annotate some logical sharing in the futex impl

94a5fb99 · Silas Boyd-Wickizer · 264a783d · 94a5fb99 · 94a5fb99
--- a/kernel/futex.cc
+++ b/kernel/futex.cc
@@ -8,6 +8,7 @@
 #include "proc.hh"
 #include "cpu.hh"
 #include "percpu.hh"
+#include "kmtrace.hh"

 //
 // futexkey
@@ -171,6 +172,7 @@ futexwait(futexkey_t key, u64 val, u64 timer)
 {
  futexaddr* fa;

+  mtreadavar("futex:ns:%lx", key);
  {
    scoped_gc_epoch gc;
  again:
@@ -185,6 +187,7 @@ futexwait(futexkey_t key, u64 val, u64 timer)
        fa->dec();
        goto again;
      }
+      mtwriteavar("futex:ns:%lx", key);
      fa->inserted_ = true;
    } else {
      if (!fa->tryinc()) {
@@ -193,6 +196,7 @@ futexwait(futexkey_t key, u64 val, u64 timer)
    }
  }
  assert(fa->key_ == key);
+  mtwriteavar("futex:%lx.%p", key, fa);

  acquire(&myproc()->futex_lock);  
  auto cleanup = scoped_cleanup([&fa](){
@@ -228,6 +232,7 @@ futexwake(futexkey_t key, u64 nwake)
  if (nwake == 0)
    return -1;

+  mtreadavar("futex:ns:%lx", key);
  {
    scoped_gc_epoch gc;
    fa = nsfutex->lookup(key);
@@ -238,7 +243,8 @@ futexwake(futexkey_t key, u64 nwake)
  auto cleanup = scoped_cleanup([&fa](){
    fa->dec();
  });
-  
+  mtwriteavar("futex:%lx.%p", key, fa);
+
  fa->nspid_->enumerate([&nwoke, &nwake](u32 pid, proc* p) {
    acquire(&p->futex_lock);
    cv_wakeup(&p->cv);

--- a/kernel/sysproc.cc
+++ b/kernel/sysproc.cc
@@ -178,6 +178,9 @@ sys_futex(const u64* addr, int op, u64 val, u64 timer)
  if (futexkey(addr, myproc()->vmap, &key) < 0)
    return -1;

+  mt_ascope ascope("%s(%p,%d,%lu,%lu)", __func__, addr, op, val, timer);
+  mtwriteavar("thread:%x", myproc()->pid);
+
  switch(op) {
  case FUTEX_WAIT:
    return futexwait(key, val, timer);