[Mesa-dev] [PATCH 2/3] radv: Use library mtime for cache UUID.

[Bas Nieuwenhuizen]

We want to also invalidate the cache when LLVM gets changed. As the
specific LLVM revision is not fixed at build time, we will need to
check at runtime. Computing a checksum for LLVM is going to be very
expensive, so just use the mtime.

Tested on my computer that the returned DSO for the LLVM symbol is
actually the LLVM DSO.

Signed-off-by: Bas Nieuwenhuizen <basni at google.com>
---
 src/amd/vulkan/radv_device.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/src/amd/vulkan/radv_device.c b/src/amd/vulkan/radv_device.c
index b731171..04c0bdc 100644
--- a/src/amd/vulkan/radv_device.c
+++ b/src/amd/vulkan/radv_device.c
@@ -25,10 +25,12 @@
  * IN THE SOFTWARE.
  */
 
+#include <dlfcn.h>
 #include <stdbool.h>
 #include <string.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <sys/stat.h>
 #include "radv_private.h"
 #include "util/strtod.h"
 
@@ -40,15 +42,37 @@
 #include "ac_llvm_util.h"
 #include "vk_format.h"
 #include "sid.h"
-#include "radv_timestamp.h"
 #include "util/debug.h"
 struct radv_dispatch_table dtable;
 
-static void
+static int
+radv_get_function_timestamp(void *ptr, uint32_t* timestamp)
+{
+	Dl_info info;
+	struct stat st;
+	if (!dladdr(ptr, &info) || !info.dli_fname) {
+		return -1;
+	}
+	if (stat(info.dli_fname, &st)) {
+		return -1;
+	}
+	*timestamp = st.st_mtim.tv_sec;
+	return 0;
+}
+
+static int
 radv_device_get_cache_uuid(void *uuid)
 {
+	uint32_t mesa_timestamp, llvm_timestamp;
 	memset(uuid, 0, VK_UUID_SIZE);
-	snprintf(uuid, VK_UUID_SIZE, "radv-%s", RADV_TIMESTAMP);
+	if (radv_get_function_timestamp(radv_device_get_cache_uuid, &mesa_timestamp) ||
+	    radv_get_function_timestamp(LLVMInitializeAMDGPUTargetInfo, &llvm_timestamp))
+		return -1;
+
+	memcpy(uuid, &mesa_timestamp, 4);
+	memcpy((char*)uuid + 4, &llvm_timestamp, 4);
+	snprintf((char*)uuid + 8, VK_UUID_SIZE - 8, "radv");
+	return 0;
 }
 
 static VkResult
@@ -96,7 +120,11 @@ radv_physical_device_init(struct radv_physical_device *device,
 		goto fail;
 	}
 
-	radv_device_get_cache_uuid(device->uuid);
+	if (radv_device_get_cache_uuid(device->uuid)) {
+		radv_finish_wsi(device);
+		device->ws->destroy(device->ws);
+		goto fail;
+	}
 
 	fprintf(stderr, "WARNING: radv is not a conformant vulkan implementation, testing use only.\n");
 	device->name = device->rad_info.name;
-- 
2.10.2