Fill in wq_for, but a race lurks somewhere..

cf5f4409 · Silas Boyd-Wickizer · cc29cea9 · cf5f4409 · cf5f4409 · cf5f4409
--- a/bin/Makefrag
+++ b/bin/Makefrag
@@ -23,8 +23,7 @@ UPROGS= \
 	preadtest \
 	scripttest \
 	ftest \
-	perf \
-	xdu
+	perf
 # pdu
 # pls


--- a/bin/xdu.cc
+++ b/bin/xdu.cc
@@ -42,6 +42,7 @@ du(int fd)
    return 0;
  }

+  // XXX(sbw) size should use an add reducer
  int size = ST_SIZE(st);
  if (ST_ISDIR(st)) {
    dirit di(fd);
@@ -69,6 +70,7 @@ du(int fd)
 int
 main(int ac, char **av)
 {
+  initwq();
  printf("%d\n", du(open(".", 0)));
  return 0;
 }
--- a/include/wq.hh
+++ b/include/wq.hh
+#pragma once
+
+#if defined(LINUX)
+#include <stdlib.h>
+#include <assert.h>
+#include <atomic>
+#define xmalloc(n)     malloc(n)
+#define xfree(p, sz)   free(p)
+#elif defined(XV6_KERNEL)
+#define xmalloc(n)   kmalloc(n) 
+#define xfree(p, sz) kmfree(p, sz)
+#else
+#warning "Unknown wq implementation"
+#endif
+
 #define WQSIZE 8192
+
 class work;

 int             wq_trywork(void);
@@ -9,7 +25,7 @@ struct work {
  virtual void run() = 0;
 };

-struct cwork : public work{
+struct cwork : public work {
  virtual void run();

  static void* operator new(unsigned long);
@@ -24,12 +40,58 @@ struct cwork : public work{
  void *arg4;
 };

+typedef std::atomic<int> forframe_t;
+
+template <typename IT, typename BODY>
+struct forwork : public work {
+  forwork(IT &it, bool (*cond)(IT &it), BODY &body, forframe_t &frame) 
+    : it_(it), cond_(cond), body_(body), frame_(frame) {}
+
+  virtual void run() {
+    decltype(*it_) v = *it_;
+    ++it_;
+    if (cond_(it_)) {
+      forwork<IT, BODY> *w = new forwork<IT, BODY>(it_, cond_, body_, frame_);
+      ++frame_;
+      wq_push(w);    
+    }
+    body_(v);
+    --frame_;
+    delete this;
+  }
+
+  static void* operator new(unsigned long nbytes) {
+    assert(nbytes == sizeof(forwork<IT, BODY>));
+    return xmalloc(sizeof(forwork));
+  }
+
+  static void operator delete(void*p) {
+    xfree(p, sizeof(forwork));
+  }
+
+  IT &it_;
+  bool (*cond_)(IT&);
+  BODY &body_;
+  forframe_t &frame_;
+};
+
 template <typename IT, typename BODY>
 static inline void
 wq_for(IT &init, bool (*cond)(IT &it), BODY body)
 {
+  forframe_t frame(0);
+
  // XXX(sbw) should be able to coarsen loop
-  for (IT &it = init; cond(it); ++it) {
-    body(*it);
+
+  decltype(*init) v = *init;
+  ++init;
+  if (cond(init)) {
+    forwork<IT, BODY> *w = new forwork<IT, BODY>(init, cond, body, frame);
+    ++frame;
+    wq_push(w);
  }
+  body(v);
+
+  while (frame != 0)
+    wq_trywork();
 }
--- a/include/wqkernel.hh
+++ b/include/wqkernel.hh
@@ -44,5 +44,3 @@ wqarch_init(void)
 }

 #define xprintf      cprintf 
-#define xmalloc(n)   kmalloc(n) 
-#define xfree(p, sz) kmfree(p, sz)