Search Results

Search found 4028 results on 162 pages for 'mysqld safe'.

Page 15/162 | < Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >

• Is this a safe/valid hash method implementation?

  - by Sean

  I have a set of classes to represent some objects loaded from a database. There are a couple variations of these objects, so I have a common base class and two subclasses to represent the differences. One of the key fields they have in common is an id field. Unfortunately, the id of an object is not unique across all variations, but within a single variation. What I mean is, a single object of type A could have an id between, say, 0 and 1,000,000. An object of type B could have an id between, 25,000 and 1,025,000. This means there's some overlap of id numbers. The objects are just variations of the same kind of thing, though, so I want to think of them as such in my code. (They were assigned ids from different sets for legacy reasons.) So I have classes like this: @class BaseClass @class TypeAClass : BaseClass @class TypeBClass : BaseClass BaseClass has a method (NSNumber *)objectId. However instances of TypeA and TypeB could have overlapping ids as discussed above, so when it comes to equality and putting these into sets, I cannot just use the id alone to check it. The unique key of these instances is, essentially, (class + objectId). So I figured that I could do this by making the following hash function on the BaseClass: -(NSUInteger)hash { return (NSUInteger)[self class] ^ [self.objectId hash]; } I also implemented isEqual like so: - (BOOL)isEqual:(id)object { return (self == object) || ([object class] == [self class] && [self.objectId isEqual:[object objectId]]); } This seems to be working, but I guess I'm just asking here to make sure I'm not overlooking something - especially with the generation of the hash by using the class pointer in that way. Is this safe or is there a better way to do this?

  Read the article

• Safe and polymorphic toEnum

  - by jetxee

  I'd like to write a safe version of toEnum: safeToEnum :: (Enum t, Bounded t) => Int -> Maybe t A naive implementation: safeToEnum :: (Enum t, Bounded t) => Int -> Maybe t safeToEnum i = if (i >= fromEnum (minBound :: t)) && (i <= fromEnum (maxBound :: t)) then Just . toEnum $ i else Nothing main = do print $ (safeToEnum 1 :: Maybe Bool) print $ (safeToEnum 2 :: Maybe Bool) And it doesn't work: safeToEnum.hs:3:21: Could not deduce (Bounded t1) from the context () arising from a use of `minBound' at safeToEnum.hs:3:21-28 Possible fix: add (Bounded t1) to the context of an expression type signature In the first argument of `fromEnum', namely `(minBound :: t)' In the second argument of `(>=)', namely `fromEnum (minBound :: t)' In the first argument of `(&&)', namely `(i >= fromEnum (minBound :: t))' safeToEnum.hs:3:56: Could not deduce (Bounded t1) from the context () arising from a use of `maxBound' at safeToEnum.hs:3:56-63 Possible fix: add (Bounded t1) to the context of an expression type signature In the first argument of `fromEnum', namely `(maxBound :: t)' In the second argument of `(<=)', namely `fromEnum (maxBound :: t)' In the second argument of `(&&)', namely `(i <= fromEnum (maxBound :: t))' As well as I understand the message, the compiler does not recognize that minBound and maxBound should produce exactly the same type as in the result type of safeToEnum inspite of the explicit type declaration (:: t). Any idea how to fix it?

  Read the article

• Returning pointers in a thread-safe way.

  - by Roddy

  Assume I have a thread-safe collection of Things (call it a ThingList), and I want to add the following function. Thing * ThingList::findByName(string name) { return &item[name]; // or something similar.. } But by doing this, I've delegated the responsibility for thread safety to the calling code, which would have to do something like this: try { list.lock(); // NEEDED FOR THREAD SAFETY Thing *foo = list.findByName("wibble"); foo->Bar = 123; list.unlock(); } catch (...) { list.unlock(); throw; } Obviously a RAII lock/unlock object would simplify/remove the try/catch/unlocks, but it's still easy for the caller to forget. There are a few alternatives I've looked at: Return Thing by value, instead of a pointer - fine unless you need to modify the Thing Add function ThingList::setItemBar(string name, int value) - fine, but these tend to proliferate Return a pointerlike object which locks the list on creation and unlocks it again on destruction. Not sure if this is good/bad practice... What's the right approach to dealing with this?

  Read the article

• Is boost shared_ptr <XXX> thread safe?

  - by sxingfeng

  I have a question about boost :: shared_ptr. There are lots of thread. class CResource { xxxxxx } class CResourceBase { public: void SetResource(shared_ptr<CResource> res) { m_Res = res; } shared_ptr<CResource> GetResource() { return m_Res; } private: shared_ptr<CResource> m_Res; } CResourceBase base; //---------------------------------------------- Thread A: while (true) { ...... shared_ptr<CResource> nowResource = base.GetResource(); nowResource.doSomeThing(); ... } Thread B: shared_ptr<CResource> nowResource; base.SetResource(nowResource); ... //----------------------------------------------------------- If thread A do not care the nowResource is the newest . Will this part of code have problem? I mean when ThreadB do not SetResource completely, Thread A get a wrong smart point by GetResource? Another question : what does thread-safe mean? If I do not care about whether the resource is newest, will the shared_ptr nowResource crash the program when the nowResource is released or will the problem destroy the shared_point?

  Read the article

• EventAggregator, is it thread-safe?

