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| author |  Saleem Abdulrasool <compnerd@compnerd.org>
| 2016-01-28 18:19:36 -0800 |
|---|---|---|
| committer | Saleem Abdulrasool <compnerd@compnerd.org>
| 2016-02-14 23:12:29 -0800 |
| commit | e42d5ffe29b4cd6cf9bac0f36fe37ec5001dfd68 (patch) | |
| tree | 618a32afdb1555e9944e68f379695b7dfe6a1234 | |
| parent | e0f11780797f6ddee5bdfd965c7f499e8810c2b4 (diff) | |
| download | paludis-e42d5ffe29b4cd6cf9bac0f36fe37ec5001dfd68.tar.gz paludis-e42d5ffe29b4cd6cf9bac0f36fe37ec5001dfd68.tar.xz | |
switch TLS to C++11 TLS semantics
Rather than using the compiler specific `__thread` mechanism for TLS, use the
C++11 standard `thread_local` keyword. This removes the check for the
`__thread` keyword and the `PALUDIS_TLS` macro in the single usage site.
Take advantage of the fact that `thread_local` can be applied to non-POD types
to avoid the heap allocation of the context buffer and letting the loader
perform the allocation. This has a slight penalty (an extra function call) on
thread construction. However, given that the heap allocation would likely be
performed, this will be largely offset by the loss of the allocation.
| -rw-r--r-- | configure.ac | 11 | ||||
| -rw-r--r-- | paludis/util/attributes.hh | 2 | ||||
| -rw-r--r-- | paludis/util/exception.cc | 22 |
3 files changed, 7 insertions, 28 deletions
diff --git a/configure.ac b/configure.ac index da6ee9b97..7c1fe4f6f 100644 --- a/configure.ac +++ b/configure.ac @@ -235,17 +235,6 @@ fi PTHREAD_LIBS="" RT_LIBS="" -AC_MSG_CHECKING([for compiler __thread support]) -AC_COMPILE_IFELSE([AC_LANG_SOURCE([ -int main(int, char **) -{ - static __thread int x(0); - return x; -} -])], -[AC_MSG_RESULT([yes])], -[AC_MSG_RESULT([no]) -AC_MSG_ERROR([Your compiler does not support __thread])]) AC_MSG_CHECKING([whether -pthread -lpthread gets us posix threads]) save_CXXFLAGS=$CXXFLAGS diff --git a/paludis/util/attributes.hh b/paludis/util/attributes.hh index 270fbc393..88877f602 100644 --- a/paludis/util/attributes.hh +++ b/paludis/util/attributes.hh @@ -63,6 +63,4 @@ # define PALUDIS_HIDDEN PALUDIS_ATTRIBUTE((visibility("hidden"))) #endif -#define PALUDIS_TLS static __thread - #endif diff --git a/paludis/util/exception.cc b/paludis/util/exception.cc index 391f1e49b..d0ce9d2ba 100644 --- a/paludis/util/exception.cc +++ b/paludis/util/exception.cc @@ -35,35 +35,28 @@ using namespace paludis; namespace { - PALUDIS_TLS std::list<std::string> * context = 0; + static thread_local std::list<std::string> context; } Context::Context(const std::string & s) { - if (! context) - context = new std::list<std::string>; - context->push_back(s); + context.push_back(s); } Context::~Context() noexcept(false) { - if (! context) + if (context.empty()) throw InternalError(PALUDIS_HERE, "no context"); - context->pop_back(); - if (context->empty()) - { - delete context; - context = 0; - } + context.pop_back(); } std::string Context::backtrace(const std::string & delim) { - if (! context) + if (context.empty()) return ""; - return join(context->begin(), context->end(), delim) + delim; + return join(context.begin(), context.end(), delim) + delim; } namespace paludis @@ -74,8 +67,7 @@ namespace paludis ContextData() { - if (context) - local_context.assign(context->begin(), context->end()); + local_context.assign(context.begin(), context.end()); } ContextData(const ContextData & other) : |