From f71a1e3618b5f095a5f8421308323f08bda2a5e5 Mon Sep 17 00:00:00 2001
From: Raghavendra Bhat <raghavendrambk@gmail.com>
Date: Wed, 13 Jul 2011 18:15:27 +0530
Subject: Custom c programs for locking and multithreaded fops

---
 c_pgms/locking/open_lock_close.c | 87 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 c_pgms/locking/open_lock_close.c

(limited to 'c_pgms/locking/open_lock_close.c')

diff --git a/c_pgms/locking/open_lock_close.c b/c_pgms/locking/open_lock_close.c
new file mode 100644
index 0000000..44505d1
--- /dev/null
+++ b/c_pgms/locking/open_lock_close.c
@@ -0,0 +1,87 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#define NUM_FILES 100000
+
+void open_lock_close (char *name);
+void delete_file (char *name);
+
+int
+main ()
+{
+        int ret = 0;
+        char filename[256] = {0,};
+        int i = 0;
+
+        for (i = 1; i <= NUM_FILES ; i++) {
+                snprintf (filename, sizeof (filename), "file-%d", i);
+                open_lock_close (filename);
+        }
+
+        /* for (i = 1; i <= 100000; i++) { */
+        /*         snprintf (filename, sizeof (filename), "file-%d", i); */
+        /*         delete_file (filename); */
+        /* } */
+
+        return 0;
+}
+
+void
+open_lock_close (char *name)
+{
+        int ret = 0;
+        int fd = -1;
+        struct flock lock;
+        char *data = "This is a line";
+
+        fd = open (name, O_CREAT|O_RDWR, 0644);
+        if (fd == -1) {
+                fprintf (stderr, "Error: cannot open the file %s (%s)\n", name,
+                         strerror (errno));
+                return;
+        }
+
+        lock.l_type = F_RDLCK;
+        lock.l_whence = SEEK_SET;
+        lock.l_start = 0;
+        lock.l_len = 0;
+        lock.l_pid = 0;
+
+        ret = fcntl (fd, F_SETLK, &lock);
+        if (ret == -1)
+                fprintf (stderr, "Error: cannot lock the file %s (%s)\n", name,
+                         strerror (errno));
+
+        ret = flock (fd, LOCK_SH);
+        if (ret == -1)
+                fprintf (stderr, "Error: cannot flock the file %s (%s)\n", name,
+                         strerror (errno));
+
+        ret = write (fd, data, strlen (data));
+        if (ret == -1)
+                fprintf (stderr, "Error: cannot write the file %s (%s)\n", name,
+                         strerror (errno));
+
+        close (fd);
+
+        return;
+}
+
+void
+delete_file (char *name)
+{
+        int ret = 0;
+
+        ret = unlink (name);
+        if (ret < 0)
+                fprintf (stderr, "Error: Cannot unlink the file %s (%s)\n",
+                         name, strerror (errno));
+
+        return;
+}
-- 
cgit