forked from OSchip/llvm-project
362 lines
11 KiB
C++
362 lines
11 KiB
C++
//===-- Mutex.cpp -----------------------------------------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#include "lldb/Host/Mutex.h"
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#include "lldb/Host/Host.h"
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#include <string.h>
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#include <stdio.h>
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#include <unistd.h>
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#if 0
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// This logging is way too verbose to enable even for a log channel.
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// This logging can be enabled by changing the "#if 0", but should be
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// reverted prior to checking in.
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#include <cstdio>
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#define DEBUG_LOG(fmt, ...) printf(fmt, ## __VA_ARGS__)
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#else
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#define DEBUG_LOG(fmt, ...)
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#endif
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// Enable extra mutex error checking
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#ifdef LLDB_CONFIGURATION_DEBUG
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#define ENABLE_MUTEX_ERROR_CHECKING 1
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#endif
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#if ENABLE_MUTEX_ERROR_CHECKING
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#include <set>
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enum MutexAction
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{
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eMutexActionInitialized,
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eMutexActionDestroyed,
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eMutexActionAssertInitialized
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};
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static bool
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error_check_mutex (pthread_mutex_t *m, MutexAction action)
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{
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typedef std::set<pthread_mutex_t *> mutex_set;
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static pthread_mutex_t g_mutex_set_mutex = PTHREAD_MUTEX_INITIALIZER;
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static mutex_set g_initialized_mutex_set;
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static mutex_set g_destroyed_mutex_set;
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bool success = true;
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int err;
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// Manually call lock so we don't to any of this error checking
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err = ::pthread_mutex_lock (&g_mutex_set_mutex);
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assert(err == 0);
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switch (action)
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{
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case eMutexActionInitialized:
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// Make sure this isn't already in our initialized mutex set...
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assert (g_initialized_mutex_set.find(m) == g_initialized_mutex_set.end());
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// Remove this from the destroyed set in case it was ever in there
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g_destroyed_mutex_set.erase(m);
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// Add the mutex to the initialized set
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g_initialized_mutex_set.insert(m);
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break;
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case eMutexActionDestroyed:
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// Make sure this isn't already in our destroyed mutex set...
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assert (g_destroyed_mutex_set.find(m) == g_destroyed_mutex_set.end());
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// Remove this from the initialized so we can put it into the destroyed set
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g_initialized_mutex_set.erase(m);
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// Add the mutex to the destroyed set
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g_destroyed_mutex_set.insert(m);
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break;
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case eMutexActionAssertInitialized:
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// This function will return true if "m" is in the initialized mutex set
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success = g_initialized_mutex_set.find(m) != g_initialized_mutex_set.end();
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assert (success);
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break;
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}
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// Manually call unlock so we don't to any of this error checking
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err = ::pthread_mutex_unlock (&g_mutex_set_mutex);
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assert(err == 0);
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return success;
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}
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#endif
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using namespace lldb_private;
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//----------------------------------------------------------------------
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// Default constructor.
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//
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// This will create a scoped mutex locking object that doesn't have
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// a mutex to lock. One will need to be provided using the Reset()
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// method.
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//----------------------------------------------------------------------
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Mutex::Locker::Locker () :
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m_mutex_ptr(NULL)
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{
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}
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//----------------------------------------------------------------------
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// Constructor with a Mutex object.
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//
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// This will create a scoped mutex locking object that extracts the
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// mutex owned by "m" and locks it.
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//----------------------------------------------------------------------
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Mutex::Locker::Locker (Mutex& m) :
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m_mutex_ptr(NULL)
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{
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Lock (m);
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}
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//----------------------------------------------------------------------
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// Constructor with a Mutex object pointer.
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//
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// This will create a scoped mutex locking object that extracts the
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// mutex owned by "m" and locks it.
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//----------------------------------------------------------------------
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Mutex::Locker::Locker (Mutex* m) :
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m_mutex_ptr(NULL)
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{
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if (m)
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Lock (m);
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}
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//----------------------------------------------------------------------
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// Destructor
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//
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// Unlocks any owned mutex object (if it is valid).
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//----------------------------------------------------------------------
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Mutex::Locker::~Locker ()
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{
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Unlock();
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}
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//----------------------------------------------------------------------
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// Unlock the current mutex in this object (if this owns a valid
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// mutex) and lock the new "mutex" object if it is non-NULL.
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//----------------------------------------------------------------------
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void
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Mutex::Locker::Lock (Mutex &mutex)
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{
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// We already have this mutex locked or both are NULL...
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if (m_mutex_ptr == &mutex)
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return;
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Unlock ();
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m_mutex_ptr = &mutex;
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m_mutex_ptr->Lock();
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}
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void
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Mutex::Locker::Unlock ()
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{
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if (m_mutex_ptr)
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{
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m_mutex_ptr->Unlock ();
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m_mutex_ptr = NULL;
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}
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}
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bool
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Mutex::Locker::TryLock (Mutex &mutex, const char *failure_message)
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{
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// We already have this mutex locked!
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if (m_mutex_ptr == &mutex)
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return true;
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Unlock ();
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if (mutex.TryLock(failure_message) == 0)
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m_mutex_ptr = &mutex;
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return m_mutex_ptr != NULL;
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}
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//----------------------------------------------------------------------
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// Default constructor.
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//
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// Creates a pthread mutex with no attributes.
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//----------------------------------------------------------------------
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Mutex::Mutex () :
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m_mutex()
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{
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int err;
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err = ::pthread_mutex_init (&m_mutex, NULL);
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#if ENABLE_MUTEX_ERROR_CHECKING
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if (err == 0)
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error_check_mutex (&m_mutex, eMutexActionInitialized);
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#endif
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assert(err == 0);
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}
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//----------------------------------------------------------------------
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// Default constructor.
