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From 04b4c8182f598b9c1b1d9cf31a547d3adc860ae1 Mon Sep 17 00:00:00 2001
From: Bert Belder <bertbelder@gmail.com>
Date: Thu, 10 May 2012 16:08:36 +0200
Subject: [PATCH 1/1] Accept backoff
---
deps/uv/include/uv-private/uv-unix.h | 4 +++-
deps/uv/include/uv.h | 15 +++++++++++++--
deps/uv/src/unix/internal.h | 3 ++-
deps/uv/src/unix/stream.c | 24 +++++++++++++++++++++++-
deps/uv/src/unix/tcp.c | 5 +++++
lib/child_process.js | 16 +++++++---------
src/tcp_wrap.cc | 4 ----
7 files changed, 53 insertions(+), 18 deletions(-)
diff --git a/deps/uv/include/uv-private/uv-unix.h b/deps/uv/include/uv-private/uv-unix.h
index 1c33684..c805155 100644
--- a/deps/uv/include/uv-private/uv-unix.h
+++ b/deps/uv/include/uv-private/uv-unix.h
@@ -109,7 +109,9 @@ typedef void* uv_lib_t;
int delayed_error; \
uv_connection_cb connection_cb; \
int accepted_fd; \
- int blocking;
+ int blocking; \
+ /* ABI change! Don't land. */ \
+ ev_idle idle_watcher;
/* UV_TCP */
diff --git a/deps/uv/include/uv.h b/deps/uv/include/uv.h
index 340ab11..21c0aa4 100644
--- a/deps/uv/include/uv.h
+++ b/deps/uv/include/uv.h
@@ -506,12 +506,23 @@ UV_EXTERN int uv_tcp_keepalive(uv_tcp_t* handle, int enable,
unsigned int delay);
/*
- * This setting applies to Windows only.
- * Enable/disable simultaneous asynchronous accept requests that are
+ * TODO: this name is not very appropriate. The function basically controls
+ * aggressive accept() mode, which is enabled by default. It can be disabled to
+ * improve load balancing in a cluster setup.
+ *
+ * TODO: consider merging with uv_pipe_pending_instances()
+ *
+ * Windows: Enable/disable simultaneous asynchronous accept requests that are
* queued by the operating system when listening for new tcp connections.
* This setting is used to tune a tcp server for the desired performance.
* Having simultaneous accepts can significantly improve the rate of
* accepting connections (which is why it is enabled by default).
+ *
+ * Unix: if enabled, accept connections as fast as possible. If disabled,
+ * temporarily back off from accepting new connections until one loop
+ * iteration passes in which no new events are dequeued. This improves
+ * load balancing in a cluster-like setup at the expense of overall
+ * performance.
*/
UV_EXTERN int uv_tcp_simultaneous_accepts(uv_tcp_t* handle, int enable);
diff --git a/deps/uv/src/unix/internal.h b/deps/uv/src/unix/internal.h
index fc7aad1..e766bb6 100644
--- a/deps/uv/src/unix/internal.h
+++ b/deps/uv/src/unix/internal.h
@@ -153,7 +153,8 @@ enum {
UV_TCP_NODELAY = 0x080, /* Disable Nagle. */
UV_TCP_KEEPALIVE = 0x100, /* Turn on keep-alive. */
UV_TIMER_ACTIVE = 0x080,
- UV_TIMER_REPEAT = 0x100
+ UV_TIMER_REPEAT = 0x100,
+ UV_STREAM_BALANCED_ACCEPT = 0x200
};
size_t uv__strlcpy(char* dst, const char* src, size_t size);
diff --git a/deps/uv/src/unix/stream.c b/deps/uv/src/unix/stream.c
index 6f0d137..720ada6 100644
--- a/deps/uv/src/unix/stream.c
+++ b/deps/uv/src/unix/stream.c
@@ -230,7 +230,13 @@ int uv_accept(uv_stream_t* server, uv_stream_t* client) {
goto out;
}
- ev_io_start(streamServer->loop->ev, &streamServer->read_watcher);
