[Libstoragemgmt-devel] [PATCH] tester.c: Make generateRandom work in all cases

[Tony Asleson]

If we happen to call the function before we start
forking other processes the existing code will
produce repeating sequences in each child process.

Signed-off-by: Tony Asleson <***@redhat.com>
---
test/tester.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/test/tester.c b/test/tester.c
index c18a915..66de783 100644
--- a/test/tester.c
+++ b/test/tester.c
@@ -36,15 +36,26 @@ static int which_plugin = 0;

lsmConnect *c = NULL;

+/**
+* Generates a random string in the buffer with specified length.
+* Note: This function should not produce repeating sequences or duplicates
+* regardless if it's used repeatedly in the same function in the same process
+* or different forked processes.
+* @param buff Buffer to write the random string to
+* @param len Length of the random string
+*/
void generateRandom(char *buff, uint32_t len)
{
uint32_t i = 0;
static int seed = 0;
-
- if( !seed ) {
- seed = time(NULL) + getpid();
- srandom(seed);
- }
+ static int pid = 0;
+
+ /* Re-seed the random number generator at least once per unique process */
+ if( (!seed || !pid) || (pid != getpid()) ) {
+ seed = time(NULL);
+ pid = getpid();
+ srandom(seed + pid);
+ }

if( buff && (len > 1) ) {
for(i = 0; i < (len - 1); ++i) {