# IPC-Debug

Allows to compare values between two running process to track divergence.
One process serves as reference (root), the other (client) sends its values over a named pipe.

See [ipc_debug.h](./include/ipc_debug.h) for available sub routines.

Test program that compares ASCII characters distributed over MPI cluster:

```
terminalA $ mkfifo /tmp/pipe
terminalA $ IPC_DEBUG_ROOT=1 IPC_DEBUG_FILE=/tmp/pipe mpirun -np 3 --use-hwthread-cpus build/mpi_test 123123
terminalB $ IPC_DEBUG_FILE=/tmp/pipe mpirun -np 2 --use-hwthread-cpus build/mpi_test 123125
[IPCDBG] Assertion failed in vector  at index 5. Root has 51 but client has 52
#5    Source "/home/christoph/Studium/HiWi2/ipc-debug/src/mpi_test.cpp", line 63, in main
         60:     debug_ipc_mpi_set_data_distribution(start_index, characters_per_rank);
         61: 
         62:     // Make actual assertion
      >  63:     debug_ipc_assert_equal_mpi_double_array(arr.data(), characters_per_rank);
         64: 
         65:     MPI_Barrier(MPI_COMM_WORLD);
         66:     MPI_Finalize();

```