added: a deadlock counter to Synchro class

now we can use Lock() more than one in the same thread
       and next Unlock() will recognize it
       sample:
       Lock(); // first lock -- resources locked
       Lock(); // second lock -- skipped (counter incremented)
       ...
       Unlock(); // first unlock -- skipped (because counter greater than zero)
       Unlock(); // second unlock -- actually unlocking


git-svn-id: svn://ttmath.org/publicrep/winix/trunk@830 e52654a7-88a9-db11-a3e9-0013d4bc506e

core/job.cpp

@@ -139,8 +139,6 @@ void Job::DoJob(PT::Space & job)
 {
 	try
 	{
-		// !! FIXME plugin.Call() can log messages
-		// we need Lock/Unlock mechanism there
 		PluginRes res = plugin.Call((Session*)0, WINIX_JOB, &job);
 
 		if( res.res_true == 0 )

core/plugin.cpp

@@ -98,6 +98,21 @@ void Plugin::SetSessionManager(SessionManager * psession_manager)
 
 
 
+void Plugin::Lock()
+{
+	if( synchro )
+		synchro->Lock();
+}
+
+
+void Plugin::Unlock()
+{
+	if( synchro )
+		synchro->Unlock();
+}
+
+
+
 
 bool Plugin::SetPointers(PluginInfo & info)
 {
@@ -105,7 +120,11 @@ bool Plugin::SetPointers(PluginInfo & info)
 	bool res = (db && config && cur && system && functions && templates && synchro && session_manager);
 
 	if( !res )
+	{
+		Lock();
 		log << log1 << "Plugin: cannot call a function - some of the winix pointers are null" << logend;
+		Unlock();
+	}
 
 	info.db        = db;
 	info.config    = config;
@@ -145,7 +164,8 @@ void Plugin::LoadPlugin(const std::string & filename)
 }
 
 
-
+// we don't have to use Lock() here because plusings are read
+// before threads are started
 void * Plugin::LoadInitFun(const char * filename, Fun1 & fun_init)
 {
 	void * p = dlopen(filename, RTLD_NOW | RTLD_LOCAL);
@@ -265,7 +285,11 @@ void Plugin::Call(Session * ses, int message, Slots::iterator & slot, PluginInfo
 	if( !slot->second.is_running )
 	{
 		if( config->log_plugin_call )
+		{
+			Lock();
 			log << log1 << "Plugin: calling plugin id: " << slot->second.index << ", message: " << message << logend;
+			Unlock();
+		}
 
 		slot->second.is_running = true;
 
@@ -278,15 +302,21 @@ void Plugin::Call(Session * ses, int message, Slots::iterator & slot, PluginInfo
 		slot->second.is_running = false;
 
 		if( config->log_plugin_call )
+		{
+			Lock();
 			log << log1 << "Plugin: returning from plugin id: " << slot->second.index << ", message: " << message
 				<< ", result: " << (info.res? "true" : "false") << logend;
+			Unlock();
+		}
 
 	}
 	else
 	{
+		Lock();
 		log << log1 << "Plugin: id: " << slot->second.index
 			<< ", message: " << message
 			<< ", recurrences are not allowed" << logend;
+		Unlock();
 	}
 }
 
@@ -430,10 +460,10 @@ size_t Plugin::Size()
 
 
 /*
-	!! IMPROVE ME
+       !! IMPROVE ME
-	Assign() can work only if other threads are not started
+       Assign() can work only if other threads are not started
-	we can add some barrier/flag so when other threads starts
+       we can add some barrier/flag so when other threads starts
-	then we cannot use Assign() method
+       then we cannot use Assign() method
 */
 void Plugin::Assign(int message, Fun1 fun1)
 {

core/plugin.h

@@ -225,19 +225,20 @@ private:
 	Synchro   * synchro;
 	SessionManager * session_manager;
 
-	std::wstring temp_path;
+	std::wstring temp_path;	// used when loading plugins
+	std::string afilename;
 
 	Plugins plugins;
 	
 	typedef std::multimap<int, Slot> Slots;
 	Slots slots;
-	
-	std::string afilename;
 
 	void * LoadInitFun(const char * filename, Fun1 & fun_init);
 	void Call(Session * ses, int message, Slots::iterator & slot, PluginInfo & info);
 
 	bool SetPointers(PluginInfo & info);
+	void Lock();
+	void Unlock();
 };
 
 

core/synchro.cpp

@@ -2,31 +2,53 @@
  * This file is a part of Winix
  * and is not publicly distributed
  * 
- * Copyright (c) 2010, Tomasz Sowa
+ * Copyright (c) 2010-2012, Tomasz Sowa
  * All rights reserved.
  * 
  */
- 
-#include "synchro.h"
 
+#include <errno.h>
+#include "synchro.h"
 
 
 Synchro::Synchro() : mutex(PTHREAD_MUTEX_INITIALIZER)
 {
 	was_stop_signal = false;
+	ref = 0;
 }
 
 
 
 bool Synchro::Lock()
 {
-	return pthread_mutex_lock(&mutex) == 0;
+	int res = pthread_mutex_lock(&mutex);
+
+	if( res == EDEADLK )
+	{
+		// Lock() method in this thread was called before
+		ref += 1;
+		return true;
+	}
+	else
+	{
+		ref = 0;
+	}
+
+return res == 0;
 }
 
 
+
 void Synchro::Unlock()
 {
-	pthread_mutex_unlock(&mutex);
+	if( ref > 0 )
+	{
+		ref -= 1;
+	}
+	else
+	{
+		pthread_mutex_unlock(&mutex);
+	}
 }
 
 

core/synchro.h

@@ -2,7 +2,7 @@
  * This file is a part of Winix
  * and is not publicly distributed
  * 
- * Copyright (c) 2010, Tomasz Sowa
+ * Copyright (c) 2010-2012, Tomasz Sowa
  * All rights reserved.
  * 
  */
@@ -28,6 +28,13 @@ struct Synchro
 
 	bool Lock();
 	void Unlock();
+
+private:
+
+	// deadlock counter
+	// we can call Lock() more than one in the same thread
+	int ref;
+
 };