Index: ps/trunk/source/ps/Profiler2.cpp
===================================================================
--- ps/trunk/source/ps/Profiler2.cpp	(nonexistent)
+++ ps/trunk/source/ps/Profiler2.cpp	(revision 10465)
@@ -0,0 +1,446 @@
+/* Copyright (C) 2011 Wildfire Games.
+ * This file is part of 0 A.D.
+ *
+ * 0 A.D. is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 0 A.D. is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "precompiled.h"
+
+#include "Profiler2.h"
+
+#include "lib/allocators/shared_ptr.h"
+#include "ps/CLogger.h"
+#include "third_party/mongoose/mongoose.h"
+
+CProfiler2 g_Profiler2;
+
+// A human-recognisable pattern (for debugging) followed by random bytes (for uniqueness)
+const u8 CProfiler2::RESYNC_MAGIC[8] = {0x11, 0x22, 0x33, 0x44, 0xf4, 0x93, 0xbe, 0x15};
+
+CProfiler2::CProfiler2() :
+	m_Initialised(false), m_MgContext(NULL)
+{
+}
+
+/**
+ * Mongoose callback. Run in an arbitrary thread (possibly concurrently with other requests).
+ */
+static void* MgCallback(mg_event event, struct mg_connection *conn, const struct mg_request_info *request_info)
+{
+	CProfiler2* profiler = (CProfiler2*)request_info->user_data;
+	ENSURE(profiler);
+
+	void* handled = (void*)""; // arbitrary non-NULL pointer to indicate successful handling
+
+	const char* header200 =
+		"HTTP/1.1 200 OK\r\n"
+		"Access-Control-Allow-Origin: *\r\n" // TODO: not great for security
+		"Content-Type: text/plain; charset=utf-8\r\n\r\n";
+
+	const char* header404 =
+		"HTTP/1.1 404 Not Found\r\n"
+		"Content-Type: text/plain; charset=utf-8\r\n\r\n"
+		"Unrecognised URI";
+
+	const char* header400 =
+		"HTTP/1.1 400 Bad Request\r\n"
+		"Content-Type: text/plain; charset=utf-8\r\n\r\n"
+		"Invalid request";
+
+	switch (event)
+	{
+	case MG_NEW_REQUEST:
+	{
+		std::stringstream stream;
+
+		std::string uri = request_info->uri;
+		if (uri == "/overview")
+		{
+			profiler->ConstructJSONOverview(stream);
+		}
+		else if (uri == "/query")
+		{
+			if (!request_info->query_string)
+			{
+				mg_printf(conn, "%s (no query string)", header400);
+				return handled;
+			}
+
+			// Identify the requested thread
+			char buf[256];
+			int len = mg_get_var(request_info->query_string, strlen(request_info->query_string), "thread", buf, ARRAY_SIZE(buf));
+			if (len < 0)
+			{
+				mg_printf(conn, "%s (no 'thread')", header400);
+				return handled;
+			}
+			std::string thread(buf);
+
+			const char* err = profiler->ConstructJSONResponse(stream, thread);
+			if (err)
+			{
+				mg_printf(conn, "%s (%s)", header400, err);
+				return handled;
+			}
+		}
+		else
+		{
+			mg_printf(conn, header404);
+			return handled;
+		}
+
+		mg_printf(conn, "%s", header200);
+		std::string str = stream.str();
+		mg_write(conn, str.c_str(), str.length());
+		return handled;
+	}
+
+	case MG_HTTP_ERROR:
+		return NULL;
+
+	case MG_EVENT_LOG:
+		// Called by Mongoose's cry()
+		LOGERROR(L"Mongoose error: %hs", request_info->log_message);
+		return NULL;
+
+	case MG_INIT_SSL:
+		return NULL;
+
+	default:
+		debug_warn(L"Invalid Mongoose event type");
+		return NULL;
+	}
+};
+
+void CProfiler2::Initialise()
+{
+	ENSURE(!m_Initialised);
+	int err = pthread_key_create(&m_TLS, &CProfiler2::TLSDtor);
+	ENSURE(err == 0);
+	m_Initialised = true;
+}
+
+void CProfiler2::EnableHTTP()
+{
+	ENSURE(m_Initialised);
+
+	// Ignore multiple enablings
+	if (m_MgContext)
+		return;
+
+	const char *options[] = {
+		"listening_ports", "127.0.0.1:8000", // bind to localhost for security
+		"num_threads", "6", // enough for the browser's parallel connection limit
+		NULL
+	};
+	m_MgContext = mg_start(MgCallback, this, options);
+	ENSURE(m_MgContext);
+}
+
+void CProfiler2::Shutdown()
+{
+	ENSURE(m_Initialised);
+
+	if (m_MgContext)
+	{
+		mg_stop(m_MgContext);
+		m_MgContext = NULL;
+	}
+
+	// TODO: free non-NULL keys, instead of leaking them
+
+	int err = pthread_key_delete(m_TLS);
+	ENSURE(err == 0);
+	m_Initialised = false;
+}
+
+/**
+ * Called by pthreads when a registered thread is destroyed.