  - by pfaz

  Is this thread-safe? The EventAggregator in Prism is a very simple class with only one method. I was surprised when I noticed that there was no lock around the null check and creation of a new type to add to the private _events collection. If two threads called GetEvent simultaneously for the same type (before it exists in _events) it looks like this would result in two entries in the collection. /// <summary> /// Gets the single instance of the event managed by this EventAggregator. Multiple calls to this method with the same <typeparamref name="TEventType"/> returns the same event instance. /// </summary> /// <typeparam name="TEventType">The type of event to get. This must inherit from <see cref="EventBase"/>.</typeparam> /// <returns>A singleton instance of an event object of type <typeparamref name="TEventType"/>.</returns> public TEventType GetEvent<TEventType>() where TEventType : EventBase { TEventType eventInstance = _events.FirstOrDefault(evt => evt.GetType() == typeof(TEventType)) as TEventType; if (eventInstance == null) { eventInstance = Activator.CreateInstance<TEventType>(); _events.Add(eventInstance); } return eventInstance; }

  Read the article

• efficient thread-safe singleton in C++

  - by user168715

  The usual pattern for a singleton class is something like static Foo &getInst() { static Foo *inst = NULL; if(inst == NULL) inst = new Foo(...); return *inst; } However, it's my understanding that this solution is not thread-safe, since 1) Foo's constructor might be called more than once (which may or may not matter) and 2) inst may not be fully constructed before it is returned to a different thread. One solution is to wrap a mutex around the whole method, but then I'm paying for synchronization overhead long after I actually need it. An alternative is something like static Foo &getInst() { static Foo *inst = NULL; if(inst == NULL) { pthread_mutex_lock(&mutex); if(inst == NULL) inst = new Foo(...); pthread_mutex_unlock(&mutex); } return *inst; } Is this the right way to do it, or are there any pitfalls I should be aware of? For instance, are there any static initialization order problems that might occur, i.e. is inst always guaranteed to be NULL the first time getInst is called?

  Read the article

• Safe json parsing with jquery?

  - by user246114

  Hi, I am using jquery with json. My client pages generate json, which I store on my server. The clients can then fetch the json back out later, parse, and show it. Since my clients are generating the json, it may not be safe. I think jquery uses eval() internally. Is that true? Is there a way to use the native json parsers from the browsers where available, otherwise fall back to manual parsing if not? I'm new to jquery so I don't know where I'd insert my own parsing code. I'm doing something like: $.ajax({ url: 'myservlet', type: 'GET', dataType: 'json', timeout: 1000, error: function(){ alert('Error loading JSON'); }, success: function(json){ alert("It worked!: " + json.name + ", " + json.grade); } }); so in the success() method, the json object is already parsed for me. Is there a way to catch it as a raw string first? Then I can decide whether to use the native parsers or manual parsing (hoping there's a jquery plugin for that..). The articles I'm reading are all from different years, so I don't know if jquery has already abandoned eval() already for json, Thank you

  Read the article

• Thread-Safe lazy instantiating using MEF

  - by Xaqron

  // Member Variable private static readonly object _syncLock = new object(); // Now inside a static method foreach (var lazyObject in plugins) { if ((string)lazyObject.Metadata["key"] = "something") { lock (_syncLock) { // It seems the `IsValueCreated` is not up-to-date if (!lazyObject.IsValueCreated) lazyObject.value.DoSomething(); } return lazyObject.value; } } Here I need synchronized access per loop. There are many threads iterating this loop and based on the key they are looking for, a lazy instance is created and returned. lazyObject should not be created more that one time. Although Lazy class is for doing so and despite of the used lock, under high threading I have more than one instance created (I track this with a Interlocked.Increment on a volatile static int and log it somewhere). The problem is I don't have access to definition of Lazy and MEF defines how the Lazy class create objects. I should notice the CompositionContainer has a thread-safe option in constructor which is already used. My questions: 1) Why the lock doesn't work ? 2) Should I use an array of locks instead of one lock for performance improvement ?

  Read the article

• Is this function thread-safe?

  - by kiddo

  Hello all,I am learning multi-threading and for the sake of understanding I have wriiten a small function using multithreading...it works fine.But I just want to know if that thread is safe to use,did I followed the correct rule. void CThreadingEx4Dlg::OnBnClickedOk() { //in thread1 100 elements are copied to myShiftArray(which is a CStringArray) thread1 = AfxBeginThread((AFX_THREADPROC)MyThreadFunction1,this); WaitForSingleObject(thread1->m_hThread,INFINITE); //thread2 waits for thread1 to finish because thread2 is going to make use of myShiftArray(in which thread1 processes it first) thread2 = AfxBeginThread((AFX_THREADPROC)MyThreadFunction2,this); thread3 = AfxBeginThread((AFX_THREADPROC)MyThreadFunction3,this); } UINT MyThreadFunction1(LPARAM lparam) { CThreadingEx4Dlg* pthis = (CThreadingEx4Dlg*)lparam; pthis->MyFunction(0,100); return 0; } UINT MyThreadFunction2(LPARAM lparam) { CThreadingEx4Dlg* pthis = (CThreadingEx4Dlg*)lparam; pthis->MyCommonFunction(0,20); return 0; } UINT MyThreadFunction3(LPARAM lparam) { CThreadingEx4Dlg* pthis = (CThreadingEx4Dlg*)lparam; WaitForSingleObject(pthis->thread3->m_hThread,INFINITE); //here thread3 waits for thread 2 to finish so that thread can continue pthis->MyCommonFunction(21,40); return 0; } void CThreadingEx4Dlg::MyFunction(int minCount,int maxCount) { for(int i=minCount;i<maxCount;i++) { //assume myArray is a CStringArray and it has 100 elemnts added to it. //myShiftArray is a CStringArray -public to the class CString temp; temp = myArray.GetAt(i); myShiftArray.Add(temp); } } void CThreadingEx4Dlg::MyCommonFunction(int min,int max) { for(int i = min;i < max;i++) { CSingleLock myLock(&myCS,TRUE); CString temp; temp = myShiftArray.GetAt(i); //threadArray is CStringArray-public to the class threadArray.Add(temp); } myEvent.PulseEvent(); }

