top: exploit that meminfo dynamic chain allocation API

The commit msg summary says it all (well, not really).

The previous statically allocated results chain served
the top program perfectly in all its lib memory needs.
But, someone needs to try out the brand new interface.

Besides, there were a few other changes which I wanted
to make. And among them were the following miscellany:

. some names were changed, like 'context' became 'ctx'

. an unnecessary redundant library call was eliminated

. the placement of a few globals was made more logical
( thanks Craig for following the capitalization rule )

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

diff --git a/top/top.c b/top/top.c
index e10fa9917b4e75d923cbc06707e9fc13c0879b35..bb3a304729ee8e7bd136a6a9ded25b98e6f28c69 100644 (file)
--- a/top/top.c
+++ b/top/top.c
@@ -66,9 +66,6 @@
 
 /*######  Miscellaneous global stuff  ####################################*/
 
-static long Hertz;
-static long Page_size;
-
         /* The original and new terminal definitions
            (only set when not in 'Batch' mode) */
 static struct termios Tty_original,    // our inherited terminal definition
@@ -93,9 +90,11 @@ static RCF_t Rc = DEF_RCFILE;
 static int   Rc_questions;
 
         /* The run-time acquired page stuff */
+static long     Page_size;
 static unsigned Pg2K_shft = 0;
 
-        /* SMP, Irix/Solaris mode, Linux 2.5.xx support */
+        /* SMP, Irix/Solaris mode, Linux 2.5.xx support (and beyond) */
+static long        Hertz;
 static int         Cpu_cnt;
 static int         Cpu_faux_cnt;
 static float       Cpu_pmax;
@@ -252,25 +251,19 @@ static const char Graph_bars[] = "||||||||||||||||||||||||||||||||||||||||||||||
 
         /* Support for the new library API -- acquired (if necessary)
            at program startup and referenced throughout our lifetime */
-static struct procps_meminfo *Mem_context;
-static struct meminfo_result Mem_chain[] = {
-   { PROCPS_MEM_FREE,      0, &Mem_chain[1] },
-   { PROCPS_MEM_USED,      0, &Mem_chain[2] },
-   { PROCPS_MEM_TOTAL,     0, &Mem_chain[3] },
-   { PROCPS_MEM_CACHED,    0, &Mem_chain[4] },
-   { PROCPS_MEM_BUFFERS,   0, &Mem_chain[5] },
-   { PROCPS_MEM_AVAILABLE, 0, &Mem_chain[6] },
-   { PROCPS_SWAP_TOTAL,    0, &Mem_chain[7] },
-   { PROCPS_SWAP_FREE,     0, &Mem_chain[8] },
-   { PROCPS_SWAP_USED,     0, NULL          }
-};
-enum mem_enums {
+static struct procps_meminfo *Mem_ctx;
+static struct meminfo_chain *Mem_chain;
+static enum meminfo_item Mem_items[] = {
+   PROCPS_MEM_FREE,   PROCPS_MEM_USED,    PROCPS_MEM_TOTAL,
+   PROCPS_MEM_CACHED, PROCPS_MEM_BUFFERS, PROCPS_MEM_AVAILABLE,
+   PROCPS_SWAP_TOTAL, PROCPS_SWAP_FREE,   PROCPS_SWAP_USED };
+enum Rel_items {
    mem_FREE,  mem_USED,  mem_TOTAL, mem_CACHE, mem_BUFFS,
    mem_AVAIL, swp_TOTAL, swp_FREE,  swp_USED
 };
-#define MEM_VAL(e) Mem_chain[e].result
+#define MEM_VAL(e) Mem_chain->head[e].result
 
-static struct procps_stat *Cpu_context;
+static struct procps_stat *Cpu_ctx;
 static struct procps_jiffs_hist *Cpu_jiffs;
 \f
 /*######  Sort callbacks  ################################################*/
@@ -579,8 +572,8 @@ static void bye_bye (const char *str) {
 #endif // end: ATEOJ_RPTHSH
 #endif // end: OFF_HST_HASH
 
-   procps_stat_unref(&Cpu_context);
-   procps_meminfo_unref(&Mem_context);
+   procps_stat_unref(&Cpu_ctx);
+   procps_meminfo_unref(&Mem_ctx);
 #ifndef NUMA_DISABLE
   if (Libnuma_handle) dlclose(Libnuma_handle);
 #endif
@@ -2401,13 +2394,13 @@ static void cpus_refresh (void) {
    }
 
    // 1st, snapshot the proc/stat cpu jiffs
-   if (procps_stat_read_jiffs(Cpu_context) < 0)
+   if (procps_stat_read_jiffs(Cpu_ctx) < 0)
       error_exit(N_txt(LIB_errorcpu_txt));
    // 2nd, retrieve just the cpu summary jiffs
-   if (procps_stat_get_jiffs_hist(Cpu_context, &Cpu_jiffs[sumSLOT], -1) < 0)
+   if (procps_stat_get_jiffs_hist(Cpu_ctx, &Cpu_jiffs[sumSLOT], -1) < 0)
       error_exit(N_txt(LIB_errorcpu_txt));
    // 3rd, retrieve all of the actual cpu jiffs
-   Cpu_faux_cnt = procps_stat_get_jiffs_hist_all(Cpu_context, Cpu_jiffs, sumSLOT);
+   Cpu_faux_cnt = procps_stat_get_jiffs_hist_all(Cpu_ctx, Cpu_jiffs, sumSLOT);
    if (Cpu_faux_cnt < 0)
       error_exit(N_txt(LIB_errorcpu_txt));
 
@@ -2670,10 +2663,9 @@ static void sysinfo_refresh (int forced) {
 
    /*** hotplug_acclimated ***/
    if (3 <= cur_secs - mem_secs) {
-      if ((procps_meminfo_read(Mem_context) < 0)
-         || (procps_meminfo_get_chain(Mem_context, Mem_chain) < 0))
-            error_exit(N_txt(LIB_errormem_txt));
-      procps_meminfo_get_chain(Mem_context, Mem_chain);
+      // 'chain_fill' also implies 'read', saving us one more call
+      if ((procps_meminfo_chain_fill(Mem_ctx, Mem_chain) < 0))
+         error_exit(N_txt(LIB_errormem_txt));
       mem_secs = cur_secs;
    }
 #ifndef PRETEND8CPUS
@@ -3271,9 +3263,11 @@ static void before (char *me) {
    while (i > 1024) { i >>= 1; Pg2K_shft++; }
 
    // prepare for new library API ...
-   if (procps_meminfo_new(&Mem_context) < 0)
+   if (procps_meminfo_new(&Mem_ctx) < 0)
+      error_exit(N_txt(LIB_errormem_txt));
+   if (!(Mem_chain = procps_meminfo_chain_alloc(Mem_ctx, MAXTBL(Mem_items), Mem_items)))
       error_exit(N_txt(LIB_errormem_txt));
-   if (procps_stat_new(&Cpu_context) < 0)
+   if (procps_stat_new(&Cpu_ctx) < 0)
       error_exit(N_txt(LIB_errorcpu_txt));
 
 #ifndef OFF_HST_HASH