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

@@ -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)
+    try:
-    v = v[i:].split(None, 3)  # whitespace
+        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

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