Reduce parallism in tests

If some tests on Windows are co-scheduled, then they run out of commit
space and crash. For example, in func-memory,
test_external_pointer_large can cause the small CI machines to run out
of commit space on Windows.

CMakeLists.txt

@@ -177,8 +177,25 @@ if(NOT DEFINED SNMALLOC_ONLY_HEADER_LIBRARY)
           add_test(${TESTNAME} ${TESTNAME})
         endif()
         if (${TEST_CATEGORY} MATCHES "perf")
+          message(STATUS "Single threaded test: ${TESTNAME}")
           set_tests_properties(${TESTNAME} PROPERTIES PROCESSORS 4)
         endif()
+        if(MSVC)
+          # On Windows these tests use a lot of memory as it doesn't support
+          # lazy commit.
+          if (${TEST} MATCHES "two_alloc_types")
+            message(STATUS "Single threaded test: ${TESTNAME}")
+            set_tests_properties(${TESTNAME} PROPERTIES PROCESSORS 4)
+          endif()
+          if (${TEST} MATCHES "fixed_region")
+            message(STATUS "Single threaded test: ${TESTNAME}")
+            set_tests_properties(${TESTNAME} PROPERTIES PROCESSORS 4)
+          endif()
+          if (${TEST} MATCHES "memory")
+            message(STATUS "Single threaded test: ${TESTNAME}")
+            set_tests_properties(${TESTNAME} PROPERTIES PROCESSORS 4)
+          endif()
+        endif()
         if (${TEST_CATEGORY} MATCHES "func")
           target_compile_definitions(${TESTNAME} PRIVATE -DUSE_SNMALLOC_STATS)
         endif ()

src/test/func/memory/memory.cc

@@ -1,3 +1,4 @@
+#include <iostream>
 #include <snmalloc.h>
 #include <test/opt.h>
 #include <test/xoroshiro.h>
@@ -215,11 +216,14 @@ void test_external_pointer_large()
   // Pre allocate all the objects
   size_t* objects[count];
 
+  size_t total_size = 0;
+
   for (size_t i = 0; i < count; i++)
   {
     size_t b = snmalloc::bits::is64() ? 28 : 26;
     size_t rand = r.next() & ((1 << b) - 1);
     size_t size = (1 << 24) + rand;
+    total_size += size;
     // store object
     objects[i] = (size_t*)alloc->alloc(size);
     // Store allocators size for this object
@@ -235,6 +239,9 @@ void test_external_pointer_large()
     check_external_pointer_large(objects[i]);
   }
 
+  std::cout << "Total size allocated in test_external_pointer_large: "
+            << total_size << std::endl;
+
   // Deallocate everything
   for (size_t i = 0; i < count; i++)
   {