Transfers data to a specified processing element(PE).
#include <shmem.h> void shmem_float_put(float *target, const float *source, size_t len, int pe);
This routine provides a high-performance method for copying a contiguous data object from the local PE to a contiguous data object on a different PE
This routine returns when the data has been copied out of the source array on the local PE, but not necessarily before the data has been delivered to the remote data object. To enforce the ordering/completion of the put routines, the use of shmem_fence, shmem_quiet, shmem_barrier or shmem_barrier_all is needed.
The function shmem_float_put() writes contiguous elements of float type to the remote PE.
Please refer to Atomicity and Coherency section for atomicity and coherence model in the OpenSHMEM documentation
#include <stdlib.h> #include <stdio.h> #include <shmem.h> #define GLOBAL_ARRAY_SIZE 10 #define INT_INIT_VALUE 1234 //can not use #define const float FLOAT_INIT_VALUE = 1234.123456; static float gFloatElement = 0; static float gFloatArray[GLOBAL_ARRAY_SIZE] = {0}; static int gIntElement = 0; static int gIntArray[GLOBAL_ARRAY_SIZE] = {0}; int main (int argc, char* argv[]) { int total_tasks = -1; int my_task = -1; start_pes(0); total_tasks = _num_pes(); if (total_tasks <= 0) { printf("FAILED\n"); exit(1); } else { printf("number of pes is %d\n", total_tasks); } if (total_tasks < 2 || total_tasks % 2) { printf("FAILED: The number of pes should be an even number. (at least 2)\n"); exit(1); } my_task = _my_pe(); if (my_task < 0){ printf("FAILED\n"); exit(1); } else { printf("my pe id is %d\n", my_task); } printf("The address of gIntElement is %p\n", &gIntElement); printf("The address of gIntArray is %p\n", gIntArray); printf("The address of gFloatElement is %p\n", &gFloatElement); printf("The address of gFloatArray is %p\n", gFloatArray); // even tasks put value to odd tasks if (my_task%2 == 0) { int tgt_task = my_task + 1; //for int gIntElement = INT_INIT_VALUE; for (int i=0; i<GLOBAL_ARRAY_SIZE; i++) { gIntArray[i] = INT_INIT_VALUE; } shmem_int_p(&gIntElement, gIntElement, tgt_task); shmem_int_put(gIntArray, gIntArray, GLOBAL_ARRAY_SIZE, tgt_task); //for float gFloatElement = FLOAT_INIT_VALUE; for (int i=0; i<GLOBAL_ARRAY_SIZE; i++) { gFloatArray[i] = FLOAT_INIT_VALUE; } shmem_float_p(&gFloatElement, gFloatElement, tgt_task); shmem_float_put(gFloatArray, gFloatArray, GLOBAL_ARRAY_SIZE, tgt_task); } shmem_barrier_all(); // odd tasks check value if (my_task%2 == 1) { //for int if (gIntElement != INT_INIT_VALUE) { printf("FAILED: element should be %d instead of %d\n", INT_INIT_VALUE, gIntElement); exit(1); } for (int i=0; i<GLOBAL_ARRAY_SIZE; i++) { if (gIntArray[i] != INT_INIT_VALUE) { printf("FAILED, array[%d] should be %d instead of %d\n", i, INT_INIT_VALUE, gIntArray[i]); } } //for float if (gFloatElement != FLOAT_INIT_VALUE) { printf("FAILED: element should be %f instead of %f\n", FLOAT_INIT_VALUE, gFloatElement); exit(1); } for (int i=0; i<GLOBAL_ARRAY_SIZE; i++) { if (gFloatArray[i] != FLOAT_INIT_VALUE) { printf("FAILED, array[%d] should be %f instead of %f\n", i, FLOAT_INIT_VALUE, gFloatArray[i]); } } } shmem_barrier_all(); printf("PASSED\n"); return 0; }
Subroutines: shmem_barrier, shmem_put, shmem_fence, shmem_iput, shmem_quiet