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batchmode_c.c
/* Copyright 2024, Gurobi Optimization, LLC */
/* This example reads a MIP model from a file, solves it in batch mode,
* and prints the JSON solution string. */
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#if defined (WIN32) || defined (WIN64)
#include <Windows.h>
#define sleep(n) Sleep(1000*n)
#else
#include <unistd.h>
#endif
#include "gurobi_c.h"
/* setup gurobi environment */
int setupbatchconnection(GRBenv **envP)
{
int error = 0;
GRBenv *env = NULL;
/* setup a batch environment */
error = GRBemptyenv(envP);
if (error) goto QUIT;
env = *envP;
error = GRBsetintparam(env, "CSBatchMode", 1);
if (error) goto QUIT;
error = GRBsetstrparam(env, "LogFile", "batchmode.log");
if (error) goto QUIT;
error = GRBsetstrparam(env, "CSManager", "http://localhost:61080");
if (error) goto QUIT;
error = GRBsetstrparam(env, "UserName", "gurobi");
if (error) goto QUIT;
error = GRBsetstrparam(env, "ServerPassword", "pass");
if (error) goto QUIT;
error = GRBstartenv(env);
if (error) goto QUIT;
QUIT:
if (error) {
printf("Failed to setup environment, error code %d\n", error);
} else {
printf("Successfully created environment\n");
}
return error;
}
/* display batch-error code if any */
void batcherrorinfo(GRBbatch *batch)
{
int error = 0;
int errorCode;
char *errorMsg;
char *BatchID;
if (!batch) goto QUIT;
/* query the last error code */
error = GRBgetbatchintattr(batch, "BatchErrorCode", &errorCode);
if (error || !errorCode) goto QUIT;
/* query the last error message */
error = GRBgetbatchstrattr(batch, "BatchErrorMessage", &errorMsg);
if (error) goto QUIT;
error = GRBgetbatchstrattr(batch, "BatchID", &BatchID);
if (error) goto QUIT;
printf("Batch ID %s Error Code %d (%s)\n", BatchID, errorCode, errorMsg);
QUIT:
return;
}
/* create a batch request for given problem file */
int newbatchrequest(const char *filename,
char *BatchID)
{
int error = 0;
GRBenv *env = NULL;
GRBenv *menv = NULL;
GRBmodel *model = NULL;
char tag[128];
int cols, j;
/* setup a batch connection */
error = setupbatchconnection(&env);
if (error) goto QUIT;
/* read a model */
error = GRBreadmodel(env, filename, &model);
if (error) goto QUIT;
/* set some params */
menv = GRBgetenv(model);
error = GRBsetdblparam(menv, "MIPGap", 0.01);
if (error) goto QUIT;
/* for extra detailed information on JSON solution string */
error = GRBsetintparam(menv, "JSONSolDetail", 1);
if (error) goto QUIT;
/* setup some tags, we need tags to be able to query results later on */
error = GRBgetintattr(model, "NumVars", &cols);
if (error) goto QUIT;
if (cols > 10) cols = 10;
for (j = 0; j < cols; j++) {
sprintf(tag, "MyUniqueVariableID%d",j);
error = GRBsetstrattrelement(model, "VTag", j, tag);
}
/* submit batch request to the Manager */
error = GRBoptimizebatch(model, BatchID);
if (error) goto QUIT;
QUIT:
if (error) {
printf("Failed to submit a new batch request, error code %d\n", error);
} else {
printf("Successfully submitted new batch request %s\n", BatchID);
}
GRBfreemodel(model);
GRBfreeenv(env);
return error;
}
/* wait for final bstatus */
int waitforfinalstatus(const char *BatchID)
{
int error = 0;
GRBenv *env = NULL;
GRBbatch *batch = NULL;
time_t start, current;
int bstatus;
/* setup a batch connection */
error = setupbatchconnection(&env);
if (error) goto QUIT;
/* create batch-object */
error = GRBgetbatch(env, BatchID, &batch);
if (error) goto QUIT;
/* query bstatus, and wait for completed */
error = GRBgetbatchintattr(batch, "BatchStatus", &bstatus);
if (error) goto QUIT;
