[Lldb-commits] [lldb] r158240 - in /lldb/trunk: include/lldb/Host/Mutex.h source/Host/common/Mutex.cpp source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
Jim Ingham
jingham at apple.com
Fri Jun 8 15:50:40 PDT 2012
Author: jingham
Date: Fri Jun 8 17:50:40 2012
New Revision: 158240
URL: http://llvm.org/viewvc/llvm-project?rev=158240&view=rev
Log:
Change the Mutex::Locker class so that it takes the Mutex object and locks it, rather
than being given the pthread_mutex_t from the Mutex and locks that. That allows us to
track ownership of the Mutex better.
Used this to switch the LLDB_CONFIGURATION_DEBUG enabled assert when we can't get the
gdb-remote sequence mutex to assert when the thread that had the mutex releases it. This
is generally more useful information than saying just who failed to get it (since the
code that had it locked often had released it by the time the assert fired.)
Modified:
lldb/trunk/include/lldb/Host/Mutex.h
lldb/trunk/source/Host/common/Mutex.cpp
lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h
lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
Modified: lldb/trunk/include/lldb/Host/Mutex.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/include/lldb/Host/Mutex.h?rev=158240&r1=158239&r2=158240&view=diff
==============================================================================
--- lldb/trunk/include/lldb/Host/Mutex.h (original)
+++ lldb/trunk/include/lldb/Host/Mutex.h Fri Jun 8 17:50:40 2012
@@ -14,6 +14,10 @@
#include <pthread.h>
#include <assert.h>
+#ifdef LLDB_CONFIGURATION_DEBUG
+#include <string>
+#endif
+
namespace lldb_private {
//----------------------------------------------------------------------
@@ -121,13 +125,13 @@
/// returns \b false otherwise.
//--------------------------------------------------------------
bool
- TryLock (Mutex &mutex);
+ TryLock (Mutex &mutex, const char *failure_message = NULL);
bool
- TryLock (Mutex *mutex)
+ TryLock (Mutex *mutex, const char *failure_message = NULL)
{
if (mutex)
- return TryLock(*mutex);
+ return TryLock(*mutex, failure_message);
else
return false;
}
@@ -139,9 +143,7 @@
//--------------------------------------------------------------
/// Member variables
//--------------------------------------------------------------
- pthread_mutex_t *m_mutex_ptr; ///< A pthread mutex that is locked when
- ///< acquired and unlocked when destroyed
- ///< or reset.
+ Mutex *m_mutex_ptr;
private:
Locker(const Locker&);
@@ -176,6 +178,9 @@
///
/// Destroys the mutex owned by this object.
//------------------------------------------------------------------
+#ifdef LLDB_CONFIGURATION_DEBUG
+ virtual
+#endif
~Mutex();
//------------------------------------------------------------------
@@ -201,8 +206,11 @@
/// @return
/// The error code from \c pthread_mutex_trylock().
//------------------------------------------------------------------
+#ifdef LLDB_CONFIGURATION_DEBUG
+ virtual
+#endif
int
- TryLock();
+ TryLock(const char *failure_message = NULL);
//------------------------------------------------------------------
/// Unlock the mutex.
@@ -215,22 +223,18 @@
/// @return
/// The error code from \c pthread_mutex_unlock().
//------------------------------------------------------------------
+#ifdef LLDB_CONFIGURATION_DEBUG
+ virtual
+#endif
int
Unlock();
- static
- int Lock (pthread_mutex_t *mutex_ptr);
-
- static
- int TryLock (pthread_mutex_t *mutex_ptr);
-
- static
- int Unlock (pthread_mutex_t *mutex_ptr);
-
protected:
//------------------------------------------------------------------
// Member variables
//------------------------------------------------------------------
+ // TODO: Hide the mutex in the implementation file in case we ever need to port to an
+ // architecture that doesn't have pthread mutexes.
pthread_mutex_t m_mutex; ///< The pthread mutex object.
