Fix various timing/threading problems in IOChannel & Driver that
were causing the prompt to be stomped on, mangled or omitted occasionally.
llvm-svn: 115059
diff --git a/lldb/tools/driver/IOChannel.cpp b/lldb/tools/driver/IOChannel.cpp
index 50fdf73..004e1da 100644
--- a/lldb/tools/driver/IOChannel.cpp
+++ b/lldb/tools/driver/IOChannel.cpp
@@ -29,6 +29,10 @@
const char *g_default_prompt = "(lldb) ";
PromptMap g_prompt_map;
+#define NSEC_PER_USEC 1000ull
+#define USEC_PER_SEC 1000000ull
+#define NSEC_PER_SEC 1000000000ull
+
static const char*
el_prompt(EditLine *el)
{
@@ -156,6 +160,8 @@
Driver *driver
) :
SBBroadcaster ("IOChannel"),
+ m_output_mutex (),
+ m_enter_elgets_time (),
m_driver (driver),
m_read_thread (LLDB_INVALID_HOST_THREAD),
m_read_thread_should_exit (false),
@@ -187,6 +193,25 @@
::history (m_history, &m_history_event, H_SETUNIQUE, 1);
// Load history
HistorySaveLoad (false);
+
+ // Set up mutex to make sure OutErr, OutWrite and RefreshPrompt do not interfere
+ // with each other when writing.
+
+ int error;
+ ::pthread_mutexattr_t attr;
+ error = ::pthread_mutexattr_init (&attr);
+ assert (error == 0);
+ error = ::pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
+ assert (error == 0);
+ error = ::pthread_mutex_init (&m_output_mutex, &attr);
+ assert (error == 0);
+ error = ::pthread_mutexattr_destroy (&attr);
+ assert (error == 0);
+
+ // Initialize time that ::el_gets was last called.
+
+ m_enter_elgets_time.tv_sec = 0;
+ m_enter_elgets_time.tv_usec = 0;
}
IOChannel::~IOChannel ()
@@ -205,6 +230,8 @@
::el_end (m_edit_line);
m_edit_line = NULL;
}
+
+ ::pthread_mutex_destroy (&m_output_mutex);
}
void
@@ -231,7 +258,23 @@
if (m_edit_line != NULL)
{
int line_len = 0;
+
+ // Set boolean indicating whether or not el_gets is trying to get input (i.e. whether or not to attempt
+ // to refresh the prompt after writing data).
+ SetGettingCommand (true);
+
+ // Get the current time just before calling el_gets; this is used by OutWrite, ErrWrite, and RefreshPrompt
+ // to make sure they have given el_gets enough time to write the prompt before they attempt to write
+ // anything.
+
+ ::gettimeofday (&m_enter_elgets_time, NULL);
+
+ // Call el_gets to prompt the user and read the user's input.
const char *line = ::el_gets (m_edit_line, &line_len);
+
+ // Re-set the boolean indicating whether or not el_gets is trying to get input.
+ SetGettingCommand (false);
+
if (line)
{
// strip any newlines off the end of the string...
@@ -399,6 +442,23 @@
void
IOChannel::RefreshPrompt ()
{
+ // If we are not in the middle of getting input from the user, there is no need to
+ // refresh the prompt.
+
+ if (! IsGettingCommand())
+ return;
+
+ // Compare the current time versus the last time el_gets was called. If less than
+ // 10000 microseconds (10000000 nanoseconds) have elapsed, wait 10000 microseconds, to ensure el_gets had time
+ // to finish writing the prompt before we start writing here.
+
+ if (ElapsedNanoSecondsSinceEnteringElGets() < 10000000)
+ usleep (10000);
+
+ // Use the mutex to make sure OutWrite, ErrWrite and Refresh prompt do not interfere with
+ // each other's output.
+
+ IOLocker locker (m_output_mutex);
::el_set (m_edit_line, EL_REFRESH);
}
@@ -407,7 +467,20 @@
{
if (len == 0)
return;
- ::fwrite (buffer, 1, len, m_out_file);
+
+ // Compare the current time versus the last time el_gets was called. If less than
+ // 10000 microseconds (10000000 nanoseconds) have elapsed, wait 10000 microseconds, to ensure el_gets had time
+ // to finish writing the prompt before we start writing here.
+
+ if (ElapsedNanoSecondsSinceEnteringElGets() < 10000000)
+ usleep (10000);
+
+ {
+ // Use the mutex to make sure OutWrite, ErrWrite and Refresh prompt do not interfere with
+ // each other's output.
+ IOLocker locker (m_output_mutex);
+ ::fwrite (buffer, 1, len, m_out_file);
+ }
}
void
@@ -415,7 +488,20 @@
{
if (len == 0)
return;
- ::fwrite (buffer, 1, len, m_err_file);
+
+ // Compare the current time versus the last time el_gets was called. If less than
+ // 10000 microseconds (10000000 nanoseconds) have elapsed, wait 10000 microseconds, to ensure el_gets had time
+ // to finish writing the prompt before we start writing here.
+
+ if (ElapsedNanoSecondsSinceEnteringElGets() < 10000000)
+ usleep (10000);
+
+ {
+ // Use the mutex to make sure OutWrite, ErrWrite and Refresh prompt do not interfere with
+ // each other's output.
+ IOLocker locker (m_output_mutex);
+ ::fwrite (buffer, 1, len, m_err_file);
+ }
}
void
@@ -452,3 +538,48 @@
{
return m_command_queue.empty();
}
+
+bool
+IOChannel::IsGettingCommand () const
+{
+ return m_getting_command;
+}
+
+void
+IOChannel::SetGettingCommand (bool new_value)
+{
+ m_getting_command = new_value;
+}
+
+uint64_t
+IOChannel::Nanoseconds (const struct timeval &time_val) const
+{
+ uint64_t nanoseconds = time_val.tv_sec * NSEC_PER_SEC + time_val.tv_usec * NSEC_PER_USEC;
+
+ return nanoseconds;
+}
+
+uint64_t
+IOChannel::ElapsedNanoSecondsSinceEnteringElGets ()
+{
+ if (! IsGettingCommand())
+ return 0;
+
+ struct timeval current_time;
+ ::gettimeofday (¤t_time, NULL);
+ return (Nanoseconds (current_time) - Nanoseconds (m_enter_elgets_time));
+}
+
+IOLocker::IOLocker (pthread_mutex_t &mutex) :
+ m_mutex_ptr (&mutex)
+{
+ if (m_mutex_ptr)
+ ::pthread_mutex_lock (m_mutex_ptr);
+
+}
+
+IOLocker::~IOLocker ()
+{
+ if (m_mutex_ptr)
+ ::pthread_mutex_unlock (m_mutex_ptr);
+}