(svn r23209) -Codechange: track the current active script instance directly, instead of assuming the current company points you to the right one.

9 files changed, 138 insertions, 52 deletions

diff --git a/src/ai/ai_core.cpp b/src/ai/ai_core.cpp
index b98c88c30..18eeef3b0 100644
--- a/src/ai/ai_core.cpp
+++ b/src/ai/ai_core.cpp
@@ -52,7 +52,8 @@
 
 	c->ai_info = info;
 	assert(c->ai_instance == NULL);
-	c->ai_instance = new AIInstance(info);
+	c->ai_instance = new AIInstance();
+	c->ai_instance->Initialize(info);
 
 	cur_company.Restore();
 
@@ -214,7 +215,7 @@
 
 	/* Queue the event */
 	Backup<CompanyByte> cur_company(_current_company, company, FILE_LINE);
-	AIEventController::InsertEvent(event);
+	Company::Get(_current_company)->ai_instance->InsertEvent(event);
 	cur_company.Restore();
 
 	event->Release();
@@ -248,15 +249,7 @@
  */
 void CcAI(const CommandCost &result, TileIndex tile, uint32 p1, uint32 p2)
 {
-	AIObject::SetLastCommandRes(result.Succeeded());
-
-	if (result.Failed()) {
-		AIObject::SetLastError(AIError::StringToError(result.GetErrorMessage()));
-	} else {
-		AIObject::IncreaseDoCommandCosts(result.GetCost());
-		AIObject::SetLastCost(result.GetCost());
-	}
-
+	Company::Get(_current_company)->ai_instance->DoCommandCallback(result, tile, p1, p2);
 	Company::Get(_current_company)->ai_instance->Continue();
 }
 
@@ -327,7 +320,7 @@ void CcAI(const CommandCost &result, TileIndex tile, uint32 p1, uint32 p2)
 
 /* static */ bool AI::ImportLibrary(const char *library, const char *class_name, int version, HSQUIRRELVM vm)
 {
-	return AI::ai_scanner->ImportLibrary(library, class_name, version, vm, Company::Get(_current_company)->ai_instance->GetController());
+	return AI::ai_scanner->ImportLibrary(library, class_name, version, vm, AIObject::GetActiveInstance()->GetController());
 }
 
 /* static */ void AI::Rescan()
diff --git a/src/ai/ai_gui.cpp b/src/ai/ai_gui.cpp
index 96c5bb0ed..d8b55c6c2 100644
--- a/src/ai/ai_gui.cpp
+++ b/src/ai/ai_gui.cpp
@@ -931,9 +931,7 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 		/* If there are no active companies, don't display anything else. */
 		if (ai_debug_company == INVALID_COMPANY) return;
 
-		Backup<CompanyByte> cur_company(_current_company, ai_debug_company, FILE_LINE);
-		AILog::LogData *log = (AILog::LogData *)AIObject::GetLogPointer();
-		cur_company.Restore();
+		AILog::LogData *log = (AILog::LogData *)Company::Get(ai_debug_company)->ai_instance->GetLogPointer();
 
 		int scroll_count = (log == NULL) ? 0 : log->used;
 		if (this->vscroll->GetCount() != scroll_count) {
@@ -986,9 +984,7 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 
 		switch (widget) {
 			case AID_WIDGET_LOG_PANEL: {
-				Backup<CompanyByte> cur_company(_current_company, ai_debug_company, FILE_LINE);
-				AILog::LogData *log = (AILog::LogData *)AIObject::GetLogPointer();
-				cur_company.Restore();
+				AILog::LogData *log = (AILog::LogData *)Company::Get(ai_debug_company)->ai_instance->GetLogPointer();
 				if (log == NULL) return;
 
 				int y = this->top_offset;
@@ -1029,9 +1025,7 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 		this->RaiseWidget(ai_debug_company + AID_WIDGET_COMPANY_BUTTON_START);
 		ai_debug_company = show_ai;
 
