#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright (C) 2003-2009 Edgewall Software
# Copyright (C) 2003-2004 Jonas Borgström <jonas@edgewall.com>
# All rights reserved.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at http://trac.edgewall.org/wiki/TracLicense.
#
# This software consists of voluntary contributions made by many
# individuals. For the exact contribution history, see the revision
# history and logs, available at http://trac.edgewall.org/log/.
#
# Author: Jonas Borgström <jonas@edgewall.com>

from trac.web._fcgi import WSGIServer
from trac.web._fcgi import Connection
from trac.web.main import dispatch_request
import threading
import time
import gc
import os
import signal

_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):
    '''Private.
    '''
    global _proc_status, _scale
     # get pseudo file  /proc/<pid>/status
    try:
        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
    if len(v) < 3:
        return 0.0  # invalid format?
     # convert Vm value to bytes
    return float(v[1]) * _scale[v[2]]


def memory(since=0.0):
    '''Return memory usage in bytes.
    '''
    return _VmB('VmSize:') - since


def resident(since=0.0):
    '''Return resident memory usage in bytes.
    '''
    return _VmB('VmRSS:') - since


def stacksize(since=0.0):
    '''Return stack size in bytes.
    '''
    return _VmB('VmStk:') - since

connectionCount = 0
connectionLock = threading.Lock()

class CountConnection(Connection):
    def __init__(self, sock, addr, server):
        global connectionCount
        connectionLock.acquire()
        connectionCount = connectionCount+1
        connectionLock.release()
        super(CountConnection, self).__init__(sock, addr, server)
    def run(self):
        global connectionCount
        super(CountConnection, self).run()
        connectionLock.acquire()
        connectionCount = connectionCount-1
        connectionLock.release()

class GCWSGIServer(WSGIServer):
    def __init__(self, application, **kw):
        super(GCWSGIServer, self).__init__(application, **kw)
        self._connectionClass = CountConnection
        self.loopCount = 0

    def _mainloopPeriodic(self):
        global connectionCount
        if(self.loopCount == 100):
            self.loopCount = 0
        else:
            self.loopCount = self.loopCount + 1
        if(self.loopCount == 100 and resident() > 1024*1024*90):
            os.kill(os.getppid(), signal.SIGUSR1)
#            print 'count is ', connectionCount
#            time.sleep(1)
            start = time.time()
            while(connectionCount > 0 and time.time() < start + 30):
                time.sleep(0.01)
#                print 'count is ', connectionCount
#                print 'waiting on:'
#                for t in threading.enumerate():
#                    print 'thread: ', t.getName()
#            main_thread = threading.currentThread()
#            for t in threading.enumerate():
#                print 'thread: '
#                print t.getName()
#                if t is not main_thread:
#                    try:
#                        t.join()
#                    except:
#                        pass
            self._keepGoing = False
            #gc.collect()
            #self.loopCount=0
#            print 'done exiting'
#    def _restoreSignalHandlers(self):
#        print 'restore'
#        super(GCWSGIServer, self)._restoreSignalHandlers()
#    def _cleanupSocket(self, sock):
#        print 'cleanup'
#        super(GCWSGIServer, self)._cleanupSocket(sock)

try:
    import os
    import pkg_resources
    if 'TRAC_ENV' not in os.environ and \
       'TRAC_ENV_PARENT_DIR' not in os.environ:
        os.environ['TRAC_ENV'] = '/var/trac/perian'
    if 'PYTHON_EGG_CACHE' not in os.environ:
        if 'TRAC_ENV' in os.environ:
            egg_cache = os.path.join(os.environ['TRAC_ENV'], '.egg-cache')
        elif 'TRAC_ENV_PARENT_DIR' in os.environ:
            egg_cache = os.path.join(os.environ['TRAC_ENV_PARENT_DIR'], 
                                     '.egg-cache')
        pkg_resources.set_extraction_path(egg_cache)
    from trac.web import fcgi_frontend
#    fcgi_frontend.run()
    params = {};
    GCWSGIServer(dispatch_request, **params).run()
#    print 'done'
except SystemExit:
    raise
except Exception, e:
    print 'Content-Type: text/plain\r\n\r\n',
    print 'Oops...'
    print
    print 'Trac detected an internal error:'
    print
    print e
    print
    import traceback
    import StringIO
    tb = StringIO.StringIO()
    traceback.print_exc(file=tb)
    print tb.getvalue()