diff --git a/liblog/include/log/log.h b/liblog/include/log/log.h
index f27b8e6..820b7cb 100644
--- a/liblog/include/log/log.h
+++ b/liblog/include/log/log.h
@@ -144,8 +144,11 @@
 /*
  * Release any logger resources (a new log write will immediately re-acquire)
  *
- * May be used to clean up File descriptors after a Fork, the resources are
- * all O_CLOEXEC so wil self clean on exec().
+ * This is specifically meant to be used by Zygote to close open file descriptors after fork()
+ * and before specialization.  O_CLOEXEC is used on file descriptors, so they will be closed upon
+ * exec() in normal use cases.
+ *
+ * Note that this is not safe to call from a multi-threaded program.
  */
 void __android_log_close(void);
 
diff --git a/liblog/logd_writer.cpp b/liblog/logd_writer.cpp
index 67376f4..a230749 100644
--- a/liblog/logd_writer.cpp
+++ b/liblog/logd_writer.cpp
@@ -32,58 +32,53 @@
 #include <time.h>
 #include <unistd.h>
 
-#include <shared_mutex>
-
 #include <private/android_filesystem_config.h>
 #include <private/android_logger.h>
 
 #include "logger.h"
-#include "rwlock.h"
 #include "uio.h"
 
-static int logd_socket;
-static RwLock logd_socket_lock;
+static atomic_int logd_socket;
 
-static void OpenSocketLocked() {
-  logd_socket = TEMP_FAILURE_RETRY(socket(PF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0));
-  if (logd_socket <= 0) {
-    return;
-  }
-
+// Note that it is safe to call connect() multiple times on DGRAM Unix domain sockets, so this
+// function is used to reconnect to logd without requiring a new socket.
+static void LogdConnect() {
   sockaddr_un un = {};
   un.sun_family = AF_UNIX;
   strcpy(un.sun_path, "/dev/socket/logdw");
-
-  if (TEMP_FAILURE_RETRY(
-          connect(logd_socket, reinterpret_cast<sockaddr*>(&un), sizeof(sockaddr_un))) < 0) {
-    close(logd_socket);
-    logd_socket = 0;
-  }
+  TEMP_FAILURE_RETRY(connect(logd_socket, reinterpret_cast<sockaddr*>(&un), sizeof(sockaddr_un)));
 }
 
-static void OpenSocket() {
-  auto lock = std::unique_lock{logd_socket_lock};
-  if (logd_socket > 0) {
-    // Someone raced us and opened the socket already.
+// logd_socket should only be opened once.  If we see that logd_socket is uninitialized, we create a
+// new socket and attempt to exchange it into the atomic logd_socket.  If the compare/exchange was
+// successful, then that will be the socket used for the duration of the program, otherwise a
+// different thread has already opened and written the socket to the atomic, so close the new socket
+// and return.
+static void GetSocket() {
+  if (logd_socket != 0) {
     return;
   }
 
-  OpenSocketLocked();
-}
-
-static void ResetSocket(int old_socket) {
-  auto lock = std::unique_lock{logd_socket_lock};
-  if (old_socket != logd_socket) {
-    // Someone raced us and reset the socket already.
+  int new_socket =
+      TEMP_FAILURE_RETRY(socket(PF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0));
+  if (new_socket <= 0) {
     return;
   }
-  close(logd_socket);
-  logd_socket = 0;
-  OpenSocketLocked();
+
+  int uninitialized_value = 0;
+  if (!logd_socket.compare_exchange_strong(uninitialized_value, new_socket)) {
+    close(new_socket);
+    return;
+  }
+
+  LogdConnect();
 }
 
+// This is the one exception to the above.  Zygote uses this to clean up open FD's after fork() and
+// before specialization.  It is single threaded at this point and therefore this function is
+// explicitly not thread safe.  It sets logd_socket to 0, so future logs will be safely initialized
+// whenever they happen.
 void LogdClose() {
-  auto lock = std::unique_lock{logd_socket_lock};
   if (logd_socket > 0) {
     close(logd_socket);
   }
@@ -99,12 +94,7 @@
   static atomic_int dropped;
   static atomic_int droppedSecurity;
 
