/* Broadcast a frame in the network. In most cases, the frame should be able to
* reach every node in the network, but no guarantee about this.
*/
uintx flood_broadcast( TiFloodNetwork * net, TiFrame * frame, uint8 option )
{
uintx count=0;
uintx i = 0;//todo
char * pc;
/* This function will try to put the frame into TiFloodNetwork's internal TX buffer.
* The real sending processing is in flood_evolve().
*/
i = frame_length( frame);//todo
if (frame_empty(net->txque))
{
net->txque->option = option;
count = frame_totalcopyfrom( net->txque, frame );
frame_skipouter( net->txque, 4, 0 );//todo 执行这一局后frame_length又变回0了！
frame_setlength( net->txque,(i+4));//todo
// assert( frame_skipouter must be success );
pc = frame_startptr( net->txque );
PACKET_SET_HOPCOUNT( pc,0 );
PACKET_SET_MAX_HOPCOUNT(pc , CONFIG_FLOOD_MAX_COUNT );
PACKET_SET_CURSEQID(pc, net->seqid );
}
flood_evolve( net, NULL );
return count;
}
// Transfers the arguments from the top of the previous piece (which the frame
// points to) to the bottom of the new stack segment.
static void transfer_top_arguments(value_t new_piece, frame_t *frame,
size_t arg_count) {
frame_t new_frame = frame_empty();
open_stack_piece(new_piece, &new_frame);
for (size_t i = 0; i < arg_count; i++) {
value_t value = frame_peek_value(frame, arg_count - i - 1);
frame_push_value(&new_frame, value);
}
close_frame(&new_frame);
}
/* Check for arrived frames, no matter who send them. The frame will be returned
* through the parameter "frame" only when the frame's destination matches the current
* node. The other frames will be forwarded or discarded.
*/
uintx flood_recv( TiFloodNetwork * net, TiFrame * frame, uint8 option )
{
uintx count=0;
flood_evolve( net, NULL );
if (!frame_empty( net->rxque))
{
count = frame_totalcopyfrom( frame, net->rxque );
frame_bufferclear( net->rxque );
}
return count;
}
static void push_stack_piece_bottom_frame(runtime_t *runtime, value_t stack_piece,
value_t arg_map) {
frame_t bottom = frame_empty();
value_t code_block = ROOT(runtime, stack_piece_bottom_code_block);
// The transferred arguments are going to appear as if they were arguments
// passed from this frame so we have to "allocate" enough room for them on
// the stack.
open_stack_piece(stack_piece, &bottom);
size_t arg_count = get_array_length(arg_map);
bool pushed = try_push_new_frame(&bottom,
get_code_block_high_water_mark(code_block) + arg_count,
ffSynthetic | ffStackPieceBottom, false);
CHECK_TRUE("pushing bottom frame", pushed);
frame_set_code_block(&bottom, code_block);
frame_set_argument_map(&bottom, arg_map);
close_frame(&bottom);
}
frame_t open_stack(value_t stack) {
CHECK_FAMILY(ofStack, stack);
frame_t result = frame_empty();
open_stack_piece(get_stack_top_piece(stack), &result);
return result;
}
// Runs the given stack within the given ambience until a condition is
// encountered or evaluation completes. This function also bails on and leaves
// it to the surrounding code to report error messages.
