how to waiter for dummies

/*** Book: Thinking in Java * Features: producer and Consumer: * Please consider such a person hotel, it has a chef and a waiter. The waiter must wait for the cook to prepare the meal. When the chef is ready, he notifies the waiter, then the waiter will serve, then return to wait. * File: restaurant.java* time: May 8,

condition. This means that thread 1 will now wake up. Thread 1 attempts to lock the mutex , because thread 2 has not yet unlocked the mutex, so thread 1 has only wait, and thread 1 takes precedence over the mutex lock, and then it can do what it wants. Here's the problem: How to get thread 1 to give priority to mutex locking instead of other threads, Pthread_mutex_lock's pseudocode [4] shows the possibility of this implementation, in which the thread in wait is first activated in the signal fun

The reasons are explained in the computer network (Shehiren translation): 1. Two handshake, then if the client to the server-initiated package A1 if the fault in the transmission link, resulting in the transfer to the server time is rather lag, in this time period because the client did not receive the server for the package A1 confirmation, then will retransmit a packet A2, Assume that the server received the A2 package normally, and then return to confirm the B2 package. Since there is no thir

), Sh_locker) Ihold=1; Else if(CONFLICTS (LT, region, lp->mode, Lock_mode)) Break; Else if(Lp->mode = = Db_lock_read | | lp->mode = =db_lock_wwrite) {Grant_dirty=1;//Holder list only read lock; or a WW lock holder= lp->Holder; } } if(LP! =NULL) {//conflicting holderif(Ihold | | Lf_isset (db_lock_upgrade) | | Lock_mode = =db_lock_read_uncommitted) Action=Head ;//dirty read request first, put waiter queue headerElseAction=TAIL; } Else {

When we use thread synchronization, we may have deadlocks when we use threads, and the cause of the deadlock is:Cases:Two classes each have two methods, and these four kinds of release synchronization, such as customer and waiter to solve the "first payment or after payment" problem, will generate deadlock.Deadlock-generated conditions:Mutex conditionsRequest hold ConditionNon-deprivation conditionsLoop waitCauses of deadlocks:Improper resource compet

"interaction", that is, the way artifacts are reacted in a particular scenario). --Wikipedia Rather than using academic statements, I prefer to explain interactive design through what it wants to do: to help users efficiently accomplish the tasks envisioned by the product and, in the process, to make the user feel happy and undisturbed. KFC Restaurant--Watch for stools and gifts I will use the common KFC, McDonald's and other fast food restaurants to explain my own definition, I

class objectAbstract class definitions in Scala Abstract class User { def login:unit } In addition to abstract methods, you can have abstract fields in an abstract class: abstract class User {def login:unit//abstract field, the definition field in the generic class must be initialized, but not in the abstract class this requires Var age:int var Name:strin G}//The name parameter is initialized with the main constructor class waiter (Var name:string

system. Interaction design is the interface that defines the behavior of the human creation (the "interaction", that is, the way artifacts are reacted in a particular scenario). --Wikipedia Rather than using academic statements, I prefer to explain interactive design through what it wants to do: to help users efficiently accomplish the tasks envisioned by the product and, in the process, to make the user feel happy and undisturbed . KFC Restaurant--Watch for stools and gifts I will

Builddough () {Pizza.setdoUgh ("Pan baked"); } public void Buildsauce () {pizza.setsauce (' hot ');} public void buildtopping () {pizza.settopping ("Pepperoni+salami");}} /* "Director" */class Waiter {private PizzaBuilder pizzabuilder; public void Setpizzabuilder (PizzaBuilder pb) {pizzabuilder = PB;} Public Pizza Getpizza () {return Pizzabuilder.getpizza ();} public void Constructpizza () {pizzabuilder.createnewpizzaproduct (); Pi

waitresource= "page: 7:1:8459005 "means the same. Objectname= "Table name", this is the table name, the specific format: Db_name.schema_name. table_name.2) There are multiple owner-list nodes under the Pagelock node, and this is a node for each process, because the deadlock is caused by two processes and only two nodes.3) The Owner-list node has an owner, which represents the grant of the lock, presumably: If you hold multiple locks, there may be multiple nodes.4) Owner node: id= "Process7abee0