+ */
+void CProfiler2::TLSDtor(void* data)
+{
+	ThreadStorage* storage = (ThreadStorage*)data;
+
+	CProfiler2& profiler = storage->GetProfiler();
+
+	{
+		CScopeLock lock(profiler.m_Mutex);
+		profiler.m_Threads.erase(std::find(profiler.m_Threads.begin(), profiler.m_Threads.end(), storage));
+	}
+
+	delete (ThreadStorage*)data;
+}
+
+void CProfiler2::RegisterCurrentThread(const std::string& name)
+{
+	ENSURE(m_Initialised);
+
+	ENSURE(pthread_getspecific(m_TLS) == NULL); // mustn't register a thread more than once
+
+	ThreadStorage* storage = new ThreadStorage(*this, name);
+	int err = pthread_setspecific(m_TLS, storage);
+	ENSURE(err == 0);
+
+	RecordSyncMarker();
+	RecordEvent("thread start");
+
+	CScopeLock lock(m_Mutex);
+	m_Threads.push_back(storage);
+}
+
+CProfiler2::ThreadStorage::ThreadStorage(CProfiler2& profiler, const std::string& name) :
+	m_Profiler(profiler), m_Name(name), m_BufferPos0(0), m_BufferPos1(0), m_LastTime(timer_Time())
+{
+	m_Buffer = new u8[BUFFER_SIZE];
+	memset(m_Buffer, ITEM_NOP, BUFFER_SIZE);
+}
+
+CProfiler2::ThreadStorage::~ThreadStorage()
+{
+	delete[] m_Buffer;
+}
+
+std::string CProfiler2::ThreadStorage::GetBuffer()
+{
+	// Called from an arbitrary thread (not the one writing to the buffer).
+	// 
+	// See comments on m_BufferPos0 etc.
+
+	shared_ptr<u8> buffer(new u8[BUFFER_SIZE], ArrayDeleter());
+
+	u32 pos1 = m_BufferPos1;
+	COMPILER_FENCE; // must read m_BufferPos1 before m_Buffer
+
+	memcpy(buffer.get(), m_Buffer, BUFFER_SIZE);
+
+	COMPILER_FENCE; // must read m_BufferPos0 after m_Buffer
+	u32 pos0 = m_BufferPos0;
+
+	// The range [pos1, pos0) modulo BUFFER_SIZE is invalid, so concatenate the rest of the buffer
+
+	if (pos1 <= pos0) // invalid range is in the middle of the buffer
+		return std::string(buffer.get()+pos0, buffer.get()+BUFFER_SIZE) + std::string(buffer.get(), buffer.get()+pos1);
+	else // invalid wrap is wrapped around the end/start buffer
+		return std::string(buffer.get()+pos0, buffer.get()+pos1);
+}
+
+void CProfiler2::ThreadStorage::RecordAttribute(const char* fmt, va_list argp)
+{
+	char buffer[MAX_ATTRIBUTE_LENGTH + 4] = {0}; // first 4 bytes are used for storing length
+	i32 len = vsprintf_s(buffer + 4, ARRAY_SIZE(buffer) - 4, fmt, argp);
+	if (len < 0)
+	{
+		debug_warn("Profiler attribute sprintf failed");
+		return;
+	}
+
+	// Store the length in the buffer
+	memcpy(buffer, &len, sizeof(len)); 
+
+	Write(ITEM_ATTRIBUTE, buffer, 4 + len);
+}
+
+
+void CProfiler2::ConstructJSONOverview(std::ostream& stream)
+{
+	CScopeLock lock(m_Mutex);
+
+	stream << "{\"threads\":[";
+	for (size_t i = 0; i < m_Threads.size(); ++i)
+	{
+		if (i != 0)
+			stream << ",";
+		stream << "{\"name\":\"" << CStr(m_Threads[i]->GetName()).EscapeToPrintableASCII() << "\"}";
+	}
+	stream << "]}";
+}
+
+/**
+ * Given a buffer and a visitor class (with functions OnEvent, OnEnter, OnLeave, OnAttribute),
+ * calls the visitor for every item in the buffer.