static value_t run_stack_pushing_signals(value_t ambience, value_t stack) {
CHECK_FAMILY(ofAmbience, ambience);
CHECK_FAMILY(ofStack, stack);
runtime_t *runtime = get_ambience_runtime(ambience);
frame_t frame = open_stack(stack);
code_cache_t cache;
code_cache_refresh(&cache, &frame);
E_BEGIN_TRY_FINALLY();
while (true) {
opcode_t opcode = (opcode_t) read_short(&cache, &frame, 0);
TOPIC_INFO(Interpreter, "Opcode: %s (%i)", get_opcode_name(opcode),
opcode_counter++);
IF_EXPENSIVE_CHECKS_ENABLED(MAYBE_INTERRUPT());
switch (opcode) {
case ocPush: {
value_t value = read_value(&cache, &frame, 1);
frame_push_value(&frame, value);
frame.pc += kPushOperationSize;
break;
}
case ocPop: {
size_t count = read_short(&cache, &frame, 1);
for (size_t i = 0; i < count; i++)
frame_pop_value(&frame);
frame.pc += kPopOperationSize;
break;
}
case ocCheckStackHeight: {
size_t expected = read_short(&cache, &frame, 1);
size_t height = frame.stack_pointer - frame.frame_pointer;
CHECK_EQ("stack height", expected, height);
frame.pc += kCheckStackHeightOperationSize;
break;
}
case ocNewArray: {
size_t length = read_short(&cache, &frame, 1);
E_TRY_DEF(array, new_heap_array(runtime, length));
for (size_t i = 0; i < length; i++) {
value_t element = frame_pop_value(&frame);
set_array_at(array, length - i - 1, element);
}
frame_push_value(&frame, array);
frame.pc += kNewArrayOperationSize;
break;
}
case ocInvoke: {
// Look up the method in the method space.
value_t tags = read_value(&cache, &frame, 1);
CHECK_FAMILY(ofCallTags, tags);
value_t fragment = read_value(&cache, &frame, 2);
CHECK_FAMILY(ofModuleFragment, fragment);
value_t helper = read_value(&cache, &frame, 3);
CHECK_FAMILY(ofSignatureMap, helper);
value_t arg_map;
value_t method = lookup_method_full(ambience, fragment, tags, &frame,
helper, &arg_map);
if (in_condition_cause(ccLookupError, method)) {
log_lookup_error(method, tags, &frame);
E_RETURN(method);
}
// The lookup may have failed with a different condition. Check for that.
E_TRY(method);
E_TRY_DEF(code_block, ensure_method_code(runtime, method));
// We should now have done everything that can fail so we advance the
// pc over this instruction. In reality we haven't, the frame push op
// below can fail so we should really push the next frame before
// storing the pc for this one. Laters.
frame.pc += kInvokeOperationSize;
// Push a new activation.
E_TRY(push_stack_frame(runtime, stack, &frame,
get_code_block_high_water_mark(code_block), arg_map));
frame_set_code_block(&frame, code_block);
code_cache_refresh(&cache, &frame);
break;
}
case ocSignalContinue:
case ocSignalEscape: {
// Look up the method in the method space.
value_t tags = read_value(&cache, &frame, 1);
CHECK_FAMILY(ofCallTags, tags);
frame.pc += kSignalEscapeOperationSize;
value_t arg_map = whatever();
value_t handler = whatever();
value_t method = lookup_signal_handler_method(ambience, tags, &frame,
&handler, &arg_map);
bool is_escape = (opcode == ocSignalEscape);
if (in_condition_cause(ccLookupError, method)) {
if (is_escape) {
// There was no handler for this so we have to escape out of the
// interpreter altogether. Push the signal frame onto the stack to
// record the state of it for the enclosing code.
E_TRY(push_stack_frame(runtime, stack, &frame, 1, nothing()));
// The stack tracing code expects all frames to have a valid code block
// object. The rest makes less of a difference.
frame_set_code_block(&frame, ROOT(runtime, empty_code_block));
E_RETURN(new_signal_condition(is_escape));
} else {
// There was no handler but this is not an escape so we skip over
// the post-handler goto to the default block.
CHECK_EQ("signal not followed by goto", ocGoto,
read_short(&cache, &frame, 0));
frame.pc += kGotoOperationSize;
}
} else {
// We found a method. Invoke it.
E_TRY(method);
E_TRY_DEF(code_block, ensure_method_code(runtime, method));
E_TRY(push_stack_frame(runtime, stack, &frame,
get_code_block_high_water_mark(code_block), arg_map));
frame_set_code_block(&frame, code_block);
CHECK_TRUE("subject not null", is_null(frame_get_argument(&frame, 0)));
frame_set_argument(&frame, 0, handler);
code_cache_refresh(&cache, &frame);
}
break;
}
case ocGoto: {
size_t delta = read_short(&cache, &frame, 1);
frame.pc += delta;
break;
}
case ocDelegateToLambda:
case ocDelegateToBlock: {
// This op only appears in the lambda and block delegator methods.