  Read the article

• safe structures embedded systems

  - by user405633

  I have a packet from a server which is parsed in an embedded system. I need to parse it in a very efficient way, avoiding memory issues, like overlapping, corrupting my memory and others variables. The packet has this structure "String A:String B:String C". As example, here the packet received is compounded of three parts separated using a separator ":", all these parts must be accesibles from an structure. Which is the most efficient and safe way to do this. A.- Creating an structure with attributes (partA, PartB PartC) sized with a criteria based on avoid exceed this sized from the source of the packet, and attaching also an index with the length of each part in a way to avoid extracting garbage, this part length indicator could be less or equal to 300 (ie: part B). typedef struct parsedPacket_struct { char partA[2];int len_partA; char partB[300];int len_partB; char partC[2];int len_partC; }parsedPacket; The problem here is that I am wasting memory, because each structure should copy the packet content to each the structure, is there a way to only save the base address of each part and still using the len_partX.

  Read the article

• May volatile be in user defined types to help writing thread-safe code

  - by David Rodríguez - dribeas

  I know, it has been made quite clear in a couple of questions/answers before, that volatile is related to the visible state of the c++ memory model and not to multithreading. On the other hand, this article by Alexandrescu uses the volatile keyword not as a runtime feature but rather as a compile time check to force the compiler into failing to accept code that could be not thread safe. In the article the keyword is used more like a required_thread_safety tag than the actual intended use of volatile. Is this (ab)use of volatile appropriate? What possible gotchas may be hidden in the approach? The first thing that comes to mind is added confusion: volatile is not related to thread safety, but by lack of a better tool I could accept it. Basic simplification of the article: If you declare a variable volatile, only volatile member methods can be called on it, so the compiler will block calling code to other methods. Declaring an std::vector instance as volatile will block all uses of the class. Adding a wrapper in the shape of a locking pointer that performs a const_cast to release the volatile requirement, any access through the locking pointer will be allowed. Stealing from the article: template <typename T> class LockingPtr { public: // Constructors/destructors LockingPtr(volatile T& obj, Mutex& mtx) : pObj_(const_cast<T*>(&obj)), pMtx_(&mtx) { mtx.Lock(); } ~LockingPtr() { pMtx_->Unlock(); } // Pointer behavior T& operator*() { return *pObj_; } T* operator->() { return pObj_; } private: T* pObj_; Mutex* pMtx_; LockingPtr(const LockingPtr&); LockingPtr& operator=(const LockingPtr&); }; class SyncBuf { public: void Thread1() { LockingPtr<BufT> lpBuf(buffer_, mtx_); BufT::iterator i = lpBuf->begin(); for (; i != lpBuf->end(); ++i) { // ... use *i ... } } void Thread2(); private: typedef vector<char> BufT; volatile BufT buffer_; Mutex mtx_; // controls access to buffer_ };

  Read the article

• Is READ UNCOMMITTED / NOLOCK safe in this situation?

  - by Ben Challenor

  I know that snapshot isolation would fix this problem, but I'm wondering if NOLOCK is safe in this specific case so that I can avoid the overhead. I have a table that looks something like this: drop table Data create table Data ( Id BIGINT NOT NULL, Date BIGINT NOT NULL, Value BIGINT, constraint Cx primary key (Date, Id) ) create nonclustered index Ix on Data (Id, Date) There are no updates to the table, ever. Deletes can occur but they should never contend with the SELECT because they affect the other, older end of the table. Inserts are regular and page splits to the (Id, Date) index are extremely common. I have a deadlock situation between a standard INSERT and a SELECT that looks like this: select top 1 Date, Value from Data where Id = @p0 order by Date desc because the INSERT acquires a lock on Cx (Date, Id; Value) and then Ix (Id, Date), but the SELECT acquires a lock on Ix (Id, Date) and then Cx (Date, Id; Value). This is because the SELECT first seeks on Ix and then joins to a seek on Cx. Swapping the clustered and non-clustered index would break this cycle, but it is not an acceptable solution because it would introduce cycles with other (more complex) SELECTs. If I add NOLOCK to the SELECT, can it go wrong in this case? Can it return: More than one row, even though I asked for TOP 1? No rows, even though one exists and has been committed? Worst of all, a row that doesn't satisfy the WHERE clause? I've done a lot of reading about this online, but the only reproductions of over- or under-count anomalies I've seen (one, two) involve a scan. This involves only seeks. Jeff Atwood has a post about using NOLOCK that generated a good discussion. I was particularly interested in a comment by Rick Townsend: Secondly, if you read dirty data, the risk you run is of reading the entirely wrong row. For example, if your select reads an index to find your row, then the update changes the location of the rows (e.g.: due to a page split or an update to the clustered index), when your select goes to read the actual data row, it's either no longer there, or a different row altogether! Is this possible with inserts only, and no updates? If so, then I guess even my seeks on an insert-only table could be dangerous. Update: I'm trying to figure out how snapshot isolation works. It seems to be row-based, where transactions read the table (with no shared lock!), find the row they are interested in, and then see if they need to get an old version of the row from the version store in tempdb. But in my case, no row will have more than one version, so the version store seems rather pointless. And if the row was found with no shared lock, how is it different to just using NOLOCK?

