PCP: support for 'dynamic columns' added at runtime

Implements support for arbitrary Performance Co-Pilot
metrics with per-process instance domains to form new
htop columns.  The column-to-metric mappings are setup
using configuration files which will be documented via
man pages as part of a follow-up commit.

We provide an initial set of column configurations so
as to provide new capabilities to pcp-htop: including
configs for containers, open fd counts, scheduler run
queue time, tcp/udp bytes/calls sent/recv, delay acct,
virtual machine guests, detailed virtual memory, swap.

Note there is a change to the configuration file path
resolution algorithm introduced for 'dynamic meters'.
First, look in any custom PCP_HTOP_DIR location.  Then
iterate, in priority order, users home directory, then
local sysadmins files in /etc/pcp/htop, then readonly
configuration files below /usr/share/pcp/htop.  This
final location becomes the preferred place for our own
shipped meter and column files.

The Settings file (htoprc) writing code is updated to
not using the numeric identifier for dynamic columns.
The same strategy used for dynamic meters is used here
where we write Dynamic(name) so the name can be setup
once more at start.  Regular (static) columns writing
to htoprc - i.e. numerically indexed - is unchanged.

1 files changed, 9 insertions, 8 deletions

diff --git a/pcp/PCPDynamicMeter.h b/pcp/PCPDynamicMeter.h
index a7390e61..cfe488e5 100644
--- a/pcp/PCPDynamicMeter.h
+++ b/pcp/PCPDynamicMeter.h
@@ -4,25 +4,26 @@
 #include "CRT.h"
 #include "DynamicMeter.h"
 
-typedef struct {
-   unsigned int id; /* index into metric array */
+
+typedef struct PCPDynamicMetric_ {
+   size_t id; /* index into metric array */
    ColorElements color;
    char* name; /* derived metric name */
    char* label;
    char* suffix;
 } PCPDynamicMetric;
 
-typedef struct {
+typedef struct PCPDynamicMeter_ {
    DynamicMeter super;
    PCPDynamicMetric* metrics;
-   unsigned int totalMetrics;
+   size_t totalMetrics;
 } PCPDynamicMeter;
 
-typedef struct {
+typedef struct PCPDynamicMeters_ {
    Hashtable* table;
-   unsigned int count; /* count of dynamic meters discovered by scan */
-   unsigned int offset; /* start offset into the Platform metric array */
-   unsigned int cursor; /* identifier allocator for each new metric used */
+   size_t count;  /* count of dynamic meters discovered by scan */
+   size_t offset; /* start offset into the Platform metric array */
+   size_t cursor; /* identifier allocator for each new metric used */
 } PCPDynamicMeters;
 
 void PCPDynamicMeters_init(PCPDynamicMeters* meters);