private:
@@ -247,6 +251,37 @@
const Mutex& operator=(const Mutex&);
};
+#ifdef LLDB_CONFIGURATION_DEBUG
+class TrackingMutex : public Mutex
+{
+public:
+ TrackingMutex() : Mutex() {}
+ TrackingMutex(Mutex::Type type) : Mutex (type) {}
+
+ virtual
+ ~TrackingMutex() {}
+
+ virtual int
+ Unlock ();
+
+ virtual int
+ TryLock (const char *failure_message = NULL)
+ {
+ int return_value = Mutex::TryLock();
+ if (return_value != 0 && failure_message != NULL)
+ {
+ m_failure_message.assign(failure_message);
+ m_thread_that_tried = pthread_self();
+ }
+ return return_value;
+ }
+
+protected:
+ pthread_t m_thread_that_tried;
+ std::string m_failure_message;
+};
+#endif
+
} // namespace lldb_private
#endif // #if defined(__cplusplus)
Modified: lldb/trunk/source/Host/common/Mutex.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Host/common/Mutex.cpp?rev=158240&r1=158239&r2=158240&view=diff
==============================================================================
--- lldb/trunk/source/Host/common/Mutex.cpp (original)
+++ lldb/trunk/source/Host/common/Mutex.cpp Fri Jun 8 17:50:40 2012
@@ -141,19 +141,14 @@
void
Mutex::Locker::Lock (Mutex &mutex)
{
- pthread_mutex_t *mutex_ptr = mutex.GetMutex();
-
// We already have this mutex locked or both are NULL...
- if (m_mutex_ptr == mutex_ptr)
+ if (m_mutex_ptr == &mutex)
return;
Unlock ();
- if (mutex_ptr)
- {
- m_mutex_ptr = mutex_ptr;
- Mutex::Lock (m_mutex_ptr);
- }
+ m_mutex_ptr = &mutex;
+ m_mutex_ptr->Lock();
}
void
@@ -161,27 +156,23 @@
{
if (m_mutex_ptr)
{
- Mutex::Unlock (m_mutex_ptr);
+ m_mutex_ptr->Unlock ();
m_mutex_ptr = NULL;
}
}
bool
-Mutex::Locker::TryLock (Mutex &mutex)
+Mutex::Locker::TryLock (Mutex &mutex, const char *failure_message)
{
- pthread_mutex_t *mutex_ptr = mutex.GetMutex();
-
// We already have this mutex locked!
- if (m_mutex_ptr == mutex_ptr)
- return m_mutex_ptr != NULL;
+ if (m_mutex_ptr == &mutex)
+ return true;
Unlock ();
- if (mutex_ptr)
- {
- if (Mutex::TryLock (mutex_ptr) == 0)
- m_mutex_ptr = mutex_ptr;
- }
+ if (mutex.TryLock(failure_message) == 0)
+ m_mutex_ptr = &mutex;
+
return m_mutex_ptr != NULL;
}
@@ -273,100 +264,98 @@
return &m_mutex;
}
+//----------------------------------------------------------------------
+// Locks the mutex owned by this object, if the mutex is already
+// locked, the calling thread will block until the mutex becomes
+// available.
+//
+// RETURNS
+// The error code from the pthread_mutex_lock() function call.
+//----------------------------------------------------------------------
int
-Mutex::Lock (pthread_mutex_t *mutex_ptr)
+Mutex::Lock()
{
DEBUG_LOG ("[%4.4x/%4.4x] pthread_mutex_lock (%p)...\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), mutex_ptr);
#if ENABLE_MUTEX_ERROR_CHECKING
- error_check_mutex (mutex_ptr, eMutexActionAssertInitialized);
+ error_check_mutex (&m_mutex, eMutexActionAssertInitialized);
#endif
- int err = ::pthread_mutex_lock (mutex_ptr);
+ int err = ::pthread_mutex_lock (&m_mutex);
#if ENABLE_MUTEX_ERROR_CHECKING
if (err)
{
- Host::SetCrashDescriptionWithFormat ("%s error: pthread_mutex_lock(%p) => err = %i (%s)", __PRETTY_FUNCTION__, mutex_ptr, err, strerror(err));
+ Host::SetCrashDescriptionWithFormat ("%s error: pthread_mutex_lock(%p) => err = %i (%s)", __PRETTY_FUNCTION__, &m_mutex, err, strerror(err));
assert(err == 0);
}
#endif
- DEBUG_LOG ("[%4.4x/%4.4x] pthread_mutex_lock (%p) => %i\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), mutex_ptr, err);
+ DEBUG_LOG ("[%4.4x/%4.4x] pthread_mutex_lock (%p) => %i\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), &m_mutex, err);
return err;
}
+//----------------------------------------------------------------------
+// Attempts to lock the mutex owned by this object without blocking.