-		Backup<CompanyByte> cur_company(_current_company, ai_debug_company, FILE_LINE);
-		AILog::LogData *log = (AILog::LogData *)AIObject::GetLogPointer();
-		cur_company.Restore();
+		AILog::LogData *log = (AILog::LogData *)Company::Get(ai_debug_company)->ai_instance->GetLogPointer();
 		this->vscroll->SetCount((log == NULL) ? 0 : log->used);
 
 		this->LowerWidget(ai_debug_company + AID_WIDGET_COMPANY_BUTTON_START);
@@ -1130,8 +1124,7 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 		 * This needs to be done in gameloop-scope, so the AI is suspended immediately. */
 		if (!gui_scope && data == ai_debug_company && this->break_check_enabled && !StrEmpty(this->edit_str_buf)) {
 			/* Get the log instance of the active company */
-			Backup<CompanyByte> cur_company(_current_company, ai_debug_company, FILE_LINE);
-			AILog::LogData *log = (AILog::LogData *)AIObject::GetLogPointer();
+			AILog::LogData *log = (AILog::LogData *)Company::Get(ai_debug_company)->ai_instance->GetLogPointer();
 
 			if (log != NULL && case_sensitive_break_check?
 					strstr(log->lines[log->pos], this->edit_str_buf) != 0 :
@@ -1149,8 +1142,6 @@ struct AIDebugWindow : public QueryStringBaseWindow {
 				/* Highlight row that matched */
 				this->highlight_row = log->pos;
 			}
-
-			cur_company.Restore();
 		}
 	}
 
diff --git a/src/ai/ai_instance.cpp b/src/ai/ai_instance.cpp
index dbc8970b1..2333ddd2e 100644
--- a/src/ai/ai_instance.cpp
+++ b/src/ai/ai_instance.cpp
@@ -100,7 +100,7 @@ static void PrintFunc(bool error_msg, const SQChar *message)
 	AIController::Print(error_msg, SQ2OTTD(message));
 }
 
-AIInstance::AIInstance(AIInfo *info) :
+AIInstance::AIInstance() :
 	controller(NULL),
 	storage(NULL),
 	engine(NULL),
@@ -111,13 +111,16 @@ AIInstance::AIInstance(AIInfo *info) :
 	suspend(0),
 	callback(NULL)
 {
-	/* Set the instance already, so we can use AIObject::Set commands */
-	Company::Get(_current_company)->ai_instance = this;
+	this->storage = new AIStorage();
+	this->engine  = new Squirrel();
+	this->engine->SetPrintFunction(&PrintFunc);
+}
+
+void AIInstance::Initialize(AIInfo *info)
+{
+	AIObject::ActiveInstance active(this);
 
 	this->controller = new AIController();
-	this->storage    = new AIStorage();
-	this->engine     = new Squirrel();
-	this->engine->SetPrintFunction(&PrintFunc);
 
 	/* The import method is available at a very early stage */
 	this->engine->AddMethod("import", &AILibrary::Import, 4, ".ssi");
@@ -163,6 +166,8 @@ AIInstance::AIInstance(AIInfo *info) :
 
 AIInstance::~AIInstance()
 {
+	AIObject::ActiveInstance active(this);
+
 	if (instance != NULL) this->engine->ReleaseObject(this->instance);
 	if (engine != NULL) delete this->engine;
 	delete this->storage;
@@ -316,6 +321,8 @@ void AIInstance::Died()
 
 void AIInstance::GameLoop()
 {
+	AIObject::ActiveInstance active(this);
+
 	if (this->IsDead()) return;
 	if (this->engine->HasScriptCrashed()) {
 		/* The script crashed during saving, kill it here. */
@@ -423,10 +430,16 @@ void AIInstance::CollectGarbage() const
 	instance->engine->InsertResult(AIObject::GetNewGroupID());
 }
 
-/* static */ AIStorage *AIInstance::GetStorage()
+AIStorage *AIInstance::GetStorage()
 {
-	assert(Company::IsValidAiID(_current_company));
-	return Company::Get(_current_company)->ai_instance->storage;
+	return this->storage;
+}
+
+void *AIInstance::GetLogPointer()
+{
+	AIObject::ActiveInstance active(this);
+
+	return AIObject::GetLogPointer();
 }
 
 /*
@@ -598,6 +611,8 @@ static const uint AISAVE_MAX_DEPTH = 25; ///< The maximum recursive depth for it
 
 void AIInstance::Save()
 {
+	AIObject::ActiveInstance active(this);
+
 	/* Don't save data if the AI didn't start yet or if it crashed. */
 	if (this->engine == NULL || this->engine->HasScriptCrashed()) {
 		SaveEmpty();
@@ -662,7 +677,6 @@ void AIInstance::Save()
 		_ai_sl_byte = 0;
 		SlObject(NULL, _ai_byte);
 	}
-
 }
 
 void AIInstance::Suspend()
@@ -739,6 +753,8 @@ void AIInstance::Suspend()
 
