MPI wait

In the C++ programming language, MPI (Message Passing Interface) is a library that allows for parallel computing. The MPI_Wait function is used to synchronize communication between processes in a parallel program. Here is an explanation of each step involved in using MPI_Wait:

  1. Import the necessary MPI library: In order to use MPI functions, you need to include the MPI library at the beginning of your code. This is done by including the header file "mpi.h" using the #include directive.

  2. Initialize MPI: Before using any MPI functions, you need to initialize MPI by calling the MPI_Init function. This function takes two arguments, the address of the argc (argument count) variable and the address of the argv (argument vector) variable.

  3. Define variables: Define the necessary variables for your program, such as the rank and size of each process. The rank is a unique identifier for each process, while the size represents the total number of processes.

  4. Perform communication: Perform the necessary communication between processes using MPI functions such as MPI_Send and MPI_Recv. These functions allow processes to send and receive messages to and from each other.

  5. Call MPI_Wait: When using non-blocking communication, you can call MPI_Wait to wait for the completion of a communication request. MPI_Wait takes a single argument, which is the address of the request variable.

  6. Finalize MPI: After completing all the necessary communication, you should call MPI_Finalize to finalize MPI and free any resources that were allocated during the initialization.

It is important to note that the steps mentioned above are a general overview of using MPI_Wait in C++. The specific implementation may vary depending on the requirements of your program. Additionally, it is recommended to consult the official MPI documentation for more detailed information and examples.