SWIG：python模塊只有在部署到Apache時纔會崩潰

Question

這個問題相當有線，它讓我瘋狂。任何幫助表示讚賞！我們有一些底層C代碼，它們將被Python模塊（Python版本2.6，Django框架，版本1.4）調用。我們通過SWIG 2.0.9構建了Python綁定。我們從python manage.py shell提示中使用了它們。他們工作得很好。

如果我們運行python manage.py runserver 0.0.0.0:8001，一切仍然正常。但是，當我們將應用程序部署爲Apache虛擬主機時，Python綁定突然失敗（其他網頁沒有使用C代碼就沒有問題）。它的網址類似http://hostname.com/basic。下面是我們的conf文件：

#Listen 80 
<VirtualHost *:80> 
    ServerName hostname.com/basic 
    ServerAdmin caisj@example.com 

    ProxyRequests Off 
    <Proxy *> 
    Order deny,allow 
    Allow from all 
    </Proxy> 

    DocumentRoot /home/browser/BASIC/basic 

    Alias /static/admin /home/browser/BASIC/_py/lib/python2.6/site-packages/Django-1.4-py2.6.egg/django/contrib/admin/static/admin 
    Alias /static /home/browser/BASIC/basic/static 

    WSGIScriptAlias /basic /home/browser/BASIC/basic/basic.wsgi 
    ErrorLog /home/browser/BASIC/basic/log/basic.error.log 

    <Directory /home/browser/BASIC/basic> 
    <Files basic.wsgi> 
     Order deny,allow 
     Allow from all 
    </Files> 
    </Directory> 

    LogLevel info 
    CustomLog /home/browser/BASIC/basic/log/basic.access.log combined 

我們需要查詢的C代碼的兩倍。第一個仍然工作並返回正確的結果。但第二次審判只是崩潰。代碼停止並且沒有返回。一些代碼片段：

from some.basic import rmq  # this is the Python binding created by SWIG 
class Maxi: 
    @staticmethod 
    @contextmanager 
    def open(rmqfile): 
    driver = None 
    try: 
     driver = Maxi(rmqfile) 
     yield driver 
    finally: 
     if driver: driver.close() 

    def __init__(self, rmqfile): 
    with open(rmqfile) as f: 
     self.rmqfile = yaml.load(f) 
    self.handlers = dict() 

    # The rmq.i: 
    # int  rmq_query (rmq_track t, unsigned int p, unsigned int q); 
    # rmq_track rmq_load (char filename[]); 
    def query(self, chrom, start, end): 
    h = rmq.rmq_load(self.rmqfile[chrom])) 
    rs = rmq.rmq_query(h, start-1, end-1)  # It works and result is correct 
    rs = rmq.rmq_query(h, start-1+1, end-1+1) # !!! Crashes here !!! 
    return rs 

    def close(self): 
     for h in self.handlers.itervalues(): 
      rmq.rmq_unload(h) 

# ==== Django views code ==== 
driver = Maxi('yaml_config_file_to_load') 
result.append(driver.query('chr1', 1, 100000) 

我猜想它是由一些文件權限問題引起的。但即使我將所有Python綁定文件設置爲777，在作爲Apache虛擬主機工作時仍會失敗。

我確實嘗試刪除dirver.close()聲明，仍然失敗。在代碼追蹤之後，close()方法永遠不會被調用。

也許有一些配置會導致python綁定的生命週期管理不當。但我無法確定原因。

請幫忙。非常感謝。

==================

更新：

閱讀http://code.google.com/p/modwsgi/wiki/ApplicationIssues#Python_Simplified_GIL_State_API後，我添加到我的conf文件：

WSGISocketPrefix /var/run/wsgi 
WSGIApplicationGroup %{GLOBAL} 
WSGIPythonHome /home/browser/BASIC/_py 
<VirtualHost *:80> 
    ...... 
    WSGIApplicationGroup %{GLOBAL} 
    WSGIDaemonProcess hostname.com/basic processes=2 threads=15 display-name=%{GROUP} 
    WSGIProcessGroup hostname.com/basic 
    ...... 
</VirtualHost> 

但它報告錯誤：

Premature end of script headers: basic.wsgi 

Answer 1

終於來了！經過大量搜索並嘗試了很多之後，我解決了這個問題。這裏是我的conf文件：

# Important! My http.conf does not contain this line. So Apache seems to 
# load the mod_wsgi.so from somewhere else, which is unluckily not compatible 
# with my C codes. 
LoadModule wsgi_module modules/mod_wsgi.so 
# Place to store file for socket communications. I created the folder manually. 
WSGISocketPrefix /var/run/wsgi 
<VirtualHost *:80> 
    ...... 
    # My wsgi configuration file 
    WSGIScriptAlias /basic /home/browser/BASIC/basic/basic.wsgi 
    # Make the virtual host using only one Python sub interpreter. 
    WSGIApplicationGroup %{GLOBAL} 
    # Make it run under the daemon mode 
    WSGIDaemonProcess hostname.com/basic processes=1 threads=15 display-name=%{GROUP} \ 
    python-path=/home/browser/BASIC/_py/lib/python2.6/site-packages 
    WSGIProcessGroup hostname.com/basic 
    ...... 
</VirtualHost> 

Answer 2

SWIG問題的解決方案記錄在這裏：

• http://code.google.com/p/modwsgi/wiki/ApplicationIssues#Python_Simplified_GIL_State_API

還要確保您閱讀：

• http://blog.dscpl.com.au/2012/10/why-are-you-using-embedded-mode-of.html