fix graceful

"apachctl graceful" was failing: we'd lock during restart.

This extension was being unloaded, which in turn unloaded libvips (since
only we referenced it), but glib was not being unloaded, since other
things used by apache were still using it.

As a result, on reload of this extension, libvips would try to init, and
discover that parts of its previous init were still there, such as the
VipsObject type.

Fix: lock libvips in memory to prevent unload.

See libvips/php-vips#26

Author: jcupitt

Diff for: ChangeLog

@@ -1,8 +1,9 @@
 vips extension changelog
 
-dev
----
+Version 1.0.3 (2016-12-27)
+--------------------------
 	* Lower min vips version to 8.2, see #4
+	* Lock libvips to fix graceful, see https://github.com/jcupitt/php-vips/issues/26
 
 Version 1.0.2 (2016-12-06)
 --------------------------

Diff for: README.md

@@ -91,7 +91,7 @@ libvips website, or build your own.
 $ pear package
 ```
 
-to make `vips-1.0.2.tgz`.
+to make `vips-1.0.3.tgz`.
 
 To install by hand:
 

Diff for: RELEASE-1.0.2 renamed to RELEASE-1.0.3

@@ -15,9 +15,9 @@ http://pear.php.net/dtd/package-2.0.xsd">
   <email>[email protected]</email>
   <active>yes</active>
  </lead>
- <date>2016-12-06</date>
+ <date>2016-12-27</date>
  <version>
-  <release>1.0.2</release>
+  <release>1.0.3</release>
   <api>1.0.0</api>
  </version>
  <stability>
@@ -34,7 +34,7 @@ http://pear.php.net/dtd/package-2.0.xsd">
    <file role='doc' name='CREDITS'/>
    <file role='doc' name='LICENSE.txt'/>
    <file role='doc' name='README.md'/>
-   <file role='doc' name='RELEASE-1.0.2'/>
+   <file role='doc' name='RELEASE-1.0.3'/>
    <file role='doc' name='ChangeLog'/>
 
    <file role='src' name='config.m4'/>
@@ -89,6 +89,16 @@ http://pear.php.net/dtd/package-2.0.xsd">
  </extsrcrelease>
  <changelog>
 
+   <release>
+   <stability><release>stable</release><api>stable</api></stability>
+   <version><release>1.0.3</release><api>1.0.0</api></version>
+   <date>2016-12-27</date>
+   <notes>
+	* Lower min vips version to 8.2, see #4
+	* Lock libvips to fix graceful, see https://github.com/jcupitt/php-vips/issues/26
+   </notes>
+  </release>
+
    <release>
    <stability><release>stable</release><api>stable</api></stability>
    <version><release>1.0.2</release><api>1.0.0</api></version>

Diff for: package.xml

@@ -5,7 +5,7 @@
 extern zend_module_entry vips_module_entry;
 #define phpext_vips_ptr &vips_module_entry
 
-#define PHP_VIPS_VERSION "1.0.2" 
+#define PHP_VIPS_VERSION "1.0.3" 
 
 #ifdef PHP_WIN32
 #	define PHP_VIPS_API __declspec(dllexport)

Diff for: php_vips.h

@@ -1621,6 +1621,23 @@ static void php_free_gobject(zend_resource *rsrc)
  */
 PHP_MINIT_FUNCTION(vips)
 {
+	/* "apachectl graceful" can cause us terrible problems. Within the main
+	 * apache process, it will unload this extension, which in turn will unload
+	 * libvips, since we are the only thing that references it, then reload 
+	 * again.
+	 *
+	 * Unfortunately, glib, which libvips uses, will often NOT get unloaded.
+	 * When libvips then tries to init again, it'll find left-over types like
+	 * VipsObject still registered in the system, and chaos will follow.
+	 *
+	 * A simple fix that will always work is just to lock libvips in memory and
+	 * prevent unload. 
+	 */
+	if (!dlopen("libvips.so", RTLD_LAZY | RTLD_NODELETE)) {
+		printf("php-vips-ext: unable to lock libvips -- "
+			"graceful may be unreliable\n");
+	}
+
 	/* If you have INI entries, uncomment these lines
 	REGISTER_INI_ENTRIES();
 	*/
@@ -1658,7 +1675,9 @@ PHP_MSHUTDOWN_FUNCTION(vips)
 	printf( "php-vips-ext shutdown\n" );
 #endif /*VIPS_DEBUG*/
 
-	vips_shutdown();
+	/* We must not call vips_shutdown() since we've locked libvips in memory
+	 * and will need to reuse it if we restart via graceful.
+	 */
 
 	return SUCCESS;
 }