From: Ben Pfaff <blp@nicira.com>
Date: Wed, 24 Dec 2008 01:02:46 +0000 (-0800)
Subject: New functions random_uint8(), random_uint16().
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8638a791704d19b689c1f23d55d1bb040a0cdcdf;p=openvswitch

New functions random_uint8(), random_uint16().

Also, reimplement random_uint32() to make fewer calls to rand().
---

diff --git a/lib/random.c b/lib/random.c
index f4fab4c8..14be87e5 100644
--- a/lib/random.c
+++ b/lib/random.c
@@ -64,12 +64,40 @@ random_bytes(void *p_, size_t n)
     }
 }
 
+uint8_t
+random_uint8(void)
+{
+    random_init();
+    return rand();
+}
+
+uint16_t
+random_uint16(void)
+{
+    if (RAND_MAX >= UINT16_MAX) {
+        random_init();
+        return rand();
+    } else {
+        uint16_t x;
+        random_bytes(&x, sizeof x);
+        return x;
+    }
+}
+
 uint32_t
 random_uint32(void)
 {
-    uint32_t x;
-    random_bytes(&x, sizeof x);
-    return x;
+    if (RAND_MAX >= UINT32_MAX) {
+        random_init();
+        return rand();
+    } else if (RAND_MAX == INT32_MAX) {
+        random_init();
+        return rand() | ((rand() & 1u) << 31);
+    } else {
+        uint32_t x;
+        random_bytes(&x, sizeof x);
+        return x;
+    }
 }
 
 int
diff --git a/lib/random.h b/lib/random.h
index d9f5f9d0..80332308 100644
--- a/lib/random.h
+++ b/lib/random.h
@@ -38,6 +38,8 @@
 #include <stdint.h>
 
 void random_bytes(void *, size_t);
+uint8_t random_uint8(void);
+uint16_t random_uint16(void);
 uint32_t random_uint32(void);
 int random_range(int max);