reader writer problem using semaphore

Internship environment: Windows XP + VC 6.0 Internship objectives: Create a console process in Windows XP, which should contain n threads. Use the n threads to represent n readers or writers. Each thread performs read/write operations according to the requirements of the corresponding test data file (described later. The semaphore mechanism is used to implement reader-first and

blockE.printstacktrace (); }} mlatchdown.countdown (); } } Public classWriter extends Thread { PublicString name =NULL; Boolean flag=true; Private intindex =0; Private intCash =0; PublicWriter (String name,intAddcash) { This. Name =name; This. Cash =Addcash; } @Override Public voidrun () {System. out. println ("[Writer]"+ name +"Start"); while(flag) {Try{Mreadwritelock.writelock ().Lock(); System. out. println ("[

Question 1: readers Level 1: Only readers are allowed. A maximum of K readers are allowed to write programs using P and V Operations. int main(){ int rspace = k; cobegin read_1(); read_2(); …… read_n(); coend}read_i(){ p(rspace); …… v(rspace);} In this operation, you need to set the signal rspace to determine whether the number of people has reached K. When the number of people reaches K, rspace = 0. In th

Code can run, but it is really not observed what the reader first, or write a priority. It is not known where this priority conflict is coming from, and it does not know what the book says. Especially in the writer of the following code, if Sem_wait (z) is introduced, the writer process blocks, causing the reader to bl

1. First, the reader's semaphore implementation Set three mutex semaphores: Rwmutex is used to access Shared data that is mutually exclusive to other readers/writers. Rmutex is used to access the reader counter readcount that is mutually exclusive to the reader. Wmutex is used by the writer to wait for the

Problem definition:Existing piece of shared memory, multiple read processes, and multiple write processes. Multiple read processes can be read at the same time, but no other read or write processes are executed when there is a write process in progress.There are 3 variants of the problem. The first is called "Reader First" (readers-preference). In this case, as l

Problem Description: On the bus, the driver and the conductor's activities are:Driver's activity: Start the vehicle, normal driving, stop.The conductor's activities: Closing the door, selling tickets, driving the door. In the continuous arrival, stop and drive of the automobile, the signal volume and p,v operation are used to realize their synchronization. Problem solving; We can use two signals to achieve