+ */
+template<typename V>
+void RunBufferVisitor(const std::string& buffer, V& visitor)
+{
+	// The buffer doesn't necessarily start at the beginning of an item
+	// (we just grabbed it from some arbitrary point in the middle),
+	// so scan forwards until we find a sync marker.
+	// (This is probably pretty inefficient.)
+
+	u32 realStart = (u32)-1; // the start point decided by the scan algorithm
+
+	for (u32 start = 0; start + 1 + sizeof(CProfiler2::RESYNC_MAGIC) <= buffer.length(); ++start)
+	{
+		if (buffer[start] == CProfiler2::ITEM_SYNC
+			&& memcmp(buffer.c_str() + start + 1, &CProfiler2::RESYNC_MAGIC, sizeof(CProfiler2::RESYNC_MAGIC)) == 0)
+		{
+			realStart = start;
+			break;
+		}
+	}
+
+	ENSURE(realStart != (u32)-1); // we should have found a sync point somewhere in the buffer
+
+	u32 pos = realStart; // the position as we step through the buffer
+
+	double lastTime = -1;
+		// set to non-negative by EVENT_SYNC; we ignore all items before that
+		// since we can't compute their absolute times
+
+	while (pos < buffer.length())
+	{
+		u8 type = buffer[pos];
+		++pos;
+
+		switch (type)
+		{
+		case CProfiler2::ITEM_NOP:
+		{
+			// ignore
+			break;
+		}
+		case CProfiler2::ITEM_SYNC:
+		{
+			u8 magic[sizeof(CProfiler2::RESYNC_MAGIC)];
+			double t;
+			memcpy(magic, buffer.c_str()+pos, ARRAY_SIZE(magic));
+			ENSURE(memcmp(magic, &CProfiler2::RESYNC_MAGIC, sizeof(CProfiler2::RESYNC_MAGIC)) == 0);
+			pos += sizeof(CProfiler2::RESYNC_MAGIC);
+			memcpy(&t, buffer.c_str()+pos, sizeof(t));
+			pos += sizeof(t);
+			lastTime = t;
+			break;
+		}
+		case CProfiler2::ITEM_EVENT:
+		{
+			CProfiler2::SItem_dt_id item;
+			memcpy(&item, buffer.c_str()+pos, sizeof(item));
+			pos += sizeof(item);
+			if (lastTime >= 0)
+			{
+				lastTime = lastTime + (double)item.dt;
+				visitor.OnEvent(lastTime, item.id);
+			}
+			break;
+		}
+		case CProfiler2::ITEM_ENTER:
+		{
+			CProfiler2::SItem_dt_id item;
+			memcpy(&item, buffer.c_str()+pos, sizeof(item));
+			pos += sizeof(item);
+			if (lastTime >= 0)
+			{
+				lastTime = lastTime + (double)item.dt;
+				visitor.OnEnter(lastTime, item.id);
+			}
+			break;
+		}
+		case CProfiler2::ITEM_LEAVE:
+		{
+			CProfiler2::SItem_dt_id item;
+			memcpy(&item, buffer.c_str()+pos, sizeof(item));
+			pos += sizeof(item);
+			if (lastTime >= 0)
+			{
+				lastTime = lastTime + (double)item.dt;
+				visitor.OnLeave(lastTime, item.id);
+			}
+			break;
+		}
+		case CProfiler2::ITEM_ATTRIBUTE:
+		{
+			u32 len;
+			memcpy(&len, buffer.c_str()+pos, sizeof(len));
+			ENSURE(len <= CProfiler2::MAX_ATTRIBUTE_LENGTH);
+			pos += sizeof(len);
+			std::string attribute(buffer.c_str()+pos, buffer.c_str()+pos+len);
+			pos += len;
+			if (lastTime >= 0)
+			{
+				visitor.OnAttribute(attribute);
+			}
+			break;
+		}
+		default:
+			debug_warn(L"Invalid profiler item when parsing buffer");
+			return;
+		}
+	}
+};
+
+/**
+ * Visitor class that dumps events as JSON.
