Eliminate the constraint that thread ids must have an LSB of 1. This

doubles the space of thread ids and will break any code that assumes
thread ids are odd numbered.

diff --git a/vm/Thread.c b/vm/Thread.c
index e4ee8e3..05c89e2 100644 (file)
--- a/vm/Thread.c
+++ b/vm/Thread.c
@@ -224,8 +224,8 @@ Some other concerns with flinging signals around:
    use printf on stdout to print GC debug messages)
 */
 
-#define kMaxThreadId        ((1<<15) - 1)
-#define kMainThreadId       ((1<<1) | 1)
+#define kMaxThreadId        ((1 << 16) - 1)
+#define kMainThreadId       1
 
 
 static Thread* allocThread(int interpStackSize);
@@ -1192,12 +1192,10 @@ static void threadExitCheck(void* arg)
  */
 static void assignThreadId(Thread* thread)
 {
-    /* Find a small unique integer.  threadIdMap is a vector of
+    /*
+     * Find a small unique integer.  threadIdMap is a vector of
      * kMaxThreadId bits;  dvmAllocBit() returns the index of a
      * bit, meaning that it will always be < kMaxThreadId.
-     *
-     * The thin locking magic requires that the low bit is always
-     * set, so we do it once, here.
      */
     int num = dvmAllocBit(gDvm.threadIdMap);
     if (num < 0) {
@@ -1205,7 +1203,7 @@ static void assignThreadId(Thread* thread)
         dvmAbort();     // TODO: make this a non-fatal error result
     }
 
-    thread->threadId = ((num + 1) << 1) | 1;
+    thread->threadId = num + 1;
 
     assert(thread->threadId != 0);
     assert(thread->threadId != DVM_LOCK_INITIAL_THIN_VALUE);