// They should never be executed because the delegation happens during
// method lookup. If we hit here something's likely wrong with the
// lookup process.
UNREACHABLE("delegate to lambda");
return new_condition(ccWat);
}
case ocBuiltin: {
value_t wrapper = read_value(&cache, &frame, 1);
builtin_method_t impl = (builtin_method_t) get_void_p_value(wrapper);
builtin_arguments_t args;
builtin_arguments_init(&args, runtime, &frame);
E_TRY_DEF(result, impl(&args));
frame_push_value(&frame, result);
frame.pc += kBuiltinOperationSize;
break;
}
case ocBuiltinMaybeEscape: {
value_t wrapper = read_value(&cache, &frame, 1);
builtin_method_t impl = (builtin_method_t) get_void_p_value(wrapper);
builtin_arguments_t args;
builtin_arguments_init(&args, runtime, &frame);
value_t result = impl(&args);
if (in_condition_cause(ccSignal, result)) {
// The builtin failed. Find the appropriate signal handler and call
// it. The invocation record is at the top of the stack.
value_t tags = frame_pop_value(&frame);
CHECK_FAMILY(ofCallTags, tags);
value_t arg_map = whatever();
value_t handler = whatever();
value_t method = lookup_signal_handler_method(ambience, tags, &frame,
&handler, &arg_map);
if (in_condition_cause(ccLookupError, method)) {
// Push the record back onto the stack to it's available to back
// tracing.
frame_push_value(&frame, tags);
frame.pc += kBuiltinMaybeEscapeOperationSize;
// There was no handler for this so we have to escape out of the
// interpreter altogether. Push the signal frame onto the stack to
// record the state of it for the enclosing code.
E_TRY(push_stack_frame(runtime, stack, &frame, 1, nothing()));
// The stack tracing code expects all frames to have a valid code block
// object. The rest makes less of a difference.
frame_set_code_block(&frame, ROOT(runtime, empty_code_block));
E_RETURN(new_signal_condition(true));
}
// Either found a signal or encountered a different condition.
E_TRY(method);
// Skip forward to the point we want the signal to return to, the
// leave-or-fire-barrier op that will do the leaving.
size_t dest_offset = read_short(&cache, &frame, 2);
frame.pc += dest_offset;
// Run the handler.
E_TRY_DEF(code_block, ensure_method_code(runtime, method));
E_TRY(push_stack_frame(runtime, stack, &frame,
get_code_block_high_water_mark(code_block), arg_map));
frame_set_code_block(&frame, code_block);
CHECK_TRUE("subject not null", is_null(frame_get_argument(&frame, 0)));
frame_set_argument(&frame, 0, handler);
code_cache_refresh(&cache, &frame);
} else {
// The builtin didn't cause a condition so we can just keep going.
E_TRY(result);
frame_push_value(&frame, result);
frame.pc += kBuiltinMaybeEscapeOperationSize;
}
break;
}
case ocReturn: {
value_t result = frame_pop_value(&frame);
frame_pop_within_stack_piece(&frame);
code_cache_refresh(&cache, &frame);
frame_push_value(&frame, result);
break;
}
case ocStackBottom: {
value_t result = frame_pop_value(&frame);
validate_stack_on_normal_exit(&frame);
E_RETURN(result);
}
case ocStackPieceBottom: {
value_t top_piece = frame.stack_piece;
value_t result = frame_pop_value(&frame);
value_t next_piece = get_stack_piece_previous(top_piece);
set_stack_top_piece(stack, next_piece);
frame = open_stack(stack);
code_cache_refresh(&cache, &frame);
frame_push_value(&frame, result);
break;
}
case ocSlap: {
value_t value = frame_pop_value(&frame);
size_t argc = read_short(&cache, &frame, 1);
for (size_t i = 0; i < argc; i++)
frame_pop_value(&frame);
frame_push_value(&frame, value);
frame.pc += kSlapOperationSize;
break;
}
case ocNewReference: {
// Create the reference first so that if it fails we haven't clobbered
// the stack yet.
