gistfile1.hpp

/*
  I Have a C++ class Sqlite3Db that inherits from EventEmitter. It has a
  private variable `db` of type (sqlite3*) which is the sqlite handle.

  Is it okay to pass this handle to the function executing
  in eio's threadpool? 
*/

  struct connect_request {                                                   
    sqlite3 *db;                                                             
    char filename[1];                                                        
  }; 

  static int eio_Connect(eio_req *req) {                                        
    // Note: this function is executed in the thread pool! CAREFUL              
    printf("eio_Connect\n");                                                    
    struct connection_request *conn_req = (connection_request *) req->data;
    
    // This is a pointer to the EventEmitter (Sqlite3Db)'s sqlite3 handle
    sqlite3 *db = conn_req->db;
                                                    
    req->result = 0;                                                            
    return 0;                                                                   
  }                                                                             
 
  // entry point to `db.connect(filename)`                                                                               
  static Handle<Value> Connect(const Arguments& args) {                         
    HandleScope scope;                                                          
    printf("Connect %s\n", *filename);                                          
    Sqlite3Db* dbo = ObjectWrap::Unwrap<Sqlite3Db>(args.This());


    /*
    Sqlite3Db has an operator overload for (sqlite3*) which returns the private `db` member
    */
    
    sqlite3 *db = *dbo;
                                                                                
    REQ_STR_ARG(0, filename);                                                   

    struct connect_request *conn_req = (struct connect_request *)
      calloc(1, sizeof(struct connect_request) + filename.length());              
    strcpy(conn_req->filename, *filename);                                         

    // PACK db handle 
    conn_req->db = db;

    eio_custom(eio_Connect, EIO_PRI_DEFAULT, eio_AfterConnect, db);             
    ev_ref(EV_DEFAULT_UC);                                                      
    printf("end\n");                                                            
    return Undefined(); 
  }