Handle relocatable class objects in JIT'ed code.

1) Split the original literal pool into class object literals and
constants. Elements in the class object pool have to match the specicial
values perfectly (ie no +delta space optimizations) since they might be
relocated.

2) Implement dvmJitScanAllClassPointers(void (*callback)(void *))
which is the entry routine to report all memory locations in the code cache
that contain class objects (ie class object pool and predicted chaining
cells for virtual calls).

3) Major codegen changes on how/when the class object pool are populated
and how predicted chains are patched. Before this change the compiler
thread is always in the VM_WAIT state, which won't prevent GC from
running. Since the class object pointers captured by a worker thread
are no longer guaranteed to be stable at JIT time, change various
internal data structures to capture the class descriptor/loader
tuple instead. The conversion from descriptor/loader tuple to actual
class object pointers are only performed when the thread state is
RUNNING or at GC safe point.

4) Separate the class object installation phase out of the main
dvmCompilerAssembleLIR routine so that the impact to blocking GC
requests is minimal. Add new stats to report the potential block time.
For example:
Potential GC blocked by compiler: max 46 us / avg 25 us

5) Various cleanup in the trace structure walkup code. Modified the
verbose print routine to show the class descriptor in the class literal
pool. For example:

D/dalvikvm( 1450): -------- end of chaining cells (0x007c)
D/dalvikvm( 1450): 0x44020628 (00b4): .class
(Lcom/android/unit_tests/PerformanceTests$EmptyClass;)
D/dalvikvm( 1450): 0x4402062c (00b8): .word (0xaca8d1a5)
D/dalvikvm( 1450): 0x44020630 (00bc): .word (0x401abc02)
D/dalvikvm( 1450): End

Bug: 3482956

Change-Id: I2e736b00d63adc255c33067544606b8b96b72ffc

1 files changed, 4 insertions, 0 deletions

diff --git a/vm/compiler/codegen/x86/Assemble.c b/vm/compiler/codegen/x86/Assemble.c
index d583001e9..03edbf109 100644
--- a/vm/compiler/codegen/x86/Assemble.c
+++ b/vm/compiler/codegen/x86/Assemble.c
@@ -142,3 +142,7 @@ JitTraceDescription *dvmCopyTraceDescriptor(const u2 *pc,
 void dvmCompilerSortAndPrintTraceProfiles()
 {
 }
+
+void dvmJitScanAllClassPointers(void (*callback)(void *))
+{
+}