SL-793: Use Boost.Fiber instead of the "dcoroutine" library.

Longtime fans will remember that the "dcoroutine" library is a Google Summer
of Code project by Giovanni P. Deretta. He originally called it
"Boost.Coroutine," and we originally added it to our 3p-boost autobuild
package as such. But when the official Boost.Coroutine library came along
(with a very different API), and we still needed the API of the GSoC project,
we renamed the unofficial one "dcoroutine" to allow coexistence.

The "dcoroutine" library had an internal low-level API more or less analogous
to Boost.Context. We later introduced an implementation of that internal API
based on Boost.Context, a step towards eliminating the GSoC code in favor of
official, supported Boost code.

However, recent versions of Boost.Context no longer support the API on which
we built the shim for "dcoroutine." We started down the path of reimplementing
that shim using the current Boost.Context API -- then realized that it's time
to bite the bullet and replace the "dcoroutine" API with the Boost.Fiber API,
which we've been itching to do for literally years now.

Naturally, most of the heavy lifting is in llcoros.{h,cpp} and
lleventcoro.{h,cpp} -- which is good: the LLCoros layer abstracts away most of
the differences between "dcoroutine" and Boost.Fiber.

The one feature Boost.Fiber does not provide is the ability to forcibly
terminate some other fiber. Accordingly, disable LLCoros::kill() and
LLCoprocedureManager::shutdown(). The only known shutdown() call was in
LLCoprocedurePool's destructor.

We also took the opportunity to remove postAndSuspend2() and its associated
machinery: FutureListener2, LLErrorEvent, errorException(), errorLog(),
LLCoroEventPumps. All that dual-LLEventPump stuff was introduced at a time
when the Responder pattern was king, and we assumed we'd want to listen on one
LLEventPump with the success handler and on another with the error handler. We
have never actually used that in practice. Remove associated tests, of course.

There is one other semantic difference that necessitates patching a number of
tests: with "dcoroutine," fulfilling a future IMMEDIATELY resumes the waiting
coroutine. With Boost.Fiber, fulfilling a future merely marks the fiber as
ready to resume next time the scheduler gets around to it. To observe the test
side effects, we've inserted a number of llcoro::suspend() calls -- also in
the main loop.

For a long time we retained a single unit test exercising the raw "dcoroutine"
API. Remove that.

Eliminate llcoro_get_id.{h,cpp}, which provided llcoro::get_id(), which was a
hack to emulate fiber-local variables. Since Boost.Fiber has an actual API for
that, remove the hack.

In fact, use (new alias) LLCoros::local_ptr for LLSingleton's dependency
tracking in place of llcoro::get_id().

In CMake land, replace BOOST_COROUTINE_LIBRARY with BOOST_FIBER_LIBRARY. We
don't actually use the Boost.Coroutine for anything (though there exist
plausible use cases).

5 files changed, 16 insertions, 16 deletions

diff --git a/indra/cmake/Boost.cmake b/indra/cmake/Boost.cmake
index 180a84dbcf..e05e3ca0e5 100644
--- a/indra/cmake/Boost.cmake
+++ b/indra/cmake/Boost.cmake
@@ -8,7 +8,7 @@ if (USESYSTEMLIBS)
   include(FindBoost)
 