+// If the mutex is already locked, TryLock() will not block waiting
+// for the mutex, but will return an error condition.
+//
+// RETURNS
+// The error code from the pthread_mutex_trylock() function call.
+//----------------------------------------------------------------------
int
-Mutex::TryLock (pthread_mutex_t *mutex_ptr)
+Mutex::TryLock(const char *failure_message)
{
#if ENABLE_MUTEX_ERROR_CHECKING
- error_check_mutex (mutex_ptr, eMutexActionAssertInitialized);
+ error_check_mutex (&m_mutex, eMutexActionAssertInitialized);
#endif
- int err = ::pthread_mutex_trylock (mutex_ptr);
- DEBUG_LOG ("[%4.4x/%4.4x] pthread_mutex_trylock (%p) => %i\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), mutex_ptr, err);
+ int err = ::pthread_mutex_trylock (&m_mutex);
+ DEBUG_LOG ("[%4.4x/%4.4x] pthread_mutex_trylock (%p) => %i\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), &m_mutex, err);
return err;
}
+//----------------------------------------------------------------------
+// If the current thread holds the lock on the owned mutex, then
+// Unlock() will unlock the mutex. Calling Unlock() on this object
+// that the calling thread does not hold will result in undefined
+// behavior.
+//
+// RETURNS
+// The error code from the pthread_mutex_unlock() function call.
+//----------------------------------------------------------------------
int
-Mutex::Unlock (pthread_mutex_t *mutex_ptr)
+Mutex::Unlock()
{
#if ENABLE_MUTEX_ERROR_CHECKING
- error_check_mutex (mutex_ptr, eMutexActionAssertInitialized);
+ error_check_mutex (&m_mutex, eMutexActionAssertInitialized);
#endif
- int err = ::pthread_mutex_unlock (mutex_ptr);
+ int err = ::pthread_mutex_unlock (&m_mutex);
#if ENABLE_MUTEX_ERROR_CHECKING
if (err)
{
- Host::SetCrashDescriptionWithFormat ("%s error: pthread_mutex_unlock(%p) => err = %i (%s)", __PRETTY_FUNCTION__, mutex_ptr, err, strerror(err));
+ Host::SetCrashDescriptionWithFormat ("%s error: pthread_mutex_unlock(%p) => err = %i (%s)", __PRETTY_FUNCTION__, &m_mutex, err, strerror(err));
assert(err == 0);
}
#endif
- DEBUG_LOG ("[%4.4x/%4.4x] pthread_mutex_unlock (%p) => %i\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), mutex_ptr, err);
+ DEBUG_LOG ("[%4.4x/%4.4x] pthread_mutex_unlock (%p) => %i\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), &m_mutex, err);
return err;
}
-//----------------------------------------------------------------------
-// Locks the mutex owned by this object, if the mutex is already
-// locked, the calling thread will block until the mutex becomes
-// available.
-//
-// RETURNS
-// The error code from the pthread_mutex_lock() function call.
-//----------------------------------------------------------------------
-int
-Mutex::Lock()
-{
- return Mutex::Lock (&m_mutex);
-}
-
-//----------------------------------------------------------------------
-// Attempts to lock the mutex owned by this object without blocking.
-// If the mutex is already locked, TryLock() will not block waiting
-// for the mutex, but will return an error condition.
-//
-// RETURNS
-// The error code from the pthread_mutex_trylock() function call.