  Read the article

• C# MultiThread Safe Class Design

  - by Robert

  I'm trying to designing a class and I'm having issues with accessing some of the nested fields and I have some concerns with how multithread safe the whole design is. I would like to know if anyone has a better idea of how this should be designed or if any changes that should be made? using System; using System.Collections; namespace SystemClass { public class Program { static void Main(string[] args) { System system = new System(); //Seems like an awkward way to access all the members dynamic deviceInstance = (((DeviceType)((DeviceGroup)system.deviceGroups[0]).deviceTypes[0]).deviceInstances[0]); Boolean checkLocked = deviceInstance.locked; //Seems like this method for accessing fields might have problems with multithreading foreach (DeviceGroup dg in system.deviceGroups) { foreach (DeviceType dt in dg.deviceTypes) { foreach (dynamic di in dt.deviceInstances) { checkLocked = di.locked; } } } } } public class System { public ArrayList deviceGroups = new ArrayList(); public System() { //API called to get names of all the DeviceGroups deviceGroups.Add(new DeviceGroup("Motherboard")); } } public class DeviceGroup { public ArrayList deviceTypes = new ArrayList(); public DeviceGroup() {} public DeviceGroup(string deviceGroupName) { //API called to get names of all the Devicetypes deviceTypes.Add(new DeviceType("Keyboard")); deviceTypes.Add(new DeviceType("Mouse")); } } public class DeviceType { public ArrayList deviceInstances = new ArrayList(); public bool deviceConnected; public DeviceType() {} public DeviceType(string DeviceType) { //API called to get hardwareIDs of all the device instances deviceInstances.Add(new Mouse("0001")); deviceInstances.Add(new Keyboard("0003")); deviceInstances.Add(new Keyboard("0004")); //Start thread CheckConnection that updates deviceConnected periodically } public void CheckConnection() { //API call to check connection and returns true this.deviceConnected = true; } } public class Keyboard { public string hardwareAddress; public bool keypress; public bool deviceConnected; public Keyboard() {} public Keyboard(string hardwareAddress) { this.hardwareAddress = hardwareAddress; //Start thread to update deviceConnected periodically } public void CheckKeyPress() { //if API returns true this.keypress = true; } } public class Mouse { public string hardwareAddress; public bool click; public Mouse() {} public Mouse(string hardwareAddress) { this.hardwareAddress = hardwareAddress; } public void CheckClick() { //if API returns true this.click = true; } } }

  Read the article

• safe dereferencing and deletion

  - by serejko

  Hi, I'm relatively new to C++ and OOP in general and currently trying to make such a class that allows to dereference and delete a dead or invalid pointer without any care of having undefined behavior or program fault in result, and I want to ask you is it a good idea and is there something similar which is already implemented by someone else? or maybe I'm doing something completely wrong? I've just started making it and here is the code I currently have: template<class T> class SafeDeref { public: T& operator *() { hash_set<T*>::iterator it = theStore.find(reinterpret_cast<T*>(ptr)); if (it != theStore.end()) return *this; return theDefaultObject; } T* operator ->() { hash_set<T*>::iterator it = theStore.find(reinterpret_cast<T*>(ptr)); if (it != theStore.end()) return this; return &theDefaultObject; } void* operator new(size_t size) { void* ptr = malloc(size * sizeof(T)); if (ptr != 0) theStore.insert(reinterpret_cast<T*>(ptr)); return ptr; } void operator delete(void* ptr) { hash_set<T*>::iterator it = theStore.find(reinterpret_cast<T*>(ptr)); if (it != theStore.end()) { theStore.erase(it); free(ptr); } } protected: static bool isInStore(T* ptr) { return theStore.find(ptr) != theStore.end(); } private: static T theDefaultObject; static hash_set<T*> theStore; }; The idea is that each class with the safe dereference should be inherited from it like this: class Foo : public SafeDeref<Foo> { void doSomething(); }; So... Any advices? Thanks in advance. P.S. If you're wondering why I need this... well, I'm creating a set of native functions for some scripting environment, and all of them use pointers to internally allocated objects as handles to them and they're able to delete them as well (input data can be wrong), so this is kinda protection from damaging host application's memory And I really sorry for my bad English

