Support PROTECT via _NMODLMUTEX{,UN}LOCK. (#1557)

* Fix thread_variable conditions.

* Support PROTECT via `_NMODLMUTEX{,UN}LOCK`.

* Add tests.

src/codegen/codegen_helper_visitor.cpp

@@ -290,7 +290,7 @@ void CodegenHelperVisitor::find_non_range_variables() {
 
         // if model is thread safe and if parameter is being written then
         // those variables should be promoted to thread safe variable
-        if (info.vectorize && info.thread_safe && var->get_write_count() > 0) {
+        if (info.vectorize && info.declared_thread_safe && var->get_write_count() > 0) {
             var->mark_thread_safe();
             info.thread_variables.push_back(var);
             info.thread_var_data_size += var->get_length();

src/codegen/codegen_neuron_cpp_visitor.cpp

@@ -1103,6 +1103,7 @@ void CodegenNeuronCppVisitor::print_neuron_includes() {
     printer->add_multi_line(R"CODE(
         #include "mech_api.h"
         #include "neuron/cache/mechanism_range.hpp"
+        #include "nmodlmutex.h"
         #include "nrniv_mf.h"
         #include "section_fwd.hpp"
     )CODE");
@@ -3063,6 +3064,14 @@ void CodegenNeuronCppVisitor::visit_for_netcon(const ast::ForNetcon& node) {
     printer->pop_block();
 }
 
+void CodegenNeuronCppVisitor::visit_protect_statement(const ast::ProtectStatement& node) {
+    printer->add_line("_NMODLMUTEXLOCK");
+    printer->add_indent();
+    node.get_expression()->accept(*this);
+    printer->add_text(";");
+    printer->add_line("_NMODLMUTEXUNLOCK");
+}
+
 
 }  // namespace codegen
 }  // namespace nmodl

src/codegen/codegen_neuron_cpp_visitor.hpp

@@ -839,6 +839,7 @@ class CodegenNeuronCppVisitor: public CodegenCppVisitor {
     void visit_for_netcon(const ast::ForNetcon& node) override;
     void visit_longitudinal_diffusion_block(const ast::LongitudinalDiffusionBlock& node) override;
     void visit_lon_diffuse(const ast::LonDiffuse& node) override;
+    void visit_protect_statement(const ast::ProtectStatement& node) override;
 
   public:
     /****************************************************************************************/

test/usecases/CMakeLists.txt

@@ -25,6 +25,7 @@ set(NMODL_USECASE_DIRS
     point_process
     pointer
     procedure
+    protect
     random
     solve
     state

test/usecases/protect/shared_counter.mod

@@ -0,0 +1,17 @@
+NEURON {
+    SUFFIX shared_counter
+    GLOBAL g_cnt
+}
+
+ASSIGNED {
+    g_cnt
+}
+
+
+INITIAL {
+    PROTECT g_cnt = 0
+}
+
+BREAKPOINT {
+    PROTECT g_cnt = g_cnt + 1
+}

test/usecases/protect/test_shared_counter.py

@@ -0,0 +1,30 @@
+from neuron import h, gui
+
+
+def test_shared_counter():
+    nthreads = 32
+    nseg = 10
+    nsteps = 100
+
+    sections = [h.Section() for _ in range(nthreads)]
+    for s in sections:
+        s.insert("shared_counter")
+        s.nseg = nseg
+
+    pc = h.ParallelContext()
+
+    pc.nthread(nthreads)
+    for k, s in enumerate(sections):
+        pc.partition(k, h.SectionList([s]))
+
+    h.finitialize()
+    for _ in range(nsteps):
+        h.step()
+
+    expected = nthreads * nseg * nsteps
+    g_cnt = h.g_cnt_shared_counter
+    assert h.g_cnt_shared_counter == expected, f"{g_cnt}"
+
+
+if __name__ == "__main__":
+    test_shared_counter()