From 05ab656b578164c30f685df9796b701d17eedc47 Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Fri, 24 Sep 2010 15:26:50 +0000
Subject: [PATCH] The upcoming 4.8.0 release of PROJ.4 is supposed to be
 threadsafe, so lets believe them and not use any locks if we are building
 against version 4.8.0 or later.

Instead we use the new proj_ctx_alloc routine to create a context and
pass that when initialising the projection structure.
---
 include/mapnik/projection.hpp | 11 ++++++++---
 src/proj_transform.cpp        |  4 ++--
 src/projection.cpp            | 25 ++++++++++++++-----------
 3 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/include/mapnik/projection.hpp b/include/mapnik/projection.hpp
index 2c044d3b1..1fb103f1f 100644
--- a/include/mapnik/projection.hpp
+++ b/include/mapnik/projection.hpp
@@ -28,8 +28,11 @@
 // mapnik
 #include <mapnik/box2d.hpp>
 
+// proj4
+#include <proj_api.h>
+
 // boost
-#ifdef MAPNIK_THREADSAFE
+#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
 #include <boost/thread/mutex.hpp>
 #endif
 
@@ -72,9 +75,11 @@ private:
        
 private:
     std::string params_;
-    void * proj_;
+    projPJ proj_;
     bool is_geographic_;
-#ifdef MAPNIK_THREADSAFE
+#if PJ_VERSION >= 480
+    projCtx proj_ctx_;
+#elif defined(MAPNIK_THREADSAFE)
     static boost::mutex mutex_;
 #endif
 };
diff --git a/src/proj_transform.cpp b/src/proj_transform.cpp
index 4da7c1649..0783cf821 100644
--- a/src/proj_transform.cpp
+++ b/src/proj_transform.cpp
@@ -56,7 +56,7 @@ bool proj_transform::forward (double & x, double & y , double & z) const
         y *= DEG_TO_RAD;
     }
 
-#ifdef MAPNIK_THREADSAFE
+#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
     mutex::scoped_lock lock(projection::mutex_);
 #endif
         
@@ -86,7 +86,7 @@ bool proj_transform::backward (double & x, double & y , double & z) const
         y *= DEG_TO_RAD;
     }
         
-#ifdef MAPNIK_THREADSAFE
+#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
     mutex::scoped_lock lock(projection::mutex_);
 #endif
 
diff --git a/src/projection.cpp b/src/projection.cpp
index 51500d43d..8a1e77deb 100644
--- a/src/projection.cpp
+++ b/src/projection.cpp
@@ -30,7 +30,7 @@
 
 namespace mapnik {
 
-#ifdef MAPNIK_THREADSAFE
+#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
 boost::mutex projection::mutex_;
 #endif
    
@@ -80,7 +80,7 @@ std::string const& projection::params() const
     
 void projection::forward(double & x, double &y ) const
 {
-#ifdef MAPNIK_THREADSAFE
+#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
     mutex::scoped_lock lock(mutex_);
 #endif
     projUV p;
@@ -98,7 +98,7 @@ void projection::forward(double & x, double &y ) const
     
 void projection::inverse(double & x,double & y) const
 {
-#ifdef MAPNIK_THREADSAFE
+#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
     mutex::scoped_lock lock(mutex_);
 #endif
     if (is_geographic_)
@@ -116,23 +116,26 @@ void projection::inverse(double & x,double & y) const
     
 projection::~projection() 
 {
-#ifdef MAPNIK_THREADSAFE
+#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
     mutex::scoped_lock lock(mutex_);
 #endif
     if (proj_) pj_free(proj_);
+#if PJ_VERSION >= 480
+    if (proj_ctx_) pj_ctx_free(proj_ctx_);
+#endif
 }
     
 void projection::init()
 {
-// Based on http://trac.osgeo.org/proj/wiki/ThreadSafety
-// you could think pj_init was threadsafe in version 4.7.0
-// but its certainly not, and must only be in >= 4.7 with
-// usage of projCtx per thread
-//#if PJ_VERSION < 470 && MAPNIK_THREADSAFE
-//    mutex::scoped_lock lock(mutex_);
-//#endif
+#if defined(MAPNIK_THREADSAFE) && PJ_VERSION < 480
     mutex::scoped_lock lock(mutex_);
+#endif
+#if PJ_VERSION >= 480
+    proj_ctx_=pj_ctx_alloc();
+    proj_=pj_init_plus_ctx(proj_ctx_, params_.c_str());
+#else
     proj_=pj_init_plus(params_.c_str());
+#endif
     if (!proj_) throw proj_init_error(params_);
     is_geographic_ = pj_is_latlong(proj_) ? true : false;
 }