gfxstream: Avoid repeated functionality

Removed a function that creates anonymous file descriptors when called.
Additionally replaced a call of said function with the one from the "util"
directory. The intention is to avoid repeated functionality

util: Allow code to be compatible in c++ compilers

Added an extern "C" statement and preprocessor directives to make the
“os_create_anonymous_file” function compatible with c++ compilers

Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32096>

src/gfxstream/guest/vulkan_enc/ResourceTracker.cpp

@@ -13,6 +13,7 @@
 #include "gfxstream_vk_private.h"
 #include "goldfish_address_space.h"
 #include "goldfish_vk_private_defs.h"
+#include "util/anon_file.h"
 #include "util/macros.h"
 #include "virtgpu_gfxstream_protocol.h"
 #include "vulkan/vulkan_core.h"
@@ -37,22 +38,6 @@
 #include <drm_fourcc.h>
 #endif
 
-#if defined(__ANDROID__) || defined(__linux__) || defined(__APPLE__)
-
-#include <sys/mman.h>
-#include <sys/syscall.h>
-
-static inline int inline_memfd_create(const char* name, unsigned int flags) {
-#if defined(__ANDROID__)
-    return syscall(SYS_memfd_create, name, flags);
-#else
-    return -1;
-#endif
-}
-
-#define memfd_create inline_memfd_create
-#endif
-
 #ifndef VK_USE_PLATFORM_FUCHSIA
 void zx_handle_close(zx_handle_t) {}
 void zx_event_create(int, zx_handle_t*) {}
@@ -5760,11 +5745,12 @@ VkResult ResourceTracker::on_vkGetSemaphoreFdKHR(void* context, VkResult, VkDevi
     } else {
         // opaque fd
         int hostFd = 0;
+        int32_t size = 0;
         VkResult result = enc->vkGetSemaphoreFdKHR(device, pGetFdInfo, &hostFd, true /* do lock */);
         if (result != VK_SUCCESS) {
             return result;
         }
-        *pFd = memfd_create("vk_opaque_fd", 0);
+        *pFd = os_create_anonymous_file(size, "vk_opaque_fd");
         write(*pFd, &hostFd, sizeof(hostFd));
         return VK_SUCCESS;
     }

src/util/anon_file.h

@@ -28,7 +28,15 @@
 
 #include <stdint.h>
 
+#ifdef __cplusplus
+extern "C"{
+#endif
+
 /* On win32, off_t is only 32 bit, so always using 64 bit size */
 int os_create_anonymous_file(int64_t size, const char *debug_name);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif