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dgram: use slab memory allocator

Change udp memory allocation scheme from uv_buf_init to slab allocation. Takes
slab allocation scheme from stream_wrap.
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1 parent 465e22e commit bd9fa2e8419dda3ecff55ca7d801af3db4aeb5b2 @mrb mrb committed with bnoordhuis Jan 11, 2012
Showing with 59 additions and 9 deletions.
  1. +59 −9 src/udp_wrap.cc
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68 src/udp_wrap.cc
@@ -59,17 +59,27 @@ namespace node {
return scope.Close(Integer::New(-1)); \
}
+#define SLAB_SIZE (1024 * 1024)
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+
// TODO share with tcp_wrap.cc
Persistent<String> address_symbol;
Persistent<String> port_symbol;
Persistent<String> buffer_sym;
+static Persistent<String> udp_slab_sym;
void AddressToJS(Handle<Object> info,
const sockaddr* addr,
int addrlen);
typedef ReqWrap<uv_udp_send_t> SendWrap;
+
+static size_t slab_used;
+size_t slab_offset_;
+static uv_handle_t* handle_that_last_alloced;
+
+
class UDPWrap: public HandleWrap {
public:
static void Initialize(Handle<Object> target);
@@ -83,6 +93,8 @@ class UDPWrap: public HandleWrap {
static Handle<Value> GetSockName(const Arguments& args);
private:
+ static inline char* NewSlab(v8::Handle<v8::Object> global, v8::Handle<v8::Object> wrap_obj);
+
UDPWrap(Handle<Object> object);
virtual ~UDPWrap();
@@ -118,6 +130,7 @@ void UDPWrap::Initialize(Handle<Object> target) {
HandleScope scope;
+ udp_slab_sym = Persistent<String>::New(String::NewSymbol("udpslab"));
buffer_sym = NODE_PSYMBOL("buffer");
port_symbol = NODE_PSYMBOL("port");
address_symbol = NODE_PSYMBOL("address");
@@ -149,7 +162,6 @@ Handle<Value> UDPWrap::New(const Arguments& args) {
return scope.Close(args.This());
}
-
Handle<Value> UDPWrap::DoBind(const Arguments& args, int family) {
HandleScope scope;
int r;
@@ -332,13 +344,44 @@ void UDPWrap::OnSend(uv_udp_send_t* req, int status) {
uv_buf_t UDPWrap::OnAlloc(uv_handle_t* handle, size_t suggested_size) {
- // FIXME switch to slab allocation, share with stream_wrap.cc
- return uv_buf_init(new char[suggested_size], suggested_size);
-}
+ HandleScope scope;
+
+ UDPWrap* wrap = static_cast<UDPWrap*>(handle->data);
+
+ char* slab = NULL;
+
+ Handle<Object> global = Context::GetCurrent()->Global();
+ Local<Value> slab_v = global->GetHiddenValue(udp_slab_sym);
+
+ if (slab_v.IsEmpty()) {
+ // No slab currently. Create a new one.
+ slab = NewSlab(global, wrap->object_);
+ } else {
+ // Use existing slab.
+ Local<Object> slab_obj = slab_v->ToObject();
+ slab = Buffer::Data(slab_obj);
+ assert(Buffer::Length(slab_obj) == SLAB_SIZE);
+ assert(SLAB_SIZE >= slab_used);
+
+ // If less than 64kb is remaining on the slab allocate a new one.
+ if (SLAB_SIZE - slab_used < 64 * 1024) {
+ slab = NewSlab(global, wrap->object_);
+ } else {
+ wrap->object_->SetHiddenValue(udp_slab_sym, slab_obj);
+ }
+ }
+
+ uv_buf_t buf;
+ buf.base = slab + slab_used;
+ buf.len = MIN(SLAB_SIZE - slab_used, suggested_size);
+ slab_offset_ = slab_used;
+ slab_used += buf.len;
+
+ handle_that_last_alloced = reinterpret_cast<uv_handle_t*>(handle);
+
+ return buf;
-static void ReleaseMemory(char* data, void* arg) {
- delete[] data; // data == buf.base
}
@@ -348,7 +391,6 @@ void UDPWrap::OnRecv(uv_udp_t* handle,
struct sockaddr* addr,
unsigned flags) {
if (nread == 0) {
- ReleaseMemory(buf.base, NULL);
return;
}
@@ -365,18 +407,26 @@ void UDPWrap::OnRecv(uv_udp_t* handle,
if (nread == -1) {
SetErrno(uv_last_error(uv_default_loop()));
- ReleaseMemory(buf.base, NULL);
}
else {
Local<Object> rinfo = Object::New();
AddressToJS(rinfo, addr, sizeof *addr);
- argv[2] = Buffer::New(buf.base, nread, ReleaseMemory, NULL)->handle_;
+ argv[2] = Buffer::New(buf.base, nread, NULL, NULL)->handle_;
argv[3] = rinfo;
}
MakeCallback(wrap->object_, "onmessage", ARRAY_SIZE(argv), argv);
}
+inline char* UDPWrap::NewSlab(Handle<Object> global,
+ Handle<Object> wrap_obj) {
+ Buffer* b = Buffer::New(SLAB_SIZE);
+ global->SetHiddenValue(udp_slab_sym, b->handle_);
+ assert(Buffer::Length(b) == SLAB_SIZE);
+ slab_used = 0;
+ wrap_obj->SetHiddenValue(udp_slab_sym, b->handle_);
+ return Buffer::Data(b);
+}
void AddressToJS(Handle<Object> info,
const sockaddr* addr,

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