt_param {
 
 typedef int pid_t;       /* PID of a task */
 
+/* obtain the PID of a thread */
+pid_t gettid(void);
+
 /*      scheduler modes */
 #define MODE_NON_RT 0
 #define MODE_RT_RUN 1
diff --git a/src/syscalls.c b/src/syscalls.c
index a42fc62..3b2f76c 100644
--- a/src/syscalls.c
+++ b/src/syscalls.c
@@ -3,6 +3,8 @@
  */
 #define _GNU_SOURCE
 #include <unistd.h>
+#include <linux/unistd.h>
+#include <sys/types.h>
 
 #include "litmus.h"
 
@@ -36,6 +38,9 @@ struct np_flag;
 #define __NR_task_mode                  343
 
 /*      Syscall stub for setting RT mode and scheduling options */
+
+_syscall0(pid_t,   gettid);
+
 _syscall0(spolicy, sched_getpolicy);
 _syscall1(int,     set_rt_mode,       int,         arg1);
 _syscall2(int,     set_rt_task_param, pid_t,       pid,    rt_param_t*, arg1);