HW2: 確保 player 的 random_key 不會重複，且 FIFO 內沒有東西HW2

1 files changed, 7 insertions, 0 deletions

diff --git a/hw2/judge.c b/hw2/judge.c
index 5e1da77..cb0d90c 100644
--- a/hw2/judge.c
+++ b/hw2/judge.c
@@ -192,8 +192,15 @@ int main (int argc, char* argv[]) {
 				if (t) {
 					write (ffd[i].fd, lastmsg, lastlen);
 				} else {
+					while (read (ffd[i].fd, trash_buf, 512) > 0);
 					fdata_clear (&ffd[i]);
 					ffd[i].key = random ();
+					for (int j = 1; j < i; j++) {
+						if (ffd[i].key == ffd[j].key) {
+							ffd[i].key = random ();
+							j = 0;
+						}
+					}
 					ffd[i].pid = fork ();
 					if (ffd[i].pid < 0) {
 						fprintf (stderr, "Cannot fork: %s\n", strerror (errno));