Aren/haiku
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Mandelbrot: Improve thread handling code.

Browse Source 
* Application is now much more stable and less likely to crash
 * Almost all communication to render threads is done through semaphores.

Change-Id: I7858cdb4a2b83ef4bfe44588cebef01bd3304346
Reviewed-on: https://review.haiku-os.org/730
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
This commit is contained in:
kerwizzy 2018-11-25 11:01:32 +00:00 committed by Adrien Destugues
parent 36f94d9e39
commit e920ab3cb6
2 changed files with 52 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

83
src/apps/mandelbrot/FractalEngine.cpp
View File

@ -33,13 +33,13 @@ FractalEngine::FractalEngine(BHandler* parent, BLooper* looper)
fRenderBuffer(NULL),
fRenderBufferLen(0),
fMessenger(parent, looper),
fThreadsRendering(0),
fIterations(1024),
fColorset(Colorset_Royal)
{
fDoSet = &FractalEngine::DoSet_Mandelbrot;
fRenderSem = create_sem(0, "RenderSem");
fRenderStoppedSem = create_sem(0,"RenderStopped");
system_info info;
get_system_info(&info);
@ -49,8 +49,6 @@ FractalEngine::FractalEngine(BHandler* parent, BLooper* looper)
fThreadCount = MAX_RENDER_THREADS;
for (uint8 i = 0; i < fThreadCount; i++) {
fRestartRenderThread[i] = false;
fRenderThreadRunning[i] = false;
fRenderThreads[i] = spawn_thread(&FractalEngine::RenderThread,
BString().SetToFormat("RenderThread%d", i).String(),
B_NORMAL_PRIORITY, this);
@ -95,6 +93,14 @@ void FractalEngine::MessageReceived(BMessage* msg)
break;
case MSG_RESIZE: {
TRACE("Got MSG_RESIZE threads rendering\n");
if (fStopRender) {
// Will be true throughout this whole handler. Set false at the end
TRACE("Breaking out of MSG_RESIZE handler\n");
break;
}
StopRender();
delete fRenderBuffer;
fRenderBuffer = NULL;
@ -102,17 +108,20 @@ void FractalEngine::MessageReceived(BMessage* msg)
fHeight = msg->GetUInt16("height", 240);
TRACE("Creating new buffer. width %u height %u\n", fWidth, fHeight);
fRenderBufferLen = fWidth * fHeight * 3;
fRenderBuffer = new uint8[fRenderBufferLen];
memset(fRenderBuffer, 0, fRenderBufferLen);
BMessage message(MSG_BUFFER_CREATED);
fMessenger.SendMessage(&message);
fStopRender = false;
break;
}
case MSG_RENDER: {
TRACE("Got MSG_RENDER. fThreadsRendering = %u\n",fThreadsRendering);
TRACE("Got MSG_RENDER.\n");
StopRender();
fStopRender = false;
Render(msg->GetDouble("locationX", 0), msg->GetDouble("locationY", 0),
msg->GetDouble("size", 0.005));
break;
@ -121,9 +130,9 @@ void FractalEngine::MessageReceived(BMessage* msg)
TRACE("Got MSG_THREAD_RENDER_COMPLETE for thread %d\n",
msg->GetUInt8("thread", 0));
fThreadsRendering--;
TRACE("Set fRendering = %d\n", fThreadsRendering);
if (!fThreadsRendering) {
int32 threadsStopped;
get_sem_count(fRenderStoppedSem, &threadsStopped);
if (threadsStopped == fThreadCount) {
TRACE("Done rendering!\n");
BMessage message(MSG_RENDER_COMPLETE);
fMessenger.SendMessage(&message);
@ -145,9 +154,32 @@ void FractalEngine::WriteToBitmap(BBitmap* bitmap)
B_RGB24);
}
void FractalEngine::StopRender()
{
if (fRenderStopped)
return;
fRenderStopped = true;
// true if another call to StopRender() won't work properly because
// the fRenderStoppedSem semaphores have already been acquired.
TRACE("Stopping render...\n");
fStopRender = true;
for (uint i = 0; i<fThreadCount; i++)
acquire_sem(fRenderStoppedSem);
TRACE("Render stopped.\n");
// note that fStopRender is NOT set to false at the end here.
// This is to allow the message handlers to use this variable to
// block duplication of stuff.
}
void FractalEngine::Render(double locationX, double locationY, double size)
{
fRenderStopped = false;
// This means that future Render calls will need to call stop render
if (fStopRender)
debugger("Error: Render shouldn't be called while fStopRender = true\n");
fLocationX = locationX;
fLocationY = locationY;
fSize = size;
@ -155,18 +187,10 @@ void FractalEngine::Render(double locationX, double locationY, double size)
TRACE("Location: %g;%g;%g\n", fLocationX, fLocationY, fSize);
for (uint8 i = 0; i < fThreadCount; i++) {
if (fRenderThreadRunning[i])
fRestartRenderThread[i] = true;
else
release_sem(fRenderSem);
fRenderThreadRunning[i] = true;
release_sem(fRenderSem);
}
fThreadsRendering = fThreadCount;
TRACE("Set fRendering = %d\n", fThreadsRendering);
}
status_t FractalEngine::RenderThread(void* data)
{
FractalEngine* engine = static_cast<FractalEngine*>(data);
@ -179,19 +203,12 @@ status_t FractalEngine::RenderThread(void* data)
}
}
bool restarting = false;
while (true) {
TRACE("Thread %d starting another render pass\n", threadNum);
if (!restarting) {
TRACE("Thread %d awaiting semaphore...\n", threadNum);
acquire_sem(engine->fRenderSem);
TRACE("Thread %d got semaphore!\n", threadNum);
} else {
TRACE("Thread %d setting restart = false\n", threadNum);
restarting = false;
}
release_sem(engine->fRenderStoppedSem);
TRACE("Thread %d awaiting semaphore...\n", threadNum);
acquire_sem(engine->fRenderSem);
TRACE("Thread %d got semaphore!\n", threadNum);
uint16 width = engine->fWidth;
uint16 height = engine->fHeight;
@ -213,17 +230,13 @@ status_t FractalEngine::RenderThread(void* data)
// halfHeight-(halfHeight-1)-1 = 0
}
if (engine->fRestartRenderThread[threadNum]) {
TRACE("Thread %d Got restart message\n", threadNum);
engine->fRestartRenderThread[threadNum] = false;
restarting = true;
if (engine->fStopRender) {
TRACE("Thread %d stopping\n", threadNum);
break; // Restart the loop to update width, height, etc.
}
}
if (!restarting) {
engine->fRenderThreadRunning[threadNum] = false;
if (!engine->fStopRender) {
BMessage message(FractalEngine::MSG_THREAD_RENDER_COMPLETE);
message.AddUInt8("thread", threadNum);
engine->PostMessage(&message);

7
src/apps/mandelbrot/FractalEngine.h
View File

@ -50,10 +50,10 @@ private:
uint8 fThreadCount;
thread_id fRenderThreads[MAX_RENDER_THREADS];
sem_id fRenderSem;
sem_id fRenderStoppedSem;
uint8 fThreadsRendering;
bool fRestartRenderThread[MAX_RENDER_THREADS];
bool fRenderThreadRunning[MAX_RENDER_THREADS];
bool fStopRender;
bool fRenderStopped;
double fLocationX;
double fLocationY;
@ -66,6 +66,7 @@ private:
int32 (FractalEngine::*fDoSet)(double real, double imaginary);
void Render(double locationX, double locationY, double size);
void StopRender();
static status_t RenderThread(void* data);
void RenderPixel(uint32 x, uint32 y);