Fix TSAN for CI

CMakeLists.txt

@@ -331,6 +331,9 @@ if(NOT SNMALLOC_HEADER_ONLY_LIBRARY)
         if(SNMALLOC_SANITIZER)
           target_compile_options(${TESTNAME} PRIVATE -g -fsanitize=${SNMALLOC_SANITIZER} -fno-omit-frame-pointer)
           target_link_libraries(${TESTNAME} -fsanitize=${SNMALLOC_SANITIZER})
+          if (${SNMALLOC_SANITIZER} MATCHES "thread")
+            target_compile_definitions(${TESTNAME} PRIVATE SNMALLOC_THREAD_SANITIZER_ENABLED)
+          endif()
         endif()
 
         add_warning_flags(${TESTNAME})

src/snmalloc/ds/mpmcstack.h

@@ -4,12 +4,6 @@
 #include "aba.h"
 #include "allocconfig.h"
 
-#if defined(__has_feature)
-#  if __has_feature(thread_sanitizer)
-#    define SNMALLOC_THREAD_SANITIZER_ENABLED
-#  endif
-#endif
-
 namespace snmalloc
 {
   template<class T, Construction c = RequiresInit>

src/snmalloc/ds/pagemap.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "../ds_core/ds_core.h"
+
 namespace snmalloc
 {
   /**
@@ -179,7 +181,13 @@ namespace snmalloc
       // Allocate a power of two extra to allow the placement of the
       // pagemap be difficult to guess if randomize_position set.
       size_t additional_size =
+#ifdef SNMALLOC_THREAD_SANITIZER_ENABLED
+        // When running with TSAN we failed to allocate the very large range
+        // randomly
+        randomize_position ? bits::next_pow2(REQUIRED_SIZE) : 0;
+#else
         randomize_position ? bits::next_pow2(REQUIRED_SIZE) * 4 : 0;
+#endif
       size_t request_size = REQUIRED_SIZE + additional_size;
 
       auto new_body_untyped = PAL::reserve(request_size);