  Read the article

• Cannot connect to MySQL over TCP locally - Connection Timeout - Ubuntu 9.04

  - by gav

  I am running Ubuntu and am ultimately trying to connect Tomcat to my MySQL database using JDBC. It has worked previously but after a reboot the instance now fails to connect. Both Tomcat 6 and MySQL 5.0.75 are on the same machine Connection string: jdbc:mysql:///localhost:3306 I can connect to MySQL on the command line using the mysql command The my.cnf file is pretty standard (Available on request) has bind address: 127.0.0.1 I cannot Telnet to the MySQL port despite netstat saying MySQL is listening I have one IpTables rule to forward 80 - 8080 and no firewall I'm aware of. I'm pretty new to this and I'm not sure what else to test. I don't know whether I should be looking in etc/interfaces and if I did what to look for. It's weird because it used to work but after a reboot it's down so I must have changed something.... :). I realise a timeout indicates the server is not responding and I assume it's because the request isn't actually getting through. I installed MySQL via apt-get and Tomcat manually. MySqld processes root@88:/var/log/mysql# ps -ef | grep mysqld root 21753 1 0 May27 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe mysql 21792 21753 0 May27 ? 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --pid-file=/var/run/mysqld/mysqld.pid --skip-external-locking --port=3306 --socket=/var/run/mysqld/mysqld.sock root 21793 21753 0 May27 ? 00:00:00 logger -p daemon.err -t mysqld_safe -i -t mysqld root 21888 13676 0 11:23 pts/1 00:00:00 grep mysqld Netstat root@88:/var/log/mysql# netstat -lnp | grep mysql tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 21792/mysqld unix 2 [ ACC ] STREAM LISTENING 1926205077 21792/mysqld /var/run/mysqld/mysqld.sock Toy Connection Class root@88:~# cat TestConnect/TestConnection.java import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class TestConnection { public static void main(String args[]) throws Exception { Connection con = null; try { Class.forName("com.mysql.jdbc.Driver").newInstance(); System.out.println("Got driver"); con = DriverManager.getConnection( "jdbc:mysql:///localhost:3306", "uname", "pass"); System.out.println("Got connection"); if(!con.isClosed()) System.out.println("Successfully connected to " + "MySQL server using TCP/IP..."); } finally { if(con != null) con.close(); } } } Toy Connection Class Output Note: This is the same error I get from Tomcat. root@88:~/TestConnect# java -cp mysql-connector-java-5.1.12-bin.jar:. TestConnection Got driver Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 1 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1122) at TestConnection.main(TestConnection.java:14) Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1122) at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2181) ... 12 more Caused by: java.net.ConnectException: Connection timed out at java.net.PlainSocketImpl.socketConnect(Native Method) ... 13 more Telnet Output root@88:~/TestConnect# telnet localhost 3306 Trying 127.0.0.1... telnet: Unable to connect to remote host: Connection timed out

  Read the article

• Error installing mysql, any way to fix it?

  - by user156355

  I was installing mysql with apt-get install mysql-server (like I always did) before that I had done an apt-get update (I am using Debian 6), and when I installed I found this problem, pretty common as I see, but Ive followed all stepts and nothing have worked, Ive tried with apt-get install -f also with apt-get remove mysql-server (and common, and mysql-server-5.1) and also with apt-get purge (every packate) and later install, but nothing... I tried also dpkg-reconfigure mysql-server-5.1 apt-get install --reinstall mysql-server (all runed as Root) Still, nothing worked, any idea??? 130130 10:11:48 InnoDB: Shutdown completed; log sequence number 0 44233 Starting MySQL database server: mysqld . . . . . . . . . . . . . . failed! invoke-rc.d: initscript mysql, action "start" failed. dpkg: error processing mysql-server-5.1 (--configure): subprocess installed post-installation script returned error exit status 1 configured to not write apport reports dpkg: dependency problems prevent configuration of mysql-server: mysql-server depends on mysql-server-5.1; however: Package mysql-server-5.1 is not configured yet. dpkg: error processing mysql-server (--configure): dependency problems - leaving unconfigured configured to not write apport reports Errors were encountered while processing: mysql-server-5.1 mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1) when I tried dpkg-reconfigure mysql-server-5.1 /usr/sbin/dpkg-reconfigure: mysql-server-5.1 is broken or not fully installed the case "Start" on /etc/init.d/mysql is 'start') sanity_checks; # Start daemon log_daemon_msg "Starting MySQL database server" "mysqld" if mysqld_status check_alive nowarn; then log_progress_msg "already running" log_end_msg 0 else # Could be removed during boot test -e /var/run/mysqld || install -m 755 -o mysql -g root -d /var/run/mysqld # Start MySQL! /usr/bin/mysqld_safe > /dev/null 2>&1 & # 6s was reported in #352070 to be too few when using ndbcluster for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14; do sleep 1 if mysqld_status check_alive nowarn ; then break; fi log_progress_msg "." done if mysqld_status check_alive warn; then log_end_msg 0 # Now start mysqlcheck or whatever the admin wants. output=$(/etc/mysql/debian-start) [ -n "$output" ] && log_action_msg "$output" else log_end_msg 1 log_failure_msg "Please take a look at the syslog" fi fi When I make mysql force-reload: Reloading MySQL database server: mysqld/usr/bin/mysqladmin: connect to server at 'localhost' failed error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)' Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists! root@americandougnuts:/etc/init.d# root@americandougnuts:/etc/init.d# Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists!

