gSoap 多线程实验报告( SOAP 协议栈的多线程实验报告)

 

gSoap 多线程实验报告

一、开发环境（客户端、服务器端均相同）

 

硬件环境：

AMD 3200+ 2.0G + 512M DDR + 10/100M 以太网卡

 

软件环境：

Operating System：Windows XP sp2

Compiler： Visual C++ 6.0

SOAP SDK： gSoap 2.7.9c

Multithread Library： pthread-2.5.0-win32-release

SSL Library: OpenSSL 0.9.7m

 

二、gSoap多线程程序的编写

2.1 服务器端程序的编写

 

对于服务器端，首先调用soap_ssl_server_contex完成SSL上下文环境的初始化，然后等待客户端发出服务请求。当主线程中检测到客户端发出新的SOAP请求时，调用 struct soap *soap_copy(struct soap *soap) 函数创建新的soap 运行时环境(Runtime enviroment),新创建的 soap 与原先的soap runtime enviroment 是相互独立的，因此在多线程环境中各个线程可以独立处理 SOAP 请求而互不干涉。要在gSoap的服务器端支持OpenSSL，必须在调用soap_accept后继续调用soap_ssl_accept函数。在soap_ssl_accept 验证后服务器和客户端建立安全的SSL通道，然后主线程调用 pthread_create 创建新的线程来完成SOAP服务。一个基本的服务器框架如下所示。

注意：要在多线程的环境中使用OpenSSL，必须使用到这两个例程CRYPTO_thread_setup()和CRYPTO_thread_cleanup()。附录中给出了在Win32 和 POSIX 的这两个例程的实现代码。

 

int main()
{
   int m, s;
   pthread_t tid;
   struct soap soap, *tsoap;
   soap_ssl_init(); /* init OpenSSL (just once) */

/* Note: CRYPTO_thread_setup() must be called in multi-thread environment */
   if (CRYPTO_thread_setup())
   {
      fprintf(stderr, "Cannot setup thread mutex/n");
      exit(1);
   }
   soap_init(&soap);
   if (soap_ssl_server_context(&soap,
      SOAP_SSL_DEFAULT,
      "server.pem", /* keyfile: required when server must authenticate to clients (see SSL docs on how to obtain this file) */
      "password", /* password to read the key file */
      "cacert.pem", /* optional cacert file to store trusted certificates */
      NULL, /* optional capath to directory with trusted certificates */
      "dh512.pem", /* DH file, if NULL use RSA */
      NULL, /* if randfile!=NULL: use a file with random data to seed randomness */
      NULL /* optional server identification to enable SSL session cache (must be a unique name) */    ))
   {
      soap_print_fault(&soap, stderr);
      exit(1);
   }
   m = soap_bind(&soap, NULL, 18000, 100); // use port 18000
   if (m < 0)
   {
      soap_print_fault(&soap, stderr);
      exit(1);
   }
   fprintf(stderr, "Socket connection successful: master socket = %d/n", m);
   for (;;)
   {
      s = soap_accept(&soap);
      fprintf(stderr, "Socket connection successful: slave socket = %d/n", s);
      if (s < 0)
      {
         soap_print_fault(&soap, stderr);
         break;
      }
      tsoap = soap_copy(&soap); /* should call soap_ssl_accept on a copy */
      if (!tsoap)
         break;
      if (soap_ssl_accept(tsoap))
      {
         soap_print_fault(tsoap, stderr);
         soap_free(tsoap);
         continue; /* when soap_ssl_accept fails, we should just go on */
      }
      pthread_create(&tid, NULL, &process_request, (void*)tsoap);
   }
   soap_done(&soap); /* deallocates SSL context */
   CRYPTO_thread_cleanup();
   return 0;
}
void *process_request(void *soap)
{
   pthread_detach(pthread_self());
   soap_serve((struct soap*)soap);
   soap_destroy((struct soap*)soap);
   soap_end((struct soap*)soap);
   soap_done((struct soap*)soap);
   free(soap);
   return NULL;
}

 

2.2 客户端程序的编写

客户端中，使用 #define MAX_THREAD 来定义最大的线程数。主线程使用pthread_create()创建 MAX_THREAD个线程。新线程创建后，调用soap_ssl_client_context初始化SSL上下文环境。SSL 验证通过后，服务器端和客户端线程之间建立SSL通道，之后客户端发出SOAP服务请求。多线程的客户端程序框架如下所示。

