NAME¶

gearman_execute - Gearmand Documentation, http://gearman.info/

SYNOPSIS¶

#include <libgearman/gearman.h>

Link with -lgearman

DESCRIPTION¶

gearman_execute() is used to create a new gearman_task_st <#c.gearman_task_st> that is executed against the function that is found via the function_name argument.

gearman_work_t <#c.gearman_work_t> can be used to describe the work that will be executed, it is built with gearman_argument_make() <#c.gearman_argument_make>. The argument unique_str is optional, but if supplied it is used for coalescence by gearmand.

gearman_argument_t <#c.gearman_argument_t> is the work that the client <#term-client> will send the to the server

If gearman_execute() is given a gearman_work_t <#c.gearman_work_t> that has been built with a reducer, it takes the gearman_argument_t <#c.gearman_argument_t> and executes it against a function <#term-function> as it normally would, but it tells the function to then process the results through a reducer <#term-reducer> function that the gearman_work_t <#c.gearman_work_t> was created with.

What is happening is that the function is mappping/splitting work up into units, and then sending each of them to the reducer function. Once all work is completed, the mapper <#term-mapper> function will aggregate the work via an aggregator function, gearman_aggregator_fn <#c.gearman_aggregator_fn>, and return a result.

If any of the units of work error, the job will be aborted. The resulting value will be stored in the gearman_task_st <#c.gearman_task_st>.

The result can be obtained from the task by calling gearman_task_result() <#c.gearman_task_result> to gain the gearman_result_st <#c.gearman_result_st>.

RETURN VALUE¶

gearman_execute() returns a c:type:gearman_task_st.

EXAMPLE¶

/*


  Example code to show how to send a string to a function called "reverse" and print the results.
*/
/*
# Gearman server and library
# Copyright (C) 2012 Data Differential, http://datadifferential.com/
# All rights reserved.
#
# Use and distribution licensed under the BSD license.  See
# the COPYING file in this directory for full text.
*/
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <libgearman/gearman.h>
int main(void)
{


  gearman_client_st *client= gearman_client_create(NULL);


  gearman_return_t ret= gearman_client_add_server(client, "localhost", 0);


  if (gearman_failed(ret))


  {


    return EXIT_FAILURE;


  }


  gearman_argument_t value= gearman_argument_make(0, 0, "Reverse Me", strlen("Reverse Me"));


  gearman_task_st *task= gearman_execute(client, 


                                         "reverse", strlen("reverse"),  // function


                                         NULL, 0,  // no unique value provided


                                         NULL, 


                                         &value, 0);


  if (task == NULL) // If gearman_execute() can return NULL on error


  {


    fprintf(stderr, "Error: %s\n", gearman_client_error(client));


    gearman_client_free(client);


    return EXIT_FAILURE;


  }


  // Make sure the task was run successfully


  if (gearman_success(gearman_task_return(task)))


  {


    // Make use of value


    gearman_result_st *result= gearman_task_result(task);


    printf("%.*s\n", (int)gearman_result_size(result), gearman_result_value(result));


  }


  gearman_client_free(client);


  return EXIT_SUCCESS;
}

HOME¶

To find out more information please check: <http://gearman.info/>

SEE ALSO¶

gearmand(8) libgearman(3)

Author¶

Data Differential http://www.datadifferential.com/

Copyright¶

2011-2014, Data Differential, http://www.datadifferential.com/