Make createShmBuffer re-useable

glfw/backend_utils.c

@@ -8,6 +8,7 @@
 #define _GNU_SOURCE
 #include "backend_utils.h"
 #include "internal.h"
+#include "memfd.h"
 
 #include <stdlib.h>
 #include <string.h>
@@ -350,3 +351,72 @@ GLFWAPI char* utf_8_strndup(const char* source, size_t max_length) {
     result[length] = 0;
     return result;
 }
+
+/*
+ * Create a new, unique, anonymous file of the given size, and
+ * return the file descriptor for it. The file descriptor is set
+ * CLOEXEC. The file is immediately suitable for mmap()'ing
+ * the given size at offset zero.
+ *
+ * The file should not have a permanent backing store like a disk,
+ * but may have if XDG_RUNTIME_DIR is not properly implemented in OS.
+ *
+ * The file name is deleted from the file system.
+ *
+ * The file is suitable for buffer sharing between processes by
+ * transmitting the file descriptor over Unix sockets using the
+ * SCM_RIGHTS methods.
+ *
+ * posix_fallocate() is used to guarantee that disk space is available
+ * for the file at the given size. If disk space is insufficient, errno
+ * is set to ENOSPC. If posix_fallocate() is not supported, program may
+ * receive SIGBUS on accessing mmap()'ed file contents instead.
+ */
+int createAnonymousFile(off_t size) {
+    int ret, fd = -1, shm_anon = 0;
+#ifdef HAS_MEMFD_CREATE
+    fd = memfd_create("glfw-shared", MFD_CLOEXEC | MFD_ALLOW_SEALING);
+    if (fd < 0) return -1;
+    // We can add this seal before calling posix_fallocate(), as the file
+    // is currently zero-sized anyway.
+    //
+    // There is also no need to check for the return value, we couldn’t do
+    // anything with it anyway.
+    fcntl(fd, F_ADD_SEALS, F_SEAL_SHRINK | F_SEAL_SEAL);
+#elif defined(SHM_ANON)
+    fd = shm_open(SHM_ANON, O_RDWR | O_CLOEXEC, 0600);
+    if (fd < 0) return -1;
+    shm_anon = 1;
+#else
+    static const char template[] = "/glfw-shared-XXXXXX";
+    const char* path;
+    char* name;
+
+    path = getenv("XDG_RUNTIME_DIR");
+    if (!path)
+    {
+        errno = ENOENT;
+        return -1;
+    }
+
+    name = calloc(strlen(path) + sizeof(template), 1);
+    strcpy(name, path);
+    strcat(name, template);
+
+    fd = createTmpfileCloexec(name);
+
+    free(name);
+
+    if (fd < 0)
+        return -1;
+#endif
+    // posix_fallocate does not work on SHM descriptors
+    ret = shm_anon ? ftruncate(fd, size) : posix_fallocate(fd, 0, size);
+    if (ret != 0)
+    {
+        close(fd);
+        errno = ret;
+        return -1;
+    }
+    return fd;
+}

glfw/backend_utils.h

@@ -29,6 +29,7 @@
 #include <poll.h>
 #include <unistd.h>
 #include <stdbool.h>
+#include <sys/types.h>
 
 #ifdef __has_include
 #if __has_include(<sys/eventfd.h>)
@@ -96,3 +97,4 @@ void finalizePollData(EventLoopData *eld);
 bool initPollData(EventLoopData *eld, int display_fd);
 void wakeupEventLoop(EventLoopData *eld);
 char* utf_8_strndup(const char* source, size_t max_length);
+int createAnonymousFile(off_t size);

glfw/wl_window.c

@@ -42,6 +42,58 @@
 #include <sys/mman.h>
 
 
+static struct wl_buffer* createShmBuffer(const GLFWimage* image)
+{
+    struct wl_shm_pool* pool;
+    struct wl_buffer* buffer;
+    int stride = image->width * 4;
+    int length = image->width * image->height * 4;
+    void* data;
+    int fd, i;
+
+    fd = createAnonymousFile(length);
+    if (fd < 0)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "Wayland: Creating a buffer file for %d B failed: %s",
+                        length, strerror(errno));
+        return NULL;
+    }
+
+    data = mmap(NULL, length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (data == MAP_FAILED)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "Wayland: mmap failed: %s", strerror(errno));
+        close(fd);
+        return NULL;
+    }
+
+    pool = wl_shm_create_pool(_glfw.wl.shm, fd, length);
+
+    close(fd);
+    unsigned char* source = (unsigned char*) image->pixels;
+    unsigned char* target = data;
+    for (i = 0;  i < image->width * image->height;  i++, source += 4)
+    {
+        unsigned int alpha = source[3];
+
+        *target++ = (unsigned char) ((source[2] * alpha) / 255);
+        *target++ = (unsigned char) ((source[1] * alpha) / 255);
+        *target++ = (unsigned char) ((source[0] * alpha) / 255);
+        *target++ = (unsigned char) alpha;
+    }
+
+    buffer =
+        wl_shm_pool_create_buffer(pool, 0,
+                                  image->width,
+                                  image->height,
+                                  stride, WL_SHM_FORMAT_ARGB8888);
+    munmap(data, length);
+    wl_shm_pool_destroy(pool);
+
+    return buffer;
+}
 static void
 setCursorImage(_GLFWwindow* window, bool on_theme_change) {
     _GLFWcursorWayland defaultCursor = {.shape = GLFW_ARROW_CURSOR};
@@ -225,129 +277,6 @@ static void dispatchChangesAfterConfigure(_GLFWwindow *window, int32_t width, in
 }
 
