1 files changed, 148 insertions, 0 deletions
diff --git a/main4.c b/main4.c
new file mode 100644
index 0000000..cd0e1d8
--- /dev/null
+++ b/main4.c
@@ -0,0 +1,148 @@
+#include <u.h>
+#include <libc.h>
+#include <thread.h>
+#include <draw.h>
+#include <memdraw.h>
+
+typedef struct Ttask Ttask;
+typedef struct Tpool Tpool;
+
+struct Ttask
+{
+	void (*fn)(void*);
+	void *arg;
+};
+
+struct Tpool
+{
+	ulong nprocs;
+	Ref issued;
+	Ref complete;
+
+	Channel *subq;	/* task submission queue */
+	Channel *done;	/* task completion signal */
+};
+
+void
+threadloop(void *arg)
+{
+	Tpool *pool;
+	Ttask *task;
+
+	pool = arg;
+
+	while((task = recvp(pool->subq)) != nil){
+		task->fn(task->arg);
+		incref(&pool->complete);
+		nbsend(pool->done, nil);
+	}
+}
+
+Tpool *
+mkthreadpool(ulong nprocs)
+{
+	Tpool *tp;
+
+	tp = malloc(sizeof *tp);
+	memset(tp, 0, sizeof *tp);
+	tp->nprocs = nprocs;
+	tp->subq = chancreate(sizeof(void*), nprocs);
+	tp->done = chancreate(sizeof(void*), 0);
+	while(nprocs--)
+		proccreate(threadloop, tp, mainstacksize);
+	return tp;
+}
+
+void
+threadpoolexec(Tpool *tp, void (*fn)(void*), void *arg)
+{
+	Ttask *t;
+
+	t = malloc(sizeof *t);
+	t->fn = fn;
+	t->arg = arg;
+
+	sendp(tp->subq, t);
+	incref(&tp->issued);
+}
+
+typedef struct Targs Targs;
+struct Targs
+{
+	Memimage *i;
+	int y;
+};
+void
+fillpix(void *arg)
+{
+	Targs *imgop;
+	Point p;
+	ulong *fb, pix;
+	double α;
+
+	imgop = arg;
+
+	for(p = Pt(0, imgop->y); p.x < Dx(imgop->i->r); p.x++){
+		fb = (ulong*)byteaddr(imgop->i, p);
+		α = atan2(p.y, p.x);
+		pix = α*25523UL*25523UL/* + truerand()*/;
+		*fb = pix|0xFF<<24;
+	}
+}
+
+void
+usage(void)
+{
+	fprint(2, "usage: %s [-t] [-n nprocs]\n", argv0);
+	exits(nil);
+}
+
+void
+threadmain(int argc, char *argv[])
+{
+	static int W = 1000, H = 1000;
+	Tpool *pool;
+	Targs *t;
+	Memimage *img;
+	int i;
+	int threaded;
+	int nprocs;
+
+	threaded = 0;
+	nprocs = 8;
+	ARGBEGIN{
+	case 't': threaded++; break;
+	case 'n': nprocs = strtoul(EARGF(usage()), nil, 0); break;
+	default: usage();
+	}ARGEND;
+	if(argc != 0)
+		usage();
+
+	if(memimageinit() != 0)
+		sysfatal("memimageinit: %r");
+
+	img = allocmemimage(Rect(0,0,W,H), XRGB32);
+	t = malloc(H*sizeof(*t));
+	if(threaded){
+		pool = mkthreadpool(nprocs);
+
+		for(i = 0; i < H; i++){
+			t[i] = (Targs){img, i};
+			threadpoolexec(pool, fillpix, &t[i]);
+		}
+
+		while(pool->issued.ref != pool->complete.ref)
+			recvp(pool->done);
+
+		writememimage(1, img);
+
+		threadexitsall(nil);
+	}
+
+	for(i = 0; i < H; i++){
+		t[i] = (Targs){img, i};
+		fillpix(&t[i]);
+	}
+	writememimage(1, img);
+	exits(nil);
+}