/** * fh is shared by all processes. * In case of reading, after one process finishes, and the fh moves to the new position, * the another process use this fh to reading. * * int MPI_File_seek_shared(MPI_File fh, MPI_Offset offset, int whence); * int MPI_File_get_position_shared(MPI_File fh, MPI_Offset * offset); * * int MPI_File_write_shared(MPI_File fh, void * buf, int count, MPI_Datatype datatype, MPI_Status * status); * int MPI_File_read_shared(MPI_File fh, void * buf, int count, MPI_Datatype datatype, MPI_Status * status); * * non-blocking read/write, need MPI_Wait to wait for finishing * int MPI_File_iread_shared(MPI_File fh, void * buf, int count, MPI_Datatype datatype, MPI_Request * request) * int MPI_File_iwrite_shared(MPI_File fh, void * buf, int count, MPI_Datatype datatype, MPI_Request * request) * * read/write in oder of rankID * int MPI_File_read_ordered(MPI_File fh, void * buf, int count, MPI_Datatype datatype, MPI_Status * status); * int MPI_File_write_ordered(MPI_File fh, void * buf, int count, MPI_Datatype datatype, MPI_Status * status); */ int main(int argc, char *argv[]) { int totalTaskNum, rankID; MPI_Init(&argc, &argv); MPI_Comm_rank(MPI_COMM_WORLD, &rankID); MPI_Comm_size(MPI_COMM_WORLD, &totalTaskNum); char *filename = "file.txt"; MPI_File fh; MPI_Status status; MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh); char write_buf[128]; sprintf(write_buf, "rankID = %d, totalTaskNum = %d\n", rankID, totalTaskNum); // MPI_File_write_shared(fh, write_buf, strlen(write_buf), MPI_CHAR, &status); // MPI_File_write_ordered(fh, write_buf, strlen(write_buf), MPI_CHAR, &status); MPI_Request request; MPI_File_iwrite_shared(fh, write_buf, strlen(write_buf), MPI_CHAR, &request); MPI_Wait(&request, &status); MPI_Offset offset; MPI_File_get_position_shared(fh, &offset); printf("1: rankID = %d, Now the position is offset = %lld\n", rankID, offset); sleep(3); MPI_Offset offset2 = 0; int whence = MPI_SEEK_SET; MPI_File_seek_shared(fh, offset2, whence); MPI_File_get_position_shared(fh, &offset); printf("2: rankID = %d, Now the position is offset = %lld\n", rankID, offset); sleep(3); char read_buf[30]; // MPI_File_read_ordered(fh, read_buf, sizeof(read_buf), MPI_CHAR, &status); // MPI_File_read_shared(fh, read_buf, sizeof(read_buf), MPI_CHAR, &status); MPI_File_iread_shared(fh, read_buf, sizeof(read_buf), MPI_CHAR, &request); MPI_Wait(&request, &status); printf("rankID = %d, content = '%s'\n", rankID, read_buf); MPI_File_close(&fh);//after open, fh has the communicator info MPI_Finalize(); return 0; }
void FORTRAN_API mpi_file_get_position_shared_(MPI_Fint *fh, MPI_Offset *offset, int *ierr ) { MPI_File fh_c; fh_c = MPI_File_f2c(*fh); *ierr = MPI_File_get_position_shared(fh_c, offset); }
static int destroyAFiledataMPINONB(void *v) { int iret = 0; aFiledataM *of; MPI_Status status; int rankNode = commInqRankNode (); MPI_Offset endpos; of = (aFiledataM * ) v; xdebug ( "IOPE%d: close file %d, name=\"%s\"", rankNode, of->fileID, of->name ); /* close file */ xmpi(MPI_Wait(&of->request, &status)); xmpi(MPI_Barrier(commInqCommNode())); xmpi(MPI_File_get_position_shared(of->fh, &endpos)); xmpi(MPI_File_set_size(of->fh, endpos)); iret = MPI_File_close ( & ( of->fh )); /* file closed, cleanup */ dbuffer_cleanup ( & ( of->db1 )); dbuffer_cleanup ( & ( of->db2 )); free ( of ); xdebug ( "IOPE%d: closed file, cleaned up, return", rankNode ); return iret == MPI_SUCCESS ? 0 : -1; }
JNIEXPORT jlong JNICALL Java_mpi_File_getPositionShared( JNIEnv *env, jobject jthis, jlong fh) { MPI_Offset offset; int rc = MPI_File_get_position_shared((MPI_File)fh, &offset); ompi_java_exceptionCheck(env, rc); return (jlong)offset; }
void ompi_file_get_position_shared_f(MPI_Fint *fh, MPI_Offset *offset, MPI_Fint *ierr) { int c_ierr; MPI_File c_fh = MPI_File_f2c(*fh); MPI_Offset c_offset; c_ierr = MPI_File_get_position_shared(c_fh, &c_offset); if (NULL != ierr) *ierr = OMPI_INT_2_FINT(c_ierr); if (MPI_SUCCESS == c_ierr) { *offset = (MPI_Offset) c_offset; } }