diff options
| -rw-r--r-- | vm/compiler/codegen/arm/Assemble.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/vm/compiler/codegen/arm/Assemble.c b/vm/compiler/codegen/arm/Assemble.c index dfc68b6f3..4f2c10a23 100644 --- a/vm/compiler/codegen/arm/Assemble.c +++ b/vm/compiler/codegen/arm/Assemble.c @@ -2272,13 +2272,25 @@ void dvmJitInstallClassObjectPointers(CompilationUnit *cUnit, char *codeAddress) int numClassPointers = *(int *)classPointerP++; intptr_t *startClassPointerP = classPointerP; - UNPROTECT_CODE_CACHE(startClassPointerP, - numClassPointers * sizeof(intptr_t)); /* * Change the thread state to VM_RUNNING so that GC won't be happening - * when the assembler looks up the class pointers. + * when the assembler looks up the class pointers. May suspend the current + * thread if there is a pending request before the state is actually + * changed to RUNNING. */ dvmChangeStatus(gDvmJit.compilerThread, THREAD_RUNNING); + + /* + * Unprotecting the code cache will need to acquire the code cache + * protection lock first. Doing so after the state change may increase the + * time spent in the RUNNING state (which may delay the next GC request + * should there be contention on codeCacheProtectionLock). In practice + * this is probably not going to happen often since a GC is just served. + * More importantly, acquiring the lock before the state change will + * cause deadlock (b/4192964). + */ + UNPROTECT_CODE_CACHE(startClassPointerP, + numClassPointers * sizeof(intptr_t)); #if defined(WITH_JIT_TUNING) u8 startTime = dvmGetRelativeTimeUsec(); #endif @@ -2305,12 +2317,12 @@ void dvmJitInstallClassObjectPointers(CompilationUnit *cUnit, char *codeAddress) gDvmJit.maxCompilerThreadBlockGCTime = blockTime; gDvmJit.numCompilerThreadBlockGC++; #endif - /* Change the thread state back to VMWAIT */ - dvmChangeStatus(gDvmJit.compilerThread, THREAD_VMWAIT); - UPDATE_CODE_CACHE_PATCHES(); PROTECT_CODE_CACHE(startClassPointerP, numClassPointers * sizeof(intptr_t)); + + /* Change the thread state back to VMWAIT */ + dvmChangeStatus(gDvmJit.compilerThread, THREAD_VMWAIT); } #if defined(WITH_SELF_VERIFICATION) |