More efficient device error logging

src/emu/device.cpp

@@ -360,6 +360,10 @@ bool device_t::findit(bool isvalidation) const
 
 void device_t::start()
 {
+	// prepare the logerror buffer
+	if (m_machine->allow_logging())
+		m_string_buffer.reserve(1024);
+
 	// find all the registered devices
 	if (!findit(false))
 		throw emu_fatalerror("Missing some required objects, unable to proceed");
@@ -380,7 +384,7 @@ void device_t::start()
 	device_sound_interface *sound;
 	if (state_registrations == 0 && (interface(exec) || interface(sound)) && type() != SPEAKER)
 	{
-		logerror("Device '%s' did not register any state to save!\n", tag());
+		logerror("Device did not register any state to save!\n");
 		if ((machine().system().flags & MACHINE_SUPPORTS_SAVE) != 0)
 			fatalerror("Device '%s' did not register any state to save!\n", tag());
 	}

src/emu/device.h

@@ -361,6 +361,9 @@ private:
 	bool                    m_config_complete;      // have we completed our configuration?
 	bool                    m_started;              // true if the start function has succeeded
 	finder_base *           m_auto_finder_list;     // list of objects to auto-find
+
+	// string formatting buffer for logerror
+	mutable util::ovectorstream m_string_buffer;
 };
 
 

src/emu/device.ipp

@@ -17,8 +17,6 @@
 #ifndef __DEVICE_IPP__
 #define __DEVICE_IPP__
 
-#include "strformat.h"
-
 //**************************************************************************
 //  MEMBER TEMPLATES
 //**************************************************************************
@@ -26,15 +24,28 @@
 template <typename Format, typename... Params>
 inline void device_t::popmessage(Format &&fmt, Params &&... args) const
 {
-	if (m_machine)
+	if (m_machine != nullptr)
 		m_machine->popmessage(std::forward<Format>(fmt), std::forward<Params>(args)...);
 }
 
 template <typename Format, typename... Params>
 inline void device_t::logerror(Format &&fmt, Params &&... args) const
 {
-	if (m_machine)
-		m_machine->logerror(string_format("[%s] %s", tag(), std::forward<Format>(fmt)), std::forward<Params>(args)...);
+	if (m_machine != nullptr && m_machine->allow_logging())
+	{
+		g_profiler.start(PROFILER_LOGERROR);
+
+		// dump to the buffer
+		m_string_buffer.clear();
+		m_string_buffer.seekp(0);
+		util::stream_format(m_string_buffer, "[%s] ", tag());
+		util::stream_format(m_string_buffer, std::forward<Format>(fmt), std::forward<Params>(args)...);
+		m_string_buffer.put('\0');
+
+		m_machine->strlog(&m_string_buffer.vec()[0]);
+
+		g_profiler.stop();
+	}
 }
 
 #endif // __DEVICE_IPP__

src/emu/emu.h

@@ -29,9 +29,11 @@
 #include "eminline.h"
 #include "profiler.h"
 
-// commonly-referenecd utilities imported from lib/util
+// commonly-referenced utilities imported from lib/util
 #include "palette.h"
 #include "unicode.h"
+#include "strformat.h"
+#include "vecstream.h"
 
 // emulator-specific utilities
 #include "attotime.h"

src/emu/machine.cpp

@@ -727,6 +727,19 @@ void running_machine::add_logerror_callback(logerror_callback callback)
 }
 
 
+//-------------------------------------------------
+//  strlog - send an error logging string to the
+//  debugger and any OSD-defined output streams
+//-------------------------------------------------
+
+void running_machine::strlog(const char *str) const
+{
+	// log to all callbacks
+	for (auto &cb : m_logerror_list)
+		cb->m_func(str);
+}
+
+
 //-------------------------------------------------
 //  debug_break - breaks into the debugger, if
 //  enabled

src/emu/machine.h

@@ -19,9 +19,6 @@
 
 #include <functional>
 
-#include "strformat.h"
-#include "vecstream.h"
-
 #include <time.h>
 
 // forward declaration instead of osdepend.h
@@ -198,6 +195,7 @@ public:
 	emu_options &options() const { return m_config.options(); }
 	attotime time() const { return m_scheduler.time(); }
 	bool scheduled_event_pending() const { return m_exit_pending || m_hard_reset_pending; }
+	bool allow_logging() const { return !m_logerror_list.empty(); }
 
 	// fetch items by name
 	inline device_t *device(const char *tag) const { return root_device().subdevice(tag); }
@@ -233,6 +231,7 @@ public:
 	void popmessage() const { popmessage(static_cast<char const *>(nullptr)); }
 	template <typename Format, typename... Params> void popmessage(Format &&fmt, Params &&... args) const;
 	template <typename Format, typename... Params> void logerror(Format &&fmt, Params &&... args) const;
+	void strlog(const char *str) const;
 	UINT32 rand();
 	const char *describe_context();
 
@@ -387,7 +386,7 @@ template <typename Format, typename... Params>
 inline void running_machine::logerror(Format &&fmt, Params &&... args) const
 {
 	// process only if there is a target
-	if (!m_logerror_list.empty())
+	if (allow_logging())
 	{
 		g_profiler.start(PROFILER_LOGERROR);
 
@@ -397,10 +396,7 @@ inline void running_machine::logerror(Format &&fmt, Params &&... args) const
 		util::stream_format(m_string_buffer, std::forward<Format>(fmt), std::forward<Params>(args)...);
 		m_string_buffer.put('\0');
 
-		// log to all callbacks
-		char const *const str(&m_string_buffer.vec()[0]);
-		for (auto &cb : m_logerror_list)
-			cb->m_func(str);
+		strlog(&m_string_buffer.vec()[0]);
 
 		g_profiler.stop();
 	}