diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b9c7200f491911d63973488067bb545a238daebe..3a03bf281f4856f6ae217f6a4bb9c86841a4159a 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,6 +1,8 @@
image: "flowdalic/debian-dev:1.13"
before_script:
+ - apt update && apt install -y pkg-config
+ - apt install -y -t testing liburcu-dev
- |
readarray TOOLS <<EOF
c++
diff --git a/emper/Emper.hpp b/emper/Emper.hpp
index 76fa35e31ccb4ed0defe0e1511cba81f1b05e5d1..d5c3dc57b40a468a3361fb40c1e6f0fdcc48395a 100644
--- a/emper/Emper.hpp
+++ b/emper/Emper.hpp
@@ -22,4 +22,12 @@ static const bool WORKER_SLEEP =
#endif
;
+static const bool LIBURCU =
+#ifdef EMPER_LIBURCU
+ true
+#else
+ false
+#endif
+ ;
+
} // namespace emper
diff --git a/emper/Runtime.cpp b/emper/Runtime.cpp
index 041bcc4bc7c52b6f634a0ed39ae513d119aa6889..2cc9e480b524f777e94f152fdda963cef656b601 100644
--- a/emper/Runtime.cpp
+++ b/emper/Runtime.cpp
@@ -8,6 +8,7 @@
// Non portable.
#include <sched.h> // for cpu_set_t, CPU_SET, CPU_ZERO
#include <sys/sysinfo.h> // for get_nprocs
+#include <urcu.h> // for rcu_register_thread
#include <cstdlib> // for rand, srand, abort
#include <cstring>
@@ -78,6 +79,10 @@ Runtime::Runtime(workerid_t workerCount, RuntimeStrategy& strategy, unsigned int
workerIds[i] = i;
auto thread_function = [](void* voidWorkerId) -> void* {
+ if constexpr (emper::LIBURCU) {
+ rcu_register_thread();
+ }
+
return currentRuntime->workerLoop(voidWorkerId);
};
errno = pthread_create(&threads[i], &attr, thread_function, &workerIds[i]);
diff --git a/emper/meson.build b/emper/meson.build
index eeee83e0fcdc45d4072b09519c49684b85ddba25..f73891a7543d0266bdeea336542a7a009957264d 100644
--- a/emper/meson.build
+++ b/emper/meson.build
@@ -45,7 +45,7 @@ emper = library(
[emper_cpp_sources, emper_generated_files],
emper_asm_objects,
include_directories: emper_all_include,
- dependencies: thread_dep,
+ dependencies: emper_dependencies,
install: true,
)
diff --git a/iwyu-mappings.imp b/iwyu-mappings.imp
index 8a64523b20e91b6a76971ec7398b9dbbcd5bfa9f..3b0d99bef9cad915b5f885595e236530608d3c27 100644
--- a/iwyu-mappings.imp
+++ b/iwyu-mappings.imp
@@ -1,4 +1,5 @@
[
{ include: ["<bits/getopt_core.h>", "private", "<unistd.h>", "public"] },
{ include: ["@<gtest/.*>", "private", "<gtest/gtest.h>", "public"] },
+ { include: ["<urcu/map/urcu-memb.h>", "private", "<urcu.h>", "public"] },
]
diff --git a/meson.build b/meson.build
index 325105c849c06f727a5fa8c03dfff3561e7ee435..6c2c21e593783963abaa0561fc907a93b5a9502d 100644
--- a/meson.build
+++ b/meson.build
@@ -12,12 +12,14 @@ project('EMPER', 'c', 'cpp',
add_project_arguments('-Wno-non-virtual-dtor', language: 'cpp')
thread_dep = dependency('threads')
-emper_dependencies = [thread_dep]
+liburcu_dep = dependency('liburcu')
+emper_dependencies = [thread_dep, liburcu_dep]
run_target('iwyu',
command: 'tools/check-iwyu')
conf_data = configuration_data()
+conf_data.set('EMPER_LIBURCU', get_option('userspace-rcu'))
conf_data.set('EMPER_WORKER_SLEEP', get_option('worker_sleep'))
conf_data.set('EMPER_LOCKED_WS_QUEUE', get_option('locked_ws_queue'))
conf_data.set('EMPER_OVERFLOW_QUEUE', get_option('overflow_queue'))
diff --git a/meson_options.txt b/meson_options.txt
index 98a9ca1502ba1b7aa5fe3a03bd7d85a587771147..8032e30c80192ddd7463a3d70e288570472e3bbd 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -1,3 +1,9 @@
+option(
+ 'userspace-rcu',
+ type: 'boolean',
+ value: true,
+ description: 'Allow EMPER fibers to use userspace RCU',
+)
option(
'worker_sleep',
type: 'boolean',
diff --git a/tests/SimpleURCUTest.cpp b/tests/SimpleURCUTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..dfd9f813b93e3060b37c8e3d66ce4a802dbca721
--- /dev/null
+++ b/tests/SimpleURCUTest.cpp
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+// Copyright © 2020 Florian Fischer
+#include <urcu.h> // for rcu_read_lock, rcu_read_unlock
+#include <urcu/rculfhash.h> // for RCU lock-free hash table
+
+#include <algorithm> // for find
+#include <cstdlib> // for exit, EXIT_FAILURE, EXIT_SUC...
