commit febb5404d3d384296146ab6e536c2cee2f084241
Author: Tom Englund <tomenglund26@gmail.com>
Date:   Mon May 25 12:51:54 2026 +0200

    drm: refactor merging and exporting fences
    
    lets move them to drm helper instead of reinventing the wheel twice.

diff --git a/src/helpers/Drm.cpp b/src/helpers/Drm.cpp
index 4f3119f8..665bb786 100644
--- a/src/helpers/Drm.cpp
+++ b/src/helpers/Drm.cpp
@@ -4,7 +4,26 @@
 #include <mutex>
 #include <optional>
 #include <sys/stat.h>
+#include <hyprutils/os/FileDescriptor.hpp>
 #include "Drm.hpp"
+#include <sys/ioctl.h>
+
+#ifdef __linux__
+#include <linux/dma-buf.h>
+#include <linux/sync_file.h>
+#else
+struct sync_merge_data {
+    char  name[32];
+    __s32 fd2;
+    __s32 fence;
+    __u32 flags;
+    __u32 pad;
+};
+#define SYNC_IOC_MAGIC '>'
+#define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 3, struct sync_merge_data)
+#endif
+
+using namespace Hyprutils::OS;
 
 namespace {
     using SDRMNodePair = std::array<dev_t, 2>;
@@ -67,3 +86,56 @@ bool DRM::sameGpu(int fd1, int fd2) {
 
     return same;
 }
+
+int DRM::doIoctl(int fd, unsigned long request, void* arg) {
+    int ret;
+
+    do {
+        ret = ioctl(fd, request, arg);
+    } while (ret == -1 && (errno == EINTR || errno == EAGAIN));
+    return ret;
+}
+
+// https://www.kernel.org/doc/html/latest/driver-api/dma-buf.html#c.dma_buf_export_sync_file
+// returns a sync file that will be signalled when dmabuf is ready to be read
+CFileDescriptor DRM::exportFence(int fd) {
+    if (fd < 0)
+        return {};
+
+    CFileDescriptor fence;
+#ifdef __linux__
+    dma_buf_export_sync_file request{
+        .flags = DMA_BUF_SYNC_READ,
+        .fd    = -1,
+    };
+
+    if (doIoctl(fd, DMA_BUF_IOCTL_EXPORT_SYNC_FILE, &request) == 0)
+        fence = CFileDescriptor{request.fd};
+#endif
+
+    return fence;
+}
+
+CFileDescriptor DRM::mergeFence(const CFileDescriptor& fd1, const CFileDescriptor& fd2) {
+    if (!fd1.isValid() || !fd2.isValid())
+        return {};
+
+    CFileDescriptor mergedFence;
+#ifdef __linux__
+    const std::string      name = "merged release fence";
+    struct sync_merge_data data{
+        .name  = {}, // zero-initialize name[]
+        .fd2   = fd2.get(),
+        .fence = -1,
+    };
+
+    std::ranges::copy_n(name.c_str(), std::min(name.size() + 1, sizeof(data.name)), data.name);
+
+    if (doIoctl(fd1.get(), SYNC_IOC_MERGE, &data) == 0)
+        mergedFence = CFileDescriptor(data.fence);
+    else
+        mergedFence = {};
+
+#endif
+    return mergedFence;
+}
diff --git a/src/helpers/Drm.hpp b/src/helpers/Drm.hpp
index 755ee050..ac05c046 100644
--- a/src/helpers/Drm.hpp
+++ b/src/helpers/Drm.hpp
@@ -2,8 +2,12 @@
 
 #include <optional>
 #include <sys/types.h>
+#include <hyprutils/os/FileDescriptor.hpp>
 
 namespace DRM {
-    std::optional<dev_t> devIDFromFD(int fd);
-    bool                 sameGpu(int fd1, int fd2);
+    std::optional<dev_t>           devIDFromFD(int fd);
+    bool                           sameGpu(int fd1, int fd2);
+    int                            doIoctl(int fd, unsigned long request, void* arg);
+    Hyprutils::OS::CFileDescriptor exportFence(int fd);
+    Hyprutils::OS::CFileDescriptor mergeFence(const Hyprutils::OS::CFileDescriptor& fd1, const Hyprutils::OS::CFileDescriptor& fd2);
 }
diff --git a/src/helpers/sync/SyncReleaser.cpp b/src/helpers/sync/SyncReleaser.cpp
index fbc585d0..c65eae4e 100644
--- a/src/helpers/sync/SyncReleaser.cpp
+++ b/src/helpers/sync/SyncReleaser.cpp
@@ -1,21 +1,7 @@
 #include "SyncReleaser.hpp"
 #include "SyncTimeline.hpp"
 #include "../../render/OpenGL.hpp"
-#include <sys/ioctl.h>
-
-#if defined(__linux__)
-#include <linux/sync_file.h>
-#else
-struct sync_merge_data {
-    char  name[32];
-    __s32 fd2;
-    __s32 fence;
-    __u32 flags;
-    __u32 pad;
-};
-#define SYNC_IOC_MAGIC '>'
-#define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 3, struct sync_merge_data)
-#endif
+#include "../../helpers/Drm.hpp"
 
 using namespace Hyprutils::OS;
 
