X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2Fsm%2FGCThread.h;h=1d0a05ce447285f9c12ec3e5bd17ae8c8ffa82ef;hb=e50364a5a8e5d736445cd8e5b10a813ec0a5a2e0;hp=338cca749dbe300bac914b3a19c19b170a3a8874;hpb=e686d8dc6cd67c35132059d0718d1501f0af1e67;p=ghc-hetmet.git

diff --git a/rts/sm/GCThread.h b/rts/sm/GCThread.h
index 338cca7..1d0a05c 100644
--- a/rts/sm/GCThread.h
+++ b/rts/sm/GCThread.h
@@ -105,7 +105,7 @@ typedef struct step_workspace_ {
    GC thread object
 
    Every GC thread has one of these. It contains all the step specific
-   workspaces and other GC thread loacl information. At some later
+   workspaces and other GC thread local information. At some later
    point it maybe useful to move this other into the TLS store of the
    GC threads
    ------------------------------------------------------------------------- */
@@ -113,10 +113,9 @@ typedef struct step_workspace_ {
 typedef struct gc_thread_ {
 #ifdef THREADED_RTS
     OSThreadId id;                 // The OS thread that this struct belongs to
-    Mutex      wake_mutex;
-    Condition  wake_cond;          // So we can go to sleep between GCs
-    rtsBool    wakeup;
-    rtsBool    exit;
+    SpinLock   gc_spin;
+    SpinLock   mut_spin;
+    volatile rtsBool wakeup;
 #endif
     nat thread_index;              // a zero based index identifying the thread
 
@@ -181,8 +180,50 @@ typedef struct gc_thread_ {
 extern nat n_gc_threads;
 
 extern gc_thread **gc_threads;
-register gc_thread *gct __asm__("%rbx");
-// extern gc_thread *gct;  // this thread's gct TODO: make thread-local
+
+/* -----------------------------------------------------------------------------
+   The gct variable is thread-local and points to the current thread's
+   gc_thread structure.  It is heavily accessed, so we try to put gct
+   into a global register variable if possible; if we don't have a
+   register then use gcc's __thread extension to create a thread-local
+   variable.
+
+   Even on x86 where registers are scarce, it is worthwhile using a
+   register variable here: I measured about a 2-5% slowdown with the
+   __thread version.
+   -------------------------------------------------------------------------- */
+
+#define GLOBAL_REG_DECL(type,name,reg) register type name REG(reg);
+
+#if defined(sparc_HOST_ARCH)
+// Don't use REG_base or R1 for gct on SPARC because they're getting clobbered 
+//	by something else. Not sure what yet. -- BL 2009/01/03
+
+extern __thread gc_thread* gct;
+#define DECLARE_GCT __thread gc_thread* gct;
+
+#elif defined(REG_Base) && !defined(i386_HOST_ARCH)
+// on i386, REG_Base is %ebx which is also used for PIC, so we don't
+// want to steal it
+
+GLOBAL_REG_DECL(gc_thread*, gct, REG_Base)
+#define DECLARE_GCT /* nothing */
+
+#elif defined(REG_R1)
+
+GLOBAL_REG_DECL(gc_thread*, gct, REG_R1)
+#define DECLARE_GCT /* nothing */
+
+#elif defined(__GNUC__)
+
+extern __thread gc_thread* gct;
+#define DECLARE_GCT __thread gc_thread* gct;
+
+#else
+
+#error Cannot find a way to declare the thread-local gct
+
+#endif
 
 #endif // GCTHREAD_H