+ if (!(handle->flags & UV_STREAM_BALANCED_ACCEPT)) {
+ ev_io_start(streamServer->loop->ev, &streamServer->read_watcher);
+ } else if (!ev_active(&streamServer->idle_watcher)) {
+ ev_idle_start(streamServer->loop->ev, &streamServer->idle_watcher);
+ uv_unref(streamServer->loop);
+ }
+
streamServer->accepted_fd = -1;
status = 0;
@@ -240,7 +246,23 @@ out:
}
+void uv__server_accept_restart(EV_P_ ev_idle* idle, int revents) {
+ uv_stream_t* stream = idle->data;
+
+ assert(revents & EV_IDLE);
+
+ ev_idle_stop(stream->loop->ev, idle);
+ uv_ref(stream->loop);
+
+ if (stream->accepted_fd < 0);
+ ev_io_start(stream->loop->ev, &stream->read_watcher);
+}
+
+
int uv_listen(uv_stream_t* stream, int backlog, uv_connection_cb cb) {
+ ev_idle_init(&stream->idle_watcher, uv__server_accept_restart);
+ stream->idle_watcher.data = stream;
+
switch (stream->type) {
case UV_TCP:
return uv_tcp_listen((uv_tcp_t*)stream, backlog, cb);
diff --git a/deps/uv/src/unix/tcp.c b/deps/uv/src/unix/tcp.c
index ee94ab3..fba352c 100644
--- a/deps/uv/src/unix/tcp.c
+++ b/deps/uv/src/unix/tcp.c
@@ -322,5 +322,10 @@ int uv_tcp_keepalive(uv_tcp_t* handle, int enable, unsigned int delay) {
int uv_tcp_simultaneous_accepts(uv_tcp_t* handle, int enable) {
+ if (enable) {
+ handle->flags &= ~UV_STREAM_BALANCED_ACCEPT;
+ } else {
+ handle->flags |= UV_STREAM_BALANCED_ACCEPT;
+ }
return 0;
}
diff --git a/lib/child_process.js b/lib/child_process.js
index f3a5bdd..ab9808b 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -73,15 +73,13 @@ function setupChannel(target, channel) {
var jsonBuffer = '';
- if (isWindows) {
- var setSimultaneousAccepts = function(handle) {
- var simultaneousAccepts = (process.env.NODE_MANY_ACCEPTS &&
- process.env.NODE_MANY_ACCEPTS != '0') ? true : false;
-
- if (handle._simultaneousAccepts != simultaneousAccepts) {
- handle.setSimultaneousAccepts(simultaneousAccepts);
- handle._simultaneousAccepts = simultaneousAccepts;
- }
+ var setSimultaneousAccepts = function(handle) {
+ var simultaneousAccepts = (process.env.NODE_MANY_ACCEPTS &&
+ process.env.NODE_MANY_ACCEPTS != '0') ? true : false;
+
+ if (handle._simultaneousAccepts != simultaneousAccepts) {
+ handle.setSimultaneousAccepts(simultaneousAccepts);
+ handle._simultaneousAccepts = simultaneousAccepts;
}
}
diff --git a/src/tcp_wrap.cc b/src/tcp_wrap.cc
index 14e6d3e..c7b0d59 100644
--- a/src/tcp_wrap.cc
+++ b/src/tcp_wrap.cc
@@ -121,9 +121,7 @@ void TCPWrap::Initialize(Handle<Object> target) {
NODE_SET_PROTOTYPE_METHOD(t, "setNoDelay", SetNoDelay);
NODE_SET_PROTOTYPE_METHOD(t, "setKeepAlive", SetKeepAlive);
-#ifdef _WIN32
NODE_SET_PROTOTYPE_METHOD(t, "setSimultaneousAccepts", SetSimultaneousAccepts);
-#endif
tcpConstructor = Persistent<Function>::New(t->GetFunction());
@@ -276,7 +274,6 @@ Handle<Value> TCPWrap::SetKeepAlive(const Arguments& args) {
}
-#ifdef _WIN32
Handle<Value> TCPWrap::SetSimultaneousAccepts(const Arguments& args) {
HandleScope scope;
@@ -290,7 +287,6 @@ Handle<Value> TCPWrap::SetSimultaneousAccepts(const Arguments& args) {
return Undefined();
}
-#endif
Handle<Value> TCPWrap::Bind(const Arguments& args) {
--
1.7.10.msysgit.1
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