usbloadergx/source/libwiigui/gui_image_async.cpp

/****************************************************************************
 * libwiigui
 *
 * Tantric 2009
 *
 * gui_imagea_sync.cpp
 *
 * GUI class definitions
 ***************************************************************************/

#include "gui.h"
//#include <string.h>
#include <unistd.h>
#include "gui_image_async.h"
static mutex_t debugLock = LWP_MUTEX_NULL;

void debug(int Line, const char* Format, ...)
{
	if(debugLock==0) LWP_MutexInit(&debugLock, false);

	LWP_MutexLock(debugLock);
	
	FILE *fp = fopen("SD:/debug.txt", "a");
	if(fp)
	{
		char theTime[10];
		time_t rawtime = time(0);                                                               //this fixes code dump caused by the clock
		struct tm * timeinfo = localtime (&rawtime);
		strftime(theTime, sizeof(theTime), "%H:%M:%S", timeinfo);
 		char format[10+strlen(Format)+strlen(theTime)];
		sprintf(format, "%s %i - %s\n", theTime, Line, Format);
		va_list va;
		va_start(va, Format);
		vfprintf(fp, format, va);
		va_end(va);
		fclose(fp);
	}
	LWP_MutexUnlock(debugLock);
}
//#define DEBUG(format, ...) debug(__LINE__, format, ##__VA_ARGS__)
#define DEBUG(format, ...) 

static void *memdup(const void* src, size_t len)
{
	void *dst = malloc(len);
	if(dst) memcpy(dst, src, len);
	return dst;
}
static std::vector<GuiImageAsync *> List;
static u32 ThreadCount = 0;
static lwp_t Thread = LWP_THREAD_NULL;
static mutex_t ListLock = LWP_MUTEX_NULL;
static mutex_t InUseLock = LWP_MUTEX_NULL;
static GuiImageAsync *InUse = NULL;
static bool Quit = false;
static bool CanSleep = true;
void *GuiImageAsyncThread(void *arg)
{
	while(!Quit)
	{
		LWP_MutexLock(ListLock);
		if(List.size())
		{
			LWP_MutexLock(InUseLock);

			InUse = List.front();
			List.erase(List.begin());

			LWP_MutexUnlock(ListLock);

			if(InUse)
			{
				GuiImageData *data = InUse->callback(InUse->arg);
				InUse->loadet_imgdata = data;
				if(InUse->loadet_imgdata && InUse->loadet_imgdata->GetImage())
				{
				//	InUse->SetImage(InUse->loadet_imgdata); can’t use here. There can occur a deadlock
				// Sets the image directly without lock. This is not fine, but it prevents a deadlock
					InUse->image = InUse->loadet_imgdata->GetImage();
					InUse->width = InUse->loadet_imgdata->GetWidth();
					InUse->height = InUse->loadet_imgdata->GetHeight();
				}
			}
			InUse = NULL;
			LWP_MutexUnlock(InUseLock);
		}
		else
		{
			LWP_MutexUnlock(ListLock);
			if(!Quit && CanSleep)
				LWP_SuspendThread(Thread);
		}
		CanSleep = true;
	}
	Quit = false;
	return NULL;
}

static u32 GuiImageAsyncThreadInit()
{
	if(0 == ThreadCount++)
	{
		CanSleep = false;
		LWP_MutexInit(&ListLock, false);
		LWP_MutexInit(&InUseLock, false);
		LWP_CreateThread(&Thread, GuiImageAsyncThread, NULL, NULL, 0, 75);
//		while(!CanSleep)
//			usleep(20);
	}
	return ThreadCount;
}
static u32 GuiImageAsyncThreadExit()
{
	if(--ThreadCount == 0)
	{
		Quit = true;
		LWP_ResumeThread(Thread);
//		while(Quit)
//			usleep(20);
		LWP_JoinThread(Thread, NULL);
		LWP_MutexDestroy(ListLock);
		LWP_MutexDestroy(InUseLock);
		Thread = LWP_THREAD_NULL;
		ListLock = LWP_MUTEX_NULL;
		InUseLock = LWP_MUTEX_NULL;
	}
	return ThreadCount;
}


static void GuiImageAsyncThread_AddImage(GuiImageAsync* Image)
{
	LWP_MutexLock(ListLock);
	List.push_back(Image);
	LWP_MutexUnlock(ListLock);
	CanSleep = false;
//	if(LWP_ThreadIsSuspended(Thread))
		LWP_ResumeThread(Thread);
}
static void GuiImageAsyncThread_RemoveImage(GuiImageAsync* Image)
{
	LWP_MutexLock(ListLock);
	for(std::vector<GuiImageAsync *>::iterator iter=List.begin(); iter != List.end(); iter++)
	{
		if(*iter == Image)
		{
			List.erase(iter);
			LWP_MutexUnlock(ListLock);
			return;
		}
	}
	if(InUse == Image)
	{
		LWP_MutexLock(InUseLock);
		LWP_MutexUnlock(InUseLock);
	}
	LWP_MutexUnlock(ListLock);
}


/**
 * Constructor for the GuiImageAsync class.
 */
GuiImageData *StdImageLoaderCallback(void *arg)
{
	return new GuiImageData((char*)arg, NULL);
}

GuiImageAsync::GuiImageAsync(const char *Filename, GuiImageData * PreloadImg) :
	GuiImage(PreloadImg),
	loadet_imgdata(NULL),
	callback(StdImageLoaderCallback),
	arg(strdup(Filename))
{
	GuiImageAsyncThreadInit();
	GuiImageAsyncThread_AddImage(this);
}
GuiImageAsync::GuiImageAsync(ImageLoaderCallback Callback, void *Arg, int ArgLen, GuiImageData * PreloadImg) :
	GuiImage(PreloadImg),
	loadet_imgdata(NULL),
	callback(Callback),
	arg(memdup(Arg, ArgLen))
{
DEBUG("Constructor %p", this);
	GuiImageAsyncThreadInit();
	GuiImageAsyncThread_AddImage(this);
}
GuiImageAsync::~GuiImageAsync()
{
	GuiImageAsyncThread_RemoveImage(this);
	GuiImageAsyncThreadExit();
DEBUG("Deconstructor %p (loadet_imgdata=%p)", this, loadet_imgdata);
	if(loadet_imgdata) delete loadet_imgdata;
	if(arg) free(arg);
}