+ * TODO: this is pretty inefficient (in implementation and in output format).
+ */
+struct BufferVisitor_Dump
+{
+	NONCOPYABLE(BufferVisitor_Dump);
+public:
+	BufferVisitor_Dump(std::ostream& stream) : m_Stream(stream)
+	{
+	}
+
+	void OnEvent(double time, const char* id)
+	{
+		m_Stream << "[1," << std::fixed << std::setprecision(9) << time;
+		m_Stream << ",\"" << CStr(id).EscapeToPrintableASCII() << "\"],\n";
+	}
+
+	void OnEnter(double time, const char* id)
+	{
+		m_Stream << "[2," << std::fixed << std::setprecision(9) << time;
+		m_Stream << ",\"" << CStr(id).EscapeToPrintableASCII() << "\"],\n";
+	}
+
+	void OnLeave(double time, const char* id)
+	{
+		m_Stream << "[3," << std::fixed << std::setprecision(9) << time;
+		m_Stream << ",\"" << CStr(id).EscapeToPrintableASCII() << "\"],\n";
+	}
+
+	void OnAttribute(const std::string& attr)
+	{
+		m_Stream << "[4,\"" << CStr(attr).EscapeToPrintableASCII() << "\"],\n";
+	}
+
+	std::ostream& m_Stream;
+};
+
+const char* CProfiler2::ConstructJSONResponse(std::ostream& stream, const std::string& thread)
+{
+	CScopeLock lock(m_Mutex);
+
+	ThreadStorage* storage = NULL;
+	for (size_t i = 0; i < m_Threads.size(); ++i)
+	{
+		if (m_Threads[i]->GetName() == thread)
+		{
+			storage = m_Threads[i];
+			break;
+		}
+	}
+
+	if (!storage)
+		return "cannot find named thread";
+
+	stream << "{\"events\":[\n";
+
+	std::string buffer = storage->GetBuffer();
+	BufferVisitor_Dump visitor(stream);
+	RunBufferVisitor(buffer, visitor);
+
+	stream << "null\n]}";
+
+	return NULL;
+}
Index: ps/trunk/source/ps/Profiler2.h
===================================================================
--- ps/trunk/source/ps/Profiler2.h	(nonexistent)
+++ ps/trunk/source/ps/Profiler2.h	(revision 10465)
@@ -0,0 +1,381 @@
+/* Copyright (C) 2011 Wildfire Games.
+ * This file is part of 0 A.D.
+ *
+ * 0 A.D. is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 0 A.D. is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * @file New profiler (complementing the older CProfileManager)
+ * 
+ * The profiler is designed for analysing framerate fluctuations or glitches,
+ * and temporal relationships between threads.
+ * This contrasts with CProfilerManager and most external profiling tools,
+ * which are designed more for measuring average throughput over a number of
+ * frames.
+ * 
+ * To view the profiler output, press F11 to enable the HTTP output mode
+ * and then open source/tools/profiler2/profiler2.html in a web browser.