-//----------------------------------------------------------------------
+#ifdef LLDB_CONFIGURATION_DEBUG
int
-Mutex::TryLock()
+TrackingMutex::Unlock ()
{
- return Mutex::TryLock (&m_mutex);
+ if (!m_failure_message.empty())
+ Host::SetCrashDescriptionWithFormat ("Unlocking lock (on thread %p) that thread: %p failed to get: %s",
+ pthread_self(),
+ m_thread_that_tried,
+ m_failure_message.c_str());
+ assert (m_failure_message.empty());
+ return Mutex::Unlock();
}
+#endif
+
-//----------------------------------------------------------------------
-// If the current thread holds the lock on the owned mutex, then
-// Unlock() will unlock the mutex. Calling Unlock() on this object
-// that the calling thread does not hold will result in undefined
-// behavior.
-//
-// RETURNS
-// The error code from the pthread_mutex_unlock() function call.
-//----------------------------------------------------------------------
-int
-Mutex::Unlock()
-{
- return Mutex::Unlock (&m_mutex);
-}
Modified: lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp?rev=158240&r1=158239&r2=158240&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp (original)
+++ lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp Fri Jun 8 17:50:40 2012
@@ -263,10 +263,10 @@
}
bool
-GDBRemoteCommunication::GetSequenceMutex (Mutex::Locker& locker)
+GDBRemoteCommunication::GetSequenceMutex (Mutex::Locker& locker, const char *failure_message)
{
if (IsRunning())
- return locker.TryLock (m_sequence_mutex);
+ return locker.TryLock (m_sequence_mutex, failure_message);
locker.Lock (m_sequence_mutex);
return true;
Modified: lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h?rev=158240&r1=158239&r2=158240&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h (original)
+++ lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h Fri Jun 8 17:50:40 2012
@@ -59,7 +59,7 @@
size_t payload_length);
bool
- GetSequenceMutex (lldb_private::Mutex::Locker& locker);
+ GetSequenceMutex (lldb_private::Mutex::Locker& locker, const char *failure_message = NULL);
bool
CheckForPacket (const uint8_t *src,
@@ -242,7 +242,11 @@
// Classes that inherit from GDBRemoteCommunication can see and modify these
//------------------------------------------------------------------
uint32_t m_packet_timeout;
+#ifdef LLDB_CONFIGURATION_DEBUG
+ lldb_private::TrackingMutex m_sequence_mutex;
+#else
lldb_private::Mutex m_sequence_mutex; // Restrict access to sending/receiving packets to a single thread at a time
+#endif
lldb_private::Predicate<bool> m_public_is_running;
lldb_private::Predicate<bool> m_private_is_running;
History m_history;
Modified: lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp?rev=158240&r1=158239&r2=158240&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp (original)
+++ lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp Fri Jun 8 17:50:40 2012
@@ -1939,7 +1939,7 @@
Mutex::Locker locker;
thread_ids.clear();
- if (GetSequenceMutex (locker))
+ if (GetSequenceMutex (locker, "ProcessGDBRemote::UpdateThreadList() failed due to not getting the sequence mutex"))
{
sequence_mutex_unavailable = false;
StringExtractorGDBRemote response;
@@ -1968,9 +1968,13 @@
}
else
{
+#if defined (LLDB_CONFIGURATION_DEBUG)
+ // assert(!"ProcessGDBRemote::UpdateThreadList() failed due to not getting the sequence mutex");
+#else
LogSP log (ProcessGDBRemoteLog::GetLogIfAnyCategoryIsSet (GDBR_LOG_PROCESS | GDBR_LOG_PACKETS));
if (log)
log->Printf("error: failed to get packet sequence mutex, not sending packet 'qfThreadInfo'");
+#endif
sequence_mutex_unavailable = true;
}
return thread_ids.size();
Modified: lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp?rev=158240&r1=158239&r2=158240&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp (original)
+++ lldb/trunk/source/Plugins/Process/gdb-remote/GDBRemoteRegisterContext.cpp Fri Jun 8 17:50:40 2012
@@ -183,7 +183,7 @@
if (!m_reg_valid[reg])
{
Mutex::Locker locker;
- if (gdb_comm.GetSequenceMutex (locker))
+ if (gdb_comm.GetSequenceMutex (locker, "Didn't get sequence mutex for read register."))