  Read the article

• Is this a SEO SAFE anchor link

  - by Mayhem

  so... Is this a safe way to use internal links on your site.. By doing this i have the index page generating the usual php content section and handing it to the div element. THE MAIN QUESTION: Will google still index the pages using this method? Common sense tells me it does.. But just double checking and leaving this here as a base example as well if it is. As in. EXAMPLE ONLY PEOPLE The Server Side if (isset($_REQUEST['page'])) {$pageID=$_REQUEST['page'];} else {$pageID="home";} if (isset($_REQUEST['pageMode']) && $_REQUEST['pageMode']=="js") { require "content/".$pageID.".php"; exit; } // ELSE - REST OF WEBSITE WILL BE GENERATED USING THE page VARIABLE The Links <a class='btnMenu' href='?page=home'>Home Page</a> <a class='btnMenu' href='?page=about'>About</a> <a class='btnMenu' href='?page=Services'>Services</a> <a class='btnMenu' href='?page=contact'>Contact</a> The Javascript $(function() { $(".btnMenu").click(function(){return doNav(this);}); }); function doNav(objCaller) { var sPage = $(objCaller).attr("href").substring(6,255); $.get("index.php", { page: sPage, pageMode: 'js'}, function(data) { ("#siteContent").html(data).scrollTop(0); }); return false; } Forgive me if there are any errors, as just copied and pasted from my script then removed a bunch of junk to simplify it as still prototyping/white boarding the project its in. So yes it does look a little nasty at the moment. REASONS WHY: The main reason is bandwidth and speed, This will allow other scripts to run and control the site/application a little better and yes it will need to be locked down with some coding. -- FURTHER EXAMPLE-- INSERT PHP AT TOP <?php // PHP CODE HERE ?> <html> <head> <link rel="stylesheet" type="text/css" href="style.css" /> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="scripts.js"></script> </head> <body> <div class='siteBody'> <div class='siteHeader'> <?php foreach ($pageList as $key => $value) { if ($pageID == $key) {$btnClass="btnMenuSel";} else {$btnClass="btnMenu";} echo "<a class='$btnClass' href='?page=".$key."'>".$pageList[$key]."</a>"; } ?> </div><div id="siteContent" style='margin-top:10px;'> <?php require "content/".$pageID.".php"; ?> </div><div class='siteFooter'> </div> </div> </body> </html>

  Read the article

• notify listener inside or outside inner synchronization

  - by Jary Zeels

  Hello all, I am struggling with a decision. I am writing a thread-safe library/API. Listeners can be registered, so the client is notified when something interesting happens. Which of the two implementations is most common? class MyModule { protected Listener listener; protected void somethingHappens() { synchronized(this) { ... do useful stuff ... listener.notify(); } } } or class MyModule { protected Listener listener; protected void somethingHappens() { Listener l = null; synchronized(this) { ... do useful stuff ... l = listener; } l.notify(); } } In the first implementation, the listener is notified inside the synchronization. In the second implementation, this is done outside the synchronization. I feel that the second one is advised, as it makes less room for potential deadlocks. But I am having trouble to convince myself. A downside of the second imlementation is that the client might receive 'incorrect' notifications, which happens if it accessed the module prior to the l.notify() statement. thanks a lot

  Read the article

• Approaches for generic, compile-time safe lazy-load methods

  - by Aaronaught

  Suppose I have created a wrapper class like the following: public class Foo : IFoo { private readonly IFoo innerFoo; public Foo(IFoo innerFoo) { this.innerFoo = innerFoo; } public int? Bar { get; set; } public int? Baz { get; set; } } The idea here is that the innerFoo might wrap data-access methods or something similarly expensive, and I only want its GetBar and GetBaz methods to be invoked once. So I want to create another wrapper around it, which will save the values obtained on the first run. It's simple enough to do this, of course: int IFoo.GetBar() { if ((Bar == null) && (innerFoo != null)) Bar = innerFoo.GetBar(); return Bar ?? 0; } int IFoo.GetBaz() { if ((Baz == null) && (innerFoo != null)) Baz = innerFoo.GetBaz(); return Baz ?? 0; } But it gets pretty repetitive if I'm doing this with 10 different properties and 30 different wrappers. So I figured, hey, let's make this generic: T LazyLoad<T>(ref T prop, Func<IFoo, T> loader) { if ((prop == null) && (innerFoo != null)) prop = loader(innerFoo); return prop; } Which almost gets me where I want, but not quite, because you can't ref an auto-property (or any property at all). In other words, I can't write this: int IFoo.GetBar() { return LazyLoad(ref Bar, f => f.GetBar()); // <--- Won't compile } Instead, I'd have to change Bar to have an explicit backing field and write explicit getters and setters. Which is fine, except for the fact that I end up writing even more redundant code than I was writing in the first place. Then I considered the possibility of using expression trees: T LazyLoad<T>(Expression<Func<T>> propExpr, Func<IFoo, T> loader) { var memberExpression = propExpr.Body as MemberExpression; if (memberExpression != null) { // Use Reflection to inspect/set the property } } This plays nice with refactoring - it'll work great if I do this: return LazyLoad(f => f.Bar, f => f.GetBar()); But it's not actually safe, because someone less clever (i.e. myself in 3 days from now when I inevitably forget how this is implemented internally) could decide to write this instead: return LazyLoad(f => 3, f => f.GetBar()); Which is either going to crash or result in unexpected/undefined behaviour, depending on how defensively I write the LazyLoad method. So I don't really like this approach either, because it leads to the possibility of runtime errors which would have been prevented in the first attempt. It also relies on Reflection, which feels a little dirty here, even though this code is admittedly not performance-sensitive. Now I could also decide to go all-out and use DynamicProxy to do method interception and not have to write any code, and in fact I already do this in some applications. But this code is residing in a core library which many other assemblies depend on, and it seems horribly wrong to be introducing this kind of complexity at such a low level. Separating the interceptor-based implementation from the IFoo interface by putting it into its own assembly doesn't really help; the fact is that this very class is still going to be used all over the place, must be used, so this isn't one of those problems that could be trivially solved with a little DI magic. The last option I've already thought of would be to have a method like: T LazyLoad<T>(Func<T> getter, Action<T> setter, Func<IFoo, T> loader) { ... } This option is very "meh" as well - it avoids Reflection but is still error-prone, and it doesn't really reduce the repetition that much. It's almost as bad as having to write explicit getters and setters for each property. Maybe I'm just being incredibly nit-picky, but this application is still in its early stages, and it's going to grow substantially over time, and I really want to keep the code squeaky-clean. Bottom line: I'm at an impasse, looking for other ideas. Question: Is there any way to clean up the lazy-loading code at the top, such that the implementation will: Guarantee compile-time safety, like the ref version; Actually reduce the amount of code repetition, like the Expression version; and Not take on any significant additional dependencies? In other words, is there a way to do this just using regular C# language features and possibly a few small helper classes? Or am I just going to have to accept that there's a trade-off here and strike one of the above requirements from the list?