 void AIInstance::Load(int version)
 {
+	AIObject::ActiveInstance active(this);
+
 	if (this->engine == NULL || version == -1) {
 		LoadEmpty();
 		return;
@@ -795,3 +811,24 @@ SQInteger AIInstance::GetOpsTillSuspend()
 {
 	return this->engine->GetOpsTillSuspend();
 }
+
+void AIInstance::DoCommandCallback(const CommandCost &result, TileIndex tile, uint32 p1, uint32 p2)
+{
+	AIObject::ActiveInstance active(this);
+
+	AIObject::SetLastCommandRes(result.Succeeded());
+
+	if (result.Failed()) {
+		AIObject::SetLastError(AIError::StringToError(result.GetErrorMessage()));
+	} else {
+		AIObject::IncreaseDoCommandCosts(result.GetCost());
+		AIObject::SetLastCost(result.GetCost());
+	}
+}
+
+void AIInstance::InsertEvent(class AIEvent *event)
+{
+	AIObject::ActiveInstance active(this);
+
+	AIEventController::InsertEvent(event);
+}
diff --git a/src/ai/ai_instance.hpp b/src/ai/ai_instance.hpp
index 65884dc71..b0b32b3b5 100644
--- a/src/ai/ai_instance.hpp
+++ b/src/ai/ai_instance.hpp
@@ -81,12 +81,17 @@ public:
 
 	/**
 	 * Create a new AI.
-	 * @param info The AI to create the instance of.
 	 */
-	AIInstance(class AIInfo *info);
+	AIInstance();
 	~AIInstance();
 
 	/**
+	 * Initialize the AI and prepare it for its first run.
+	 * @param info The AI to create the instance of.
+	 */
+	void Initialize(class AIInfo *info);
+
+	/**
 	 * An AI in multiplayer waits for the server to handle his DoCommand.
 	 *  It keeps waiting for this until this function is called.
 	 */
@@ -105,7 +110,12 @@ public:
 	/**
 	 * Get the storage of this AI.
 	 */
-	static class AIStorage *GetStorage();
+	class AIStorage *GetStorage();
+
+	/**
+	 * Get the log pointer of this AI.
+	 */
+	void *GetLogPointer();
 
 	/**
 	 * Return a true/false reply for a DoCommand.
@@ -173,6 +183,22 @@ public:
 	 * @return The number of operations to execute.
 	 */
 	SQInteger GetOpsTillSuspend();
+
+	/**
+	 * DoCommand callback function for all commands executed by AIs.
+	 * @param result The result of the command.
+	 * @param tile The tile on which the command was executed.
+	 * @param p1 p1 as given to DoCommandPInternal.
+	 * @param p2 p2 as given to DoCommandPInternal.
+	 */
+	void DoCommandCallback(const CommandCost &result, TileIndex tile, uint32 p1, uint32 p2);
+
+	/**
+	 * Insert an event for this AI.
+	 * @param event The event to insert.
+	 */
+	void InsertEvent(class AIEvent *event);
+
 private:
 	class AIController *controller;  ///< The AI main class.
 	class AIStorage *storage;        ///< Some global information for each running AI.
diff --git a/src/ai/api/ai_controller.cpp b/src/ai/api/ai_controller.cpp
index 0c478cf4a..78dee1d21 100644
--- a/src/ai/api/ai_controller.cpp
+++ b/src/ai/api/ai_controller.cpp
@@ -63,12 +63,12 @@ AIController::~AIController()
 
 /* static */ uint AIController::GetTick()
 {
-	return ::Company::Get(_current_company)->ai_instance->GetController()->ticks;
+	return AIObject::GetActiveInstance()->GetController()->ticks;
 }
 
 /* static */ int AIController::GetOpsTillSuspend()
 {
-	return ::Company::Get(_current_company)->ai_instance->GetOpsTillSuspend();
+	return AIObject::GetActiveInstance()->GetOpsTillSuspend();
 }
 
 /* static */ int AIController::GetSetting(const char *name)
diff --git a/src/ai/api/ai_execmode.cpp b/src/ai/api/ai_execmode.cpp
index e661a1068..f5e1e502b 100644
--- a/src/ai/api/ai_execmode.cpp
+++ b/src/ai/api/ai_execmode.cpp
@@ -32,9 +32,8 @@ AIExecMode::AIExecMode()
 AIExecMode::~AIExecMode()
 {
 	if (this->GetDoCommandModeInstance() != this) {
-		AIInstance *instance = Company::Get(_current_company)->ai_instance;
 		/* Ignore this error if the AI already died. */
-		if (!instance->IsDead()) {
+		if (!AIObject::GetActiveInstance()->IsDead()) {
 			throw AI_FatalError("AIExecMode object was removed while it was not the latest AI*Mode object created.");
 		}
 	}
diff --git a/src/ai/api/ai_object.cpp b/src/ai/api/ai_object.cpp
index 4c415524b..53f2f2b55 100644
--- a/src/ai/api/ai_object.cpp
+++ b/src/ai/api/ai_object.cpp
@@ -12,8 +12,6 @@
 #include "../../stdafx.h"
 #include "../../script/squirrel.hpp"
 #include "../../command_func.h"
-#include "../../company_base.h"
-#include "../../company_func.h"
 #include "../../network/network.h"
 #include "../../tunnelbridge.h"
 
