add curl share locks to make things threadsafe

Author: tanmaykm

src/curl.jl

@@ -42,6 +42,55 @@ function buffer_send_data(input::Channel{T}) where T <: ProtoType
 end
 =#
 
+function share_lock(easy_p::Ptr{Cvoid}, data::curl_lock_data, access::curl_lock_access, userptr::Ptr{Cvoid})
+    share = unsafe_pointer_to_objref(Ptr{CurlShare}(userptr))::CurlShare
+    lock(share.locks[data])
+    nothing
+end
+
+function share_unlock(easy_p::Ptr{Cvoid}, data::curl_lock_data, userptr::Ptr{Cvoid})
+    share = unsafe_pointer_to_objref(Ptr{CurlShare}(userptr))::CurlShare
+    unlock(share.locks[data])
+    nothing
+end
+
+mutable struct CurlShare
+    shptr::Ptr{CURLSH}
+    locks::Vector{ReentrantLock}
+    closed::Bool
+
+    function CurlShare()
+        shptr = curl_share_init()
+        curl_share_setopt(shptr, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE)
+        curl_share_setopt(shptr, CURLSHOPT_SHARE, CURL_LOCK_DATA_DNS)
+        curl_share_setopt(shptr, CURLSHOPT_SHARE, CURL_LOCK_DATA_PSL)
+
+        share_lock_cb = @cfunction(share_lock, Cvoid, (Ptr{Cvoid}, Cuint, Cuint, Ptr{Cvoid}))
+        share_unlock_cb = @cfunction(share_unlock, Cvoid, (Ptr{Cvoid}, Cuint, Ptr{Cvoid}))
+
+        @ccall LibCURL.LibCURL_jll.libcurl.curl_share_setopt(shptr::Ptr{CURLSH}, CURLSHOPT_LOCKFUNC::CURLSHoption; share_lock_cb::Ptr{Cvoid})::CURLSHcode
+        @ccall LibCURL.LibCURL_jll.libcurl.curl_share_setopt(shptr::Ptr{CURLSH}, CURLSHOPT_UNLOCKFUNC::CURLSHoption; share_unlock_cb::Ptr{Cvoid})::CURLSHcode
+
+        locks = Vector(undef, CURL_LOCK_DATA_LAST)
+        for idx in 1:CURL_LOCK_DATA_LAST
+            locks[idx] = ReentrantLock()
+        end
+
+        obj = new(shptr, locks, false)
+        userptr = pointer_from_objref(obj)
+        @ccall LibCURL.LibCURL_jll.libcurl.curl_share_setopt(shptr::Ptr{CURLSH}, CURLSHOPT_USERDATA::CURLSHoption; userptr::Ptr{Cvoid})::CURLSHcode
+        obj
+    end
+end
+
+function close(share::CurlShare)
+    if share.closed
+        curl_share_cleanup(share.shptr)
+        share.closed = true
+    end
+    nothing
+end
+
 function send_data(easy::Curl.Easy, input::Channel{T}, max_send_message_length::Int) where T <: ProtoType
     while true
         yield()
@@ -95,7 +144,7 @@ function grpc_request_header(request_timeout::Real)
     end
 end
 
-function easy_handle(maxage::Clong, keepalive::Clong, negotiation::Symbol, revocation::Bool, request_timeout::Real)
+function easy_handle(curlshare::Ptr{CURLSH}, maxage::Clong, keepalive::Clong, negotiation::Symbol, revocation::Bool, request_timeout::Real)
     easy = Curl.Easy()
     http_version = (negotiation === :http2) ? CURL_HTTP_VERSION_2_0 :
                    (negotiation === :http2_tls) ? CURL_HTTP_VERSION_2TLS :
@@ -105,6 +154,7 @@ function easy_handle(maxage::Clong, keepalive::Clong, negotiation::Symbol, revoc
     Curl.setopt(easy, CURLOPT_PIPEWAIT, Clong(1))
     Curl.setopt(easy, CURLOPT_POST, Clong(1))
     Curl.setopt(easy, CURLOPT_HTTPHEADER, grpc_request_header(request_timeout))
+    Curl.setopt(easy, CURLOPT_SHARE, curlshare)
     if !revocation
         Curl.setopt(easy, CURLOPT_SSL_OPTIONS, CURLSSLOPT_NO_REVOKE)
     end
@@ -172,7 +222,7 @@ function set_connect_timeout(easy::Curl.Easy, timeout::Real)
     end
 end
 