同样地，为了在多线程环境中使用使用OpenSSL，必须使用到这两个例程CRYPTO_thread_setup()和CRYPTO_thread_cleanup()。

 

int main(void)

{

       int i=0;

       for(i=0; i<MAX_THREAD; i++)

       {

              /* create the threads to send the SOAP request */

              THREAD_CREATE(tid[i],(void(*)(void*))test,NULL);

       }

/* stay forever for the sub-threads to execute */

       while (1)

       {

              /* Do something here. */

       }

       return 0;

}

void test()

{

struct soap soap;

struct _ns1__Query q;

struct _ns1__QueryResponse response;

 

struct _ns1__Pay p;

struct _ns1__PayResponse p_res;

 

/* Init OpenSSL */

 

soap_ssl_init();

 

/* Note: CRYPTO_thread_setup() must be called in multi-thread environment */

if (CRYPTO_thread_setup())

{ fprintf(stderr, "Cannot setup thread mutex/n");

exit(1);

}

 

if (soap_ssl_client_context(&soap,

    SOAP_SSL_REQUIRE_SERVER_AUTHENTICATION|SOAP_SSL_SKIP_HOST_CHECK|SOAP_SSL_REQUIRE_CLIENT_AUTHENTICATION ,//| SOAP_SSL_SKIP_HOST_CHECK, /* use SOAP_SSL_DEFAULT in production code, we don't want the host name checks since these will change from machine to machine */

    "client2003.pem",//NULL,               /* keyfile: required only when client must authenticate to server (see SSL docs on how to obtain this file) */

    "crusader",//NULL,            /* password to read the keyfile */

    "ca2003.pem",       /* optional cacert file to store trusted certificates, use cacerts.pem for all public certificates issued by common CAs */

    NULL,        /* optional capath to directory with trusted certificates */

    NULL          /* if randfile!=NULL: use a file with random data to seed randomness */

       ))

{ soap_print_fault(&soap, stderr);

exit(1);

}

 

while(1)

{

 

       /* the thread must stop for a while. Will be explaned later */

       Sleep(1000);

       q.UserID =”test”;;

       q.Pasword = "test";

       q.QueryType = 100;

/* send the SOAP request to query */

       if (soap_call___ns1__query(&soap,server,"",&q,&response)==SOAP_OK)

       {

       printf("Status=%d,Amount=%d,SerialNO=%d/n",response.Status,response.Amount,response.SerialNO);

       }

       else

       {

              soap_print_fault(&soap, stderr);

       }

      

  

       srand((int)time(NULL));

       p.Amount = rand()%10000+300;   

       p.Password =”password”;

       p.PayType = rand()%4;

       p.Description =”descrpition”;

       p.UserID = names[rand()%4];

/* send the request to pay */

       if (soap_call___ns1__pay(&soap,server,"",&p,&p_res)==SOAP_OK)

       {

       printf("Status=%d,Amount=%d,SerialNO=%d/n",p_res.Status,p_res.Amount,p_res.SerialNO);

       }

       else

       {

              soap_print_fault(&soap, stderr);

       }

}

 

soap_destroy(&soap); /* C++ */

soap_end(&soap);

soap_done(&soap);

CRYPTO_thread_cleanup();

}

 

三、实验结果及分析

实验中我们发现：虽然我们可以在客户端中开启大量的线程（如设置最大线程数MAX_THREAD=200），但我们如果使用netstat命令来观察socket连接时可以看到：实际上同一时刻只有部分线程的socket 的状态是 ESTABLISHED（已连接），其他的socket处于TIME_WAIT状态。查阅资料后总结原因：服务器的一个端口监听多个socket 连接的soap_bind(struct soap *soap, char *host, int port, int backlog) 函数中的backlog指定了请求的队列大小。backlog的值受到系统的限制（在Linux下默认为128，在Windows下，根据MSDN 的内容，没有确定值）。当同一时刻有大量的线程发送请求时，队列过小无法处理所有的请求，部分线程要等待服务器处理完原有的队列后才能得到服务。如：在MAX_THREAD=300的情况下，某一时刻，真正接受服务的线程只有 125 个。同时我们在实验中也可以看到，在MAX_THREAD=300 的情况下，所有的线程都能够得到服务，但各个线程得到的服务的次数有些差别，如：某一时刻，得到最多服务次数的线程完成服务次数为399次，而得到最少服务次数的线程完成服务次数为364次。