  Read the article

• Web Safe Area (optimal resolution) for web app design?

  - by M.A.X

  I'm in the process of designing a new web app and I'm wondering for what 'Web Safe Area' should I optimize the app layout and design. By Web Safe Area I mean the actual area available to display the website in the browser (which is influenced by monitor resolution as well as the space taken up by the browser and OS) I did some investigation and thinking on my own but wanted to share this to see what the general opinion is. Here is what I found: Optimal Display Resolution: w3schools web stats seems to be the most referenced source (however they state that these are results from their site and is biased towards tech savvy users) http://www.w3counter.com/globalstats.php (aggregate data from something like 15,000 different sites that use their tracking services) StatCounter Global Stats Display Resolution (Stats are based on aggregate data collected by StatCounter on a sample exceeding 15 billion pageviews per month collected from across the StatCounter network of more than 3 million websites) NetMarketShare Screen Resolutions (marketshare.hitslink.com) (a web analytics consulting firm, they get data from browsers of site visitors to their on-demand network of live stats customers. The data is compiled from approximately 160 million visitors per month) Display Resolution Summary: There is a bit of variation between the above sources but in general as of Jan 2011 looks like 1024x768 is about 20%, while ~85% have a higher resolution of at least 1280x768 (1280x800 is the most common of these with 15-20% of total web, depending on the source; 1280x1024 and 1366x768 follow behind with 9-14% of the share). My guess would be that the higher resolution values will be even more common if we filter on North America, and even higher if we filter on N.American corporate users (unfortunately I couldn't find any free geographically filtered statistics). Another point to note is that the 1024x768 desktop user population is likely lower than the aforementioned 20%, seeing as the iPad (1024x768 native display) is likely propping up those number (the app I'm designing is flash based, Apple mobile devices don't support flash so iPad support isn't a concern). My recommendation would be to optimize around the 1280x768 constraint (*note: 1280x768 is actually a relatively rare resolution, but I think it's a valid constraint range considering that 1366x768 is relatively common and 1280 is the most common horizontal resolution). Browser + OS Constraints: To further add to the constraints we have to subtract the space taken up by the browser (assuming IE, which is the most space consuming) and the OS (assuming WinXP-Win7): Win7 has the biggest taskbar footprint at a height of 40px (XP's and Vista's is 30px) The default IE8 view uses up 25px at the bottom of the screen with the status bar and a further 120px at the top of the screen with the windows title bar and the browser UI (assuming the default 'favorites' toolbar is present, it would instead be 91px without the favorites toolbar). Assuming no scrollbar, we also loose a total of 4px horizontally for the window outline. This means that we are left with 583px of vertical space and 1276px of horizontal. In other words, a Web Safe Area of 1276 x 583 Is this a correct line of thinking? I'm really surprised that I couldn't find this type of investigation anywhere on the web. Lots of websites talk about designing for 1024x768, but that's only half the equation! There is no mention of browser/OS influences on the actual area you have to display the site/app. Any help on this would be greatly appreciated! Thanks. EDIT Another caveat to my line of thinking above is that different browsers actually take up different amounts of pixels based on the OS they're running on. For example, under WinXP IE8 takes up 142px on top of the screen (instead the aforementioned 120px for Win7) because the file menu shows up by default on XP while in Win7 the file menu is hidden by default. So it looks like on WinXP + IE8 the Web Safe Area would be a mere 572px (768px-142-30-24=572)

  Read the article

• How do I get VB6 to integrate with Visual Source Safe 6.0?

  - by Ben McCormack

  We use Visual Source Safe 6.0 at work and VB6 is supposed to integrate smoothly with Source Safe. Both applications are installed on my PC, but VB6 is not showing the options to integrate with Source Safe (e.g. checking out a file, seeing if a file is shared, etc.). What do I need to do to get VB6 to integrate with Source Safe 6.0?

  Read the article

• mysqladmin - Unknown MySQL server host

  - by ert

  I'm trying to connect to a mysql server over a local network. The server is running and listening to post 41322. dylan~$ netstat -ln | s mysql unix 2 [ ACC ] STREAM LISTENING 41322 /var/run/mysqld/mysqld.sock My user is granted all rights from all addresses, and I can log in locally. dylan~$ mysqladmin -P 41322 -h [email protected] create database test mysqladmin: connect to server at '[email protected]' failed error: 'Unknown MySQL server host '[email protected]' (1)' Check that mysqld is running on [email protected] and that the port is 41322. You can check this by doing 'telnet [email protected] 41322' Adding a --verbose flag gives no additional output. I've commented out bind-address=127.0.0.1 in /etc/mysql/my.cnf on the server. I can ssh into the server without a problem. dylan~$ ps a | grep mysql 11131 pts/3 S 0:00 /bin/sh /usr/bin/mysqld_safe 11170 pts/3 Sl 0:03 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --pid-file=/var/run/mysqld/mysqld.pid --skip-external-locking --port=3306 --socket=/var/run/mysqld/mysqld.sock 11171 pts/3 S 0:00 logger -p daemon.err -t mysqld_safe -i -t mysqld 13710 pts/1 S+ 0:00 grep mysq Any help or thoughts are appreciated.

