From a05a2cb52d1b99af9c6e3d1c7b7ce66ebb1cb4e4 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 27 Feb 2019 14:23:43 +0000
Subject: [PATCH] mild refactoring of threadpool

clean up and simplify after https://github.com/libvips/libvips/pull/1240
---
 ChangeLog                    |  2 ++
 libvips/iofuncs/threadpool.c | 42 +++++++++++-------------------------
 2 files changed, 15 insertions(+), 29 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6cae5f3b..20819463 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -25,6 +25,8 @@
 - tilecache speedups
 - add vips_heifload(), vips_heifsave()
 - add heif thumbnail support to vips_thumbnail()
+- free threadpool earlier, reducing mem growth for some long-running 
+  processes [jtorresfabra]
 
 4/1/19 started 8.7.4
 - magickload with magick6 API did not chain exceptions correctly causing a
diff --git a/libvips/iofuncs/threadpool.c b/libvips/iofuncs/threadpool.c
index 3793018f..b815d605 100644
--- a/libvips/iofuncs/threadpool.c
+++ b/libvips/iofuncs/threadpool.c
@@ -21,6 +21,8 @@
  * 23/4/17
  * 	- add ->stall
  * 	- don't depend on image width when setting n_lines
+ * 27/2/19 jtorresfabra
+ * 	- free threadpool earlier 
  */
 
 /*
@@ -579,9 +581,8 @@ vips_thread_free( VipsThread *thr )
 
 	VIPS_FREEF( g_object_unref, thr->state );
 	thr->pool = NULL;
-	/* Free the thread memory
-	*/
-	g_free(thr);
+
+	VIPS_FREE( thr );
 }
 
 static int
@@ -591,10 +592,9 @@ vips_thread_allocate( VipsThread *thr )
 
 	g_assert( !pool->stop );
 
-	if( !thr->state ) {
-		if( !(thr->state = pool->start( pool->im, pool->a )) ) 
-			return( -1 );
-	}
+	if( !thr->state &&
+		!(thr->state = pool->start( pool->im, pool->a )) ) 
+		return( -1 );
 
 	if( pool->allocate( thr->state, pool->a, &pool->stop ) ) 
 		return( -1 );
@@ -728,7 +728,8 @@ vips_thread_new( VipsThreadpool *pool )
 	return( thr );
 }
 
-/* Kill all threads in a threadpool, if there are any.
+/* Kill all threads in a threadpool, if there are any. Can be called multiple
+ * times. 
  */
 static void
 vips_threadpool_kill_threads( VipsThreadpool *pool )
@@ -737,23 +738,14 @@ vips_threadpool_kill_threads( VipsThreadpool *pool )
 		int i;
 
 		for( i = 0; i < pool->nthr; i++ ) 
-			if( pool->thr[i] ) {
-				vips_thread_free( pool->thr[i] );
-				pool->thr[i] = NULL;
-			}
-		/* Free the thread array
-		*/
-		g_free(pool->thr);
-		pool->thr = NULL;
+			VIPS_FREEF( vips_thread_free, pool->thr[i] );
 
 		VIPS_DEBUG_MSG( "vips_threadpool_kill_threads: "
 			"killed %d threads\n", pool->nthr );
 	}
 }
 
-/* This can be called multiple times, careful.
- */
-static int
+static void
 vips_threadpool_free( VipsThreadpool *pool )
 {
 	VIPS_DEBUG_MSG( "vips_threadpool_free: \"%s\" (%p)\n", 
@@ -763,16 +755,8 @@ vips_threadpool_free( VipsThreadpool *pool )
 	VIPS_FREEF( vips_g_mutex_free, pool->allocate_lock );
 	vips_semaphore_destroy( &pool->finish );
 	vips_semaphore_destroy( &pool->tick );
-	/* Free pool memory
-	*/
-	g_free(pool);
-	return( 0 );
-}
-
-static void
-vips_threadpool_new_cb( VipsImage *im, VipsThreadpool *pool )
-{
-	vips_threadpool_free( pool );
+	VIPS_FREE( pool->thr );
+	VIPS_FREE( pool );
 }
 
 static VipsThreadpool *