[Mesa-dev] [PATCH v5 03/12] gallium: add common pipe_screen reference counting functions

Rob Herring robh at kernel.org
Mon Aug 7 22:58:02 UTC 2017


In order to prevent multiple pipe_screens being created in the same
process, lookup of the DRM FD and reference counting of the pipe_screen
are needed. Several implementations of this exist in various gallium
drivers/winsys already. This creates a common version which is opt-in
for winsys implementations.

The callers of pipe_screen_{un}reference() functions are responsible for
serializing the calls. Currently, this is done by the pipe-loader mutex.

Signed-off-by: Rob Herring <robh at kernel.org>
---
 src/gallium/auxiliary/Makefile.sources |   2 +
 src/gallium/auxiliary/util/u_screen.c  | 112 +++++++++++++++++++++++++++++++++
 src/gallium/auxiliary/util/u_screen.h  |  32 ++++++++++
 src/gallium/include/pipe/p_screen.h    |   3 +
 4 files changed, 149 insertions(+)
 create mode 100644 src/gallium/auxiliary/util/u_screen.c
 create mode 100644 src/gallium/auxiliary/util/u_screen.h

diff --git a/src/gallium/auxiliary/Makefile.sources b/src/gallium/auxiliary/Makefile.sources
index 9ae8e6c8ca53..f84bfec60fe7 100644
--- a/src/gallium/auxiliary/Makefile.sources
+++ b/src/gallium/auxiliary/Makefile.sources
@@ -283,6 +283,8 @@ C_SOURCES := \
 	util/u_ringbuffer.h \
 	util/u_sampler.c \
 	util/u_sampler.h \
+	util/u_screen.c \
+	util/u_screen.h \
 	util/u_simple_shaders.c \
 	util/u_simple_shaders.h \
 	util/u_split_prim.h \
diff --git a/src/gallium/auxiliary/util/u_screen.c b/src/gallium/auxiliary/util/u_screen.c
new file mode 100644
index 000000000000..dec83b736883
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_screen.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2016-2017 Linaro, Ltd., Rob Herring <robh at kernel.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * Functions for managing pipe_screen's
+ */
+
+#include <sys/stat.h>
+
+#include "pipe/p_screen.h"
+#include "util/u_hash_table.h"
+#include "util/u_inlines.h"
+#include "util/u_pointer.h"
+#include "util/u_screen.h"
+
+static struct util_hash_table *fd_tab = NULL;
+
+static unsigned hash_fd(void *key)
+{
+   int fd = pointer_to_intptr(key);
+   struct stat stat;
+   fstat(fd, &stat);
+
+   return stat.st_dev ^ stat.st_ino ^ stat.st_rdev;
+}
+
+static int compare_fd(void *key1, void *key2)
+{
+   int fd1 = pointer_to_intptr(key1);
+   int fd2 = pointer_to_intptr(key2);
+   struct stat stat1, stat2;
+   fstat(fd1, &stat1);
+   fstat(fd2, &stat2);
+
+   return stat1.st_dev != stat2.st_dev ||
+         stat1.st_ino != stat2.st_ino ||
+         stat1.st_rdev != stat2.st_rdev;
+}
+
+struct pipe_screen *
+pipe_screen_reference(int fd)
+{
+   struct pipe_screen *pscreen;
+
+   if (!fd_tab) {
+      fd_tab = util_hash_table_create(hash_fd, compare_fd);
+      return NULL;
+   }
+
+   pscreen = util_hash_table_get(fd_tab, intptr_to_pointer(fd));
+   if (pscreen)
+      pipe_reference(NULL, &pscreen->reference);
+
+   return pscreen;
+}
+
+boolean
+pipe_screen_unreference(struct pipe_screen *pscreen)
+{
+   boolean destroy;
+
+   if (!pscreen)
+      return FALSE;
+
+   /* Work-around until all pipe_screens have ref counting */
+   if (!pipe_is_referenced(&pscreen->reference)) {
+      pscreen->destroy(pscreen);
+      return TRUE;
+   }
+
+   destroy = pipe_reference(&pscreen->reference, NULL);
+   if (destroy) {
+      int fd = pscreen->fd;
+
+      pscreen->destroy(pscreen);
+
+      if (fd >= 0) {
+         util_hash_table_remove(fd_tab, intptr_to_pointer(fd));
+         close(fd);
+      }
+   }
+   return destroy;
+}
+
+
+void pipe_screen_reference_init(struct pipe_screen *pscreen, int fd)
+{
+   pscreen->fd = fd;
+   pipe_reference_init(&pscreen->reference, 1);
+   util_hash_table_set(fd_tab, intptr_to_pointer(fd), pscreen);
+}
diff --git a/src/gallium/auxiliary/util/u_screen.h b/src/gallium/auxiliary/util/u_screen.h
new file mode 100644
index 000000000000..a7b1e9ff2787
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_screen.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2016-2017 Linaro, Ltd., Rob Herring <robh at kernel.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "pipe/p_defines.h"
+
+struct pipe_screen;
+
+struct pipe_screen *pipe_screen_reference(int fd);
+
+boolean pipe_screen_unreference(struct pipe_screen *pscreen);
+
+void pipe_screen_reference_init(struct pipe_screen *pscreen, int fd);
diff --git a/src/gallium/include/pipe/p_screen.h b/src/gallium/include/pipe/p_screen.h
index b6623d1dd71e..dbb14ef882c0 100644
--- a/src/gallium/include/pipe/p_screen.h
+++ b/src/gallium/include/pipe/p_screen.h
@@ -41,6 +41,7 @@
 #include "pipe/p_compiler.h"
 #include "pipe/p_format.h"
 #include "pipe/p_defines.h"
+#include "pipe/p_state.h"
 #include "pipe/p_video_enums.h"
 
 
@@ -68,6 +69,8 @@ struct driOptionCache;
  * context.
  */
 struct pipe_screen {
+   struct pipe_reference reference;
+   int fd;
    void (*destroy)( struct pipe_screen * );
 
    const char *(*get_name)( struct pipe_screen * );
-- 
2.11.0



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