Switch audio fifo queue to a faster non-STL one.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@718 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Core/Common/Src/FixedSizeQueue.h

@@ -0,0 +1,81 @@
+// Copyright (C) 2003-2008 Dolphin Project.
+
+// This program 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, version 2.0.
+
+// This program 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 2.0 for more details.
+
+// A copy of the GPL 2.0 should have been included with the program.
+// If not, see http://www.gnu.org/licenses/
+
+// Official SVN repository and contact information can be found at
+// http://code.google.com/p/dolphin-emu/
+
+#ifndef _FIXED_SIZE_QUEUE_H
+#define _FIXED_SIZE_QUEUE_H
+
+// STL-look-a-like interface, but name is mixed case to distinguish it clearly from the
+// real STL classes.
+
+// Not fully featured, no safety checking yet. Add features as needed.
+
+// TODO: "inline" storage?
+
+template <class T, int N>
+class FixedSizeQueue
+{
+	T *storage;
+	int head;
+	int tail;
+	int count;  // sacrifice 4 bytes for a simpler implementation. may optimize away in the future.
+
+	// Make copy constructor private for now.
+	FixedSizeQueue(FixedSizeQueue &other) {	}
+
+public:
+	FixedSizeQueue()
+	{
+		head = 0;
+		tail = 0;
+		storage = new T[N];
+	}
+
+	~FixedSizeQueue()
+	{
+		delete storage;
+	}
+
+	void push(T t) {
+		storage[tail] = t;
+		tail++;
+		if (tail == N)
+			tail = 0;
+		count++;
+	}
+
+	void pop() {
+		head++;
+		if (head == N)
+			head = 0;
+		count--;
+	}
+
+	T pop_front() {
+		const T &temp = storage[head];
+		pop();
+		return temp;
+	}
+
+	T &front() { return storage[head]; }
+	const T &front() const { return storage[head]; }
+
+	size_t size() const {
+		return count;
+	}
+};
+
+#endif  // _FIXED_SIZE_QUEUE_H

Source/Plugins/Plugin_DSP_HLE/Src/PCHW/Mixer.cpp

@@ -23,6 +23,8 @@
 #include "../DSPHandler.h"
 #include "Thread.h"
 #include "Mixer.h"
+#include "FixedSizeQueue.h"
+
 #ifdef _WIN32
 #include "../PCHW/DSoundStream.h"
 #endif
@@ -31,8 +33,11 @@ namespace {
 Common::CriticalSection push_sync;
 
 // On real hardware, this fifo is much, much smaller. But timing is also tighter than under Windows, so...
-int queue_maxlength = 1024 * 8;
-std::queue<s16> sample_queue;
+const int queue_minlength = 1024 * 4;
+const int queue_maxlength = 1024 * 28;
+
+FixedSizeQueue<s16, queue_maxlength> sample_queue;
+
 }  // namespace
 
 volatile bool mixer_HLEready = false;
@@ -59,15 +64,20 @@ void Mixer(short *buffer, int numSamples, int bits, int rate, int channels)
 
 	push_sync.Enter();
 	int count = 0;
-	while (sample_queue.size() && count < numSamples * 2) {
+	while (queue_size > queue_minlength && count < numSamples * 2) {
 		int x = buffer[count];
 		x += sample_queue.front();
 		if (x > 32767) x = 32767;
 		if (x < -32767) x = -32767;
-		buffer[count] = x;
-		count++;
+		buffer[count++] = x;
 		sample_queue.pop();
-		queue_size--;
+		x = buffer[count];
+		x += sample_queue.front();
+		if (x > 32767) x = 32767;
+		if (x < -32767) x = -32767;
+		buffer[count++] = x;
+		sample_queue.pop();
+		queue_size-=2;
 	}
 	push_sync.Leave();
 }
@@ -77,6 +87,12 @@ void Mixer_PushSamples(short *buffer, int num_stereo_samples, int sample_rate) {
 //	if (!f)
 //		f = fopen("d:\\hello.raw", "wb");
 //	fwrite(buffer, num_stereo_samples * 4, 1, f);
+	if (queue_size == 0)
+	{
+		queue_size = queue_minlength;
+		for (int i = 0; i < queue_minlength; i++)
+			sample_queue.push((s16)0);
+	}
 
 	static int PV1l=0,PV2l=0,PV3l=0,PV4l=0;
 	static int PV1r=0,PV2r=0,PV3r=0,PV4r=0;
@@ -92,7 +108,7 @@ void Mixer_PushSamples(short *buffer, int num_stereo_samples, int sample_rate) {
 		return;
 	}
 #else
-	while (queue_size > queue_maxlength / 2) {
+	while (queue_size > queue_maxlength) {
 		sleep(0);
 	}
 #endif
@@ -103,7 +119,7 @@ void Mixer_PushSamples(short *buffer, int num_stereo_samples, int sample_rate) {
 	while (num_stereo_samples) 
 	{
 		acc += sample_rate;
- 		while (num_stereo_samples && (acc>=48000))
+ 		while (num_stereo_samples && (acc >= 48000))
  		{
  			PV4l=PV3l;
  			PV3l=PV2l;