Remove duplicate RandomizeBuffer implementation from socket util.

Instead use the one from test_util, which uses a more random seed for rand_r().

Suggested-by: Jamie Liu <jamieliu@google.com>
Suggested-by: Andrei Vagin <avagin@google.com>
PiperOrigin-RevId: 574243850

test/util/socket_util.cc

@@ -24,7 +24,6 @@
 #include <stack>
 
 #include "gtest/gtest.h"
-#include "absl/memory/memory.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_split.h"
 #include "absl/time/clock.h"
@@ -32,6 +31,7 @@
 #include "test/util/file_descriptor.h"
 #include "test/util/posix_error.h"
 #include "test/util/temp_path.h"
+#include "test/util/test_util.h"
 #include "test/util/thread_util.h"
 
 namespace gvisor {
@@ -598,14 +598,6 @@ void TransferTest(int fd1, int fd2) {
   EXPECT_EQ(0, memcmp(buf1, buf2, sizeof(buf1)));
 }
 
-// Initializes the given buffer with random data.
-void RandomizeBuffer(char* ptr, size_t len) {
-  uint32_t seed = time(nullptr);
-  for (size_t i = 0; i < len; ++i) {
-    ptr[i] = static_cast<char>(rand_r(&seed));
-  }
-}
-
 size_t CalculateUnixSockAddrLen(const char* sun_path) {
   // Abstract addresses always return the full length.
   if (sun_path[0] == 0) {

test/util/socket_util.h

@@ -401,9 +401,6 @@ SocketPairKind NoOp(SocketPairKind const& base);
 // ASSERT_NO_FATAL_FAILURE().
 void TransferTest(int fd1, int fd2);
 
-// Fills [buf, buf+len) with random bytes.
-void RandomizeBuffer(char* buf, size_t len);
-
 // Base test fixture for tests that operate on pairs of connected sockets.
 class SocketPairTest : public ::testing::TestWithParam<SocketPairKind> {
  protected:

test/util/test_util.cc

@@ -185,13 +185,12 @@ PosixErrorOr<uint64_t> Links(const std::string& path) {
   return static_cast<uint64_t>(st.st_nlink);
 }
 
-void RandomizeBuffer(void* buffer, size_t len) {
+void RandomizeBuffer(char* buffer, size_t len) {
   struct timespec ts = {};
   clock_gettime(CLOCK_MONOTONIC, &ts);
   uint32_t seed = static_cast<uint32_t>(ts.tv_nsec);
-  char* const buf = static_cast<char*>(buffer);
   for (size_t i = 0; i < len; i++) {
-    buf[i] = rand_r(&seed) % 255;
+    buffer[i] = rand_r(&seed) % 255;
   }
 }
 

test/util/test_util.h

@@ -738,7 +738,7 @@ std::vector<T> VecCat(Args&&... args) {
   } while (false)
 
 // Fill the given buffer with random bytes.
-void RandomizeBuffer(void* buffer, size_t len);
+void RandomizeBuffer(char* buffer, size_t len);
 
 template <typename T>
 inline PosixErrorOr<T> Atoi(absl::string_view str) {