first commit

user/forktest.c

@@ -0,0 +1,56 @@
+// Test that fork fails gracefully.
+// Tiny executable so that the limit can be filling the proc table.
+
+#include "kernel/types.h"
+#include "kernel/stat.h"
+#include "user/user.h"
+
+#define N  1000
+
+void
+print(const char *s)
+{
+  write(1, s, strlen(s));
+}
+
+void
+forktest(void)
+{
+  int n, pid;
+
+  print("fork test\n");
+
+  for(n=0; n<N; n++){
+    pid = fork();
+    if(pid < 0)
+      break;
+    if(pid == 0)
+      exit(0);
+  }
+
+  if(n == N){
+    print("fork claimed to work N times!\n");
+    exit(1);
+  }
+
+  for(; n > 0; n--){
+    if(wait(0) < 0){
+      print("wait stopped early\n");
+      exit(1);
+    }
+  }
+
+  if(wait(0) != -1){
+    print("wait got too many\n");
+    exit(1);
+  }
+
+  print("fork test OK\n");
+}
+
+int
+main(void)
+{
+  forktest();
+  exit(0);
+}