E_TRY_DEF(ref, new_heap_reference(runtime, nothing()));
value_t value = frame_pop_value(&frame);
set_reference_value(ref, value);
frame_push_value(&frame, ref);
frame.pc += kNewReferenceOperationSize;
break;
}
case ocSetReference: {
value_t ref = frame_pop_value(&frame);
CHECK_FAMILY(ofReference, ref);
value_t value = frame_peek_value(&frame, 0);
set_reference_value(ref, value);
frame.pc += kSetReferenceOperationSize;
break;
}
case ocGetReference: {
value_t ref = frame_pop_value(&frame);
CHECK_FAMILY(ofReference, ref);
value_t value = get_reference_value(ref);
frame_push_value(&frame, value);
frame.pc += kGetReferenceOperationSize;
break;
}
case ocLoadLocal: {
size_t index = read_short(&cache, &frame, 1);
value_t value = frame_get_local(&frame, index);
frame_push_value(&frame, value);
frame.pc += kLoadLocalOperationSize;
break;
}
case ocLoadGlobal: {
value_t ident = read_value(&cache, &frame, 1);
CHECK_FAMILY(ofIdentifier, ident);
value_t fragment = read_value(&cache, &frame, 2);
CHECK_FAMILY(ofModuleFragment, fragment);
value_t module = get_module_fragment_module(fragment);
E_TRY_DEF(value, module_lookup_identifier(runtime, module,
get_identifier_stage(ident), get_identifier_path(ident)));
frame_push_value(&frame, value);
frame.pc += kLoadGlobalOperationSize;
break;
}
case ocLoadArgument: {
size_t param_index = read_short(&cache, &frame, 1);
value_t value = frame_get_argument(&frame, param_index);
frame_push_value(&frame, value);
frame.pc += kLoadArgumentOperationSize;
break;
}
case ocLoadRefractedArgument: {
size_t param_index = read_short(&cache, &frame, 1);
size_t block_depth = read_short(&cache, &frame, 2);
value_t subject = frame_get_argument(&frame, 0);
frame_t home = frame_empty();
get_refractor_refracted_frame(subject, block_depth, &home);
value_t value = frame_get_argument(&home, param_index);
frame_push_value(&frame, value);
frame.pc += kLoadRefractedArgumentOperationSize;
break;
}
case ocLoadRefractedLocal: {
size_t index = read_short(&cache, &frame, 1);
size_t block_depth = read_short(&cache, &frame, 2);
value_t subject = frame_get_argument(&frame, 0);
frame_t home = frame_empty();
get_refractor_refracted_frame(subject, block_depth, &home);
value_t value = frame_get_local(&home, index);
frame_push_value(&frame, value);
frame.pc += kLoadRefractedLocalOperationSize;
break;
}
case ocLoadLambdaCapture: {
size_t index = read_short(&cache, &frame, 1);
value_t subject = frame_get_argument(&frame, 0);
CHECK_FAMILY(ofLambda, subject);
value_t value = get_lambda_capture(subject, index);
frame_push_value(&frame, value);
frame.pc += kLoadLambdaCaptureOperationSize;
break;
}
case ocLoadRefractedCapture: {
size_t index = read_short(&cache, &frame, 1);
size_t block_depth = read_short(&cache, &frame, 2);
value_t subject = frame_get_argument(&frame, 0);
frame_t home = frame_empty();
get_refractor_refracted_frame(subject, block_depth, &home);
value_t lambda = frame_get_argument(&home, 0);
CHECK_FAMILY(ofLambda, lambda);
value_t value = get_lambda_capture(lambda, index);
frame_push_value(&frame, value);
frame.pc += kLoadRefractedLocalOperationSize;
break;
}
case ocLambda: {
value_t space = read_value(&cache, &frame, 1);
CHECK_FAMILY(ofMethodspace, space);
size_t capture_count = read_short(&cache, &frame, 2);
value_t captures;
E_TRY_DEF(lambda, new_heap_lambda(runtime, space, nothing()));
if (capture_count == 0) {
captures = ROOT(runtime, empty_array);
frame.pc += kLambdaOperationSize;
} else {
E_TRY_SET(captures, new_heap_array(runtime, capture_count));
// The pc gets incremented here because it is after we've done all
// the allocation but before anything has been popped off the stack.