  Read the article

• nginx+mysql5 loadtesting configuration strangeness

  - by genseric

  i am trying to setup a new server running on debian6 and trying to make it work smooth under load. i ve used a wordpress site as a test object, and tried the configurations on http://blitz.io. when i increase the mysql max_connections from 50 to 200 lots of timeouts start to occur. but on 50 , no timeouts and pretty well response times. nginx configuration is fine , i tuned the config so i dont see errors. so i presume it's related to the other configuration options of my.cnf . i read some about options but still cant find what max_connections problem is all about. btw, the server has 16gb of ram and a fine i7 cpu. here is the current my.cnf [client] port = 3306 socket = /var/run/mysqld/mysqld.sock [mysqld_safe] socket = /var/run/mysqld/mysqld.sock nice = 0 [mysqld] wait_timeout=60 connect_timeout=10 interactive_timeout=120 user = mysql pid-file = /var/run/mysqld/mysqld.pid socket = /var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp language = /usr/share/mysql/english skip-external-locking bind-address = 127.0.0.1 key_buffer = 384M max_allowed_packet = 16M thread_stack = 192K thread_cache_size = 20 myisam-recover = BACKUP max_connections = 50 table_cache = 1024 thread_concurrency = 8 query_cache_limit = 2M query_cache_size = 128M expire_logs_days = 10 max_binlog_size = 100M [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 16M thanks in advance. i asked this question on SO but it's closed as off topic so i believe this is a SF question.

  Read the article

• MySQL password changed every other day in windows?

  - by PHP

  Every morning when I check server status,I will find MySQL's password is changed: mysql -uuser -ppassword will report ERROR 1045 (28000): Access denied for user 'user'@'localhost' (using password: YES) And then I restart server,and when it's up,MySQL will be back to normal. It has now become a routinely job. What can be the cause for this? How can I know what's exactly happening to MySQL? Here is the error log: 100122 10:11:16 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Normal shutdown 100122 10:11:16 InnoDB: Starting shutdown... 100122 10:11:18 InnoDB: Shutdown completed; log sequence number 0 22939338 100122 10:11:18 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Shutdown complete 100122 10:12:40 InnoDB: Started; log sequence number 0 22939338 100122 10:12:42 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: ready for connections. Version: '5.0.24-community-nt' socket: '' port: 3306 MySQL Community Edition (GPL) 100123 16:20:44 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Normal shutdown 100123 16:20:44 InnoDB: Starting shutdown... 100123 16:20:46 InnoDB: Shutdown completed; log sequence number 0 22939832 100123 16:20:46 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Shutdown complete 100123 16:22:09 InnoDB: Started; log sequence number 0 22939832 100123 16:22:11 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: ready for connections. Version: '5.0.24-community-nt' socket: '' port: 3306 MySQL Community Edition (GPL) 100125 9:18:59 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Normal shutdown 100125 9:18:59 InnoDB: Starting shutdown... 100125 9:19:00 InnoDB: Shutdown completed; log sequence number 0 22941001 100125 9:19:00 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: Shutdown complete 100125 9:20:22 InnoDB: Started; log sequence number 0 22941001 100125 9:20:25 [Note] D:\MySQL\MySQL Server 5.0\bin\mysqld-nt: ready for connections. Version: '5.0.24-community-nt' socket: '' port: 3306 MySQL Community Edition (GPL)

  Read the article

• cause for mysql crash

  - by user1322092

  A cron job automatically restarted my mysql database. What's the cause for the crash, or can you suggest how to resolve or monitor. I would REALLY appreciate your input. 120715 14:38:58 mysqld started 120715 14:38:58 InnoDB: Started; log sequence number 0 411137570 120715 14:38:58 [Note] /usr/libexec/mysqld: ready for connections. Version: '5.0.95' socket: '/var/lib/mysql/mysql.sock' port: 3306 Source distribution 120715 15:14:21 [Note] /usr/libexec/mysqld: Normal shutdown 120715 15:14:23 InnoDB: Starting shutdown... 120715 15:14:25 InnoDB: Shutdown completed; log sequence number 0 411166467 120715 15:14:25 [Note] /usr/libexec/mysqld: Shutdown complete 120715 08:14:25 mysqld ended 120715 08:14:26 mysqld started 120715 8:14:26 InnoDB: Started; log sequence number 0 411166467 120715 8:14:26 [Note] /usr/libexec/mysqld: ready for connections. Version: '5.0.95' socket: '/var/lib/mysql/mysql.sock' port: 3306 Source distribution 121212 09:15:32 mysqld started InnoDB: The log sequence number in ibdata files does not match InnoDB: the log sequence number in the ib_logfiles! 121212 9:15:58 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files... InnoDB: Restoring possible half-written data pages from the doublewrite InnoDB: buffer... 121212 9:17:28 InnoDB: Started; log sequence number 0 554145193 121212 9:17:57 [Note] /usr/libexec/mysqld: ready for connections. Version: '5.0.95' socket: '/var/lib/mysql/mysql.sock' port: 3306 Source distribution

  Read the article

< Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >