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authorMole Shang <[email protected]>2024-02-17 11:55:33 +0800
committerMole Shang <[email protected]>2024-02-17 12:22:07 +0800
commite8e0a7b4c97064eb5e9415726d7e38aaceccd3fd (patch)
treefb42ba5be7a8ae608b968266f62fd71fa889a89d /user/pingpong.c
parenta6af72924b115c1177d18d9b1eaba56623e4248b (diff)
parentd85aec2689c4250d0384904bdc11aa618c726bec (diff)
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Merge branch 'thread' into fs
Conflicts: .gitignore Makefile conf/lab.mk kernel/param.h
Diffstat (limited to 'user/pingpong.c')
-rw-r--r--user/pingpong.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/user/pingpong.c b/user/pingpong.c
new file mode 100644
index 0000000..7b03a76
--- /dev/null
+++ b/user/pingpong.c
@@ -0,0 +1,44 @@
+#include "kernel/types.h"
+#include "user/user.h"
+
+int
+main(int argc, char* argv[])
+{
+ int p[2];
+
+ if (argc > 1) {
+ fprintf(2, "usage: pingpong\n");
+ exit(1);
+ }
+
+ pipe(p);
+
+ int pid = fork();
+
+ if (pid == 0) {
+ short n;
+ read(p[0], &n, sizeof(n));
+ if (n == 42) {
+ fprintf(1, "%d: received ping\n", getpid());
+ }
+ n++;
+ write(p[1], &n, sizeof(n));
+ close(p[0]);
+ close(p[1]);
+ exit(0);
+ }
+
+ short n = 42;
+
+ write(p[1], &n, sizeof(n));
+ read(p[0], &n, sizeof(n));
+ if (n == 43) {
+ fprintf(1, "%d: received pong\n", getpid());
+ }
+ close(p[0]);
+ close(p[1]);
+
+ wait(0);
+
+ exit(0);
+}