{
const bool thread_suffix_supported = gdb_comm.GetThreadSuffixSupported();
ProcessSP process_sp (m_thread.GetProcess());
@@ -357,7 +357,7 @@
m_reg_data.GetByteOrder())) // dst byte order
{
Mutex::Locker locker;
- if (gdb_comm.GetSequenceMutex (locker))
+ if (gdb_comm.GetSequenceMutex (locker, "Didn't get sequence mutex for write register."))
{
const bool thread_suffix_supported = gdb_comm.GetThreadSuffixSupported();
ProcessSP process_sp (m_thread.GetProcess());
@@ -445,12 +445,6 @@
else
{
LogSP log (ProcessGDBRemoteLog::GetLogIfAnyCategoryIsSet (GDBR_LOG_THREAD | GDBR_LOG_PACKETS));
-#if LLDB_CONFIGURATION_DEBUG
- StreamString strm;
- gdb_comm.DumpHistory(strm);
- Host::SetCrashDescription (strm.GetData());
- assert (!"Didn't get sequence mutex for write register.");
-#else
if (log)
{
if (log->GetVerbose())
@@ -462,7 +456,6 @@
else
log->Printf("error: failed to get packet sequence mutex, not sending write register for \"%s\"", reg_info->name);
}
-#endif
}
}
return false;
@@ -484,7 +477,7 @@
StringExtractorGDBRemote response;
Mutex::Locker locker;
- if (gdb_comm.GetSequenceMutex (locker))
+ if (gdb_comm.GetSequenceMutex (locker, "Didn't get sequence mutex for read all registers."))
{
char packet[32];
const bool thread_suffix_supported = gdb_comm.GetThreadSuffixSupported();
@@ -522,12 +515,6 @@
else
{
LogSP log (ProcessGDBRemoteLog::GetLogIfAnyCategoryIsSet (GDBR_LOG_THREAD | GDBR_LOG_PACKETS));
-#if LLDB_CONFIGURATION_DEBUG
- StreamString strm;
- gdb_comm.DumpHistory(strm);
- Host::SetCrashDescription (strm.GetData());
- assert (!"Didn't get sequence mutex for read all registers.");
-#else
if (log)
{
if (log->GetVerbose())
@@ -539,7 +526,6 @@
else
log->Printf("error: failed to get packet sequence mutex, not sending read all registers");
}
-#endif
}
data_sp.reset();
@@ -563,7 +549,7 @@
StringExtractorGDBRemote response;
Mutex::Locker locker;
- if (gdb_comm.GetSequenceMutex (locker))
+ if (gdb_comm.GetSequenceMutex (locker, "Didn't get sequence mutex for write all registers."))
{
const bool thread_suffix_supported = gdb_comm.GetThreadSuffixSupported();
ProcessSP process_sp (m_thread.GetProcess());
@@ -662,12 +648,6 @@
else
{
LogSP log (ProcessGDBRemoteLog::GetLogIfAnyCategoryIsSet (GDBR_LOG_THREAD | GDBR_LOG_PACKETS));
-#if LLDB_CONFIGURATION_DEBUG
- StreamString strm;
- gdb_comm.DumpHistory(strm);
- Host::SetCrashDescription (strm.GetData());
- assert (!"Didn't get sequence mutex for write all registers.");
-#else
if (log)
{
if (log->GetVerbose())
@@ -679,7 +659,6 @@
else
log->Printf("error: failed to get packet sequence mutex, not sending write all registers");
}
-#endif
}
return false;
}
Modified: lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp?rev=158240&r1=158239&r2=158240&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp (original)
+++ lldb/trunk/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp Fri Jun 8 17:50:40 2012
@@ -1190,9 +1190,6 @@
m_gdb_comm.GetCurrentThreadIDs (m_thread_ids, sequence_mutex_unavailable);
if (sequence_mutex_unavailable)
{
-#if defined (LLDB_CONFIGURATION_DEBUG)
- assert(!"ProcessGDBRemote::UpdateThreadList() failed due to not getting the sequence mutex");
-#endif
return false; // We just didn't get the list
}
return true;
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