Move the functions that directly manipulate the global state singleton

into global_state.{h,cpp}. Move all of the functions into a new
namespace Global_State_Management, though exposing global_state() into
the Botan namespace for compatability.

Also add new functions global_state_exists and
set_global_state_unless_set which may be helpful in certain tricky
initialization scenarios (eg when an application using botan also uses
a library which may or may not itself use botan).

6 files changed, 165 insertions, 67 deletions

diff --git a/src/libstate/global_state.cpp b/src/libstate/global_state.cpp
new file mode 100644
index 000000000..0ffb49fdc
--- /dev/null
+++ b/src/libstate/global_state.cpp
@@ -0,0 +1,88 @@
+/*
+* Global State Management
+* (C) 2010 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/global_state.h>
+#include <botan/libstate.h>
+
+namespace Botan {
+
+/*
+* @todo There should probably be a lock to avoid racy manipulation
+* of the state among different threads
+*/
+
+namespace Global_State_Management {
+
+/*
+* Botan's global state
+*/
+namespace {
+
+Library_State* global_lib_state = 0;
+
+}
+
+/*
+* Access the global state object
+*/
+Library_State& global_state()
+   {
+   /* Lazy initialization. Botan still needs to be deinitialized later
+      on or memory might leak.
+   */
+   if(!global_lib_state)
+      {
+      global_lib_state = new Library_State;
+      global_lib_state->initialize(true);
+      }
+
+   return (*global_lib_state);
+   }
+
+/*
+* Set a new global state object
+*/
+void set_global_state(Library_State* new_state)
+   {
+   delete swap_global_state(new_state);
+   }
+
+/*
+* Set a new global state object unless one already existed
+*/
+bool set_global_state_unless_set(Library_State* new_state)
+   {
+   if(global_lib_state)
+      {
+      delete new_state;
+      return false;
+      }
+   else
+      delete swap_global_state(new_state);
+   }
+
+/*
+* Swap two global state objects
+*/
+Library_State* swap_global_state(Library_State* new_state)
+   {
+   Library_State* old_state = global_lib_state;
+   global_lib_state = new_state;
+   return old_state;
+   }
+
+/*
+* Query if library is initialized
+*/
+bool global_state_exists()
+   {
+   return (global_lib_state);
+   }
+
+}
+
+}
diff --git a/src/libstate/global_state.h b/src/libstate/global_state.h
new file mode 100644
index 000000000..486aed17e
--- /dev/null
+++ b/src/libstate/global_state.h
@@ -0,0 +1,69 @@
+/*
+* Global State Management
+* (C) 2010 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_GLOBAL_STATE_H__
+#define BOTAN_GLOBAL_STATE_H__
+
+#include <botan/build.h>
+
+namespace Botan {
+
+/*
+* Forward declare to avoid recursive dependency between this header
+* and libstate.h
+*/
+class Library_State;
+
+/**
+* Namespace for management of the global state
+*/
+namespace Global_State_Management {
+
+/**
+* Access the global library state
+* @return reference to the global library state
+*/
+BOTAN_DLL Library_State& global_state();
+
+/**
+* Set the global state object
+* @param state the new global state to use
+*/
+BOTAN_DLL void set_global_state(Library_State* state);
+
+/**
+* Set the global state object unless it is already set
+* @param state the new global state to use
+* @return true if the state parameter is now being used as the global
+*         state, or false if one was already set, in which case the
+*         parameter was deleted immediately
+*/
+BOTAN_DLL bool set_global_state_unless_set(Library_State* state);
+
+/**
+* Swap the current state for another
+* @param new_state the new state object to use
+* @return previous state (or NULL if none)
+*/
+BOTAN_DLL Library_State* swap_global_state(Library_State* new_state);
+
+/**
+* Query if the library is currently initialized
+* @return true iff the library is initialized
+*/
+BOTAN_DLL bool global_state_exists();
+
+}
+
+/*
+* Insert into Botan ns for convenience/backwards compatability
+*/
+using Global_State_Management::global_state;
+
+}
+
+#endif
diff --git a/src/libstate/info.txt b/src/libstate/info.txt
index 22095d1a3..94ae8101a 100644
--- a/src/libstate/info.txt
+++ b/src/libstate/info.txt
@@ -4,8 +4,9 @@ define LIBSTATE_MODULE
 
