Merge pull request #501 from mikekaganski/master

thread_local: one more (hopefully portable) attempt
CoolProp · Feb 25, 2015 · 004d497 · 004d497
2 parents f2e23cd + 4c84211
commit 004d497
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Showing 2 changed files with 22 additions and 1 deletion.
diff --git a/include/CoolPropTools.h b/include/CoolPropTools.h
@@ -37,6 +37,27 @@
         #include <pwd.h>
     #endif
 
+    // see http://stackoverflow.com/questions/18298280/how-to-declare-a-variable-as-thread-local-portably
+    #ifndef thread_local
+        #if __STDC_VERSION__ >= 201112 && !defined __STDC_NO_THREADS__
+        # define thread_local _Thread_local
+        #elif defined _WIN32 && ( \
+              defined _MSC_VER || \
+              defined __ICL || \
+              defined __DMC__ || \
+              defined __BORLANDC__ )
+            #define thread_local __declspec(thread) 
+        /* note that ICC (linux) and Clang are covered by __GNUC__ */
+        #elif defined __GNUC__ || \
+              defined __SUNPRO_C || \
+              defined __xlC__
+            #define thread_local __thread
+        #else
+            #error "Cannot define thread_local"
+//          #define thread_local
+        #endif
+    #endif
+
     typedef long double CoolPropDbl;
 
     #ifndef M_PI

diff --git a/src/CoolPropTools.cpp b/src/CoolPropTools.cpp
@@ -17,7 +17,7 @@
 #include <stdint.h>
 #include <iostream>
 
-static unsigned long long ftw_summer; // An evil global variable for the ftw function
+static thread_local unsigned long long ftw_summer; // An evil global variable for the ftw function
 int ftw_function(const char *fpath, const struct stat *sb, int tflag, struct FTW *ftwbuf){
    ftw_summer += sb->st_size;
    return 0;           /* To tell nftw() to continue */