Revert "Unregister pthread_atfork handlers on dlclose()"

 The visibility control in pthread_atfork.h is incorrect.
 It breaks 64bit libc.so by hiding pthread_atfork.

 This reverts commit 6df122f8528f9b9fcf7dfea14ae98b0ef66274e1.

Change-Id: I21e4b344d500c6f6de0ccb7420b916c4e233dd34
diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index b8cfd56..a299f02 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -16,7 +16,6 @@
 
 #include <gtest/gtest.h>
 
-#include <dlfcn.h>
 #include <errno.h>
 #include <inttypes.h>
 #include <limits.h>
@@ -988,14 +987,14 @@
 }
 
 static int g_atfork_prepare_calls = 0;
-static void AtForkPrepare1() { g_atfork_prepare_calls = (g_atfork_prepare_calls * 10) + 1; }
-static void AtForkPrepare2() { g_atfork_prepare_calls = (g_atfork_prepare_calls * 10) + 2; }
+static void AtForkPrepare1() { g_atfork_prepare_calls = (g_atfork_prepare_calls << 4) | 1; }
+static void AtForkPrepare2() { g_atfork_prepare_calls = (g_atfork_prepare_calls << 4) | 2; }
 static int g_atfork_parent_calls = 0;
-static void AtForkParent1() { g_atfork_parent_calls = (g_atfork_parent_calls * 10) + 1; }
-static void AtForkParent2() { g_atfork_parent_calls = (g_atfork_parent_calls * 10) + 2; }
+static void AtForkParent1() { g_atfork_parent_calls = (g_atfork_parent_calls << 4) | 1; }
+static void AtForkParent2() { g_atfork_parent_calls = (g_atfork_parent_calls << 4) | 2; }
 static int g_atfork_child_calls = 0;
-static void AtForkChild1() { g_atfork_child_calls = (g_atfork_child_calls * 10) + 1; }
-static void AtForkChild2() { g_atfork_child_calls = (g_atfork_child_calls * 10) + 2; }
+static void AtForkChild1() { g_atfork_child_calls = (g_atfork_child_calls << 4) | 1; }
+static void AtForkChild2() { g_atfork_child_calls = (g_atfork_child_calls << 4) | 2; }
 
 TEST(pthread, pthread_atfork_smoke) {
   ASSERT_EQ(0, pthread_atfork(AtForkPrepare1, AtForkParent1, AtForkChild1));
@@ -1006,71 +1005,13 @@
 
   // Child and parent calls are made in the order they were registered.
   if (pid == 0) {
-    ASSERT_EQ(12, g_atfork_child_calls);
+    ASSERT_EQ(0x12, g_atfork_child_calls);
     _exit(0);
   }
-  ASSERT_EQ(12, g_atfork_parent_calls);
+  ASSERT_EQ(0x12, g_atfork_parent_calls);
 
   // Prepare calls are made in the reverse order.
-  ASSERT_EQ(21, g_atfork_prepare_calls);
-  int status;
-  ASSERT_EQ(pid, waitpid(pid, &status, 0));
-}
-
-static void AtForkPrepare3() { g_atfork_prepare_calls = (g_atfork_prepare_calls * 10) + 3; }
-static void AtForkPrepare4() { g_atfork_prepare_calls = (g_atfork_prepare_calls * 10) + 4; }
-
-static void AtForkParent3() { g_atfork_parent_calls = (g_atfork_parent_calls * 10) + 3; }
-static void AtForkParent4() { g_atfork_parent_calls = (g_atfork_parent_calls * 10) + 4; }
-
-static void AtForkChild3() { g_atfork_child_calls = (g_atfork_child_calls * 10) + 3; }
-static void AtForkChild4() { g_atfork_child_calls = (g_atfork_child_calls * 10) + 4; }
-
-TEST(pthread, pthread_atfork_with_dlclose) {
-  ASSERT_EQ(0, pthread_atfork(AtForkPrepare1, AtForkParent1, AtForkChild1));
-
-  void* handle = dlopen("libtest_pthread_atfork.so", RTLD_NOW | RTLD_LOCAL);
-  ASSERT_TRUE(handle != nullptr) << dlerror();
-  typedef int (*fn_t)(void (*)(void), void (*)(void), void (*)(void));
-  fn_t fn = reinterpret_cast<fn_t>(dlsym(handle, "proxy_pthread_atfork"));
-  ASSERT_TRUE(fn != nullptr) << dlerror();
-  // the library registers 2 additional atfork handlers in a constructor
-  ASSERT_EQ(0, fn(AtForkPrepare2, AtForkParent2, AtForkChild2));
-  ASSERT_EQ(0, fn(AtForkPrepare3, AtForkParent3, AtForkChild3));
-
-  ASSERT_EQ(0, pthread_atfork(AtForkPrepare4, AtForkParent4, AtForkChild4));
-
-  int pid = fork();
-
-  ASSERT_NE(-1, pid) << strerror(errno);
-
-  if (pid == 0) {
-    ASSERT_EQ(1234, g_atfork_child_calls);
-    _exit(0);
-  }
-
-  ASSERT_EQ(1234, g_atfork_parent_calls);
-  ASSERT_EQ(4321, g_atfork_prepare_calls);
-
-  EXPECT_EQ(0, dlclose(handle));
-  g_atfork_prepare_calls = g_atfork_parent_calls = g_atfork_child_calls = 0;
-
-  int status;
-  ASSERT_EQ(pid, waitpid(pid, &status, 0));
-
-  pid = fork();
-
-  ASSERT_NE(-1, pid) << strerror(errno);
-
-  if (pid == 0) {
-    ASSERT_EQ(14, g_atfork_child_calls);
-    _exit(0);
-  }
-
-  ASSERT_EQ(14, g_atfork_parent_calls);
-  ASSERT_EQ(41, g_atfork_prepare_calls);
-
-  ASSERT_EQ(pid, waitpid(pid, &status, 0));
+  ASSERT_EQ(0x21, g_atfork_prepare_calls);
 }
 
 TEST(pthread, pthread_attr_getscope) {