   set(BOOST_CONTEXT_LIBRARY boost_context-mt)
-  set(BOOST_COROUTINE_LIBRARY boost_coroutine-mt)
+  set(BOOST_FIBER_LIBRARY boost_fiber-mt)
   set(BOOST_FILESYSTEM_LIBRARY boost_filesystem-mt)
   set(BOOST_PROGRAM_OPTIONS_LIBRARY boost_program_options-mt)
   set(BOOST_REGEX_LIBRARY boost_regex-mt)
@@ -49,9 +49,9 @@ else (USESYSTEMLIBS)
       set(BOOST_CONTEXT_LIBRARY 
           optimized libboost_context-mt
           debug libboost_context-mt-gd)
-      set(BOOST_COROUTINE_LIBRARY 
-          optimized libboost_coroutine-mt
-          debug libboost_coroutine-mt-gd)
+      set(BOOST_FIBER_LIBRARY 
+          optimized libboost_fiber-mt
+          debug libboost_fiber-mt-gd)
       set(BOOST_FILESYSTEM_LIBRARY 
           optimized libboost_filesystem-mt
           debug libboost_filesystem-mt-gd)
@@ -75,9 +75,9 @@ else (USESYSTEMLIBS)
     set(BOOST_CONTEXT_LIBRARY
         optimized boost_context-mt
         debug boost_context-mt-d)
-    set(BOOST_COROUTINE_LIBRARY
-        optimized boost_coroutine-mt
-        debug boost_coroutine-mt-d)
+    set(BOOST_FIBER_LIBRARY
+        optimized boost_fiber-mt
+        debug boost_fiber-mt-d)
     set(BOOST_FILESYSTEM_LIBRARY
         optimized boost_filesystem-mt
         debug boost_filesystem-mt-d)
@@ -100,9 +100,9 @@ else (USESYSTEMLIBS)
     set(BOOST_CONTEXT_LIBRARY
         optimized boost_context-mt
         debug boost_context-mt-d)
-    set(BOOST_COROUTINE_LIBRARY
-        optimized boost_coroutine-mt
-        debug boost_coroutine-mt-d)
+    set(BOOST_FIBER_LIBRARY
+        optimized boost_fiber-mt
+        debug boost_fiber-mt-d)
     set(BOOST_FILESYSTEM_LIBRARY
         optimized boost_filesystem-mt
         debug boost_filesystem-mt-d)
diff --git a/indra/cmake/LLAddBuildTest.cmake b/indra/cmake/LLAddBuildTest.cmake
index b3f42c1a5e..ee6396e473 100644
--- a/indra/cmake/LLAddBuildTest.cmake
+++ b/indra/cmake/LLAddBuildTest.cmake
@@ -53,7 +53,7 @@ INCLUDE(GoogleMock)
     ${GOOGLEMOCK_INCLUDE_DIRS}
     )
   SET(alltest_LIBRARIES
-    ${BOOST_COROUTINE_LIBRARY}
+    ${BOOST_FIBER_LIBRARY}
     ${BOOST_CONTEXT_LIBRARY}
     ${BOOST_SYSTEM_LIBRARY}
     ${GOOGLEMOCK_LIBRARIES}
@@ -201,7 +201,7 @@ FUNCTION(LL_ADD_INTEGRATION_TEST
 
   SET(libraries
     ${library_dependencies}
-    ${BOOST_COROUTINE_LIBRARY}
+    ${BOOST_FIBER_LIBRARY}
     ${BOOST_CONTEXT_LIBRARY}
     ${BOOST_SYSTEM_LIBRARY}
     ${GOOGLEMOCK_LIBRARIES}
diff --git a/indra/cmake/LLAppearance.cmake b/indra/cmake/LLAppearance.cmake
index ae265d07e3..675330ec72 100644
--- a/indra/cmake/LLAppearance.cmake
+++ b/indra/cmake/LLAppearance.cmake
@@ -18,7 +18,7 @@ endif (BUILD_HEADLESS)
 set(LLAPPEARANCE_LIBRARIES llappearance
     llmessage
     llcorehttp
-    ${BOOST_COROUTINE_LIBRARY}
+    ${BOOST_FIBER_LIBRARY}
     ${BOOST_CONTEXT_LIBRARY}
     ${BOOST_SYSTEM_LIBRARY}
     )
diff --git a/indra/cmake/LLCommon.cmake b/indra/cmake/LLCommon.cmake
index 3e29297c58..8900419f9b 100644
--- a/indra/cmake/LLCommon.cmake
+++ b/indra/cmake/LLCommon.cmake
@@ -19,7 +19,7 @@ if (LINUX)
     # specify all libraries that llcommon uses.
     # llcommon uses `clock_gettime' which is provided by librt on linux.
     set(LLCOMMON_LIBRARIES llcommon 
-        ${BOOST_COROUTINE_LIBRARY} 
+        ${BOOST_FIBER_LIBRARY} 
         ${BOOST_CONTEXT_LIBRARY} 
         ${BOOST_THREAD_LIBRARY} 
         ${BOOST_SYSTEM_LIBRARY} 
@@ -27,7 +27,7 @@ if (LINUX)
         )
 else (LINUX)
     set(LLCOMMON_LIBRARIES llcommon
-        ${BOOST_COROUTINE_LIBRARY} 
+        ${BOOST_FIBER_LIBRARY} 
         ${BOOST_CONTEXT_LIBRARY} 
         ${BOOST_THREAD_LIBRARY} 
         ${BOOST_SYSTEM_LIBRARY} )
diff --git a/indra/cmake/LLCoreHttp.cmake b/indra/cmake/LLCoreHttp.cmake
index 379ae207de..613453ab5d 100644
--- a/indra/cmake/LLCoreHttp.cmake
+++ b/indra/cmake/LLCoreHttp.cmake
@@ -12,6 +12,6 @@ set(LLCOREHTTP_INCLUDE_DIRS
     )
 
 set(LLCOREHTTP_LIBRARIES llcorehttp
-    ${BOOST_COROUTINE_LIBRARY}
+    ${BOOST_FIBER_LIBRARY}
     ${BOOST_CONTEXT_LIBRARY}
     ${BOOST_SYSTEM_LIBRARY})