fcgi + leveldb =核心转储？

Question

在RHEL 5.7 x86_64中，当fcgi和leveldb一起运行时，max_open_files = 4000，当客户端发送请求时，它会出现分段错误。怎么样？

使用mysql时不会发生。

ulimit -n = 655360

GDB：

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x52b09940 (LWP 47717)]
0x0000000000000f32 in ?? ()
(gdb) bt
#0  0x0000000000000f32 in ?? ()
#1  0x0000000052b09120 in ?? ()
#2  0x0000000000000000 in ?? ()

示例代码：

vector<pthread_t> mthread;
const int  THREAD_COUNT = 20;
static int counts[THREAD_COUNT];
pthread_t id[THREAD_COUNT];
int mSocketFd = 0;
vector<int> mfd;
static void *doit(void* arg)
{
    int rc, i;
    pid_t pid = getpid();
    FCGX_Request request;
    char *server_name;
    FCGX_InitRequest(&request, mSocketFd, 0);
    for (;;)
    {
        static pthread_mutex_t accept_mutex = PTHREAD_MUTEX_INITIALIZER;
        static pthread_mutex_t counts_mutex = PTHREAD_MUTEX_INITIALIZER;

        /* Some platforms require accept() serialization, some don't.. */
        pthread_mutex_lock(&accept_mutex);
        rc = FCGX_Accept_r(&request);
        pthread_mutex_unlock(&accept_mutex);

        if (rc < 0)
            continue;
        server_name = FCGX_GetParam("SERVER_NAME", request.envp);

        FCGX_FPrintF(request.out,
                "Content-type: text/html\r\n"
                "\r\n"
                "<title>FastCGI Hello! (multi-threaded C, fcgiapp library)</title>"
                "<h1>FastCGI Hello! (multi-threaded C, fcgiapp library)</h1>"
                "Thread %d, Process %ld<p>"
                "Request counts for %d threads running on host <i>%s</i><p><code>",
                123, pid, THREAD_COUNT, server_name ? server_name : "?");

        sleep(2);

        pthread_mutex_lock(&counts_mutex);
//        ++counts[thread_id];
        for (i = 0; i < THREAD_COUNT; i++)
            FCGX_FPrintF(request.out, "%5d " , counts[i]);
        pthread_mutex_unlock(&counts_mutex);

        FCGX_Finish_r(&request);
    }
    cout << "end doit" << endl;

    return NULL;
}
class A
{
public:
    static void Init()
    {
        if(NULL == db)
        {
            leveldb::Options options;
            options.create_if_missing = true;
            options.max_open_files = 3000;
            leveldb::Status status = leveldb::DB::Open(options,"/disk1/leveldb/rand1y", &db);
            assert(status.ok());
            cout << status.ToString() << endl;
        }
    }
    static  leveldb::DB* Get(){return db;}
private:
        A(){}
        static leveldb::DB* db;
};
leveldb::DB* A::db = NULL;
void* Get(void *arg)
{
    string value("");
    int rnd = rand()%100000000;
    leveldb::Status status;
    string key("");
    char str[50];
    leveldb::DB* db = A::Get();
    stringstream ss;
    while(1)
    {
        rnd = rand()%100000000;
        sprintf(str, "test$%d->test$%d", rnd, rnd);
        key = str;
        status = db->Get(leveldb::ReadOptions(),key, &value);
        if(status.IsNotFound())
            value = "NotFound!";
    }
    cout << "Open end" <<endl;
}
int main(){
    A::Init();
    int err;
    for(int i = 0; i < 20; ++i)
    {
        pthread_t p1;
        err = pthread_create(&p1, NULL, Get, NULL);
        mthread.push_back(p1);
        if(0 != err)
            cout << "error" << endl;
    }
    FCGX_Init();
    for (int i = 0; i < THREAD_COUNT; ++i)
    {
        pthread_create(&id[i], NULL, doit, NULL);
    }
    for(int i = 0; i < THREAD_COUNT; ++i)
    {
        pthread_join(id[i], NULL);
    }
    for(unsigned int i = 0; i < mthread.size(); ++i)
    {
        pthread_join(mthread[i], NULL);
    }
    cout << "end " << endl;
    return 0;
}