Clean up vestigial remnants of locking primitives

This finally removes the use of the Mutex and Condition classes. This is an
intricate patch as the Mutex and Condition classes were tied together.
Furthermore, many places had slightly differing uses of time values. Convert
timeout values to relative everywhere to permit the use of
std::chrono::duration, which is required for the use of
std::condition_variable's timeout. Adjust all Condition and related Mutex
classes over to std::{,recursive_}mutex and std::condition_variable.

This change primarily comes at the cost of breaking the TracingMutex which was
based around the Mutex class. It would be possible to write a wrapper to
provide similar functionality, but that is beyond the scope of this change.

llvm-svn: 277011

1 files changed, 30 insertions, 31 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
index f164b14..9d6b976f 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
@@ -152,23 +152,22 @@ GDBRemoteCommunication::History::Dump (Log *log) const
 //----------------------------------------------------------------------
 // GDBRemoteCommunication constructor
 //----------------------------------------------------------------------
-GDBRemoteCommunication::GDBRemoteCommunication(const char *comm_name, 
-                                               const char *listener_name) :
-    Communication(comm_name),
+GDBRemoteCommunication::GDBRemoteCommunication(const char *comm_name, const char *listener_name)
+    : Communication(comm_name),
 #ifdef LLDB_CONFIGURATION_DEBUG
-    m_packet_timeout (1000),
+      m_packet_timeout(1000),
 #else
-    m_packet_timeout (1),
+      m_packet_timeout(1),
 #endif
-    m_echo_number(0),
-    m_supports_qEcho (eLazyBoolCalculate),
-    m_sequence_mutex (Mutex::eMutexTypeRecursive),
-    m_public_is_running (false),
-    m_private_is_running (false),
-    m_history (512),
-    m_send_acks (true),
-    m_compression_type (CompressionType::None),
-    m_listen_url ()
+      m_echo_number(0),
+      m_supports_qEcho(eLazyBoolCalculate),
+      m_sequence_mutex(),
+      m_public_is_running(false),
+      m_private_is_running(false),
+      m_history(512),
+      m_send_acks(true),
+      m_compression_type(CompressionType::None),
+      m_listen_url()
 {
 }
 
@@ -229,7 +228,7 @@ GDBRemoteCommunication::SendNack ()
 GDBRemoteCommunication::PacketResult
 GDBRemoteCommunication::SendPacket (const char *payload, size_t payload_length)
 {
-    Mutex::Locker locker(m_sequence_mutex);
+    std::lock_guard<std::recursive_mutex> guard(m_sequence_mutex);
     return SendPacketNoLock (payload, payload_length);
 }
 
@@ -323,20 +322,19 @@ GDBRemoteCommunication::GetAck ()
 }
 
 bool
-GDBRemoteCommunication::GetSequenceMutex (Mutex::Locker& locker, const char *failure_message)
+GDBRemoteCommunication::GetSequenceMutex(std::unique_lock<std::recursive_mutex> &lock, const char *failure_message)
 {
     if (IsRunning())
-        return locker.TryLock (m_sequence_mutex, failure_message);
+        return (lock = std::unique_lock<std::recursive_mutex>(m_sequence_mutex, std::try_to_lock)).owns_lock();
 
-    locker.Lock (m_sequence_mutex);
+    lock = std::unique_lock<std::recursive_mutex>(m_sequence_mutex);
     return true;
 }
 
-
 bool
-GDBRemoteCommunication::WaitForNotRunningPrivate (const TimeValue *timeout_ptr)
+GDBRemoteCommunication::WaitForNotRunningPrivate(const std::chrono::microseconds &timeout)
 {
-    return m_private_is_running.WaitForValueEqualTo (false, timeout_ptr, NULL);
+    return m_private_is_running.WaitForValueEqualTo(false, timeout, NULL);
 }
 
 GDBRemoteCommunication::PacketResult
@@ -356,20 +354,22 @@ GDBRemoteCommunication::ReadPacket (StringExtractorGDBRemote &response, uint32_t
 GDBRemoteCommunication::PacketResult
 GDBRemoteCommunication::PopPacketFromQueue (StringExtractorGDBRemote &response, uint32_t timeout_usec)
 {
-    // Calculate absolute timeout value
-    TimeValue timeout = TimeValue::Now();
-    timeout.OffsetWithMicroSeconds(timeout_usec);
+    auto until = std::chrono::system_clock::now() + std::chrono::microseconds(timeout_usec);
 
-    do
+    while (true)
     {
         // scope for the mutex
         {
             // lock down the packet queue
-            Mutex::Locker locker(m_packet_queue_mutex);
+            std::unique_lock<std::mutex> lock(m_packet_queue_mutex);
 
             // Wait on condition variable.
             if (m_packet_queue.size() == 0)
-                m_condition_queue_not_empty.Wait(m_packet_queue_mutex, &timeout);
+            {
+                std::cv_status result = m_condition_queue_not_empty.wait_until(lock, until);
+                if (result == std::cv_status::timeout)
+                  break;
+            }
 
             if (m_packet_queue.size() > 0)
             {
@@ -389,7 +389,7 @@ GDBRemoteCommunication::PopPacketFromQueue (StringExtractorGDBRemote &response,
              return PacketResult::ErrorDisconnected;
 
       // Loop while not timed out
-    } while (TimeValue::Now() < timeout);
+    }
 
     return PacketResult::ErrorReplyTimeout;
 }
@@ -1479,12 +1479,11 @@ void GDBRemoteCommunication::AppendBytesToCache (const uint8_t * bytes, size_t l
             // scope for the mutex
             {
                 // lock down the packet queue
-                Mutex::Locker locker(m_packet_queue_mutex);
+                std::lock_guard<std::mutex> guard(m_packet_queue_mutex);
                 // push a new packet into the queue
                 m_packet_queue.push(packet);
                 // Signal condition variable that we have a packet
-                m_condition_queue_not_empty.Signal();
-
+                m_condition_queue_not_empty.notify_one();
             }
         }