__cxa_guard_acquire / __cxa_guard_release

82968e19 · Nickolai Zeldovich · 49db292c · 82968e19 · 82968e19
--- a/include/cpputil.hh
+++ b/include/cpputil.hh
@@ -103,7 +103,14 @@ namespace std {
 void *operator new[](unsigned long nbytes);
 // void operator delete(void *p);
 void operator delete[](void *p);
+
+/* Ref: http://sourcery.mentor.com/public/cxx-abi/abi.html */
 extern "C" void __cxa_pure_virtual(void);
+extern "C" int  __cxa_guard_acquire(s64 *guard_object);
+extern "C" void __cxa_guard_release(s64 *guard_object);
+extern "C" void __cxa_guard_abort(s64 *guard_object);
+extern "C" int  __cxa_atexit(void (*f)(void *), void *p, void *d);
+extern void *__dso_handle;

 #define NEW_DELETE_OPS(classname)                           \
  static void* operator new(unsigned long nbytes) {         \

--- a/kernel/cpprt.cc
+++ b/kernel/cpprt.cc
 #include "types.h"
 #include "kernel.hh"
 #include "cpputil.hh"
+#include "spinlock.h"
+#include "amd64.h"

 void *
 operator new[](unsigned long nbytes)
@@ -24,6 +26,44 @@ __cxa_pure_virtual(void)
  panic("__cxa_pure_virtual");
 }

+int
+__cxa_guard_acquire(s64 *guard)
+{
+  volatile u8 *x = (u8*) guard;
+  volatile u32 *l = (u32*) (x+4);
+
+  pushcli();
+  while (xchg32(l, 1) != 0)
+    ; /* spin */
+
+  if (*x) {
+    xchg32(l, 0);
+    popcli();
+    return 0;
+  }
+  return 1;
+}
+
+void
+__cxa_guard_release(s64 *guard)
+{
+  volatile u8 *x = (u8*) guard;
+  volatile u32 *l = (u32*) (x+4);
+
+  *x = 1;
+  __sync_synchronize();
+  xchg32(l, 0);
+  popcli();
+}
+
+int
+__cxa_atexit(void (*f)(void*), void *p, void *d)
+{
+  return 0;
+}
+
+void *__dso_handle;
+
 namespace std {

 template<>