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//
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// Creates a pthread mutex with "type" as the mutex type.
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//----------------------------------------------------------------------
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Mutex::Mutex (Mutex::Type type) :
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m_mutex()
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{
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int err;
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::pthread_mutexattr_t attr;
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err = ::pthread_mutexattr_init (&attr);
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assert(err == 0);
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switch (type)
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{
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case eMutexTypeNormal:
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#if ENABLE_MUTEX_ERROR_CHECKING
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err = ::pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_ERRORCHECK);
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#else
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err = ::pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_NORMAL);
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#endif
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break;
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case eMutexTypeRecursive:
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err = ::pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
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break;
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default:
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err = -1;
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break;
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}
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assert(err == 0);
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err = ::pthread_mutex_init (&m_mutex, &attr);
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#if ENABLE_MUTEX_ERROR_CHECKING
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if (err == 0)
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error_check_mutex (&m_mutex, eMutexActionInitialized);
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#endif
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assert(err == 0);
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err = ::pthread_mutexattr_destroy (&attr);
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assert(err == 0);
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}
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//----------------------------------------------------------------------
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// Destructor.
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//
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// Destroys the mutex owned by this object.
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//----------------------------------------------------------------------
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Mutex::~Mutex()
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{
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int err;
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err = ::pthread_mutex_destroy (&m_mutex);
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#if ENABLE_MUTEX_ERROR_CHECKING
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if (err == 0)
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error_check_mutex (&m_mutex, eMutexActionDestroyed);
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else
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{
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Host::SetCrashDescriptionWithFormat ("%s error: pthread_mutex_destroy() => err = %i (%s)", __PRETTY_FUNCTION__, err, strerror(err));
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assert(err == 0);
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}
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memset (&m_mutex, '\xba', sizeof(m_mutex));
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#endif
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}
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//----------------------------------------------------------------------
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// Mutex get accessor.
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//----------------------------------------------------------------------
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pthread_mutex_t *
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Mutex::GetMutex()
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{
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return &m_mutex;
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}
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//----------------------------------------------------------------------
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// Locks the mutex owned by this object, if the mutex is already
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// locked, the calling thread will block until the mutex becomes
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// available.
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//
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// RETURNS
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// The error code from the pthread_mutex_lock() function call.
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//----------------------------------------------------------------------
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int
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Mutex::Lock()
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{
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DEBUG_LOG ("[%4.4llx/%4.4llx] pthread_mutex_lock (%p)...\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), &m_mutex);
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#if ENABLE_MUTEX_ERROR_CHECKING
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error_check_mutex (&m_mutex, eMutexActionAssertInitialized);
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#endif
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int err = ::pthread_mutex_lock (&m_mutex);
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#if ENABLE_MUTEX_ERROR_CHECKING
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if (err)
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{
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Host::SetCrashDescriptionWithFormat ("%s error: pthread_mutex_lock(%p) => err = %i (%s)", __PRETTY_FUNCTION__, &m_mutex, err, strerror(err));
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assert(err == 0);
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}
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#endif
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DEBUG_LOG ("[%4.4llx/%4.4llx] pthread_mutex_lock (%p) => %i\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), &m_mutex, err);
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return err;
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}
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//----------------------------------------------------------------------
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// Attempts to lock the mutex owned by this object without blocking.
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// If the mutex is already locked, TryLock() will not block waiting
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// for the mutex, but will return an error condition.
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//
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// RETURNS
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// The error code from the pthread_mutex_trylock() function call.
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//----------------------------------------------------------------------
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int
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Mutex::TryLock(const char *failure_message)
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{
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#if ENABLE_MUTEX_ERROR_CHECKING
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error_check_mutex (&m_mutex, eMutexActionAssertInitialized);
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#endif
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int err = ::pthread_mutex_trylock (&m_mutex);
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DEBUG_LOG ("[%4.4llx/%4.4llx] pthread_mutex_trylock (%p) => %i\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), &m_mutex, err);
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return err;
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}
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//----------------------------------------------------------------------
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// If the current thread holds the lock on the owned mutex, then
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// Unlock() will unlock the mutex. Calling Unlock() on this object
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// that the calling thread does not hold will result in undefined
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// behavior.
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//
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// RETURNS
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// The error code from the pthread_mutex_unlock() function call.
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//----------------------------------------------------------------------
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int
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Mutex::Unlock()
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{
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#if ENABLE_MUTEX_ERROR_CHECKING
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error_check_mutex (&m_mutex, eMutexActionAssertInitialized);
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#endif
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int err = ::pthread_mutex_unlock (&m_mutex);
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#if ENABLE_MUTEX_ERROR_CHECKING
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if (err)
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{
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Host::SetCrashDescriptionWithFormat ("%s error: pthread_mutex_unlock(%p) => err = %i (%s)", __PRETTY_FUNCTION__, &m_mutex, err, strerror(err));
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assert(err == 0);
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}
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#endif
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DEBUG_LOG ("[%4.4llx/%4.4llx] pthread_mutex_unlock (%p) => %i\n", Host::GetCurrentProcessID(), Host::GetCurrentThreadID(), &m_mutex, err);
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return err;
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}
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#ifdef LLDB_CONFIGURATION_DEBUG
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int
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TrackingMutex::Unlock ()
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{
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if (!m_failure_message.empty())
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Host::SetCrashDescriptionWithFormat ("Unlocking lock (on thread %p) that thread: %p failed to get: %s",
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pthread_self(),
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m_thread_that_tried,
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m_failure_message.c_str());
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assert (m_failure_message.empty());
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return Mutex::Unlock();
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}
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#endif
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