-  auto lock = std::shared_lock{logd_socket_lock};
-  if (logd_socket <= 0) {
-    lock.unlock();
-    OpenSocket();
-    lock.lock();
-  }
+  GetSocket();
 
   if (logd_socket <= 0) {
     return -EBADF;
@@ -183,10 +173,7 @@
   // the connection, so we reset it and try again.
   ret = TEMP_FAILURE_RETRY(writev(logd_socket, newVec, i));
   if (ret < 0 && errno != EAGAIN) {
-    int old_socket = logd_socket;
-    lock.unlock();
-    ResetSocket(old_socket);
-    lock.lock();
+    LogdConnect();
 
     ret = TEMP_FAILURE_RETRY(writev(logd_socket, newVec, i));
   }
diff --git a/liblog/pmsg_writer.cpp b/liblog/pmsg_writer.cpp
index 06e5e04..0751e2c 100644
--- a/liblog/pmsg_writer.cpp
+++ b/liblog/pmsg_writer.cpp
@@ -23,30 +23,36 @@
 #include <sys/types.h>
 #include <time.h>
 
-#include <shared_mutex>
-
 #include <log/log_properties.h>
 #include <private/android_logger.h>
 
 #include "logger.h"
-#include "rwlock.h"
 #include "uio.h"
 
-static int pmsg_fd;
-static RwLock pmsg_fd_lock;
+static atomic_int pmsg_fd;
 
-static void PmsgOpen() {
-  auto lock = std::unique_lock{pmsg_fd_lock};
-  if (pmsg_fd > 0) {
-    // Someone raced us and opened the socket already.
+// pmsg_fd should only beopened once.  If we see that pmsg_fd is uninitialized, we open "/dev/pmsg0"
+// then attempt to compare/exchange it into pmsg_fd.  If the compare/exchange was successful, then
+// that will be the fd used for the duration of the program, otherwise a different thread has
+// already opened and written the fd to the atomic, so close the new fd and return.
+static void GetPmsgFd() {
+  if (pmsg_fd != 0) {
     return;
   }
 
-  pmsg_fd = TEMP_FAILURE_RETRY(open("/dev/pmsg0", O_WRONLY | O_CLOEXEC));
+  int new_fd = TEMP_FAILURE_RETRY(open("/dev/pmsg0", O_WRONLY | O_CLOEXEC));
+  if (new_fd <= 0) {
+    return;
+  }
+
+  int uninitialized_value = 0;
+  if (!pmsg_fd.compare_exchange_strong(uninitialized_value, new_fd)) {
+    close(new_fd);
+    return;
+  }
 }
 
 void PmsgClose() {
-  auto lock = std::unique_lock{pmsg_fd_lock};
   if (pmsg_fd > 0) {
     close(pmsg_fd);
   }
@@ -77,13 +83,7 @@
     }
   }
 
-  auto lock = std::shared_lock{pmsg_fd_lock};
-
-  if (pmsg_fd <= 0) {
-    lock.unlock();
-    PmsgOpen();
-    lock.lock();
-  }
+  GetPmsgFd();
 