-function grpc_request(downloader::Downloader, url::String, input::Channel{T1}, output::Channel{T2};
+function grpc_request(curlshare::Ptr{CURLSH}, downloader::Downloader, url::String, input::Channel{T1}, output::Channel{T2};
         maxage::Clong = typemax(Clong),
         keepalive::Clong = 60,
         negotiation::Symbol = :http2_prior_knowledge,
@@ -182,7 +232,7 @@ function grpc_request(downloader::Downloader, url::String, input::Channel{T1}, o
         max_recv_message_length::Int = DEFAULT_MAX_RECV_MESSAGE_LENGTH,
         max_send_message_length::Int = DEFAULT_MAX_SEND_MESSAGE_LENGTH,
         verbose::Bool = false)::gRPCStatus where {T1 <: ProtoType, T2 <: ProtoType}
-    Curl.with_handle(easy_handle(maxage, keepalive, negotiation, revocation, request_timeout)) do easy
+    Curl.with_handle(easy_handle(curlshare, maxage, keepalive, negotiation, revocation, request_timeout)) do easy
         # setup the request
         Curl.set_url(easy, url)
         Curl.set_timeout(easy, request_timeout)

src/gRPCClient.jl

@@ -6,6 +6,7 @@ using ProtoBuf
 
 import Downloads: Curl
 import ProtoBuf: call_method
+import Base: close
 
 export gRPCController, gRPCChannel, gRPCException, gRPCServiceCallException, gRPCMessageTooLargeException, gRPCStatus, gRPCCheck, StatusCode
 

src/grpc.jl

@@ -146,16 +146,22 @@ the server.
 struct gRPCChannel <: ProtoRpcChannel
     downloader::Downloader
     baseurl::String
+    curlshare::CurlShare    # TODO: this should be optional to avoid unnecessary overheads when possible
 
     function gRPCChannel(baseurl::String)
         downloader = Downloader(; grace=Inf)
         Curl.init!(downloader.multi)
         Curl.setopt(downloader.multi, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX)
         endswith(baseurl, '/') && (baseurl = baseurl[1:end-1])
-        new(downloader, baseurl)
+        new(downloader, baseurl, CurlShare())
     end
 end
 
+function close(channel::gRPCChannel)
+    close(channel.curlshare)
+    nothing
+end
+
 function to_delimited_message_bytes(msg, max_message_length::Int)
     iob = IOBuffer()
     limitiob = LimitIO(iob, max_message_length)
@@ -193,7 +199,7 @@ function call_method(channel::gRPCChannel, service::ServiceDescriptor, method::M
 end
 function call_method(channel::gRPCChannel, service::ServiceDescriptor, method::MethodDescriptor, controller::gRPCController, input::Channel{T1}, outchannel::Channel{T2}) where {T1 <: ProtoType, T2 <: ProtoType}
     url = string(channel.baseurl, "/", service.name, "/", method.name)
-    status_future = @async grpc_request(channel.downloader, url, input, outchannel;
+    status_future = @async grpc_request(channel.curlshare.shptr, channel.downloader, url, input, outchannel;
         maxage = controller.maxage,
         keepalive = controller.keepalive,
         negotiation = controller.negotiation,

test/runtests_routeguide.jl

@@ -5,6 +5,7 @@ using Downloads
 using Random
 using Sockets
 using Test
+using Base.Threads
 
 const SERVER_RELEASE = "https://github.com/JuliaComputing/gRPCClient.jl/releases/download/testserver_v0.2/"
 function server_binary()
@@ -91,6 +92,11 @@ server_endpoint = isempty(ARGS) ? "http://localhost:10000/" : ARGS[1]
     @debug("testing async safety...")
     test_task_safety(server_endpoint)
 
+    if Threads.nthreads() > 1
+        @debug("testing multithreaded clients...", threadcount=Threads.nthreads())
+        test_threaded_clients(server_endpoint)
+    end
+
     kill(serverproc)
     @info("stopped test server")
 end

test/test_routeclient.jl

@@ -139,13 +139,29 @@ end
 
 function test_async_client(server_endpoint::String)
     client = RouteGuideClient(server_endpoint; verbose=false)
+    try
+        test_async_client(client)
+    finally
+        close(client.channel)
+    end
+    nothing
+end
+function test_async_client(client::RouteGuideClient)
     @testset "GetFeature" begin
         test_async_get_feature(client)
     end
 end
 
 function test_blocking_client(server_endpoint::String)
     client = RouteGuideBlockingClient(server_endpoint; verbose=false)
+    try
+        test_blocking_client(client)
+    finally
+        close(client.channel)
+    end
+    nothing
+end
+function test_blocking_client(client::RouteGuideBlockingClient)
     @testset "request response" begin
         test_get_feature(client)
     end
@@ -189,4 +205,20 @@ function test_task_safety(server_endpoint::String)
             end
         end
     end
-end
+end
+
+function test_threaded_clients(server_endpoint::String)
+    @info("testing threaded blocking client")
+    Threads.@threads for idx in 1:10
+        client = RouteGuideBlockingClient(server_endpoint; verbose=false)
+        test_blocking_client(client)
+        close(client.channel)
+    end
+
+    @info("testing threaded async client")
+    Threads.@threads for idx in 1:10
+        client = RouteGuideClient(server_endpoint; verbose=false)
+        test_async_client(client)
+        close(client.channel)
+    end
+end