numam-dpdk/lib/librte_eal/common/eal_common_proc.c
Harry van Haaren dd3e00138d eal: check if primary process is alive
This patch adds a new function to the EAL API:
int rte_eal_primary_proc_alive(const char *path);

The function indicates if a primary process is alive right now.
This functionality is implemented by testing for a write-
lock on the config file, and the function tests for a lock.

The use case for this functionality is that a secondary
process can wait until a primary process starts by polling
the function and waiting. When the primary is running, the
secondary continues to poll to detect if the primary process
has quit unexpectedly, the secondary process can detect this.

Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: Maryam Tahhan <maryam.tahhan@intel.com>
2016-03-09 16:13:09 +01:00

62 lines
2.2 KiB
C

/*-
* BSD LICENSE
*
* Copyright(c) 2016 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <rte_eal.h>
#include "eal_filesystem.h"
#include "eal_internal_cfg.h"
int
rte_eal_primary_proc_alive(const char *config_file_path)
{
int config_fd;
if (config_file_path)
config_fd = open(config_file_path, O_RDONLY);
else {
char default_path[PATH_MAX+1];
snprintf(default_path, PATH_MAX, RUNTIME_CONFIG_FMT,
default_config_dir, "rte");
config_fd = open(default_path, O_RDONLY);
}
if (config_fd < 0)
return 0;
int ret = lockf(config_fd, F_TEST, 0);
close(config_fd);
return !!ret;
}