Attachment 121989 Details for Bug 90318 – Hack adding C11 atomics for setting pool->top

[patch] Hack adding C11 atomics for setting pool->top

cairo-C11-atomics-for-freed-pool.patch (text/plain), 2.48 KB, created by Uli Schlachter on 2016-02-26 20:39:59 UTC

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Creator: Uli Schlachter

Created: 2016-02-26 20:39:59 UTC

Size: 2.48 KB

patch

obsolete

>diff --git a/src/cairo-freed-pool-private.h b/src/cairo-freed-pool-private.h
>index 0ec6de3..b5ced1a 100644
>--- a/src/cairo-freed-pool-private.h
>+++ b/src/cairo-freed-pool-private.h
>@@ -45,13 +45,15 @@ CAIRO_BEGIN_DECLS
> #define DISABLE_FREED_POOLS 0
> 
> #if HAS_ATOMIC_OPS && ! DISABLE_FREED_POOLS
>+#include <stdatomic.h>
>+
> /* Keep a stash of recently freed clip_paths, since we need to
>  * reallocate them frequently.
>  */
> #define MAX_FREED_POOL_SIZE 16
> typedef struct {
>     void *pool[MAX_FREED_POOL_SIZE];
>-    int top;
>+    _Atomic int top;
> } freed_pool_t;
> 
> static cairo_always_inline void *
>@@ -81,13 +83,13 @@ _freed_pool_get (freed_pool_t *pool)
>     void *ptr;
>     int i;
> 
>-    i = pool->top - 1;
>+    i = atomic_load_explicit(&pool->top, memory_order_relaxed) - 1;
>     if (i < 0)
> 	i = 0;
> 
>     ptr = _atomic_fetch (&pool->pool[i]);
>     if (likely (ptr != NULL)) {
>-	pool->top = i;
>+	atomic_store_explicit(&pool->top, i, memory_order_relaxed);
> 	return ptr;
>     }
> 
>@@ -103,11 +105,11 @@ _freed_pool_put (freed_pool_t *pool, void *ptr)
> {
>     int i;
> 
>-    i = pool->top;
>+    i = atomic_load_explicit(&pool->top, memory_order_relaxed);
>     if (likely (i < ARRAY_LENGTH (pool->pool) &&
> 		_atomic_store (&pool->pool[i], ptr)))
>     {
>-	pool->top = i + 1;
>+	atomic_store_explicit(&pool->top, i + 1, memory_order_relaxed);
> 	return;
>     }
> 
>diff --git a/src/cairo-freed-pool.c b/src/cairo-freed-pool.c
>index cfdc8e9..0228c77 100644
>--- a/src/cairo-freed-pool.c
>+++ b/src/cairo-freed-pool.c
>@@ -50,13 +50,13 @@ _freed_pool_get_search (freed_pool_t *pool)
>     for (i = ARRAY_LENGTH (pool->pool); i--;) {
> 	ptr = _atomic_fetch (&pool->pool[i]);
> 	if (ptr != NULL) {
>-	    pool->top = i;
>+	    atomic_store_explicit(&pool->top, i, memory_order_relaxed);
> 	    return ptr;
> 	}
>     }
> 
>     /* empty */
>-    pool->top = 0;
>+    atomic_store_explicit(&pool->top, 0, memory_order_relaxed);
>     return NULL;
> }
> 
>@@ -67,13 +67,13 @@ _freed_pool_put_search (freed_pool_t *pool, void *ptr)
> 
>     for (i = 0; i < ARRAY_LENGTH (pool->pool); i++) {
> 	if (_atomic_store (&pool->pool[i], ptr)) {
>-	    pool->top = i + 1;
>+	    atomic_store_explicit(&pool->top, i + 1, memory_order_relaxed);
> 	    return;
> 	}
>     }
> 
>     /* full */
>-    pool->top = i;
>+    atomic_store_explicit(&pool->top, i, memory_order_relaxed);
>     free (ptr);
> }
> 
>@@ -87,7 +87,7 @@ _freed_pool_reset (freed_pool_t *pool)
> 	pool->pool[i] = NULL;
>     }
> 
>-    pool->top = 0;
>+    atomic_store_explicit(&pool->top, 0, memory_order_relaxed);
> }
> 
> #endif

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Attachments on bug 90318: 115548 | 121989 | 122070

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