// This way all the above is idempotent, and the below is guaranteed
// to succeed.
frame.pc += kLambdaOperationSize;
for (size_t i = 0; i < capture_count; i++)
set_array_at(captures, i, frame_pop_value(&frame));
}
set_lambda_captures(lambda, captures);
frame_push_value(&frame, lambda);
break;
}
case ocCreateBlock: {
value_t space = read_value(&cache, &frame, 1);
CHECK_FAMILY(ofMethodspace, space);
// Create the block object.
E_TRY_DEF(block, new_heap_block(runtime, nothing()));
// Create the stack section that describes the block.
value_t section = frame_alloc_derived_object(&frame, get_genus_descriptor(dgBlockSection));
set_barrier_state_payload(section, block);
refraction_point_init(section, &frame);
set_block_section_methodspace(section, space);
set_block_section(block, section);
value_validate(block);
value_validate(section);
// Push the block object.
frame_push_value(&frame, block);
frame.pc += kCreateBlockOperationSize;
break;
}
case ocCreateEnsurer: {
value_t code_block = read_value(&cache, &frame, 1);
value_t section = frame_alloc_derived_object(&frame,
get_genus_descriptor(dgEnsureSection));
set_barrier_state_payload(section, code_block);
refraction_point_init(section, &frame);
value_validate(section);
frame_push_value(&frame, section);
frame.pc += kCreateEnsurerOperationSize;
break;
}
case ocCallEnsurer: {
value_t value = frame_pop_value(&frame);
value_t shard = frame_pop_value(&frame);
frame_push_value(&frame, value);
frame_push_value(&frame, shard);
CHECK_GENUS(dgEnsureSection, shard);
value_t code_block = get_barrier_state_payload(shard);
CHECK_FAMILY(ofCodeBlock, code_block);
// Unregister the barrier before calling it, otherwise if we leave
// by escaping we'll end up calling it over again.
barrier_state_unregister(shard, stack);
frame.pc += kCallEnsurerOperationSize;
value_t argmap = ROOT(runtime, array_of_zero);
push_stack_frame(runtime, stack, &frame,
get_code_block_high_water_mark(code_block), argmap);
frame_set_code_block(&frame, code_block);
code_cache_refresh(&cache, &frame);
break;
}
case ocDisposeEnsurer: {
// Discard the result of the ensure block. If an ensure blocks needs
// to return a useful value it can do it via an escape.
frame_pop_value(&frame);
value_t shard = frame_pop_value(&frame);
CHECK_GENUS(dgEnsureSection, shard);
value_t value = frame_pop_value(&frame);
frame_destroy_derived_object(&frame, get_genus_descriptor(dgEnsureSection));
frame_push_value(&frame, value);
frame.pc += kDisposeEnsurerOperationSize;
break;
}
case ocInstallSignalHandler: {
value_t space = read_value(&cache, &frame, 1);
CHECK_FAMILY(ofMethodspace, space);
size_t dest_offset = read_short(&cache, &frame, 2);
// Allocate the derived object that's going to hold the signal handler
// state.
value_t section = frame_alloc_derived_object(&frame,
get_genus_descriptor(dgSignalHandlerSection));
// Initialize the handler.
set_barrier_state_payload(section, space);
refraction_point_init(section, &frame);
// Bring the frame state to the point we'll want to escape to (modulo
// the destination offset).
frame_push_value(&frame, section);
frame.pc += kInstallSignalHandlerOperationSize;
// Finally capture the escape state.
capture_escape_state(section, &frame, dest_offset);
value_validate(section);
break;
}
case ocUninstallSignalHandler: {
// The result has been left at the top of the stack.
value_t value = frame_pop_value(&frame);
value_t section = frame_pop_value(&frame);
CHECK_GENUS(dgSignalHandlerSection, section);
barrier_state_unregister(section, stack);
frame_destroy_derived_object(&frame, get_genus_descriptor(dgSignalHandlerSection));
frame_push_value(&frame, value);
frame.pc += kUninstallSignalHandlerOperationSize;
break;
}
case ocCreateEscape: {
size_t dest_offset = read_short(&cache, &frame, 1);
// Create an initially empty escape object.
