PR6930: stapio: support file switching

Add file-switching option(-S size[,N]) to stapio. This option has two
arguments, 'size' and 'N', and requires -o option.

- When the size of output file exceeds specified 'size'MB, staprun switches
 output file to the next file. For this purpose, all output file has a serial
 number as a suffix only when user specifies this option.

- Using this option in bulk mode, the output file name will be
 'FILE_cpuX.SERIAL'.

- When the number of files exceeds specified N, staprun removes the oldest
 file. This argument can be omitted.

1 files changed, 4 insertions, 11 deletions

diff --git a/runtime/staprun/mainloop.c b/runtime/staprun/mainloop.c
index b0d88073..c80bbba4 100644
--- a/runtime/staprun/mainloop.c
+++ b/runtime/staprun/mainloop.c
@@ -489,18 +489,11 @@ int stp_main_loop(void)
     switch (type) {
 #ifdef STP_OLD_TRANSPORT
     case STP_REALTIME_DATA:
-      {
-        ssize_t bw = write(out_fd[0], data, nb);
-        if (bw >= 0 && bw != nb) {
-          nb = nb - bw;
-          bw = write(out_fd[0], data, nb);
-        }
-        if (bw != nb) {
-          _perr("write error (nb=%ld)", (long)nb);
-          cleanup_and_exit(0);
-        }
-        break;
+      if (write_realtime_data(data, nb)) {
+        _perr("write error (nb=%ld)", (long)nb);
+        cleanup_and_exit(0);
       }
+      break;
 #endif
     case STP_OOB_DATA:
       eprintf("%s", (char *)data);