Message passing / mail system

libmsl/m/system.h

@@ -65,4 +65,16 @@ int read (const char* path, size_t off, uint8_t* buffer, size_t size);
 /* describe a file */
 int describe (const char* path, struct fs_desc_buffer* desc);
 
+/* send a message to a procgroup's mail */
+int mail_send (int pgid, void* mesg, size_t mesg_size);
+
+/* receive a message from mail */
+int mail_receive (void* mesg, size_t mesg_size);
+
+/* get procgroup id of a perticular process */
+int get_procgroup (int pid);
+
+/* get PID of process, which exec'ed the current process */
+int get_exec_pid (void);
+
 #endif // _LIBMSL_M_SYSTEM_H