E_TRY_DEF(escape, new_heap_escape(runtime, nothing()));
// Allocate the escape section on the stack, hooking the barrier into
// the barrier chain.
value_t section = frame_alloc_derived_object(&frame, get_genus_descriptor(dgEscapeSection));
// Point the state and object to each other.
set_barrier_state_payload(section, escape);
set_escape_section(escape, section);
// Get execution ready for the next operation.
frame_push_value(&frame, escape);
frame.pc += kCreateEscapeOperationSize;
// This is the execution state the escape will escape to (modulo the
// destination offset) so this is what we want to capture.
capture_escape_state(section, &frame,
dest_offset);
break;
}
case ocLeaveOrFireBarrier: {
size_t argc = read_short(&cache, &frame, 1);
// At this point the handler has been set as the subject of the call
// to the handler method. Above the arguments are also two scratch
// stack entries.
value_t handler = frame_peek_value(&frame, argc + 2);
CHECK_GENUS(dgSignalHandlerSection, handler);
if (maybe_fire_next_barrier(&cache, &frame, runtime, stack, handler)) {
// Pop the scratch entries off.
frame_pop_value(&frame);
frame_pop_value(&frame);
// Pop the value off.
value_t value = frame_pop_value(&frame);
// Escape to the handler's home.
restore_escape_state(&frame, stack, handler);
code_cache_refresh(&cache, &frame);
// Push the value back on, now in the handler's home frame.
frame_push_value(&frame, value);
} else {
// If a barrier was fired we'll want to let the interpreter loop
// around again so just break without touching .pc.
}
break;
}
case ocFireEscapeOrBarrier: {
value_t escape = frame_get_argument(&frame, 0);
CHECK_FAMILY(ofEscape, escape);
value_t section = get_escape_section(escape);
// Fire the next barrier or, if there are no more barriers, apply the
// escape.
if (maybe_fire_next_barrier(&cache, &frame, runtime, stack, section)) {
value_t value = frame_get_argument(&frame, 2);
restore_escape_state(&frame, stack, section);
code_cache_refresh(&cache, &frame);
frame_push_value(&frame, value);
} else {
// If a barrier was fired we'll want to let the interpreter loop
// around again so just break without touching .pc.
}
break;
}
case ocDisposeEscape: {
value_t value = frame_pop_value(&frame);
value_t escape = frame_pop_value(&frame);
CHECK_FAMILY(ofEscape, escape);
value_t section = get_escape_section(escape);
value_validate(section);
barrier_state_unregister(section, stack);
on_escape_section_exit(section);
frame_destroy_derived_object(&frame, get_genus_descriptor(dgEscapeSection));
frame_push_value(&frame, value);
frame.pc += kDisposeEscapeOperationSize;
break;
}
case ocDisposeBlock: {
value_t value = frame_pop_value(&frame);
value_t block = frame_pop_value(&frame);
CHECK_FAMILY(ofBlock, block);
value_t section = get_block_section(block);
barrier_state_unregister(section, stack);
on_block_section_exit(section);
frame_destroy_derived_object(&frame, get_genus_descriptor(dgBlockSection));
frame_push_value(&frame, value);
frame.pc += kDisposeBlockOperationSize;
break;
}
default:
ERROR("Unexpected opcode %i", opcode);
UNREACHABLE("unexpected opcode");
break;
}
}
E_FINALLY();
close_frame(&frame);
E_END_TRY_FINALLY();
}
/* This function receive event from other services/objects and drive the evolution
* of the TiFloodNetwork service.
*
* This function can also be the listener of the MAC layer, Though it's not mandatory.
*
* @attention:
* This function cannot run in the interrupt mode.
