Structures

VkImportFenceFdInfoKHR

(None)

The VkImportFenceFdInfoKHR structure is defined as:

typedef struct VkImportFenceFdInfoKHR {
    VkStructureType sType;
    const void* pNext;
    VkFence fence;
    VkFenceImportFlags flags;
    VkExternalFenceHandleTypeFlagBits handleType;
    int fd;
} VkImportFenceFdInfoKHR;
  • sType is a VkStructureType value identifying this structure.
  • pNext is NULL or a pointer to a structure extending this structure.
  • fence is the fence into which the payload will be imported.
  • flags is a bitmask of VkFenceImportFlagBits specifying additional parameters for the fence payload import operation.
  • handleType is a VkExternalFenceHandleTypeFlagBits value specifying the type of fd.
  • fd is the external handle to import.

The handle types supported by handleType are:

Table 1. Handle Types Supported by VkImportFenceFdInfoKHR
Handle TypeTransferencePermanence Supported

VK_EXTERNAL_FENCE_HANDLE_TYPE_OPAQUE_FD_BIT

Reference

Temporary,Permanent

VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD_BIT

Copy

Temporary

Valid Usage

VUID-VkImportFenceFdInfoKHR-fd-01541

fd must obey any requirements listed for handleType in external fence handle types compatibility

VUID-VkImportFenceFdInfoKHR-handleType-07306

If handleType refers to a handle type with copy payload transference semantics, flags must contain VK_FENCE_IMPORT_TEMPORARY_BIT

If handleType is VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD_BIT, the special value -1 for fd is treated like a valid sync file descriptor referring to an object that has already signaled. The import operation will succeed and the VkFence will have a temporarily imported payload as if a valid file descriptor had been provided.

This special behavior for importing an invalid sync file descriptor allows easier interoperability with other system APIs which use the convention that an invalid sync file descriptor represents work that has already completed and does not need to be waited for. It is consistent with the option for implementations to return a -1 file descriptor when exporting a VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD_BIT from a VkFence which is signaled.

Valid Usage (Implicit)

Host Synchronization

  • Host access to fence must be externally synchronized ::