The OMPT-Multiplexing header file allows a tool to load a second tool to overcome the restriction of the OpenMP to only load one tool at a time. The header file can also be used to load more than two tools using a cascade of tools that include the header file. OMPT-Multiplexing takes care of the multiplexing of OMPT callbacks, data pointers and runtime entry functions.
Examples can be found under ./tests
Either build llvm and find lit+FileCheck in build directory of llvm or install using
$ pip install --upgrade --user pip $ export PATH=$HOME/.local/bin:$PATH $ export PYTHONPATH=$HOME/.local/lib/python3.*/site-packages/ $ pip install --user lit
$ make check-ompt-multiplex
Code of first tool must include the following with the convention, that the environment variable containing the path to the client tool is the tool name with the suffix “_TOOL_LIBRARIES”:
#define CLIENT_TOOL_LIBRARIES_VAR "EXAMPLE_TOOL_LIBRARIES" #include <ompt-multiplex.h>
Note that functions and variables with prefix “ompt_multiplex” are reserved by the tool
To use both tools execute the following:
$ clang -fopenmp -o program.exe $ OMP_TOOL_LIBRARIES=/path/to/first/tool.so EXAMPLE_TOOL_LBRARIES=/path/to/second/tool.so ./program.exe
Note that EXAMPLE_TOOL_LIBRARIES may also contain a list of paths to tools which will be tried to load in order (similar to lists in OMP_TOOL_LIBRARIES).
To reduce the amount of memory allocations, the user can define macros before including the ompt-multiplex.h file, that specify custom data access handlers:
#define OMPT_MULTIPLEX_CUSTOM_GET_CLIENT_THREAD_DATA get_client_thread_data #define OMPT_MULTIPLEX_CUSTOM_GET_CLIENT_PARALLEL_DATA get_client_parallel_data #define OMPT_MULTIPLEX_CUSTOM_GET_CLIENT_TASK_DATA get_client_task_data
This will reverse the calling order of the current tool and its client. In order to avoid this, one can specify a custom delete handler as well:
#define OMPT_MULTIPLEX_CUSTOM_DELETE_THREAD_DATA delete_thread_data #define OMPT_MULTIPLEX_CUSTOM_DELETE_PARALLEL_DATA delete_parallel_data #define OMPT_MULTIPLEX_CUSTOM_DELETE_TASK_DATA delete_task_data