limit connections before async

Author: pankgeorg

src/HTTP.jl

@@ -77,6 +77,7 @@ include("clientlayers/ConnectionRequest.jl");        using .ConnectionRequest
 include("clientlayers/StreamRequest.jl");            using .StreamRequest
 
 include("download.jl")
+include("accept.jl")
 include("Servers.jl")                  ;using .Servers; using .Servers: listen
 include("Handlers.jl")                 ;using .Handlers; using .Handlers: serve
 include("parsemultipart.jl")           ;using .MultiPartParsing: parse_multipart_form

src/Servers.jl

@@ -16,6 +16,7 @@ using MbedTLS: SSLContext, SSLConfig
 using ConcurrentUtilities: ConcurrentUtilities, Lockable, lock
 using ..IOExtras, ..Streams, ..Messages, ..Parsers, ..Connections, ..Exceptions
 import ..access_threaded, ..SOCKET_TYPE_TLS, ..@logfmt_str
+using ..Accept: acceptmany
 
 TRUE(x) = true
 getinet(host::String, port::Integer) = Sockets.InetAddr(parse(IPAddr, host), port)
@@ -366,47 +367,6 @@ function listen!(f, listener::Listener;
     return Server(listener, on_shutdown, conns, tsk)
 end
 
-using Base: iolock_begin, iolock_end, uv_error, preserve_handle, unpreserve_handle,
-    StatusClosing, StatusClosed, StatusActive, UV_EAGAIN, UV_ECONNABORTED
-using Sockets: accept_nonblock
-
-function acceptmany(server; MAXSIZE=Sockets.BACKLOG_DEFAULT)
-    result = Vector{TCPSocket}()
-    sizehint!(result, MAXSIZE)
-    iolock_begin()
-    if server.status != StatusActive && server.status != StatusClosing && server.status != StatusClosed
-        throw(ArgumentError("server not connected, make sure \"listen\" has been called"))
-    end
-    while isopen(server)
-        client = TCPSocket()
-        err = Sockets.accept_nonblock(server, client)
-        while err == 0 && length(result) < MAXSIZE  # Don't try to fill more than half the buffer
-            push!(result, client)
-            client = TCPSocket()
-            err = Sockets.accept_nonblock(server, client)
-        end
-        if length(result) > 0
-            iolock_end()
-            return result
-        end
-        if err != UV_EAGAIN
-            uv_error("accept", err)
-        end
-        preserve_handle(server)
-        lock(server.cond)
-        iolock_end()
-        try
-            wait(server.cond)
-        finally
-            unlock(server.cond)
-            unpreserve_handle(server)
-        end
-        iolock_begin()
-    end
-    uv_error("accept", UV_ECONNABORTED)
-    nothing
-end
-
 """"
 Main server loop.
 Accepts new tcp connections and spawns async tasks to handle them."
@@ -421,8 +381,10 @@ function listenloop(f, listener, conns, tcpisvalid,
     while isopen(listener)
         try
             for io in acceptmany(listener.server)
+                # I would prefer this inside the async, so we can loop and accept again, 
+                # but https://github.com/JuliaWeb/HTTP.jl/pull/647/files says it's bad for performance
+                max_connections < typemax(Int) && Base.acquire(sem)
                 @async begin
-                    max_connections < typemax(Int) && Base.acquire(sem)
                     local conn = nothing
                     isssl = !isnothing(listener.ssl)
                     try

src/accept.jl

@@ -0,0 +1,47 @@
+
+module Accept
+
+export acceptmany
+
+using Base: iolock_begin, iolock_end, uv_error, preserve_handle, unpreserve_handle,
+    StatusClosing, StatusClosed, StatusActive, UV_EAGAIN, UV_ECONNABORTED
+using Sockets
+
+function acceptmany(server; MAXSIZE=Sockets.BACKLOG_DEFAULT)
+    result = Vector{TCPSocket}()
+    sizehint!(result, MAXSIZE)
+    iolock_begin()
+    if server.status != StatusActive && server.status != StatusClosing && server.status != StatusClosed
+        throw(ArgumentError("server not connected, make sure \"listen\" has been called"))
+    end
+    while isopen(server)
+        client = TCPSocket()
+        err = Sockets.accept_nonblock(server, client)
+        while err == 0 && length(result) < MAXSIZE  # Don't try to fill more than half the buffer
+            push!(result, client)
+            client = TCPSocket()
+            err = Sockets.accept_nonblock(server, client)
+        end
+        if length(result) > 0
+            iolock_end()
+            return result
+        end
+        if err != UV_EAGAIN
+            uv_error("accept", err)
+        end
+        preserve_handle(server)
+        lock(server.cond)
+        iolock_end()
+        try
+            wait(server.cond)
+        finally
+            unlock(server.cond)
+            unpreserve_handle(server)
+        end
+        iolock_begin()
+    end
+    uv_error("accept", UV_ECONNABORTED)
+    nothing
+end
+
+end