Initial structure of shmem segment

src/slurmd/shmem_struct.h

+#ifndef _SHMEM_STRUCT_H
+#define _SHMEM_STRUCT_H 
+
+typedef struct slurmd_shmem
+{
+	pthread_mutex mutex;
+	task_desc tasks[128];
+} slurmd_shmem_t ;
+#endif