MPI_PUT is a function in the C++ programming language that is used in parallel computing with the Message Passing Interface (MPI) library. This function is used to transfer data from the local memory of one process to the memory of another process in a parallel computing environment.

Here are the steps involved in using MPI_PUT:

  1. Initialize the MPI library: Before using any MPI function, you need to initialize the MPI library by calling the MPI_Init function. This function initializes the MPI environment and sets up the necessary data structures for communication between processes.

  2. Allocate memory for the data: In order to transfer data using MPI_PUT, you need to allocate memory for the data that you want to send. This can be done using the appropriate data type in C++, such as arrays or structures.

  3. Set the target process: Determine the rank of the target process to which you want to send the data. The rank is a unique identifier for each process in the parallel computing environment.

  4. Call the MPI_PUT function: Use the MPI_PUT function to transfer the data from the local memory of the current process to the memory of the target process. The function takes parameters such as the data to be sent, the size of the data, the target process rank, and the memory address where the data should be stored in the target process.

  5. Synchronize the processes: After calling MPI_PUT, you need to synchronize the processes to ensure that the data transfer is complete. This can be done using the MPI_Barrier function, which blocks the execution of each process until all processes have reached the same point in the code.

  6. Clean up: Once the data transfer is complete, you need to clean up the MPI environment by calling the MPI_Finalize function. This function frees any resources that were allocated during the initialization of the MPI library.

By following these steps, you can use the MPI_PUT function in C++ to transfer data between processes in a parallel computing environment.