实验中我们还发现，在gSoap完成请求并断开socket之后，原有的socket并不能立即被重用，必须等待一定的时间（该值可以在注册表中设置：HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Tcpip/Parameters/ TcpTimedWaitDelay。 取值范围为30-240s）在客户端开启线程较多的情况下，socket没有立即回收导致socket资源很快就耗竭的问题。我们通过在客户端程序中的每次SOAP请求之后调用Sleep(1000)，降低请求频率来解决这个问题。

 

 

 

 

 

 

 

 

 

四、附录

CRYPTO_thread_setup() 和CRYPTO_thread_cleanup() 的实现代码。

#include < unistd.h > /* defines _POSIX_THREADS if pthreads are available */
#ifdef _POSIX_THREADS
# include < pthread.h >
#endif
#if defined(WIN32)
# define MUTEX_TYPE HANDLE
# define MUTEX_SETUP(x) (x) = CreateMutex(NULL, FALSE, NULL)
# define MUTEX_CLEANUP(x) CloseHandle(x)
# define MUTEX_LOCK(x) WaitForSingleObject((x), INFINITE)
# define MUTEX_UNLOCK(x) ReleaseMutex(x)
# define THREAD_ID GetCurrentThreadID()
#elif defined(_POSIX_THREADS)
# define MUTEX_TYPE pthread_mutex_t
# define MUTEX_SETUP(x) pthread_mutex_init(&(x), NULL)
# define MUTEX_CLEANUP(x) pthread_mutex_destroy(&(x))
# define MUTEX_LOCK(x) pthread_mutex_lock(&(x))
# define MUTEX_UNLOCK(x) pthread_mutex_unlock(&(x))
# define THREAD_ID pthread_self()
#else
# error "You must define mutex operations appropriate for your platform"
# error "See OpenSSL /threads/th-lock.c on how to implement mutex on your platform"
#endif
struct CRYPTO_dynlock_value { MUTEX_TYPE mutex; };
static MUTEX_TYPE *mutex_buf;
static struct CRYPTO_dynlock_value *dyn_create_function(const char *file, int line)
{
   struct CRYPTO_dynlock_value *value;
   value = (struct CRYPTO_dynlock_value*)malloc(sizeof(struct CRYPTO_dynlock_value));
   if (value)
      MUTEX_SETUP(value->mutex);
   return value;
}
static void dyn_lock_function(int mode, struct CRYPTO_dynlock_value *l, const char *file, int line)
{
   if (mode & CRYPTO_LOCK)
      MUTEX_LOCK(l->mutex);
   else
      MUTEX_UNLOCK(l->mutex);
}
static void dyn_destroy_function(struct CRYPTO_dynlock_value *l, const char *file, int line)
{
   MUTEX_CLEANUP(l->mutex);
   free(l);
}
void locking_function(int mode, int n, const char *file, int line)
{
   if (mode & CRYPTO_LOCK)
      MUTEX_LOCK(mutex_buf[n]);
   else
      MUTEX_UNLOCK(mutex_buf[n]);
}
unsigned long id_function()
{
   return (unsigned long)THREAD_ID;
}
int CRYPTO_thread_setup()
{
   int i;
   mutex_buf = (MUTEX_TYPE*)malloc(CRYPTO_num_locks() * sizeof(MUTEX_TYPE));
   if (!mutex_buf)
      return SOAP_EOM;
   for (i = 0; i < CRYPTO_num_locks(); i++)
      MUTEX_SETUP(mutex_buf[i]);
   CRYPTO_set_id_callback(id_function);
   CRYPTO_set_locking_callback(locking_function);
   CRYPTO_set_dynlock_create_callback(dyn_create_function);
   CRYPTO_set_dynlock_lock_callback(dyn_lock_function);
   CRYPTO_set_dynlock_destroy_callback(dyn_destroy_function);
   return SOAP_OK;
}
void CRYPTO_thread_cleanup()
{
   int i;
   if (!mutex_buf)
      return;
   CRYPTO_set_id_callback(NULL);
   CRYPTO_set_locking_callback(NULL);
   CRYPTO_set_dynlock_create_callback(NULL);
   CRYPTO_set_dynlock_lock_callback(NULL);
   CRYPTO_set_dynlock_destroy_callback(NULL);
   for (i = 0; i < CRYPTO_num_locks(); i++)
      MUTEX_CLEANUP(mutex_buf[i]);
   free(mutex_buf);
   mutex_buf = NULL;
}

 

欢迎光临我的blog: http://www.info-life.cn