watchdog stop() は外からコールしてjoinしないといけなかった

gistfile1.py

import ParamJsonGenerator

import time
import os,sys
import cgi

from watchdog.events import FileSystemEventHandler
from watchdog.observers import Observer

def DEBUG(msg):
    sys.stderr.write("".join(["[DEBUG] ", msg, "\n"]))

class CaptureStatus():
    def __init__(self, cams):
        self.cams = cams
        self.status = {} # key: int

        for cam in cams:
            self.status[cam] = 'wait'
        # { 0:wait
        #   1:wait
        #   2:wait }

    def showStatus(self):
        print self.status

    def setStatus(self,key,status):
        self.status[key] = status

    # True if all cameras are exit
    def is_all_exit(self):
        for key, val in self.status.iteritems():
            if val != 'exit':
                return False
        return True

class ChangeHandler(FileSystemEventHandler):
    def __init__(self, capture_status):
        self.capture_status = capture_status

    def on_created(self, event):
        if event.is_directory:
            return
        if self.getext(event.src_path) in ('.json'):
            # /tmp/cam0/cam0_capture.json
            camnum = os.path.dirname(event.src_path)[-1]
            self.capture_status.setStatus( int(camnum), 'capturing')
            DEBUG('%s has been created.' % event.src_path)
            self.capture_status.showStatus()

    def on_modified(self, event):
        if event.is_directory:
            return
        if self.getext(event.src_path) in ('.json'):
            DEBUG('%s has been modified.' % event.src_path)
            #raise Exception, 'thread terminates'

    def on_moved(self, event):
        pass
        #raise Exception, 'thread terminates'

    def on_deleted(self, event):
        if event.is_directory:
            return
        if self.getext(event.src_path) in ('.json'):
            camnum = os.path.dirname(event.src_path)[-1]
            self.capture_status.setStatus( int(camnum), 'exit')
            self.capture_status.showStatus()
            DEBUG('%s has been deleted.' % event.src_path)
            if self.capture_status.is_all_exit():
                raise Exception, 'watch termiantes'

    @staticmethod
    def getext(filename):
        return os.path.splitext(filename)[-1].lower()

def main():

    BASEDIR = './monitor'
    BASE_IMG_DIR = './data/'

    cams = [0]
    capture_status = CaptureStatus(cams)

    observer = Observer()
    event_handler = ChangeHandler(capture_status)

    observer.schedule(event_handler,BASEDIR,recursive=True)
    observer.start()

    cams = [0,1,2]
    for cam in cams:
        pj_generator = ParamJsonGenerator.ParamJsonGenerator({
            'json_dir'  : BASEDIR + '/',
           'img_dir'   : BASE_IMG_DIR,
            'fname'     : 'test',
            'fext'      : '.pgm',
            'cam_num'   : cam,
           'set_num'   : 0
        })
        pj_generator.save_json()

#    try:
#        while True:
#            time.sleep(1)
#            print capture_sta.showStatus()
#            if capture_sta.is_all_exit():
#                observer.stop()
#                break
#    except KeyboardInterrupt:
#        observer.stop()#    observer.join()

if __name__ in '__main__':
    main()
    print 'EXITED'