Change to using gopsutil for cross-OS process ops

Instead of trying to write out own code to do basic process
operations (e.g. checking if a PID is still running in a multi-OS
friendly manner), use shirou/gopsutil, a multi-platform library
that should abstract all the complexity away. Unlike our previous
approach on Windows, this one should actually work.

Signed-off-by: Matt Heon <mheon@redhat.com>

vendor/github.com/power-devops/perfstat/c_helpers.c

@@ -0,0 +1,159 @@
+#include "c_helpers.h"
+
+GETFUNC(cpu)
+GETFUNC(disk)
+GETFUNC(diskadapter)
+GETFUNC(diskpath)
+GETFUNC(fcstat)
+GETFUNC(logicalvolume)
+GETFUNC(memory_page)
+GETFUNC(netadapter)
+GETFUNC(netbuffer)
+GETFUNC(netinterface)
+GETFUNC(pagingspace)
+GETFUNC(process)
+GETFUNC(thread)
+GETFUNC(volumegroup)
+
+double get_partition_mhz(perfstat_partition_config_t pinfo) {
+	return pinfo.processorMHz;
+}
+
+char *get_ps_hostname(perfstat_pagingspace_t *ps) {
+	return ps->u.nfs_paging.hostname;
+}
+
+char *get_ps_filename(perfstat_pagingspace_t *ps) {
+	return ps->u.nfs_paging.filename;
+}
+
+char *get_ps_vgname(perfstat_pagingspace_t *ps) {
+	return ps->u.lv_paging.vgname;
+}
+
+time_t boottime()
+{
+        register struct utmpx *utmp;
+
+	setutxent();
+        while ( (utmp = getutxent()) != NULL ) {
+                if (utmp->ut_type == BOOT_TIME) {
+                        return utmp->ut_tv.tv_sec;
+                }
+        }
+	endutxent();
+        return -1;
+}
+
+struct fsinfo *get_filesystem_stat(struct fsinfo *fs_all, int n) {
+	if (!fs_all) return NULL;
+	return &(fs_all[n]);
+}
+
+int get_mounts(struct vmount **vmountpp) {
+        int size;
+        struct vmount *vm;
+        int nmounts;
+
+        size = BUFSIZ;
+
+        while (1) {
+                if ((vm = (struct vmount *)malloc((size_t)size)) == NULL) {
+                        perror("malloc failed");
+                        exit(-1);
+                }
+                if ((nmounts = mntctl(MCTL_QUERY, size, (caddr_t)vm)) > 0) {
+                        *vmountpp = vm;
+                        return nmounts;
+                } else if (nmounts == 0) {
+                        size = *(int *)vm;
+                        free((void *)vm);
+                } else {
+                        free((void *)vm);
+                        return -1;
+                }
+        }
+}
+
+void fill_fsinfo(struct statfs statbuf, struct fsinfo *fs) {
+        fsblkcnt_t freeblks, totblks, usedblks;
+        fsblkcnt_t tinodes, ninodes, ifree;
+        uint    cfactor;
+
+        if (statbuf.f_blocks == -1) {
+                fs->totalblks = 0;
+                fs->freeblks = 0;
+                fs->totalinodes = 0;
+                fs->freeinodes = 0;
+                return;
+        }
+
+        cfactor = statbuf.f_bsize / 512;
+        fs->freeblks = statbuf.f_bavail * cfactor;
+        fs->totalblks = statbuf.f_blocks * cfactor;
+
+        fs->freeinodes = statbuf.f_ffree;
+        fs->totalinodes = statbuf.f_files;
+
+        if (fs->freeblks < 0)
+                fs->freeblks = 0;
+}
+
+int getfsinfo(char *fsname, char *devname, char *host, char *options, int flags, int fstype, struct fsinfo *fs) {
+        struct statfs statbuf;
+	int devname_size = strlen(devname);
+	int fsname_size = strlen(fsname);
+        char buf[BUFSIZ];
+        char *p;
+
+        if (fs == NULL) {
+                return 1;
+        }
+
+        for (p = strtok(options, ","); p != NULL; p = strtok(NULL, ","))
+                if (strcmp(p, "ignore") == 0)
+                        return 0;
+
+        if (*host != 0 && strcmp(host, "-") != 0) {
+                sprintf(buf, "%s:%s", host, devname);
+                devname = buf;
+        }
+        fs->devname = (char *)calloc(devname_size+1, 1);
+        fs->fsname = (char *)calloc(fsname_size+1, 1);
+        strncpy(fs->devname, devname, devname_size);
+        strncpy(fs->fsname, fsname, fsname_size);
+	fs->flags = flags;
+	fs->fstype = fstype;
+
+        if (statfs(fsname,&statbuf) < 0) {
+                return 1;
+        }
+
+        fill_fsinfo(statbuf, fs);
+        return 0;
+}
+
+struct fsinfo *get_all_fs(int *rc) {
+        struct vmount *mnt;
+        struct fsinfo *fs_all;
+        int nmounts;
+
+        *rc = -1;
+        if ((nmounts = get_mounts(&mnt)) <= 0) {
+                perror("Can't get mount table info");
+                return NULL;
+        }
+
+        fs_all = (struct fsinfo *)calloc(sizeof(struct fsinfo), nmounts);
+        while ((*rc)++, nmounts--) {
+                getfsinfo(vmt2dataptr(mnt, VMT_STUB),
+                          vmt2dataptr(mnt, VMT_OBJECT),
+                          vmt2dataptr(mnt, VMT_HOST),
+                          vmt2dataptr(mnt, VMT_ARGS),
+			  mnt->vmt_flags,
+			  mnt->vmt_gfstype,
+                          &fs_all[*rc]);
+                mnt = (struct vmount *)((char *)mnt + mnt->vmt_length);
+        }
+        return fs_all;
+}