start = time(NULL);
while (bstatus == GRB_BATCH_SUBMITTED) {
/* abort if taking too long */
current = time(NULL);
if (current - start >= 3600) {
/* request to abort the batch */
error = GRBabortbatch(batch);
if (error) goto QUIT;
}
/* do not bombard the server */
sleep(1u);
/* update local attributes */
error = GRBupdatebatch(batch);
if (error) goto QUIT;
/* query bstatus */
error = GRBgetbatchintattr(batch, "BatchStatus", &bstatus);
if (error) goto QUIT;
/* deal with failed bstatus */
if (bstatus == GRB_BATCH_FAILED) {
/* retry the batch request */
error = GRBretrybatch(batch);
if (error) goto QUIT;
bstatus = GRB_BATCH_SUBMITTED;
}
}
QUIT:
if (error) {
printf("Failed to wait for final bstatus, error code %d\n", error);
} else {
printf("Final Batch Status %d\n", bstatus);
}
batcherrorinfo(batch);
/* release local resources */
GRBfreebatch(batch);
GRBfreeenv(env);
return error;
}
/* final report on batch request */
int finalreport(const char *BatchID)
{
int error = 0;
GRBenv *env = NULL;
GRBbatch *batch = NULL;
char *jsonsol = NULL;
int bstatus;
/* setup a batch connection */
error = setupbatchconnection(&env);
if (error) goto QUIT;
/* create batch object */
error = GRBgetbatch(env, BatchID, &batch);
if (error) goto QUIT;
/* query bstatus, and wait for completed */
error = GRBgetbatchintattr(batch, "BatchStatus", &bstatus);
if (error) goto QUIT;
/* display depending on batch bstatus */
switch (bstatus) {
case GRB_BATCH_CREATED:
printf("Batch is 'CREATED'\n");
printf("maybe batch-creation process was killed?\n");
break;
case GRB_BATCH_SUBMITTED:
printf("Batch is 'SUBMITTED'\n");
printf("Some other user re-submitted this Batch object?\n");
break;
case GRB_BATCH_ABORTED:
printf("Batch is 'ABORTED'\n");
break;
case GRB_BATCH_FAILED:
printf("Batch is 'FAILED'\n");
break;
case GRB_BATCH_COMPLETED:
/* print JSON solution into string */
error = GRBgetbatchjsonsolution(batch, &jsonsol);
if (error) goto QUIT;
printf("JSON solution: %s\n", jsonsol);
/* save solution into a file */
error = GRBwritebatchjsonsolution(batch, "batch-sol.json.gz");
if (error) goto QUIT;
break;
default:
printf("This should not happen, probably points to a"
" user-memory corruption problem\n");
exit(EXIT_FAILURE);
break;
}
QUIT:
if (error) {
printf("Failed to perform final report, error code %d\n", error);
} else {
printf("Reporting done\n");
}
batcherrorinfo(batch);
if (jsonsol)
GRBfree(jsonsol);
GRBfreebatch(batch);
GRBfreeenv(env);
return error;
}
/* remove batch ID from manager */
int discardbatch(const char *BatchID)
{
int error = 0;
GRBenv *env = NULL;
GRBbatch *batch = NULL;
/* setup a batch connection */
error = setupbatchconnection(&env);
if (error) goto QUIT;
/* create batch object */
error = GRBgetbatch(env, BatchID, &batch);
if (error) goto QUIT;
/* discard the batch object in the manager */
error = GRBdiscardbatch(batch);
if (error) goto QUIT;
QUIT:
batcherrorinfo(batch);
GRBfreebatch(batch);
GRBfreeenv(env);
return error;
}
int
main(int argc,
char **argv)
{
int error = 0;
char BatchID[GRB_MAX_STRLEN+1];
/* ensure enough parameters */
if (argc < 2) {
fprintf(stderr, "Usage: %s filename\n", argv[0]);
goto QUIT;
}
/* create a new batch request */
error = newbatchrequest(argv[1], BatchID);
if (error) goto QUIT;
/* wait for final bstatus */
error = waitforfinalstatus(BatchID);
if (error) goto QUIT;
/* query final bstatus, and if completed, print JSON solution */
error = finalreport(BatchID);
if (error) goto QUIT;
/* eliminate batch from the manager */
error = discardbatch(BatchID);
if (error) goto QUIT;
QUIT:
return error;
}
