From 96101a5bd0d05ef498481b5aeb2a65b8c23164b3 Mon Sep 17 00:00:00 2001
From: Aaron Giles <aaron@aarongiles.com>
Date: Thu, 26 Jan 2012 21:16:17 +0000
Subject: [PATCH] Change device reset so that the resets proceed
 hierarchically. Added a device_reset_after_children() hook for things that
 need to wait for the children to finish. Moved calling the
 driver/machine/sound/video reset callbacks to the after children time, to
 align more with how it was happening before.

Fixed siblingdevice("") so that it returns the current device and not
the owner.
---
 src/emu/device.c  | 20 ++++++++++++++++++++
 src/emu/device.h  | 23 ++++++++++++++++++++++-
 src/emu/machine.c | 13 ++++++-------
 src/emu/machine.h |  2 +-
 4 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/src/emu/device.c b/src/emu/device.c
index 9b166287dc4..c9c83b12cbd 100644
--- a/src/emu/device.c
+++ b/src/emu/device.c
@@ -262,6 +262,13 @@ void device_t::reset()
 
 	// reset the device
 	device_reset();
+	
+	// reset all child devices
+	for (device_t *child = m_subdevice_list.first(); child != NULL; child = child->next())
+		child->reset();
+	
+	// now allow for some post-child reset action
+	device_reset_after_children();
 
 	// let the interfaces do their post-work
 	for (device_interface *intf = m_interface_list; intf != NULL; intf = intf->interface_next())
@@ -579,6 +586,19 @@ void device_t::device_reset()
 }
 
 
+//-------------------------------------------------
+//  device_reset_after_children - hook to do
+//  reset logic that must happen after the children
+//  are reset; designed to be overriden by the
+//  actual device implementation
+//-------------------------------------------------
+
+void device_t::device_reset_after_children()
+{
+	// do nothing by default
+}
+
+
 //-------------------------------------------------
 //  device_stop - clean up anything that needs to
 //  happen before the running_machine goes away
diff --git a/src/emu/device.h b/src/emu/device.h
index 4be5c1c1170..fbe3fbaff0b 100644
--- a/src/emu/device.h
+++ b/src/emu/device.h
@@ -186,7 +186,7 @@ public:
 	astring &siblingtag(astring &dest, const char *tag) const { return (this != NULL && m_owner != NULL) ? m_owner->subtag(dest, tag) : dest.cpy(tag); }
 	const memory_region *subregion(const char *tag) const;
 	device_t *subdevice(const char *tag) const;
-	device_t *siblingdevice(const char *tag) const { return (this != NULL && m_owner != NULL) ? m_owner->subdevice(tag) : NULL; }
+	device_t *siblingdevice(const char *tag) const;
 	template<class _DeviceClass> inline _DeviceClass *subdevice(const char *tag) const { return downcast<_DeviceClass *>(subdevice(tag)); }
 	template<class _DeviceClass> inline _DeviceClass *siblingdevice(const char *tag) const { return downcast<_DeviceClass *>(siblingdevice(tag)); }
 	const memory_region *region() const { return m_region; }
@@ -248,6 +248,7 @@ protected:
 	virtual void device_start() ATTR_COLD = 0;
 	virtual void device_stop() ATTR_COLD;
 	virtual void device_reset() ATTR_COLD;
+	virtual void device_reset_after_children() ATTR_COLD;
 	virtual void device_pre_save() ATTR_COLD;
 	virtual void device_post_load() ATTR_COLD;
 	virtual void device_clock_changed();
@@ -753,6 +754,26 @@ inline device_t *device_t::subdevice(const char *tag) const
 }
 
 
+//-------------------------------------------------
+//  siblingdevice - given a tag, find the device 
+//  by name relative to this device's parent
+//-------------------------------------------------
+
+inline device_t *device_t::siblingdevice(const char *tag) const
+{
+	// safety first
+	if (this == NULL)
+		return NULL;
+
+	// empty string or NULL means this device
+	if (tag == NULL || *tag == 0)
+		return const_cast<device_t *>(this);
+
+	// query relative to the parent
+	return (m_owner != NULL) ? m_owner->subdevice(tag) : NULL;
+}
+
+
 //-------------------------------------------------
 //  bind_relative_to - perform a late binding of
 //  a device_delegate
diff --git a/src/emu/machine.c b/src/emu/machine.c
index 4118d3b0370..2206628b4e4 100644
--- a/src/emu/machine.c
+++ b/src/emu/machine.c
@@ -932,10 +932,8 @@ void running_machine::start_all_devices()
 
 void running_machine::reset_all_devices()
 {
-	// iterate over devices and reset them
-	device_iterator iter(root_device());
-	for (device_t *device = iter.first(); device != NULL; device = iter.next())
-		device->reset();
+	// reset the root and it will reset children
+	root_device().reset();
 }
 
 
@@ -1268,11 +1266,12 @@ void driver_device::device_start()
 
 
 //-------------------------------------------------
-//  device_reset - device override which calls
-//  the various helpers
+//  device_reset_after_children - device override 
+//  which calls the various helpers; must happen
+//  after all child devices are reset
 //-------------------------------------------------
 
-void driver_device::device_reset()
+void driver_device::device_reset_after_children()
 {
 	// reset each piece
 	driver_reset();
diff --git a/src/emu/machine.h b/src/emu/machine.h
index dbaf69f93fc..ba99c76534b 100644
--- a/src/emu/machine.h
+++ b/src/emu/machine.h
@@ -682,7 +682,7 @@ protected:
 	virtual const rom_entry *device_rom_region() const;
 	virtual ioport_constructor device_input_ports() const;
 	virtual void device_start();
-	virtual void device_reset();
+	virtual void device_reset_after_children();
 
 	// internal helpers
 	inline UINT16 paletteram16_le(offs_t offset) const { return m_generic_paletteram[offset & ~1] | (m_generic_paletteram[offset |  1] << 8); }