PR target/49461

[pf3gnuchains/gcc-fork.git] / libjava / interpret-run.cc

diff --git a/libjava/interpret-run.cc b/libjava/interpret-run.cc
index 1eea57e..a4c2d4d 100644 (file)
--- a/libjava/interpret-run.cc
+++ b/libjava/interpret-run.cc
@@ -23,18 +23,22 @@ details.  */
   // returns.
   java::lang::Thread *thread = java::lang::Thread::currentThread();
   
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
   _Jv_InterpFrame frame_desc (meth, thread, NULL, &pc);
 #else
   _Jv_InterpFrame frame_desc (meth, thread);
 #endif
 
+#ifdef DIRECT_THREADED
+  ThreadCountAdjuster adj (meth, &frame_desc);
+#endif // DIRECT_THREADED
+
   _Jv_word stack[meth->max_stack];
   _Jv_word *sp = stack;
 
   _Jv_word locals[meth->max_locals];
 
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
   // This is the information needed to get and set local variables with
   // proper type checking.
   frame_desc.locals = locals;
@@ -122,7 +126,7 @@ details.  */
           continue;
         }
     }
-#endif /* DEBUG */
+#endif /* __GCJ_DEBUG */
 
 #define INSN_LABEL(op) &&insn_##op
 
@@ -343,7 +347,7 @@ details.  */
 
 #ifdef DIRECT_THREADED
 
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
 #undef NEXT_INSN
 #define NEXT_INSN                                                      \
   do                                                                   \
@@ -361,37 +365,58 @@ details.  */
     }                                                                  \
   while (0)
 
+// We fail to rewrite a breakpoint if there is another thread
+// currently executing this method.  This is a bug, but there's
+// nothing else we can do that doesn't cause a data race.
 #undef REWRITE_INSN
 #define REWRITE_INSN(INSN,SLOT,VALUE)                                  \
-  do {                                                                 \
-    if (pc[-2].insn == breakpoint_insn->insn)                          \
-      {                                                                        \
-       using namespace ::gnu::gcj::jvmti;                              \
-       jlocation location = meth->insn_index (pc - 2);                 \
-       _Jv_RewriteBreakpointInsn (meth->self, location, (pc_t) INSN);  \
-      }                                                                        \
-    else                                                               \
-      pc[-2].insn = INSN;                                              \
+  do                                                                   \
+    {                                                                  \
+      _Jv_MutexLock (&rewrite_insn_mutex);                             \
+      if (meth->thread_count <= 1)                                     \
+       {                                                               \
+         if (pc[-2].insn == breakpoint_insn->insn)                     \
+           {                                                           \
+             using namespace ::gnu::gcj::jvmti;                        \
+             jlocation location = meth->insn_index (pc - 2);           \
+             _Jv_RewriteBreakpointInsn (meth->self, location, (pc_t) INSN); \
+           }                                                           \
+         else                                                          \
+           pc[-2].insn = INSN;                                         \
                                                                        \
-    pc[-1].SLOT = VALUE;                                               \
-  }                                                                    \
+         pc[-1].SLOT = VALUE;                                          \
+       }                                                               \
+      _Jv_MutexUnlock (&rewrite_insn_mutex);                           \
+    }                                                                  \
   while (0)
 
 #undef INTERP_REPORT_EXCEPTION
 #define INTERP_REPORT_EXCEPTION(Jthrowable) REPORT_EXCEPTION (Jthrowable)
-#else // !DEBUG
+#else // !__GCJ_DEBUG
 #undef NEXT_INSN
 #define NEXT_INSN goto *((pc++)->insn)
+
+// Rewriting a multi-word instruction in the presence of multiple
+// threads is a data race if a thread reads part of an instruction
+// while some other thread is rewriting that instruction.  We detect
+// more than one thread executing a method and don't rewrite the
+// instruction.  A thread entering a method blocks on
+// rewrite_insn_mutex until the write is complete.
 #define REWRITE_INSN(INSN,SLOT,VALUE)          \
   do {                                         \
-    pc[-2].insn = INSN;                                \
-    pc[-1].SLOT = VALUE;                       \
+    _Jv_MutexLock (&rewrite_insn_mutex);       \
+    if (meth->thread_count <= 1)               \
+      {                                                \
+       pc[-2].insn = INSN;                     \
+       pc[-1].SLOT = VALUE;                    \
+      }                                                \
+    _Jv_MutexUnlock (&rewrite_insn_mutex);     \
   }                                            \
   while (0)
 
 #undef INTERP_REPORT_EXCEPTION
 #define INTERP_REPORT_EXCEPTION(Jthrowable) /* not needed when not debugging */
-#endif // !DEBUG
+#endif // !__GCJ_DEBUG
 
 #define INTVAL() ((pc++)->int_val)
 #define AVAL() ((pc++)->datum)
@@ -425,7 +450,7 @@ details.  */
 
 #else
 
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
 #define NEXT_INSN                                                      \
   do                                                                   \
     {                                                                  \
@@ -563,6 +588,7 @@ details.  */
          }
        else
          {
+           NULLCHECK (sp[0].o);
            jobject rcv = sp[0].o;
            _Jv_VTable *table = *(_Jv_VTable**) rcv;
            fun = (void (*)()) table->get_method (rmeth->method->index);
@@ -575,7 +601,7 @@ details.  */
       {
        /* here goes the magic again... */
        ffi_cif *cif = &rmeth->cif;
-       ffi_raw *raw = (ffi_raw*) sp;
+       INTERP_FFI_RAW_TYPE *raw = (INTERP_FFI_RAW_TYPE *) sp;
 
        _Jv_value rvalue;
 
@@ -2651,7 +2677,7 @@ details.  */
         {
           sp = stack;
           sp++->o = ex; // Push exception.
-#ifdef DEBUG
+#ifdef __GCJ_DEBUG
           if (JVMTI_REQUESTED_EVENT (ExceptionCatch))
             {
               using namespace gnu::gcj::jvmti;