+ * 
+ * There is a single global CProfiler2 instance (g_Profiler2),
+ * providing the API used by the rest of the game.
+ * The game can record the entry/exit timings of a region of code
+ * using the PROFILE2 macro, and can record other events using
+ * PROFILE2_EVENT.
+ * Regions and events can be annotated with arbitrary string attributes,
+ * specified with printf-style format strings, using PROFILE2_ATTR
+ * (e.g. PROFILE2_ATTR("frame: %d", m_FrameNum) ).
+ * 
+ * This is designed for relatively coarse-grained profiling, or for rare events.
+ * Don't use it for regions that are typically less than ~0.1msecs, or that are
+ * called hundreds of times per frame. (The old CProfilerManager is better
+ * for that.)
+ * 
+ * New threads must call g_Profiler2.RegisterCurrentThread before any other
+ * profiler functions.
+ * 
+ * The main thread should call g_Profiler2.RecordFrameStart at the start of
+ * each frame.
+ * Other threads should call g_Profiler2.RecordSyncMarker occasionally,
+ * especially if it's been a long time since their last call to the profiler,
+ * or if they've made thousands of calls since the last sync marker.
+ * 
+ * The profiler is implemented with thread-local fixed-size ring buffers,
+ * which store a sequence of variable-length items indicating the time
+ * of the event and associated data (pointers to names, attribute strings, etc).
+ * An HTTP server provides access to the data: when requested, it will make
+ * a copy of a thread's buffer, then parse the items and return them in JSON
+ * format. The profiler2.html requests and processes and visualises this data.
+ * 
+ * The RecordSyncMarker calls are necessary to correct for time drift and to
+ * let the buffer parser accurately detect the start of an item in the byte stream.
+ * 
+ * This design aims to minimise the performance overhead of recording data,
+ * and to simplify the visualisation of the data by doing it externally in an
+ * environment with better UI tools (i.e. HTML) instead of within the game engine.
+ * 
+ * The initial setup of g_Profiler2 must happen in the game's main thread.
+ * RegisterCurrentThread and the Record functions may be called from any thread.
+ * The HTTP server runs its own threads, which may call the ConstructJSON functions.
+ */
+
+#ifndef INCLUDED_PROFILER2
+#define INCLUDED_PROFILER2
+
+#include "lib/timer.h"
+#include "ps/ThreadUtil.h"
+
+struct mg_context;
+
+// Note: Lots of functions are defined inline, to hypothetically
+// minimise performance overhead.
+
+class CProfiler2
+{
+public:
+	// Items stored in the buffers:
+
+	/// Item type identifiers
+	enum EItem
+	{
+		ITEM_NOP = 0,
+		ITEM_SYNC = 1, // magic value used for parse syncing
+		ITEM_EVENT = 2, // single event
+		ITEM_ENTER = 3, // entering a region
+		ITEM_LEAVE = 4, // leaving a region (must be correctly nested)
+		ITEM_ATTRIBUTE = 5, // arbitrary string associated with current region, or latest event (if the previous item was an event)
+	};
+
+	static const size_t MAX_ATTRIBUTE_LENGTH = 256; // includes null terminator, which isn't stored
+
+	/// An arbitrary number to help resyncing with the item stream when parsing.
+	static const u8 RESYNC_MAGIC[8];
+	
+	/**
+	 * An item with a relative time and an ID string pointer.
+	 */
+	struct SItem_dt_id
+	{
+		float dt; // time relative to last event
+		const char* id;
+	};
+
+private:
+	// TODO: what's a good size?
+	// TODO: different threads might want different sizes
+	static const size_t BUFFER_SIZE = 128*1024;
+
+	/**
+	 * Class instantiated in every registered thread.
