From 04f55519b5cd2a736eb939a12eef97a40a6c218c Mon Sep 17 00:00:00 2001
From: Mark Dewing <markdewing@gmail.com>
Date: Thu, 19 Jan 2017 14:40:56 -0600
Subject: [PATCH] Nexus: Display memory of child processes

Currently the polling output only shows the memory of the python process
running Nexus.  Show the memory used by all the child processes as well.
---
 nexus/library/memory.py          | 77 +++++++++++++++++++++++++++-----
 nexus/library/project_manager.py |  2 +-
 2 files changed, 66 insertions(+), 13 deletions(-)

diff --git a/nexus/library/memory.py b/nexus/library/memory.py
index ff3571307..ff529f8da 100644
--- a/nexus/library/memory.py
+++ b/nexus/library/memory.py
@@ -2,6 +2,11 @@
 ##  (c) Copyright 2015-  by Jaron T. Krogel                     ##
 ##################################################################
 
+######################################################################
+# The following is adapted from
+# http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/286222
+# Python Cookbook, by Jean Brouwers
+######################################################################
 
 #====================================================================#
 #  memory.py                                                         #
@@ -21,44 +26,92 @@
 
 
 import os
-_proc_status = '/proc/%d/status' % os.getpid()
 
 _scale = {'kB': 1024.0, 'mB': 1024.0*1024.0,
           'KB': 1024.0, 'MB': 1024.0*1024.0}
 
-def _VmB(VmKey):
+def _VmB(VmKey, pid=None):
     '''Private.
     '''
-    global _proc_status, _scale
+    global _scale
      # get pseudo file  /proc/<pid>/status
+ 
+    if not pid:
+        pid = os.getpid()
+    proc_status = '/proc/%d/status' % pid
     try:
-        t = open(_proc_status)
+        t = open(proc_status)
         v = t.read()
         t.close()
     except:
         return 0.0  # non-Linux?
      # get VmKey line e.g. 'VmRSS:  9999  kB\n ...'
-    i = v.index(VmKey)
-    v = v[i:].split(None, 3)  # whitespace
+    try:
+        i = v.index(VmKey)
+        v = v[i:].split(None, 3)  # whitespace
+    except ValueError:
+        return 0.0
+
     if len(v) < 3:
         return 0.0  # invalid format?
      # convert Vm value to bytes
     return float(v[1]) * _scale[v[2]]
 
+def get_children(pid):
+    proc_children = '/proc/%d/task/%d/children'%(pid,pid)
+    try:
+        t = open(proc_children,'r')
+        v = t.read()
+        t.close()
+    except:
+        return []
 
-def memory(since=0.0):
+    children = [int(c) for c in v.split()]
+    return children
+
+
+def all_children(pid=None):
+    if not pid:
+        pid = os.getpid()
+
+    child_list = get_children(pid)
+    all_list = child_list[:]
+    for child_pid in child_list:
+        child2 = all_children(child_pid)
+        all_list.extend(child2)
+    return all_list
+
+
+def memory(since=0.0, children=False):
     '''Return memory usage in bytes.
     '''
-    return _VmB('VmSize:') - since
+    mem = 0.0
+    if children:
+        for child_pid in all_children():
+            mem += _VmB('VmSize:',pid=child_pid)
+    mem += _VmB('VmSize:') - since
+    return mem
 
 
-def resident(since=0.0):
+def resident(since=0.0, children=False):
     '''Return resident memory usage in bytes.
     '''
-    return _VmB('VmRSS:') - since
+    mem = 0.0
+    if children:
+        for child_pid in all_children():
+            mem += _VmB('VmRSS:',pid=child_pid)
+
+    mem += _VmB('VmRSS:') - since
+    return mem
+    #return _VmB('VmRSS:') - since
 
 
-def stacksize(since=0.0):
+def stacksize(since=0.0, children=False):
     '''Return stack size in bytes.
     '''
-    return _VmB('VmStk:') - since
+    mem = 0.0
+    if children:
+        for child_pid in all_children():
+            mem += _VmB('VmStk:',pid=child_pid)
+    mem += _VmB('VmStk:') - since
+    return mem
diff --git a/nexus/library/project_manager.py b/nexus/library/project_manager.py
index 9d0207009..a4d78ddc9 100644
--- a/nexus/library/project_manager.py
+++ b/nexus/library/project_manager.py
@@ -100,7 +100,7 @@ class ProjectManager(NexusCore):
                 while len(self.progressing_cascades)>0:
                     elapsed_time = time.time() - start_time
                     self.log('elapsed time %.1f s'%elapsed_time,
-                             ' memory %3.2f MB'%(memory.resident()/1e6),
+                             ' memory %3.2f MB'%(memory.resident(children=True)/1e6),
                              n=1,progress=True)
                     NexusCore.wrote_something = False
                     ipoll+=1