@@ -27,9 +25,30 @@
  */
 static AIStorage *GetStorage()
 {
-	return AIInstance::GetStorage();
+	return AIObject::GetActiveInstance()->GetStorage();
 }
 
+
+/* static */ AIInstance *AIObject::ActiveInstance::active = NULL;
+
+AIObject::ActiveInstance::ActiveInstance(AIInstance *instance)
+{
+	this->last_active = AIObject::ActiveInstance::active;
+	AIObject::ActiveInstance::active = instance;
+}
+
+AIObject::ActiveInstance::~ActiveInstance()
+{
+	AIObject::ActiveInstance::active = this->last_active;
+}
+
+/* static */ AIInstance *AIObject::GetActiveInstance()
+{
+	assert(AIObject::ActiveInstance::active != NULL);
+	return AIObject::ActiveInstance::active;
+}
+
+
 /* static */ void AIObject::SetDoCommandDelay(uint ticks)
 {
 	assert(ticks > 0);
@@ -179,7 +198,7 @@ static AIStorage *GetStorage()
 
 /* static */ bool AIObject::CanSuspend()
 {
-	Squirrel *squirrel = Company::Get(_current_company)->ai_instance->engine;
+	Squirrel *squirrel = AIObject::GetActiveInstance()->engine;
 	return GetStorage()->allow_do_command && squirrel->CanSuspend();
 }
 
diff --git a/src/ai/api/ai_object.hpp b/src/ai/api/ai_object.hpp
index 3df150bac..deac277dd 100644
--- a/src/ai/api/ai_object.hpp
+++ b/src/ai/api/ai_object.hpp
@@ -35,10 +35,26 @@ typedef bool (AIModeProc)();
  *   command processing, and command-validation checks.
  */
 class AIObject : public SimpleCountedObject {
-friend void CcAI(const CommandCost &result, TileIndex tile, uint32 p1, uint32 p2);
 friend class AIInstance;
-friend class AIController;
 #ifndef DOXYGEN_AI_DOCS
+protected:
+	/**
+	 * A class that handles the current active instance. By instantiating it at
+	 *  the beginning of a function with the current active instance, it remains
+	 *  active till the scope of the variable closes. It then automatically
+	 *  reverts to the active instance it was before instantiating.
+	 */
+	class ActiveInstance {
+	friend class AIObject;
+	public:
+		ActiveInstance(AIInstance *instance);
+		~ActiveInstance();
+	private:
+		AIInstance *last_active;    ///< The active instance before we go instantiated.
+
+		static AIInstance *active;  ///< The global current active instance.
+	};
+
 public:
 	/**
 	 * Store the latest result of a DoCommand per company.
@@ -47,9 +63,10 @@ public:
 	static void SetLastCommandRes(bool res);
 
 	/**
-	 * Get the pointer to store log message in.
+	 * Get the currently active instance.
+	 * @return The instance.
 	 */
-	static void *&GetLogPointer();
+	static class AIInstance *GetActiveInstance();
 
 protected:
 	/**
@@ -197,6 +214,11 @@ protected:
 	 */
 	static void *&GetEventPointer();
 
+	/**
+	 * Get the pointer to store log message in.
+	 */
+	static void *&GetLogPointer();
+
 private:
 	/**
 	 * Store a new_vehicle_id per company.
diff --git a/src/ai/api/ai_testmode.cpp b/src/ai/api/ai_testmode.cpp
index 996b27874..6e2f515b4 100644
--- a/src/ai/api/ai_testmode.cpp
+++ b/src/ai/api/ai_testmode.cpp
@@ -32,9 +32,8 @@ AITestMode::AITestMode()
 AITestMode::~AITestMode()
 {
 	if (this->GetDoCommandModeInstance() != this) {
-		AIInstance *instance = Company::Get(_current_company)->ai_instance;
 		/* Ignore this error if the AI already died. */
-		if (!instance->IsDead()) {
+		if (!AIObject::GetActiveInstance()->IsDead()) {
 			throw AI_FatalError("AITestmode object was removed while it was not the latest AI*Mode object created.");
 		}
 	}