MPI Module

The HIPP::MPI module includes high-level OOP APIs that encapsulates Standard Message Passing Interface (MPI) library. It also provides non-standard extensions of MPI, which are useful in synchronization, task management and task distribution, etc.

Although the high-level APIs are always preferred to use, sometimes, user may need to go back to the oringinal MPI calls, possibly due to the demands of better performance or more flexible and detailed control of the communication behavior. The intermediate-level APIs, which is only semi-OOP, therefore provide convient tools for this purpose.

All the definitions in the MPI module can be accessed by including the header file <hippmpi.h>. Classes, functions and variables are all defined within the HIPP::MPI namespace. Code that uses the MPI module would be like

/* src.cpp */

#include <hippmpi.h>                    // include all definitions in HIPP MPI

int main(int argc, char const *argv[]){
    HIPP::MPI::Env env;                 // initialize the MPI environment
    auto world = env.world();           // the communication world object

    // use HIPP MPI to make communications
}

To generate the executable binary, the links to “libhippmpi.so” and “libhippcntl.so” are necessary. The compiling command in an Unix-like system would be like

$ mpicxx -std=c++17 src.cpp -lhippmpi -lhippcntl

To avoid confusion, we list the conventions used in this API reference:

  • The term Standard means the MPI standard APIs (types, functions, variables, macros, etc.) defined by the MPI Forum . E.g. The Standard call MPI_Init() is the entrance of (almost) all Standard MPI applications.

  • The HIPP MPI library has three components: the High-level API, the MPI Extensions and the Intermediate-level API (see below for the detail API references of each component). Therefore, when we say “high-level” class communicator, we mean the class HIPP::MPI::Comm in the high-level API, and when we say “extension” class Mutex, we mean the class HIPP::MPI::Mutex in the extension API.

  • The documentation text of one definition would probably refer to other definitions. If they are in the same namespace (HIPP::MPI here), we drop the namespace specifiers for clarity (e.g., class Comm means class HIPP::MPI::Comm).

  • The example code that uses C++ standard library may ignore the std:: namespace specifier (namely, assume a global using namespace std is used). This is not good in practice, but makes the example code more compact.

High-level API

MPI Extensions

Intermediate-level API