Prior to the end of the call service management, is to maintain the call service, including the increase in the type of call service or modify the call service type. Today, assigned to a new task, is to do the customer's order of the call service type, which is the type of call service is taken out of the database, and then click on the call service, will certainly send a service request to the corresponding responsible waiter, This request is tempora

from BLOCKING SESSION"From V$session Waiter,V$session blocker,V$sql W_sql,V$sql B_sqlWHERE Waiter. Event= ' Enq:tx-row lock contention ' and waiter. Blocking_session=blocker. Sidand W_sql. Sql_id=waiter. sql_idand B_sql. Sql_id =nvl (blocker. Sql_id,blocker. prev_sql_id) ';OPEN cur_lock02 for V_SQL02;LOOPFETCH cur_loc

cigarettes with tips.Some smokers do not like to smoke paper cigarettes with filters.Vt.1. Add an object to the top...A filter-tipped cigaretteCigarettes with Filters2. cover (or decorate) the tip of... [(+ with)]Hills tipped with treesTop of a tree3. Remove the tip of a growth objectTip2KK: []DJ: []Vt.1. Tilt2. Reverse [(+ over/up)]I'm sorry I tipped the bottle over.Sorry, I overturned the bottle.3. Close your hat and say hello.4. DumpingHe tipped the money in his pocket on to the counter.He d

Record the deadlock process and solution of the company's warehouse database server, and the warehouse database Four Conditions for deadlock: Mutual exclusion: resources cannot be shared and can only be used by one process. Hold and wait: processes that have obtained resources can apply for new resources again. No pre-emption: allocated resources cannot be forcibly deprived from the corresponding process. Loop wait condition (Circular wait): several processes in the system form a loop in which e

) createSlot (index); // slot = null, create a slot, return to the for loop, and start else if (y = slot. get ())! = Null. compareAndSet (y, null) {// Key Point 1: slot is cleared, Node is taken out, and the two interact in the Node. Give the Slot to the people behind the Slot and make the interaction location Node you = (Node) y; if (you. compareAndSet (null, item) {// Replace the items in Node with your own LockSupport. unpark (you. waiter); // wake

I mean, what is a connection? If a process connects to mysql and mysql assigns a process to connect to PHP, is this a connection? For example, the maximum number of connections in mysql is 50, does it mean that there are 50 waiters in the restaurant mysql, right? If you use persistence..., what does it mean to be a connection? If a process connects to mysql and mysql assigns a process to connect to PHP, is this a connection? For example, the maximum number of connections in mysql is 50, does i

); if (Likely (List_empty (sem->wait_list))) sem->count++; else __up (SEM); Spin_unlock_irqrestore (sem->lock,flags);}function Analysis: Assuming that the wait_list queue of the SEM is empty, it indicates that no other process is waiting for the semaphore, so it is only necessary to add the count of the SEM to 1. Assuming the wait_list queue is not empty, it indicates that other processes are sleeping on wait_list waiting for the signal. This calls __U

heir male heir heiress heiress waiter waiter waitress waitress 2016 December 31 First, noun name: the person, the thing, the place 1, the hat: The general situation Front adds a title a gril A girl the gril This girl a citythe Citya stationthe station SpecialConditions: stevenbeijingpeking university2, single plural rule of noun 1: plus esa bus--busesa Brush--brusheda box--boxesa bench--with s sh x c

traditional Japanese noodle shop, customers often encounter a large crowd of hungry diners huddled on a table, when they can hear the noise of the bowls and the sounds of people sucking noodles. This kind of atmosphere is very comfortable, especially when you are not used to it. Yoshitomi that this makes it impossible for people to focus on the delicious ramen. And in Ichiran ramen you can't see too much of this scene. When you enter the Ichiran Ramen Museum in Japan and Hong Kong, you are gree

synchronous and asynchronous is whether to wait for the results of IO execution. Like you go to McDonald's order, you say "to a hamburger", waiter told you, sorry, hamburger to do now, need to wait 5 minutes, so you stand in front of the cashier waiting for 5 minutes, get hamburger and then go shopping mall, this is synchronous IO.You say "Come a hamburger", the waiter tells you, Hamburg needs to wait 5 mi