add freebsd support.

server/pse_freebsd.go

@@ -2,11 +2,71 @@
 
 package server
 
+/*
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#include <sys/user.h>
+#include <stddef.h>
+#include <unistd.h>
+
+long pagetok(long size)
+{
+    int pageshift, pagesize;
+
+    pagesize = getpagesize();
+    pageshift = 0;
+
+    while (pagesize > 1) {
+        pageshift++;
+        pagesize >>= 1;
+    }
+
+    return (size << pageshift);
+}
+
+int getusage(double *pcpu, unsigned int *rss, unsigned int *vss)
+{
+    int mib[4], ret;
+    size_t len;
+    struct kinfo_proc kp;
+
+    len = 4;
+    sysctlnametomib("kern.proc.pid", mib, &len);
+
+    mib[3] = getpid();
+    len = sizeof(kp);
+
+    ret = sysctl(mib, 4, &kp, &len, NULL, 0);
+    if (ret != 0) {
+        return (errno);
+    }
+
+    *rss = pagetok(kp.ki_rssize);
+    *vss = kp.ki_size;
+    *pcpu = kp.ki_pctcpu;
+
+    return 0;
+}
+
+*/
+import "C"
+
+import (
+	"syscall"
+)
+
 // This is a placeholder for now.
 func procUsage(pcpu *float64, rss, vss *int64) error {
-	*pcpu = 0.0
-	*rss = 0
-	*vss = 0
+	var r, v C.uint
+	var c C.double
+
+	if ret := C.getusage(&c, &r, &v); ret != 0 {
+		return syscall.Errno(ret)
+	}
+
+	*pcpu = float64(c)
+	*rss = int64(r)
+	*vss = int64(v)
 
 	return nil
 }