+#include <functional> // for hash
+#include <iostream> // for hash
+#include <vector> // for vector
+
+#include "Common.hpp" // for die
+#include "CountingPrivateSemaphore.hpp" // for CPS
+#include "Fiber.hpp" // for Fiber
+#include "Runtime.hpp" // for Runtime
+#include "emper.hpp" // for spawn
+
+struct node {
+ int value;
+ struct cds_lfht_node node; /* Chaining in hash table */
+};
+
+using node_t = struct node;
+
+auto main() -> int {
+ Runtime runtime;
+ struct cds_lfht* ht;
+ std::vector<int> values = {
+ -5, 42, 42, 36, 24,
+ }; /* 42 is duplicated */
+
+ // Allocate new hash table.
+ ht = cds_lfht_new(1, 1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, nullptr);
+ if (!ht) {
+ die("Error allocating hash table", false);
+ }
+
+ Fiber* verifier = Fiber::from([&]() {
+ CPS cps;
+ for (auto& value : values) {
+ // add each value to the hash table
+ spawn(
+ [&ht, value] {
+ auto* node = reinterpret_cast<node_t*>(malloc(sizeof(node_t)));
+ if (!node) {
+ die("allocating node failed", true);
+ }
+
+ cds_lfht_node_init(&node->node);
+ node->value = value;
+ size_t hash = std::hash<int>{}(value);
+
+ rcu_read_lock();
+ cds_lfht_add(ht, hash, &node->node);
+ rcu_read_unlock();
+ },
+ cps);
+ }
+
+ // Wait for the adders to finish
+ cps.wait();
+
+ // Verify the content of the hash table.
+ // Iterate over each hash table node.
+ // Iteration needs to be performed within RCU read-side critical section.
+ struct cds_lfht_iter iter;
+ node_t* node;
+ rcu_read_lock();
+ size_t i = 0;
+ cds_lfht_for_each_entry(ht, &iter, node, node) {
+ ++i;
+ auto it = std::find(values.begin(), values.end(), node->value);
+ if (it == values.end()) {
+ std::cerr << "value: " << node->value << " not found in cds_lfht" << std::endl;
+ exit(EXIT_FAILURE);
+ }
+ }
+ rcu_read_unlock();
+
+ if (i != values.size()) {
+ std::cerr << "number of values in cds_lfht: " << i
+ << " differ number of added ones: " << values.size() << std::endl;
+ exit(EXIT_FAILURE);
+ }
+
+ exit(EXIT_SUCCESS);
+ });
+
+ runtime.schedule(*verifier);
+ runtime.waitUntilFinished();
+
+ return EXIT_FAILURE;
+}
diff --git a/tests/meson.build b/tests/meson.build
index 2ac875c0ee7d3dc4c9f4b46f8437b9a815ec26b3..e1c2f709cb7c25948cb176c905825b400a8ca4d2 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -1,3 +1,7 @@
+cc = meson.get_compiler('c')
+liburcu_memb = cc.find_library('urcu-memb')
+liburcu_cds = cc.find_library('urcu-cds')
+
tests = {
'SimpleFibTest.cpp':
{
@@ -29,10 +33,14 @@ tests = {
{
'description': 'Simple LAWS scheduling strategy test',
},
+ 'SimpleURCUTest.cpp':
+ {
+ 'description': 'Simple userspace-rcu hash table test',
+ 'dependencies': [liburcu_memb, liburcu_cds]
+ },
}
undef_ndebug = '-UNDEBUG'
-test_dep = [thread_dep]
test_env = environment(
{
# Set glibc's MALLOC_PERTURB to 1. This means that newly allocated
@@ -50,12 +58,17 @@ foreach source, test_dict : tests
# The test_name is the name of the source file without the file suffix.
test_name = source.split('.')[0]
+ test_dep = [thread_dep]
+ if test_dict.has_key('dependencies')
+ test_dep += test_dict['dependencies']
+ endif
+
test_exe = executable(test_name,
source,
include_directories: emper_all_include,
c_args: undef_ndebug,
cpp_args: undef_ndebug,
- dependencies: test_dep,
+ dependencies: emper_dependencies + test_dep,
link_with: [emper, emper_c],
)