Add a platform for Performance Co-Pilot (PCP) metrics

This introduces an initial platform for extracting metrics
using the PCP performance metrics API - PMAPI(3).  It can
be used via the --enable-pcp=yes configure option.

So far I've added support for live localhost metrics only,
and only using pre-defined metrics already found in htop.
If available, all sampling is performed by pmcd(1) - else,
we fallback to htop doing the metric sampling itself (all
below the PMAPI).  When pmcd is used, it may be configured
to run children with elevated privileges, so htop does not
need to be setuid (authentication with pmcd is available).

Additionally, the PMAPI allows us to support archives (for
historical analysis and for automated regression tests in
htop).  We'll need platform-specific command line argument
additions, which isn't yet feasible in htop (not difficult
to add though).

The goal of this first version is minimal impact in terms
of modifying the htop codebase, to introduce key ideas in
PCP (metric namespace, metadata, APIs and so on) and give
us something to discuss, experiment with and build on.

1 files changed, 140 insertions, 0 deletions

diff --git a/pcp/PCPProcess.h b/pcp/PCPProcess.h
new file mode 100644
index 00000000..9819f5c9
--- /dev/null
+++ b/pcp/PCPProcess.h
@@ -0,0 +1,140 @@
+#ifndef HEADER_PCPProcess
+#define HEADER_PCPProcess
+/*
+htop - PCPProcess.h
+(C) 2014 Hisham H. Muhammad
+(C) 2020 htop dev team
+(C) 2020-2021 Red Hat, Inc.  All Rights Reserved.
+Released under the GNU GPLv2, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "config.h"
+
+#include <stdbool.h>
+#include <sys/types.h>
+
+#include "Object.h"
+#include "Process.h"
+#include "RichString.h"
+#include "Settings.h"
+
+#define PROCESS_FLAG_LINUX_CGROUP   0x0800
+#define PROCESS_FLAG_LINUX_OOM      0x1000
+#define PROCESS_FLAG_LINUX_SMAPS    0x2000
+#define PROCESS_FLAG_LINUX_CTXT     0x4000
+#define PROCESS_FLAG_LINUX_SECATTR  0x8000
+
+/* PCPProcessMergedCommand is populated by PCPProcess_makeCommandStr: It
+ * contains the merged Command string, and the information needed by
+ * PCPProcess_writeCommand to color the string. str will be NULL for kernel
+ * threads and zombies */
+typedef struct PCPProcessMergedCommand_ {
+   char *str;           /* merged Command string */
+   int maxLen;          /* maximum expected length of Command string */
+   int baseStart;       /* basename's start offset */
+   int baseEnd;         /* basename's end offset */
+   int commStart;       /* comm's start offset */
+   int commEnd;         /* comm's end offset */
+   int sep1;            /* first field separator, used if non-zero */
+   int sep2;            /* second field separator, used if non-zero */
+   bool separateComm;   /* whether comm is a separate field */
+   bool cmdlineChanged; /* whether cmdline changed */
+   bool commChanged;    /* whether comm changed */
+   bool prevMergeSet;   /* whether showMergedCommand was set */
+   bool prevPathSet;    /* whether showProgramPath was set */
+   bool prevCommSet;    /* whether findCommInCmdline was set */
+   bool prevCmdlineSet; /* whether findCommInCmdline was set */
+} PCPProcessMergedCommand;
+
+typedef struct PCPProcess_ {
+   Process super;
+   char *procComm;
+   int procCmdlineBasenameOffset;
+   int procCmdlineBasenameEnd;
+   PCPProcessMergedCommand mergedCommand;
+   bool isKernelThread;
+   unsigned long int cminflt;
+   unsigned long int cmajflt;
+   unsigned long long int utime;
+   unsigned long long int stime;
+   unsigned long long int cutime;
+   unsigned long long int cstime;
+   long m_share;
+   long m_pss;
+   long m_swap;
+   long m_psswp;
+   long m_trs;
+   long m_drs;
+   long m_lrs;
+   long m_dt;
+
+   /* Data read (in kilobytes) */
+   unsigned long long io_rchar;
+
+   /* Data written (in kilobytes) */
+   unsigned long long io_wchar;
+
+   /* Number of read(2) syscalls */
+   unsigned long long io_syscr;
+
+   /* Number of write(2) syscalls */
+   unsigned long long io_syscw;
+
+   /* Storage data read (in kilobytes) */
+   unsigned long long io_read_bytes;
+
+   /* Storage data written (in kilobytes) */
+   unsigned long long io_write_bytes;
+
+   /* Storage data cancelled (in kilobytes) */
+   unsigned long long io_cancelled_write_bytes;
+
+   /* Point in time of last io scan (in seconds elapsed since the Epoch) */
+   unsigned long long io_last_scan_time;
+
+   double io_rate_read_bps;
+   double io_rate_write_bps;
+   char* cgroup;
+   unsigned int oom;
+   char* ttyDevice;
+   unsigned long long int delay_read_time;
+   unsigned long long cpu_delay_total;
+   unsigned long long blkio_delay_total;
+   unsigned long long swapin_delay_total;
+   float cpu_delay_percent;
+   float blkio_delay_percent;
+   float swapin_delay_percent;
+   unsigned long ctxt_total;
+   unsigned long ctxt_diff;
+   char* secattr;
+   unsigned long long int last_mlrs_calctime;
+} PCPProcess;
+
+static inline void Process_setKernelThread(Process* this, bool truth) {
+   ((PCPProcess*)this)->isKernelThread = truth;
+}
+
+static inline bool Process_isKernelThread(const Process* this) {
+   return ((const PCPProcess*)this)->isKernelThread;
+}
+
+static inline bool Process_isUserlandThread(const Process* this) {
+   return this->pid != this->tgid;
+}
+
+extern const ProcessFieldData Process_fields[LAST_PROCESSFIELD];
+
+extern const ProcessClass PCPProcess_class;
+
+Process* PCPProcess_new(const Settings* settings);
+
+void Process_delete(Object* cast);
+
+/* This function constructs the string that is displayed by
+ * PCPProcess_writeCommand and also returned by PCPProcess_getCommandStr */
+void PCPProcess_makeCommandStr(Process *this);
+
+bool Process_isThread(const Process* this);
+
+#endif