   if (pmsg_fd <= 0) {
     return -EBADF;
diff --git a/liblog/rwlock.h b/liblog/rwlock.h
deleted file mode 100644
index 00f1806..0000000
--- a/liblog/rwlock.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Copyright (C) 2019 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include <pthread.h>
-
-// As of the end of Dec 2019, std::shared_mutex is *not* simply a pthread_rwlock, but rather a
-// combination of std::mutex and std::condition variable, which is obviously less efficient.  This
-// immitates what std::shared_mutex should be doing and is compatible with std::shared_lock and
-// std::unique_lock.
-
-class RwLock {
- public:
-  RwLock() {}
-  ~RwLock() {}
-
-  void lock() { pthread_rwlock_wrlock(&rwlock_); }
-  void unlock() { pthread_rwlock_unlock(&rwlock_); }
-
-  void lock_shared() { pthread_rwlock_rdlock(&rwlock_); }
-  void unlock_shared() { pthread_rwlock_unlock(&rwlock_); }
-
- private:
-  pthread_rwlock_t rwlock_ = PTHREAD_RWLOCK_INITIALIZER;
-};
diff --git a/liblog/tests/Android.bp b/liblog/tests/Android.bp
index 385b079..50800c5 100644
--- a/liblog/tests/Android.bp
+++ b/liblog/tests/Android.bp
@@ -63,8 +63,8 @@
         "log_system_test.cpp",
         "log_time_test.cpp",
         "log_wrap_test.cpp",
+        "logd_writer_test.cpp",
         "logprint_test.cpp",
-        "rwlock_test.cpp",
     ],
     shared_libs: [
         "libcutils",
@@ -108,7 +108,6 @@
         "liblog_host_test.cpp",
         "liblog_default_tag.cpp",
         "liblog_global_state.cpp",
-        "rwlock_test.cpp",
     ],
     isolated: true,
 }
diff --git a/liblog/tests/logd_writer_test.cpp b/liblog/tests/logd_writer_test.cpp
new file mode 100644
index 0000000..c856720
--- /dev/null
+++ b/liblog/tests/logd_writer_test.cpp
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <sys/un.h>
+#include <unistd.h>
+
+#include <android-base/file.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <gtest/gtest.h>
+
+using android::base::StringPrintf;
+using android::base::unique_fd;
+
+// logd_writer takes advantage of the fact that connect() can be called multiple times for a DGRAM
+// socket.  This tests for that behavior.
+TEST(liblog, multi_connect_dgram_socket) {
+#ifdef __ANDROID__
+  auto temp_dir = TemporaryDir();
+  auto socket_path = StringPrintf("%s/test_socket", temp_dir.path);
+
+  unique_fd server_socket;
+
+  auto open_server_socket = [&] {
+    server_socket.reset(TEMP_FAILURE_RETRY(socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0)));
+    ASSERT_TRUE(server_socket.ok());
+
+    sockaddr_un server_sockaddr = {};
+    server_sockaddr.sun_family = AF_UNIX;
+    strlcpy(server_sockaddr.sun_path, socket_path.c_str(), sizeof(server_sockaddr.sun_path));
+    ASSERT_EQ(0,
+              TEMP_FAILURE_RETRY(bind(server_socket, reinterpret_cast<sockaddr*>(&server_sockaddr),
+                                      sizeof(server_sockaddr))));
+  };
+
+  // Open the server socket.
+  open_server_socket();
+
+  // Open the client socket.
+  auto client_socket =
+      unique_fd{TEMP_FAILURE_RETRY(socket(AF_UNIX, SOCK_DGRAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0))};
+  ASSERT_TRUE(client_socket.ok());
+  sockaddr_un client_sockaddr = {};
+  client_sockaddr.sun_family = AF_UNIX;
+  strlcpy(client_sockaddr.sun_path, socket_path.c_str(), sizeof(client_sockaddr.sun_path));
+  ASSERT_EQ(0,
+            TEMP_FAILURE_RETRY(connect(client_socket, reinterpret_cast<sockaddr*>(&client_sockaddr),