*/
void flood_evolve( void * netptr, TiEvent * e )
{
TiFloodNetwork * net = (TiFloodNetwork *)netptr;
uint8 len, count, cur_hopcount, max_hopcount;
bool done = true, cont= false;
char * pc;
aloha_evolve( net->mac,e );
// This event is sent from MAC layer.
//
// @todo
// Currently, all the frames from MAC layer will submitted the listener function.
// Actually, this isn't necessary. Only those to this node should submitted to
// the listener.
//
if (e->id == EVENT_DATA_ARRIVAL)
{
if (net->listener != NULL)
{
net->listener( net->lisowner, e );
return;
}
}
do{
switch (net->state)
{
// IDLE is the initial and default state of this state machine.
case FLOOD_STATE_IDLE:
// Check if the TX queue is empty. If not then try to send the frame.
if (!frame_empty(net->txque))
{
len = aloha_broadcast( net->mac, net->txque, net->txque->option );
if (len > 0)
{
frame_bufferclear( net->txque );
}
// @attention
// @todo: if the aloha_send() is non-blocked operation, then you should
// transfer to FLOOD_STATE_WAITFOR_TXREPLY state to wait. You should empty
// the buffer only when this service receives the reply from MAC layer.
//net->state = FLOOD_STATE_WAIT_TXREPLY
done = true;
}
// Check if the RX queue is empty, then try to receive one from MAC layer
if ((frame_empty(net->rxbuf)) && frame_empty(net->rxque))
{
cont = true;
count = aloha_recv( net->mac, net->rxbuf, 0x00 );
if (count <= 0)
cont = false;
// Check: whether the same frame has already been received. This
// is by searching it in the cache. If it cannot find it in the
// cache, then put the frame in the cache.
//
// @modified by zhangwei on 2011.03.14
// - we use the first 4 bytes in the frame (which is essentially
// the header of flood protocol as the key to visit the cache.
//
if (cont)
{
if (flood_cache_visit( net->cache, (char*)frame_startptr(net->rxbuf) ))//todo 我将CONFIG_FLOOD_CACHE_CAPACITY改成了1原先为8，不改的话不再接收新的帧.
{
frame_bufferclear( net->rxbuf );
cont = false;
}
}
if (cont)
{
frame_totalcopyto( net->rxbuf, net->rxque );
// Check whether this frame has reaches its maximum hopcount.
// Discard this frame if this is true.
char * pc;
pc = frame_startptr( net->rxbuf);
cur_hopcount = PACKET_CUR_HOPCOUNT( pc );
max_hopcount = PACKET_MAX_HOPCOUNT( pc);
cur_hopcount ++;
if (cur_hopcount > max_hopcount)
frame_bufferclear( net->rxbuf );
else
PACKET_SET_HOPCOUNT( pc, cur_hopcount );
}
done = true;
}
// Check whether there's frame pending for forwarding
if ((!frame_empty(net->rxbuf)) && frame_empty(net->txque))
{
pc = frame_startptr( net->txque);
// move the frame from rxbuf to txque. For efficiency reasons, this is implmented
// by switching the two pointers.
_switch_ptr( &(net->rxbuf), &(net->txque) );
// @attention
// generally, you should change the frame in "txque" with the PAN id
// and BROADCAST_ADDRESS configured in this flood component. However,
// here we assume the low level medium access protocol helps us to do so.
cur_hopcount = PACKET_CUR_HOPCOUNT( pc );
PACKET_SET_HOPCOUNT( pc, cur_hopcount++ );
done = false;
}
break;
// This's the state waiting for MAC layer's reply. The sending process of the
// MAC layer may last for quite a long time due to re-transmission. Only at the
// end of the transmission, the MAC layer does possible to notify the NET layer
// the transmission results of the sending request.
//
/*case FLOOD_STATE_WAITFOR_TXREPLY:
ioresult = aloha_ioresult(net->mac);
if ioresult == IDLE|TXDONE
{
opf_clear( net->txque );
net->state = FLOOD_STATE_IDLE;
}
// if ioresult indicate there's error or failure
// report to the master program by call net->listener
net->state = FLOOD_STATE_IDLE;
break;*/
default:
net->state = FLOOD_STATE_IDLE;
}
}while (!done);
return;
}
