diff --git a/src/DynareMain.cc b/src/DynareMain.cc
index c1cf3eae9785378fe9672e4c2ee6e542d7eca847..4acd1bd2359929e991029a2ff383aff1402641ce 100644
--- a/src/DynareMain.cc
+++ b/src/DynareMain.cc
@@ -535,12 +535,11 @@ main(int argc, char **argv)
nointeractive, config_file, check_model_changes, minimal_workspace, compute_xrefs,
mexext, matlabroot, dynareroot, onlymodel, gui, notime);
- /* Ensures that the preprocessor final message is printed after the end of
- compilation (and is not printed in case of compilation failure); also
- avoids potential issues with destroying the thread synchronization
- mechanism too soon. */
+ /* Ensures that workers are not destroyed before they finish compiling.
+ Also ensures that the preprocessor final message is printed after the end of
+ compilation (and is not printed in case of compilation failure). */
if (mod_file->use_dll)
- ModelTree::terminateMEXCompilationWorkers();
+ ModelTree::waitForMEXCompilationWorkers();
cout << "Preprocessing completed." << endl;
return EXIT_SUCCESS;
diff --git a/src/ModelTree.cc b/src/ModelTree.cc
index e9cd191fe12f6b6a52f4cbd280a52b83d63ac345..acef5a5ac19fe935864c23fa0633f28815125e5c 100644
--- a/src/ModelTree.cc
+++ b/src/ModelTree.cc
@@ -37,11 +37,15 @@
#include <utility>
#include <algorithm>
-vector<jthread> ModelTree::mex_compilation_workers {};
-condition_variable ModelTree::mex_compilation_cv;
+/* NB: The workers must be listed *after* all the other static variables
+ related to MEX compilation, so that when the preprocessor exits, the workers
+ are destroyed *before* those variables (since the former rely on the latter
+ for their functioning). */
+condition_variable_any ModelTree::mex_compilation_cv;
mutex ModelTree::mex_compilation_mut;
vector<tuple<filesystem::path, set<filesystem::path>, string>> ModelTree::mex_compilation_queue;
set<filesystem::path> ModelTree::mex_compilation_done;
+vector<jthread> ModelTree::mex_compilation_workers;
void
ModelTree::copyHelper(const ModelTree &m)
@@ -1892,64 +1896,52 @@ ModelTree::initializeMEXCompilationWorkers(int numworkers)
mex_compilation_workers.emplace_back([](stop_token stoken)
{
unique_lock<mutex> lk {mex_compilation_mut};
+ filesystem::path output;
+ string cmd;
- look_for_job:
- for (auto it {mex_compilation_queue.begin()}; it != mex_compilation_queue.end(); ++it)
- {
- /* The following is a copy and not a reference, because we need it
- after erasing it, and also after releasing the lock (at which
- point the mex_compilation_queue may be modified by others). */
- const auto [output, prerequisites, cmd] {*it};
- if (includes(mex_compilation_done.begin(), mex_compilation_done.end(),
+ /* Look for an object to compile, whose prerequisites are already
+ compiled. If found, remove it from the queue, save the output path and
+ the compilation command, and return true. Must be run under the lock. */
+ auto pick_job = [&cmd, &output]
+ {
+ for (auto it {mex_compilation_queue.begin()}; it != mex_compilation_queue.end(); ++it)
+ if (const auto &prerequisites {get<1>(*it)}; // Will become dangling after erase
+ includes(mex_compilation_done.begin(), mex_compilation_done.end(),
prerequisites.begin(), prerequisites.end()))
{
+ output = get<0>(*it);
+ cmd = get<2>(*it);
mex_compilation_queue.erase(it);
- lk.unlock(); // After that point, the iterator may become invalid
- if (system(cmd.c_str()))
- {
- cerr << "Compilation failed" << endl;
- exit(EXIT_FAILURE);
- }
- lk.lock();
- mex_compilation_done.insert(output);
- /* The object just compiled may be a prerequisite for several
- other objects, so notify all waiting workers. Also needed to
- notify the main thread when in
- ModelTree::terminateMEXCompilationWorkers(). */
- mex_compilation_cv.notify_all();
- goto look_for_job;
+ return true;
}
- }
-
- if (stoken.stop_requested())
- return;
+ return false;
+ };
- mex_compilation_cv.wait(lk);
-
- goto look_for_job;
+ while (!stoken.stop_requested())
+ if (mex_compilation_cv.wait(lk, stoken, pick_job))
+ {
+ lk.unlock();
+ if (system(cmd.c_str()))
+ {
+ cerr << "Compilation failed" << endl;
+ exit(EXIT_FAILURE);
+ }
+ lk.lock();
+ mex_compilation_done.insert(output);
+ /* The object just compiled may be a prerequisite for several
+ other objects, so notify all waiting workers. Also needed to
+ notify the main thread when in
+ ModelTree::waitForMEXCompilationWorkers().*/
+ mex_compilation_cv.notify_all();
+ }
});
}
void
-ModelTree::terminateMEXCompilationWorkers()
+ModelTree::waitForMEXCompilationWorkers()
{
- // Wait until the queue is empty
unique_lock<mutex> lk {mex_compilation_mut};
mex_compilation_cv.wait(lk, [] { return mex_compilation_queue.empty(); });
-
- /* Request stop while still holding the lock, so we are sure that workers are
- either compiling or waiting right now. Otherwise there could theoretically
- be a race condition where the condition variable is notified just after
- the thread has checked for its stoken, and just before it begins waiting;
- this would be deadlock. */
- for (auto &it : mex_compilation_workers)
- it.request_stop();
-
- lk.unlock();
-
- mex_compilation_cv.notify_all();
- for (auto &it : mex_compilation_workers)
- it.join();
}
void
diff --git a/src/ModelTree.hh b/src/ModelTree.hh
index 1f3bfe737a420e679de1e684d86e0e1f7b045e0c..fcc59547e4358869c4f1f374e4f7c1256514ce67 100644
--- a/src/ModelTree.hh
+++ b/src/ModelTree.hh
@@ -345,7 +345,7 @@ private:
/* The following variables implement the thread synchronization mechanism for
limiting the number of concurrent GCC processes and tracking dependencies
between object files. */
- static condition_variable mex_compilation_cv;
+ static condition_variable_any mex_compilation_cv;
static mutex mex_compilation_mut;
/* Object/MEX files waiting to be compiled (with their prerequisites as 2nd
element and compilation command as the 3rd element) */
@@ -557,9 +557,8 @@ public:
// Initialize the MEX compilation workers
static void initializeMEXCompilationWorkers(int numworkers);
- /* Terminates all MEX compilation workers (after they have emptied the
- waiting queue) */
- static void terminateMEXCompilationWorkers();
+ // Waits until the MEX compilation queue is empty
+ static void waitForMEXCompilationWorkers();
//! Returns all the equation tags associated to an equation
map<string, string>