+                                       sizeof(client_sockaddr))));
+
+  // Ensure that communication works.
+  constexpr static char kSmoke[] = "smoke test";
+  ssize_t smoke_len = sizeof(kSmoke);
+  ASSERT_EQ(smoke_len, TEMP_FAILURE_RETRY(write(client_socket, kSmoke, sizeof(kSmoke))));
+  char read_buf[512];
+  ASSERT_EQ(smoke_len, TEMP_FAILURE_RETRY(read(server_socket, read_buf, sizeof(read_buf))));
+  ASSERT_STREQ(kSmoke, read_buf);
+
+  // Close the server socket.
+  server_socket.reset();
+  ASSERT_EQ(0, unlink(socket_path.c_str())) << strerror(errno);
+
+  // Ensure that write() from the client returns an error since the server is closed.
+  ASSERT_EQ(-1, TEMP_FAILURE_RETRY(write(client_socket, kSmoke, sizeof(kSmoke))));
+  ASSERT_EQ(errno, ECONNREFUSED) << strerror(errno);
+
+  // Open the server socket again.
+  open_server_socket();
+
+  // Reconnect the same client socket.
+  ASSERT_EQ(0,
+            TEMP_FAILURE_RETRY(connect(client_socket, reinterpret_cast<sockaddr*>(&client_sockaddr),
+                                       sizeof(client_sockaddr))))
+      << strerror(errno);
+
+  // Ensure that communication works.
+  ASSERT_EQ(smoke_len, TEMP_FAILURE_RETRY(write(client_socket, kSmoke, sizeof(kSmoke))));
+  ASSERT_EQ(smoke_len, TEMP_FAILURE_RETRY(read(server_socket, read_buf, sizeof(read_buf))));
+  ASSERT_STREQ(kSmoke, read_buf);
+#else
+  GTEST_LOG_(INFO) << "This test does nothing.\n";
+#endif
+}
\ No newline at end of file
diff --git a/liblog/tests/rwlock_test.cpp b/liblog/tests/rwlock_test.cpp
deleted file mode 100644
index 617d5c4..0000000
--- a/liblog/tests/rwlock_test.cpp
+++ /dev/null
@@ -1,91 +0,0 @@
-/*
- * Copyright (C) 2019 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "../rwlock.h"
-
-#include <chrono>
-#include <shared_mutex>
-#include <thread>
-
-#include <gtest/gtest.h>
-
-using namespace std::literals;
-
-TEST(rwlock, reader_then_reader_lock) {
-  RwLock lock;
-
-  bool thread_ran = false;
-  auto read_guard = std::shared_lock{lock};
-
-  auto reader_thread = std::thread([&] {
-    auto read_guard = std::shared_lock{lock};
-    thread_ran = true;
-  });
-
-  auto end_time = std::chrono::steady_clock::now() + 1s;
-
-  while (std::chrono::steady_clock::now() < end_time) {
-    if (thread_ran) {
-      break;
-    }
-  }
-
-  EXPECT_EQ(true, thread_ran);
-
-  // Unlock the lock in case something went wrong, to ensure that we can still join() the thread.
-  read_guard.unlock();
-  reader_thread.join();
-}
-
-template <template <typename> typename L1, template <typename> typename L2>
-void TestBlockingLocks() {
-  RwLock lock;
-
-  bool thread_ran = false;
-  auto read_guard = L1{lock};
-
-  auto reader_thread = std::thread([&] {
-    auto read_guard = L2{lock};
-    thread_ran = true;
-  });
-
-  auto end_time = std::chrono::steady_clock::now() + 1s;
-
-  while (std::chrono::steady_clock::now() < end_time) {
-    if (thread_ran) {
-      break;
-    }
-  }
-
-  EXPECT_EQ(false, thread_ran);
-
-  read_guard.unlock();
-  reader_thread.join();
-
-  EXPECT_EQ(true, thread_ran);
-}
-
-TEST(rwlock, reader_then_writer_lock) {
-  TestBlockingLocks<std::shared_lock, std::unique_lock>();
-}
-
-TEST(rwlock, writer_then_reader_lock) {
-  TestBlockingLocks<std::unique_lock, std::shared_lock>();
-}
-
-TEST(rwlock, writer_then_writer_lock) {
-  TestBlockingLocks<std::unique_lock, std::unique_lock>();
-}