@@ -35,28 +21,9 @@ CSyncReleaser::~CSyncReleaser() {
         m_timeline->signal(m_point);
 }
 
-static CFileDescriptor mergeSyncFds(const CFileDescriptor& fd1, const CFileDescriptor& fd2) {
-    // combines the fences of both sync_fds into a dma_fence_array (https://www.kernel.org/doc/html/latest/driver-api/dma-buf.html#c.dma_fence_array_create)
-    // with the signal_on_any param set to false, so the new sync_fd will "signal when all fences in the array signal."
-
-    struct sync_merge_data data{
-        .name  = "merged release fence",
-        .fd2   = fd2.get(),
-        .fence = -1,
-    };
-    int err = -1;
-    do {
-        err = ioctl(fd1.get(), SYNC_IOC_MERGE, &data);
-    } while (err == -1 && (errno == EINTR || errno == EAGAIN));
-    if (err < 0)
-        return CFileDescriptor{};
-    else
-        return CFileDescriptor(data.fence);
-}
-
 void CSyncReleaser::addSyncFileFd(const Hyprutils::OS::CFileDescriptor& syncFd) {
     if (m_fd.isValid())
-        m_fd = mergeSyncFds(m_fd, syncFd);
+        m_fd = DRM::mergeFence(m_fd, syncFd);
     else
         m_fd = syncFd.duplicate();
 }
diff --git a/src/protocols/types/DMABuffer.cpp b/src/protocols/types/DMABuffer.cpp
index 37c46338..1a3f787d 100644
--- a/src/protocols/types/DMABuffer.cpp
+++ b/src/protocols/types/DMABuffer.cpp
@@ -3,14 +3,9 @@
 #include "../../desktop/view/LayerSurface.hpp"
 #include "../../render/Renderer.hpp"
 #include "../../helpers/Format.hpp"
+#include "helpers/Drm.hpp"
 #include <hyprgraphics/egl/Egl.hpp>
 
-#if defined(__linux__)
-#include <linux/dma-buf.h>
-#include <linux/sync_file.h>
-#endif
-#include <sys/ioctl.h>
-
 using namespace Hyprutils::OS;
 using namespace Hyprgraphics::Egl;
 
@@ -92,22 +87,11 @@ void CDMABuffer::closeFDs() {
     m_attrs.planes = 0;
 }
 
-static int doIoctl(int fd, unsigned long request, void* arg) {
-    int ret;
-
-    do {
-        ret = ioctl(fd, request, arg);
-    } while (ret == -1 && (errno == EINTR || errno == EAGAIN));
-    return ret;
-}
-
-// https://www.kernel.org/doc/html/latest/driver-api/dma-buf.html#c.dma_buf_export_sync_file
-// returns a sync file that will be signalled when dmabuf is ready to be read
 CFileDescriptor CDMABuffer::exportSyncFile() {
     if (!good())
         return {};
 
-#if !defined(__linux__)
+#ifndef __linux__
     return {};
 #else
     std::vector<CFileDescriptor> syncFds;
@@ -124,13 +108,9 @@ CFileDescriptor CDMABuffer::exportSyncFile() {
                 continue;
         }
 
-        dma_buf_export_sync_file request{
-            .flags = DMA_BUF_SYNC_READ,
-            .fd    = -1,
-        };
-
-        if (doIoctl(fd, DMA_BUF_IOCTL_EXPORT_SYNC_FILE, &request) == 0)
-            syncFds.emplace_back(request.fd);
+        CFileDescriptor fence = DRM::exportFence(fd);
+        if (fence.isValid())
+            syncFds.emplace_back(std::move(fence));
     }
 
     if (syncFds.empty())
@@ -143,19 +123,7 @@ CFileDescriptor CDMABuffer::exportSyncFile() {
             continue;
         }
 
-        const std::string      name = "merged release fence";
-        struct sync_merge_data data{
-            .name  = {}, // zero-initialize name[]
-            .fd2   = fd.get(),
-            .fence = -1,
-        };
-
-        std::ranges::copy_n(name.c_str(), std::min(name.size() + 1, sizeof(data.name)), data.name);
-
-        if (doIoctl(syncFd.get(), SYNC_IOC_MERGE, &data) == 0)
-            syncFd = CFileDescriptor(data.fence);
-        else
-            syncFd = {};
+        syncFd = DRM::mergeFence(syncFd, fd);
     }
 
     return syncFd;