On Tue, 2011-05-03 at 14:58 +0200, Karel Zak wrote:
> On Tue, May 03, 2011 at 09:50:41AM -0300, Davidlohr Bueso wrote:
...
> PATH_MAX (... although GNU/Hurd guys hate it, because they follow
> the universe and the universe is unlimited in space:-)
...
> yes, but without err()/warn(), proc_get_next_tid() has to return -1
> on errors.
>
Here is v2 of the procutils file with the suggested changes. Once we are
all set with this, I will resend the chrt patch, along with other
schedutil changes.
From: Davidlohr Bueso <dave@xxxxxxx>
Date: Tue, 3 May 2011 15:52:00 -0300
Subject: [PATCH] procutils: general purpose procfs parsing utilities
We include the following functions as a first approach:
- proc_open_tasks(): allocate resources and setup basic data
- proc_next_tid(): iterate over the thread group
- proc_close_tasks(): free used resources
Signed-off-by: Davidlohr Bueso <dave@xxxxxxx>
---
include/procutils.h | 12 +++++
lib/Makefile.am | 3 +-
lib/procutils.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 126 insertions(+), 1 deletions(-)
create mode 100644 include/procutils.h
create mode 100644 lib/procutils.c
diff --git a/include/procutils.h b/include/procutils.h
new file mode 100644
index 0000000..0af296b
--- /dev/null
+++ b/include/procutils.h
@@ -0,0 +1,12 @@
+#ifndef UTIL_LINUX_PROCUTILS
+#define UTIL_LINUX_PROCUTILS
+
+struct proc_tasks {
+ DIR *dir;
+};
+
+struct proc_tasks *proc_open_tasks(pid_t pid);
+void proc_close_tasks(struct proc_tasks *tasks);
+int proc_next_tid(struct proc_tasks *tasks, pid_t *tid);
+
+#endif
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 2b64459..7d966ff 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -3,7 +3,7 @@ include $(top_srcdir)/config/include-Makefile.am
AM_CPPFLAGS += -DTEST_PROGRAM
noinst_PROGRAMS = test_blkdev test_ismounted test_wholedisk test_mangle \
- test_tt test_canonicalize test_at test_strutils
+ test_tt test_canonicalize test_at test_strutils test_procutils
if LINUX
if HAVE_CPU_SET_T
noinst_PROGRAMS += test_cpuset
@@ -16,6 +16,7 @@ test_wholedisk_SOURCES = wholedisk.c
test_mangle_SOURCES = mangle.c
test_at_SOURCES = at.c
test_strutils_SOURCES = strutils.c
+test_procutils_SOURCES = procutils.c
if LINUX
test_cpuset_SOURCES = cpuset.c
endif
diff --git a/lib/procutils.c b/lib/procutils.c
new file mode 100644
index 0000000..c40b779
--- /dev/null
+++ b/lib/procutils.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2011 Davidlohr Bueso <dave@xxxxxxx>
+ *
+ * procutils.c: General purpose procfs parsing utilities
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library Public License for more details.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <dirent.h>
+
+#include "procutils.h"
+
+/*
+ * @pid: process ID for which we want to obtain the threads group
+ *
+ * Returns: newly allocated tasks structure
+ */
+struct proc_tasks *proc_open_tasks(pid_t pid)
+{
+ struct proc_tasks *tasks;
+ char path[PATH_MAX];
+
+ sprintf(path, "/proc/%d/task/", pid);
+
+ tasks = malloc(sizeof(struct proc_tasks));
+ if (!tasks)
+ return NULL;
+
+ tasks->dir = opendir(path);
+ if (!tasks->dir)
+ return NULL;
+
+ return tasks;
+}
+
+/*
+ * @tasks: allocated tasks structure
+ *
+ * Returns: nothing
+ */
+void proc_close_tasks(struct proc_tasks *tasks)
+{
+ if (tasks->dir) {
+ closedir(tasks->dir);
+ free(tasks);
+ }
+}
+
+/*
+ * @tasks: allocated task structure
+ * @tid: [output] one of the thread IDs belonging to the thread group
+ * If when an error occurs, it is set to 0.
+ *
+ * Returns: 0 on success, -1 on failure or no more threads
+ */
+int proc_next_tid(struct proc_tasks *tasks, pid_t *tid)
+{
+ struct dirent *d;
+
+ d = readdir(tasks->dir);
+ if (!d) /* no more listings or error */
+ goto err;
+
+ /* When we strtol "." or "..", *tid will be 0 */
+ *tid = (pid_t) strtol(d->d_name, (char **)NULL, 10);
+ if (errno)
+ goto err;
+
+ return 0;
+err:
+ *tid = 0;
+ return -1;
+}
+
+#ifdef TEST_PROGRAM
+int main(int argc, char *argv[])
+{
+ int i = 0;
+ pid_t tid, pid;
+ struct proc_tasks *ts;
+
+ if (argc != 2) {
+ fprintf(stderr, "usage: %s <pid>\n", argv[0]);
+ exit(EXIT_FAILURE);
+ }
+
+ pid = strtol(argv[1], (char **) NULL, 10);
+ ts = proc_open_tasks(pid);
+
+ printf("%d: ", pid);
+ while (proc_next_tid(ts, &tid) == 0)
+ if (tid)
+ printf("%d ", tid);
+ printf("\n");
+
+ proc_close_tasks(ts);
+ return EXIT_SUCCESS;
+}
+#endif /* TEST_PROGRAM */
--
1.7.1
--
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