top: refactor 3 routines ahead of the separate threads

This commit sets the stage for turning three functions
into code that can support a separate thread to update
their respective data while working in the background.

It involved relocating 1 function, renaming 2 routines
and adding parameters plus return addresses to each of
three functions. Those latter changes will be required
when issuing 'pthread_create' calls in the next patch.

The final step was organizing this code into what will
become the infinite do-while loop supporting a thread.

Signed-off-by: Jim Warner <james.warner@comcast.net>

top/top.c

@@ -2356,9 +2356,10 @@ static void zap_fieldstab (void) {
          * This guy's responsible for interfacing with the library <stat> API
          * and reaping all cpu or numa node tics.
          * ( his task is now embarassingly small under the new api ) */
-static void cpus_refresh (void) {
+static void *cpus_refresh (void *unused) {
    enum stat_reap_type which;
 
+   do {
       which = STAT_REAP_CPUS_ONLY;
       if (CHKw(Curwin, View_CPUNOD))
          which = STAT_REAP_NUMA_NODES_TOO;
@@ -2379,14 +2380,39 @@ static void cpus_refresh (void) {
          Cpu_cnt = 48;
 #endif
       }
-   return;
+   } while (0);
+   return NULL;
+   (void)unused;
 } // end: cpus_refresh
 
 
+        /*
+         * This serves as our interface to the memory portion of libprocps.
+         * The sampling frequency is reduced in order to minimize overhead. */
+static void *memory_refresh (void *unused) {
+   static time_t sav_secs;
+   time_t cur_secs;
+
+   do {
+      if (Frames_signal)
+         sav_secs = 0;
+      cur_secs = time(NULL);
+
+      if (3 <= cur_secs - sav_secs) {
+         if (!(Mem_stack = procps_meminfo_select(Mem_ctx, Mem_items, MAXTBL(Mem_items))))
+            error_exit(fmtmk(N_fmt(LIB_errormem_fmt),__LINE__, strerror(errno)));
+         sav_secs = cur_secs;
+      }
+   } while (0);
+   return NULL;
+   (void)unused;
+} // end: memory_refresh
+
+
         /*
          * This guy's responsible for interfacing with the library <pids> API
          * then refreshing the WIN_t ptr arrays, growing them as appropirate. */
-static void procs_refresh (void) {
+static void *tasks_refresh (void *unused) {
  #define nALIGN(n,m) (((n + m - 1) / m) * m)     // unconditionally align
  #define nALGN2(n,m) ((n + m - 1) & ~(m - 1))    // with power of 2 align
  #define n_reap  Pids_reap->counts->total
@@ -2396,6 +2422,7 @@ static void procs_refresh (void) {
    float et;
    int i, what;
 
+   do {
       procps_uptime(&uptime_cur, NULL);
       et = uptime_cur - uptime_sav;
       if (et < 0.01) et = 0.005;
@@ -2424,29 +2451,13 @@ static void procs_refresh (void) {
          for (i = 0; i < GROUPSMAX; i++)
             memcpy(Winstk[i].ppt, Pids_reap->stacks, sizeof(void *) * PIDSmaxt);
       }
+   } while (0);
+   return NULL;
+   (void)unused;
  #undef nALIGN
  #undef nALGN2
  #undef n_reap
-} // end: procs_refresh
+} // end: tasks_refresh
-
-
-        /*
-         * This serves as our interface to the memory portion of libprocps.
-         * The sampling frequency is reduced in order to minimize overhead. */
-static void sysinfo_refresh (int forced) {
-   static time_t sav_secs;
-   time_t cur_secs;
-
-   if (forced)
-      sav_secs = 0;
-   cur_secs = time(NULL);
-
-   if (3 <= cur_secs - sav_secs) {
-      if (!(Mem_stack = procps_meminfo_select(Mem_ctx, Mem_items, MAXTBL(Mem_items))))
-         error_exit(fmtmk(N_fmt(LIB_errormem_fmt),__LINE__, strerror(errno)));
-      sav_secs = cur_secs;
-   }
-} // end: sysinfo_refresh
 
 /*######  Inspect Other Output  ##########################################*/
 
@@ -5586,7 +5597,6 @@ static void do_key (int ch) {
 
    show_msg(N_txt(UNKNOWN_cmds_txt));
 all_done:
-   sysinfo_refresh(1);       // let's be more responsive to hot-pluggin'
    putp((Cursor_state = Cap_curs_hide));
 } // end: do_key
 
@@ -6258,15 +6268,15 @@ static void frame_make (void) {
 
    // whoa either first time or thread/task mode change, (re)prime the pump...
    if (Pseudo_row == PROC_XTRA) {
-      procs_refresh();
+      tasks_refresh(NULL);
       usleep(LIB_USLEEP);
       putp(Cap_clr_scr);
    } else
       putp(Batch ? "\n\n" : Cap_home);
 
-   sysinfo_refresh(0);
+   cpus_refresh(NULL);
-   procs_refresh();
+   memory_refresh(NULL);
-   cpus_refresh();
+   tasks_refresh(NULL);
 
    Tree_idx = Pseudo_row = Msg_row = scrlins = 0;
    summary_show();

top/top.h

@@ -628,9 +628,9 @@ typedef struct WIN_t {
 //atic inline void   widths_resize (void);
 //atic void          zap_fieldstab (void);
 /*------  Library Interface  ---------------------------------------------*/
-//atic void          cpus_refresh (void);
+//atic void         *cpus_refresh (void *unused);
-//atic void          procs_refresh (void);
+//atic void         *memory_refresh (void *unused);
-//atic void          sysinfo_refresh (int forced);
+//atic void         *tasks_refresh (void *unused);
 /*------  Inspect Other Output  ------------------------------------------*/
 //atic void          insp_cnt_nl (void);
 #ifndef INSP_OFFDEMO