+	 */
+	class ThreadStorage
+	{
+		NONCOPYABLE(ThreadStorage);
+	public:
+		ThreadStorage(CProfiler2& profiler, const std::string& name);
+		~ThreadStorage();
+	
+		void RecordSyncMarker(double t)
+		{
+			// Store the magic string followed by the absolute time
+			// (to correct for drift caused by the precision of relative
+			// times stored in other items)
+			u8 buffer[sizeof(RESYNC_MAGIC) + sizeof(t)];
+			memcpy(buffer, &RESYNC_MAGIC, sizeof(RESYNC_MAGIC));
+			memcpy(buffer + sizeof(RESYNC_MAGIC), &t, sizeof(t));
+			Write(ITEM_SYNC, buffer, ARRAY_SIZE(buffer));
+			m_LastTime = t;
+		}
+
+		void Record(EItem type, double t, const char* id)
+		{
+			// Store a relative time instead of absolute, so we can use floats
+			// (to save memory) without suffering from precision problems
+			SItem_dt_id item = { (float)(t - m_LastTime), id };
+			Write(type, &item, sizeof(item));
+			m_LastTime = t;
+		}
+
+		void RecordFrameStart(double t)
+		{
+			RecordSyncMarker(t);
+			Record(ITEM_EVENT, t, "__framestart"); // magic string recognised by the visualiser
+		}
+
+		void RecordAttribute(const char* fmt, va_list argp);
+
+		CProfiler2& GetProfiler()
+		{
+			return m_Profiler;
+		}
+
+		const std::string& GetName()
+		{
+			return m_Name;
+		}
+
+		/**
+		 * Returns a copy of a subset of the thread's buffer.
+		 * Not guaranteed to start on an item boundary.
+		 * May be called by any thread.
+		 */
+		std::string GetBuffer();
+
+	private:
+		/**
+		 * Store an item into the buffer.
+		 */
+		void Write(EItem type, const void* item, u32 itemSize)
+		{
+			// See m_BufferPos0 etc for comments on synchronisation
+
+			u32 size = 1 + itemSize;
+			u32 start = m_BufferPos0;
+			if (start + size > BUFFER_SIZE)
+			{
+				// The remainder of the buffer is too small - fill the rest
+				// with NOPs then start from offset 0, so we don't have to
+				// bother splitting the real item across the end of the buffer
+
+				m_BufferPos0 = size;
+				COMPILER_FENCE; // must write m_BufferPos0 before m_Buffer
+
+				memset(m_Buffer + start, 0, BUFFER_SIZE - start);
+				start = 0;
+			}
+			else
+			{
+				m_BufferPos0 = start + size;
+				COMPILER_FENCE; // must write m_BufferPos0 before m_Buffer
+			}
+
+			m_Buffer[start] = (u8)type;
+			memcpy(&m_Buffer[start + 1], item, itemSize);
+			
+			COMPILER_FENCE; // must write m_BufferPos1 after m_Buffer
+			m_BufferPos1 = start + size;
+		}
+
+		CProfiler2& m_Profiler;
+		std::string m_Name;
+
+		double m_LastTime; // used for computing relative times
+
+		u8* m_Buffer;
+
+		// To allow hopefully-safe reading of the buffer from a separate thread,
+		// without any expensive synchronisation in the recording thread,
+		// two copies of the current buffer write position are stored.
+		// BufferPos0 is updated before writing; BufferPos1 is updated after writing.
+		// GetBuffer can read Pos1, copy the buffer, read Pos0, then assume any bytes
+		// outside the range Pos1 <= x < Pos0 are safe to use. (Any in that range might
+		// be half-written and corrupted.) (All ranges are modulo BUFFER_SIZE.)
+		// Outside of Write(), these will always be equal.
+		// 
+		// TODO: does this attempt at synchronisation (plus use of COMPILER_FENCE etc)
+		// actually work in practice?
+		u32 m_BufferPos0;
+		u32 m_BufferPos1;
+	};
+
+public:
+	CProfiler2();
+
+	/**
+	 * Call in main thread to set up the profiler,
+	 * before calling any other profiler functions.
+	 */
+	void Initialise();
+
+	/**
+	 * Call in main thread to enable the HTTP server.
+	 * (Disabled by default for security and performance
+	 * and to avoid annoying a firewall.)
