os: implement loadavg (not working on cygwin/win)

include/uv.h

@@ -1044,6 +1044,9 @@ struct uv_fs_event_s {
 };
 
 
+/* Gets load avg */
+void uv_loadavg(double avg[3]);
+
 /*
 * If filename is a directory then we will watch for all events in that
 * directory. If filename is a file - we will only get events from that

src/unix/cygwin.c

@@ -36,6 +36,11 @@ uint64_t uv_hrtime() {
   return (ts.tv_sec * NANOSEC + ts.tv_nsec);
 }
 
+void uv_loadavg(double avg[3]) {
+  /* Unsupported as of cygwin 1.7.7 */
+  avg[0] = avg[1] = avg[2] = 0;
+}
+
 
 int uv_exepath(char* buffer, size_t* size) {
   uint32_t usize;

src/unix/darwin.c

@@ -30,6 +30,9 @@
 #include <mach/mach_time.h>
 #include <mach-o/dyld.h> /* _NSGetExecutablePath */
 
+#include <sys/resource.h>
+#include <sys/sysctl.h>
+
 
 uint64_t uv_hrtime() {
   uint64_t time;
@@ -92,6 +95,17 @@ double uv_get_total_memory(void) {
   return (double) info;
 }
 
+void uv_loadavg(double avg[3]) {
+  struct loadavg info;
+  size_t size = sizeof(info);
+  int which[] = {CTL_VM, VM_LOADAVG};
+
+  if (sysctl(which, 2, &info, &size, NULL, 0) < 0) return;
+
+  avg[0] = (double) info.ldavg[0] / info.fscale;
+  avg[1] = (double) info.ldavg[1] / info.fscale;
+  avg[2] = (double) info.ldavg[2] / info.fscale;
+}
 
 int uv_fs_event_init(uv_loop_t* loop,
                      uv_fs_event_t* handle,

src/unix/freebsd.c

@@ -25,6 +25,7 @@
 #include <errno.h>
 
 #include <sys/types.h>
+#include <sys/resource.h>
 #include <sys/sysctl.h>
 #include <time.h>
 
@@ -92,6 +93,17 @@ double uv_get_total_memory(void) {
   return (double) info;
 }
 
+void uv_loadavg(double avg[3]) {
+  struct loadavg info;
+  size_t size = sizeof(info);
+  int which[] = {CTL_VM, VM_LOADAVG};
+
+  if (sysctl(which, 2, &info, &size, NULL, 0) < 0) return;
+
+  avg[0] = (double) info.ldavg[0] / info.fscale;
+  avg[1] = (double) info.ldavg[1] / info.fscale;
+  avg[2] = (double) info.ldavg[2] / info.fscale;
+}
 
 int uv_fs_event_init(uv_loop_t* loop,
                      uv_fs_event_t* handle,

src/unix/linux.c

@@ -28,6 +28,7 @@
 #include <errno.h>
 
 #include <sys/inotify.h>
+#include <sys/sysinfo.h>
 #include <unistd.h>
 #include <time.h>
 
@@ -52,6 +53,16 @@ uint64_t uv_hrtime() {
   return (ts.tv_sec * NANOSEC + ts.tv_nsec);
 }
 
+void uv_loadavg(double avg[3]) {
+  struct sysinfo info;
+
+  if (sysinfo(&info) < 0) return;
+
+  avg[0] = (double) info.loads[0] / 65536.0;
+  avg[1] = (double) info.loads[1] / 65536.0;
+  avg[2] = (double) info.loads[2] / 65536.0;
+}
+
 
 int uv_exepath(char* buffer, size_t* size) {
   if (!buffer || !size) {

src/unix/netbsd.c

@@ -24,6 +24,7 @@
 #include <string.h>
 #include <errno.h>
 
+#include <sys/resource.h>
 #include <sys/types.h>
 #include <sys/sysctl.h>
 
@@ -40,6 +41,17 @@ uint64_t uv_hrtime(void) {
   return (ts.tv_sec * NANOSEC + ts.tv_nsec);
 }
 
+void uv_loadavg(double avg[3]) {
+  struct loadavg info;
+  size_t size = sizeof(info);
+  int which[] = {CTL_VM, VM_LOADAVG};
+
+  if (sysctl(which, 2, &info, &size, NULL, 0) < 0) return;
+
+  avg[0] = (double) info.ldavg[0] / info.fscale;
+  avg[1] = (double) info.ldavg[1] / info.fscale;
+  avg[2] = (double) info.ldavg[2] / info.fscale;
+}
 
 int uv_exepath(char* buffer, size_t* size) {
   uint32_t usize;

src/unix/sunos.c

@@ -27,6 +27,7 @@
 #include <errno.h>
 
 #include <sys/time.h>
+#include <sys/loadavg.h>
 #include <unistd.h>
 #include <kstat.h>
 
@@ -93,6 +94,10 @@ double uv_get_total_memory(void) {
   return (double) sysconf(_SC_PAGESIZE) * sysconf(_SC_PHYS_PAGES);
 }
 
+void uv_loadavg(double avg[3]) {
+  (void) getloadavg(avg, 3);
+}
+
 
 int uv_fs_event_init(uv_loop_t* loop,
                      uv_fs_event_t* handle,

src/win/util.c

@@ -95,6 +95,11 @@ done:
   return retVal;
 }
 
+void uv_loadavg(double avg[3]) {
+  /* Can't be implemented */
+  avg[0] = avg[1] = avg[2] = 0;
+}
+
 double uv_get_free_memory(void) {
   MEMORYSTATUSEX memory_status;
   memory_status.dwLength = sizeof(memory_status);

test/test-get-loadavg.c

@@ -0,0 +1,36 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "uv.h"
+#include "task.h"
+
+TEST_IMPL(get_loadavg) {
+
+  double avg[3];
+  uv_loadavg(avg);
+
+  ASSERT(avg != NULL);
+  ASSERT(avg[0] >= 0);
+  ASSERT(avg[1] >= 0);
+  ASSERT(avg[2] >= 0);
+
+  return 0;
+}

test/test-list.h

@@ -61,6 +61,7 @@ TEST_DECLARE   (idle_starvation)
 TEST_DECLARE   (loop_handles)
 TEST_DECLARE   (ref)
 TEST_DECLARE   (idle_ref)
+TEST_DECLARE   (get_loadavg)
 TEST_DECLARE   (async_ref)
 TEST_DECLARE   (prepare_ref)
 TEST_DECLARE   (check_ref)
@@ -188,6 +189,8 @@ TASK_LIST_START
 
   TEST_ENTRY  (get_memory)
 
+  TEST_ENTRY  (get_loadavg)
+
   TEST_ENTRY  (hrtime)
 
   TEST_ENTRY  (getaddrinfo_basic)

uv.gyp

@@ -241,6 +241,7 @@
         'test/run-tests.c',
         'test/runner.c',
         'test/runner.h',
+        'test/test-get-loadavg.c',
         'test/task.h',
         'test/test-async.c',
         'test/test-callback-stack.c',