c# - sqlite.net + monotouch = SIGSEGV crashes -

we're using following:

• xamarin 3 (xamarin forms)
• monotouch
• sqlite.net
• ios simulator/hardware

the app synchronizes data server on background thread. there 1 sqlite connection object shared entire app. foreground queries executed @ same time background sync running. of has worked fine on windows 8.1 version of app (i.e., on msft surface , similar). once switched xamarin/mono started getting constant crashes shown below.

research led article: http://www.aaronheise.com/2012/12/monotouch-sqlite-sigsegv/

he's using using mono.data.sqliteclient, not sqlite.net are.

his solution involves explicitly disposing of command objects in order ensure gc can keep etc. when tried wrap command objects (from sqlite.net) in using(){} clause found out not disposable.

i've tried inserting 100ms delays , stops crashes, it's not viable solution us.

is there hope sqlite.net here, or should different way use sqlite?

    mono-rt: stacktrace:   mono-rt:   @ <unknown> <0xffffffff>  mono-rt:   @ (wrapper managed-to-native) sqlite.sqlite3.prepare2 (intptr,string,int,intptr&,intptr) <il 0x0003c, 0xffffffff>  ...  mono-rt:  native stacktrace:   mono-rt:  got sigsegv while executing native code. indicates fatal error in mono runtime or 1 of native libraries  used application. 

i'm pretty sure getting meaningful errors instead of sigsegv's when tried hammering same sqlite.net connection multiple threads, if believe that's culprit, solution simple: need restrict access sqlite.net methods touch database 1 thread @ time.

in scenario you're sharing single sqliteconnection instance in app (which valid way of doing things), recommend creating simplified proxy class wrapping sqlite.net connection, exposing methods want , protecting access lock statements, i.e:

public class databasewrapper : idisposable {     // fields.     private readonly sqliteconnection connection;     private readonly object lock = new object();      public databasewrapper(string databasepath)     {         if (string.isnullorempty(databasepath)) throw new argumentexception("database path cannot null or empty.");          this.connection = new sqliteconnection(databasepath);     }      public ienumerable<t> entities<t>() t : new()     {         lock (this.lock)         {             return this.connection.table<t>();         }     }      public ienumerable<t> query<t>(string query, params object[] args) t : new()     {         lock (this.lock)         {             return this.connection.query<t>(query, args);         }     }      public int executenonquery(string sql, params object[] args)     {         lock (this.lock)         {             return this.connection.execute(sql, args);         }     }      public t executescalar<t>(string sql, params object[] args)     {         lock (this.lock)         {             return this.connection.executescalar<t>(sql, args);         }     }      public void insert<t>(t entity)     {         lock (this.lock)         {             this.connection.insert(entity);         }     }      public void update<t>(t entity)     {         lock (this.lock)         {             this.connection.update(entity);         }     }      public void upsert<t>(t entity)     {         lock (this.lock)         {             var rowcount = this.connection.update(entity);              if (rowcount == 0)             {                 this.connection.insert(entity);             }         }     }      public void delete<t>(t entity)     {         lock (this.lock)         {             this.connection.delete(entity);         }     }      public void dispose()     {         this.connection.dispose();     } } 

p.s. since you're doing things on multiple threads need careful not introduce race conditions, why, example, included upsert method guaranteed perform two-step "update or insert" operation atomically.