+	 */
+	void EnableHTTP();
+
+	/**
+	 * Call in main thread to shut everything down.
+	 * All other profiled threads should have been terminated already.
+	 */
+	void Shutdown();
+
+	/**
+	 * Call in any thread to enable the profiler in that thread.
+	 * @p name should be unique, and is used by the visualiser to identify
+	 * this thread.
+	 */
+	void RegisterCurrentThread(const std::string& name);
+
+	/**
+	 * Non-main threads should call this occasionally,
+	 * especially if it's been a long time since their last call to the profiler,
+	 * or if they've made thousands of calls since the last sync marker.
+	 */
+	void RecordSyncMarker()
+	{
+		GetThreadStorage().RecordSyncMarker(GetTime());
+	}
+
+	/**
+	 * Call in main thread at the start of a frame.
+	 */
+	void RecordFrameStart()
+	{
+		GetThreadStorage().RecordFrameStart(GetTime());
+	}
+
+	void RecordEvent(const char* id)
+	{
+		GetThreadStorage().Record(ITEM_EVENT, GetTime(), id);
+	}
+
+	void RecordRegionEnter(const char* id)
+	{
+		GetThreadStorage().Record(ITEM_ENTER, GetTime(), id);
+	}
+
+	void RecordRegionLeave(const char* id)
+	{
+		GetThreadStorage().Record(ITEM_LEAVE, GetTime(), id);
+	}
+
+	void RecordAttribute(const char* fmt, ...)
+	{
+		va_list argp;
+		va_start(argp, fmt);
+		GetThreadStorage().RecordAttribute(fmt, argp);
+		va_end(argp);
+	}
+
+	/**
+	 * Call in any thread to produce a JSON representation of the general
+	 * state of the application.
+	 */
+	void ConstructJSONOverview(std::ostream& stream);
+
+	/**
+	 * Call in any thread to produce a JSON representation of the buffer
+	 * for a given thread.
+	 * Returns NULL on success, or an error string.
+	 */
+	const char* ConstructJSONResponse(std::ostream& stream, const std::string& thread);
+
+private:
+	static void TLSDtor(void* data);
+
+	ThreadStorage& GetThreadStorage()
+	{
+		ThreadStorage* storage = (ThreadStorage*)pthread_getspecific(m_TLS);
+		ASSERT(storage);
+		return *storage;
+	}
+
+	double GetTime()
+	{
+		return timer_Time();
+	}
+
+	bool m_Initialised;
+	
+	mg_context* m_MgContext;
+	
+	pthread_key_t m_TLS;
+
+	CMutex m_Mutex;
+	std::vector<ThreadStorage*> m_Threads; // thread-safe; protected by m_Mutex
+};
+
+extern CProfiler2 g_Profiler2;
+
+/**
+ * Scope-based enter/leave helper.
+ */
+class CProfile2Region
+{
+public:
+	CProfile2Region(const char* name) : m_Name(name)
+	{
+		g_Profiler2.RecordRegionEnter(m_Name);
+	}
+	~CProfile2Region()
+	{
+		g_Profiler2.RecordRegionLeave(m_Name);
+	}
+private:
+	const char* m_Name;
+};
+
+/**
+ * Starts timing from now until the end of the current scope.
+ * @p region is the name to associate with this region (should be
+ * a constant string literal; the pointer must remain valid forever).
+ * Regions may be nested, but preferably shouldn't be nested deeply since
+ * it hurts the visualisation.
+ */
+#define PROFILE2(region) CProfile2Region profile2__(region)
+
+/**
+ * Record the named event at the current time.
+ */
+#define PROFILE2_EVENT(name) g_Profiler2.RecordEvent(name)
+
+/**
+ * Associates a string (with printf-style formatting) with the current
+ * region or event.
+ * (If the last profiler call was PROFILE2_EVENT, it associates with that
+ * event; otherwise it associates with the currently-active region.)
+ */
+#define PROFILE2_ATTR g_Profiler2.RecordAttribute
+
+#endif // INCLUDED_PROFILER2