private BlockNode processMonitorEnter(
IRegion curRegion, BlockNode block, InsnNode insn, RegionStack stack) {
SynchronizedRegion synchRegion = new SynchronizedRegion(curRegion, insn);
synchRegion.getSubBlocks().add(block);
curRegion.getSubBlocks().add(synchRegion);
Set<BlockNode> exits = new HashSet<BlockNode>();
cacheSet.clear();
traverseMonitorExits(synchRegion, insn.getArg(0), block, exits, cacheSet);
for (InsnNode exitInsn : synchRegion.getExitInsns()) {
InstructionRemover.unbindInsn(mth, exitInsn);
}
BlockNode body = getNextBlock(block);
if (body == null) {
ErrorsCounter.methodError(mth, "Unexpected end of synchronized block");
return null;
}
BlockNode exit;
if (exits.size() == 1) {
exit = getNextBlock(exits.iterator().next());
} else {
cacheSet.clear();
exit = traverseMonitorExitsCross(body, exits, cacheSet);
}
stack.push(synchRegion);
stack.addExit(exit);
synchRegion.getSubBlocks().add(makeRegion(body, stack));
stack.pop();
return exit;
}
/** Traverse from monitor-enter thru successors and collect blocks contains monitor-exit */
private static void traverseMonitorExits(
SynchronizedRegion region,
InsnArg arg,
BlockNode block,
Set<BlockNode> exits,
Set<BlockNode> visited) {
visited.add(block);
for (InsnNode insn : block.getInstructions()) {
if (insn.getType() == InsnType.MONITOR_EXIT && insn.getArg(0).equals(arg)) {
exits.add(block);
region.getExitInsns().add(insn);
return;
}
}
for (BlockNode node : block.getSuccessors()) {
if (!visited.contains(node)) {
traverseMonitorExits(region, arg, node, exits, visited);
}
}
}