patch: hash synchronization for mingw/cygwin

[Adam Megacz]

This patch enables hash synchronization on mingw/cygwin.  The
JV_LINKER_CANNOT_8BYTE_ALIGN_STATICS hack to work around the broken
Win32 linker has been discussed before:

  http://gcc.gnu.org/ml/java/2002-03/msg00038.html

Ok to commit?

  - a

2002-10-11  Adam Megacz <adam@xwt.org>

        * java/lang/natObject.cc (_Jv_MonitorEnter, _Jv_MonitorExit,
        heavy_lock_obj_finalization_proc, wait, notify, notifyAll):
        removed some posix-isms, added code to clear bottom three bits if
        platform has a broken linker.
        * include/win32-threads.h (_Jv_ThreadId_t): added.
        * configure.in: add JV_LINKER_CANNOT_8BYTE_ALIGN_STATICS, permit
        -fhash-sync on non-posix OSes.

Index: include/win32-threads.h
===================================================================
RCS file: /cvs/gcc/gcc/libjava/include/win32-threads.h,v
retrieving revision 1.5
diff -u -r1.5 win32-threads.h
--- include/win32-threads.h	2 Feb 2002 04:27:34 -0000	1.5
+++ include/win32-threads.h	12 Oct 2002 01:08:51 -0000
@@ -33,6 +33,14 @@
   java::lang::Thread *thread_obj;
 } _Jv_Thread_t;
 
+typedef DWORD _Jv_ThreadId_t;
+
+inline _Jv_ThreadId_t
+_Jv_ThreadSelf (void)
+{
+  return GetCurrentThreadId();
+}
+
 typedef void _Jv_ThreadStartFunc (java::lang::Thread *);
 
 //
Index: java/lang/natObject.cc
===================================================================
RCS file: /cvs/gcc/gcc/libjava/java/lang/natObject.cc,v
retrieving revision 1.22
diff -u -r1.22 natObject.cc
--- java/lang/natObject.cc	10 Mar 2002 03:53:13 -0000	1.22
+++ java/lang/natObject.cc	12 Oct 2002 01:09:00 -0000
@@ -305,9 +305,9 @@
 #include <assert.h>
 #include <limits.h>
 #include <unistd.h>	// for usleep, sysconf.
-#include <sched.h>	// for sched_yield.
 #include <gcj/javaprims.h>
 #include <sysdep/locks.h>
+#include <java/lang/Thread.h>
 
 // Try to determine whether we are on a multiprocessor, i.e. whether
 // spinning may be profitable.
@@ -525,14 +525,14 @@
     }
   else if (n < yield_limit)
     {
-      sched_yield();
+      _Jv_ThreadYield();
     }
   else
     {
       unsigned duration = MIN_SLEEP_USECS << (n - yield_limit);
       if (n >= 15 + yield_limit || duration > MAX_SLEEP_USECS)
-	duration = MAX_SLEEP_USECS;
-      usleep(duration);
+        duration = MAX_SLEEP_USECS;
+      java::lang::Thread::sleep(0, duration);
     }
 }
 
@@ -574,7 +574,11 @@
 heavy_lock_obj_finalization_proc (void *obj, void *cd)
 {
   heavy_lock *hl = (heavy_lock *)cd;
+#ifdef JV_LINKER_CANNOT_8BYTE_ALIGN_STATICS
+  obj_addr_t addr = (obj_addr_t)obj & ~((obj_addr_t)0x7);
+#else
   obj_addr_t addr = (obj_addr_t)obj;
+#endif
   hash_entry *he = light_locks + JV_SYNC_HASH(addr);
   obj_addr_t he_address = (he -> address & ~LOCKED);
 
@@ -753,7 +757,11 @@
 void
 _Jv_MonitorEnter (jobject obj)
 {
+#ifdef JV_LINKER_CANNOT_8BYTE_ALIGN_STATICS
+  obj_addr_t addr = (obj_addr_t)obj & ~((obj_addr_t)FLAGS);
+#else
   obj_addr_t addr = (obj_addr_t)obj;
+#endif
   obj_addr_t address;
   unsigned hash = JV_SYNC_HASH(addr);
   hash_entry * he = light_locks + hash;
@@ -898,7 +906,11 @@
 void
 _Jv_MonitorExit (jobject obj)
 {
+#ifdef JV_LINKER_CANNOT_8BYTE_ALIGN_STATICS
+  obj_addr_t addr = (obj_addr_t)obj & ~((obj_addr_t)FLAGS);
+#else
   obj_addr_t addr = (obj_addr_t)obj;
+#endif
   _Jv_ThreadId_t self = _Jv_ThreadSelf();
   unsigned hash = JV_SYNC_HASH(addr);
   hash_entry * he = light_locks + hash;
@@ -1078,7 +1090,11 @@
 void
 java::lang::Object::wait (jlong timeout, jint nanos)
 {
+#ifdef JV_LINKER_CANNOT_8BYTE_ALIGN_STATICS
+  obj_addr_t addr = (obj_addr_t)this & ~((obj_addr_t)FLAGS);
+#else
   obj_addr_t addr = (obj_addr_t)this;
+#endif
   _Jv_ThreadId_t self = _Jv_ThreadSelf();
   unsigned hash = JV_SYNC_HASH(addr);
   hash_entry * he = light_locks + hash;
@@ -1155,7 +1171,11 @@
 void
 java::lang::Object::notify (void)
 {
+#ifdef JV_LINKER_CANNOT_8BYTE_ALIGN_STATICS
+  obj_addr_t addr = (obj_addr_t)this & ~((obj_addr_t)FLAGS);
+#else
   obj_addr_t addr = (obj_addr_t)this;
+#endif
   _Jv_ThreadId_t self = _Jv_ThreadSelf();
   unsigned hash = JV_SYNC_HASH(addr);
   hash_entry * he = light_locks + hash;
@@ -1200,7 +1220,11 @@
 void
 java::lang::Object::notifyAll (void)
 {
+#ifdef JV_LINKER_CANNOT_8BYTE_ALIGN_STATICS
+  obj_addr_t addr = (obj_addr_t)this & ~((obj_addr_t)FLAGS);
+#else
   obj_addr_t addr = (obj_addr_t)this;
+#endif
   _Jv_ThreadId_t self = _Jv_ThreadSelf();
   unsigned hash = JV_SYNC_HASH(addr);
   hash_entry * he = light_locks + hash;
Index: configure.in
===================================================================
RCS file: /cvs/gcc/gcc/libjava/configure.in,v
retrieving revision 1.140
diff -u -r1.140 configure.in
--- configure.in	17 Sep 2002 06:58:39 -0000	1.140
+++ configure.in	12 Oct 2002 01:09:02 -0000
@@ -226,6 +226,8 @@
             PLATFORM=Win32
             PLATFORMOBJS=win32.lo
 	    PLATFORMH=win32.h
+        AC_DEFINE(JV_LINKER_CANNOT_8BYTE_ALIGN_STATICS, 1,
+                  [Indicate that linker is not able to 8-byte align static data])
       ;;
       *)
             PLATFORM=Posix
@@ -444,7 +446,7 @@
 
 HASH_SYNC_SPEC=
 # Hash synchronization is only useful with posix threads right now.
-if test "$enable_hash_synchronization" = yes && test "$THREADS" = "posix"; then
+if test "$enable_hash_synchronization" = yes; then
    HASH_SYNC_SPEC=-fhash-synchronization
    AC_DEFINE(JV_HASH_SYNCHRONIZATION, 1, [Define if hash synchronization is in use])
 fi


-- 
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