Fix concurrent update/view creation segfault

Signed-off-by: Andrew Stein <steinlink@gmail.com>

Author: texodus

rust/perspective-python/perspective/tests/multi_threaded/test_multi_threaded.py

@@ -16,6 +16,10 @@
 import random
 import threading
 
+from random import sample
+from string import ascii_letters
+from threading import Thread
+from time import sleep
 
 class TestServer(object):
     def test_sync_updates_with_loop_callback_are_sync(self):
@@ -86,9 +90,7 @@ def update(x):
         loop.close()
 
     def test_concurrent_updates_with_limit_tables_are_threadsafe(self):
-        # This is a tricky tune - at time of writing, 1000 is has a >50%
-        # chance of triggering this o my dev machine
-        TEST_ITERATIONS = 1000
+        TEST_ITERATIONS = 100
         global running
         perspective_server = Server()
         client = perspective_server.new_local_client()
@@ -156,3 +158,43 @@ def run_perspective():
         thread2.start()
         thread1.join()
         thread2.join()
+
+    def test_concurrent_view_creation_with_updates_are_threadsafe(self):
+        s = Server()
+        schema = {
+            "a": "string",
+            "b": "string",
+            "c": "string",
+        }
+
+        group_bys = ["a", "b", "c"]
+        c = s.new_local_client()
+        t = c.table(schema, limit=10000)
+        running = True
+
+        def gen_views():
+            global running
+            for _ in range(100):
+                t.view(columns=list(schema.keys()), group_by=group_bys)
+                sleep(0.01)
+            running = False
+
+        def run_psp():
+            global running
+            while running:
+                t.update(
+                    [
+                        {
+                            "a": "".join(sample(ascii_letters, 4)),
+                            "b": "".join(sample(ascii_letters, 4)),
+                            "c": "".join(sample(ascii_letters, 4)),
+                        }
+                    ]
+                )
+
+        thread1 = Thread(target=run_psp, daemon=True)
+        thread2 = Thread(target=gen_views, daemon=True)
+        thread1.start()
+        thread2.start()
+        thread1.join()
+        thread2.join()

rust/perspective-server/cpp/perspective/src/cpp/context_two.cpp

@@ -508,6 +508,7 @@ void
 t_ctx2::column_sort_by(const std::vector<t_sortspec>& sortby) {
     PSP_TRACE_SENTINEL();
     PSP_VERBOSE_ASSERT(m_init, "touching uninited object");
+    m_column_sortby = sortby;
     m_ctraversal->sort_by(m_config, sortby, *(ctree()));
 }
 
@@ -577,6 +578,10 @@ t_ctx2::notify(const t_data_table& flattened) {
     if (!m_sortby.empty()) {
         sort_by(m_sortby);
     }
+
+    if (!m_column_sortby.empty()) {
+        column_sort_by(m_column_sortby);
+    }
 }
 
 void
@@ -651,6 +656,10 @@ t_ctx2::notify(
     if (!m_sortby.empty()) {
         sort_by(m_sortby);
     }
+
+    if (!m_column_sortby.empty()) {
+        column_sort_by(m_column_sortby);
+    }
 }
 
 t_uindex

rust/perspective-server/cpp/perspective/src/cpp/server.cpp

@@ -184,6 +184,15 @@ make_context(
 
     auto pool = table->get_pool();
     auto gnode = table->get_gnode();
+
+    if (!sortspec.empty()) {
+        ctx2->sort_by(sortspec);
+    }
+
+    if (!col_sortspec.empty()) {
+        ctx2->column_sort_by(col_sortspec);
+    }
+
     pool->register_context(
         gnode->get_id(),
         name,
@@ -203,14 +212,6 @@ make_context(
         ctx2->set_depth(t_header::HEADER_COLUMN, column_pivots.size());
     }
 
-    if (!sortspec.empty()) {
-        ctx2->sort_by(sortspec);
-    }
-
-    if (!col_sortspec.empty()) {
-        ctx2->column_sort_by(col_sortspec);
-    }
-
     return ctx2;
 }