 <header:public>
 botan.h
-libstate.h
+global_state.h
 init.h
+libstate.h
 look_pk.h
 lookup.h
 scan_name.h
@@ -13,8 +14,9 @@ scan_name.h
 
 <source>
 get_enc.cpp
-init.cpp
 global_rng.cpp
+global_state.cpp
+init.cpp
 libstate.cpp
 lookup.cpp
 policy.cpp
diff --git a/src/libstate/init.cpp b/src/libstate/init.cpp
index 386767b04..e2139f42e 100644
--- a/src/libstate/init.cpp
+++ b/src/libstate/init.cpp
@@ -8,6 +8,7 @@
 #include <botan/init.h>
 #include <botan/parsing.h>
 #include <botan/libstate.h>
+#include <botan/global_state.h>
 
 namespace Botan {
 
@@ -53,7 +54,7 @@ void LibraryInitializer::initialize(const std::string& arg_string)
       allocators and so for, so global_state() has to be a valid
       reference before initialize() can be called. Yeah, gross.
       */
-      set_global_state(new Library_State);
+      Global_State_Management::set_global_state(new Library_State);
 
       global_state().initialize(thread_safe);
       }
@@ -69,7 +70,7 @@ void LibraryInitializer::initialize(const std::string& arg_string)
 */
 void LibraryInitializer::deinitialize()
    {
-   set_global_state(0);
+   Global_State_Management::set_global_state(0);
    }
 
 }
diff --git a/src/libstate/libstate.cpp b/src/libstate/libstate.cpp
index 8d8634bab..a20fc76c6 100644
--- a/src/libstate/libstate.cpp
+++ b/src/libstate/libstate.cpp
@@ -56,50 +56,6 @@
 namespace Botan {
 
 /*
-* Botan's global state
-*/
-namespace {
-
-Library_State* global_lib_state = 0;
-
-}
-
-/*
-* Access the global state object
-*/
-Library_State& global_state()
-   {
-   /* Lazy initialization. Botan still needs to be deinitialized later
-      on or memory might leak.
-   */
-   if(!global_lib_state)
-      {
-      global_lib_state = new Library_State;
-      global_lib_state->initialize(true);
-      }
-
-   return (*global_lib_state);
-   }
-
-/*
-* Set a new global state object
-*/
-void set_global_state(Library_State* new_state)
-   {
-   delete swap_global_state(new_state);
-   }
-
-/*
-* Swap two global state objects
-*/
-Library_State* swap_global_state(Library_State* new_state)
-   {
-   Library_State* old_state = global_lib_state;
-   global_lib_state = new_state;
-   return old_state;
-   }
-
-/*
 * Get a new mutex object
 */
 Mutex* Library_State::get_mutex() const
diff --git a/src/libstate/libstate.h b/src/libstate/libstate.h
index eeb38287a..aa957c8c9 100644
--- a/src/libstate/libstate.h
+++ b/src/libstate/libstate.h
@@ -8,6 +8,7 @@
 #ifndef BOTAN_LIB_STATE_H__
 #define BOTAN_LIB_STATE_H__
 
+#include <botan/global_state.h>
 #include <botan/allocate.h>
 #include <botan/algo_factory.h>
 #include <botan/rng.h>
@@ -140,25 +141,6 @@ class BOTAN_DLL Library_State
       Algorithm_Factory* m_algorithm_factory;
    };
 
-/**
-* Access the global library state
-* @return reference to the global library state
-*/
-BOTAN_DLL Library_State& global_state();
-
-/**
-* Set the global state object
-* @param state the new global state to use
-*/
-BOTAN_DLL void set_global_state(Library_State* state);
-
-/**
-* Swap the current state for another
-* @param new_state the new state object to use
-* @return previous state (or NULL if none)
-*/
-BOTAN_DLL Library_State* swap_global_state(Library_State* new_state);
-
 }
 
 #endif