patch: hash synchronization for mingw/cygwin

Fri Oct 11 18:09:00 GMT 2002

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年10月11日 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
-- 
"Through your rags I see your vanity" -- Socrates