 
-/*
- * Create a new, unique, anonymous file of the given size, and
- * return the file descriptor for it. The file descriptor is set
- * CLOEXEC. The file is immediately suitable for mmap()'ing
- * the given size at offset zero.
- *
- * The file should not have a permanent backing store like a disk,
- * but may have if XDG_RUNTIME_DIR is not properly implemented in OS.
- *
- * The file name is deleted from the file system.
- *
- * The file is suitable for buffer sharing between processes by
- * transmitting the file descriptor over Unix sockets using the
- * SCM_RIGHTS methods.
- *
- * posix_fallocate() is used to guarantee that disk space is available
- * for the file at the given size. If disk space is insufficient, errno
- * is set to ENOSPC. If posix_fallocate() is not supported, program may
- * receive SIGBUS on accessing mmap()'ed file contents instead.
- */
-static int createAnonymousFile(off_t size)
-{
-    int ret, fd = -1, shm_anon = 0;
-#ifdef HAS_MEMFD_CREATE
-    fd = memfd_create("glfw-shared", MFD_CLOEXEC | MFD_ALLOW_SEALING);
-    if (fd < 0) return -1;
-    // We can add this seal before calling posix_fallocate(), as the file
-    // is currently zero-sized anyway.
-    //
-    // There is also no need to check for the return value, we couldn’t do
-    // anything with it anyway.
-    fcntl(fd, F_ADD_SEALS, F_SEAL_SHRINK | F_SEAL_SEAL);
-#elif defined(SHM_ANON)
-    fd = shm_open(SHM_ANON, O_RDWR | O_CLOEXEC, 0600);
-    if (fd < 0) return -1;
-    shm_anon = 1;
-#else
-    static const char template[] = "/glfw-shared-XXXXXX";
-    const char* path;
-    char* name;
-
-    path = getenv("XDG_RUNTIME_DIR");
-    if (!path)
-    {
-        errno = ENOENT;
-        return -1;
-    }
-
-    name = calloc(strlen(path) + sizeof(template), 1);
-    strcpy(name, path);
-    strcat(name, template);
-
-    fd = createTmpfileCloexec(name);
-
-    free(name);
-
-    if (fd < 0)
-        return -1;
-#endif
-    // posix_fallocate does not work on SHM descriptors
-    ret = shm_anon ? ftruncate(fd, size) : posix_fallocate(fd, 0, size);
-    if (ret != 0)
-    {
-        close(fd);
-        errno = ret;
-        return -1;
-    }
-    return fd;
-}
-
-static struct wl_buffer* createShmBuffer(const GLFWimage* image)
-{
-    struct wl_shm_pool* pool;
-    struct wl_buffer* buffer;
-    int stride = image->width * 4;
-    int length = image->width * image->height * 4;
-    void* data;
-    int fd, i;
-
-    fd = createAnonymousFile(length);
-    if (fd < 0)
-    {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
-                        "Wayland: Creating a buffer file for %d B failed: %s",
-                        length, strerror(errno));
-        return NULL;
-    }
-
-    data = mmap(NULL, length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-    if (data == MAP_FAILED)
-    {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
-                        "Wayland: mmap failed: %s", strerror(errno));
-        close(fd);
-        return NULL;
-    }
-
-    pool = wl_shm_create_pool(_glfw.wl.shm, fd, length);
-
-    close(fd);
-    unsigned char* source = (unsigned char*) image->pixels;
-    unsigned char* target = data;
-    for (i = 0;  i < image->width * image->height;  i++, source += 4)
-    {
-        unsigned int alpha = source[3];
-
-        *target++ = (unsigned char) ((source[2] * alpha) / 255);
-        *target++ = (unsigned char) ((source[1] * alpha) / 255);
-        *target++ = (unsigned char) ((source[0] * alpha) / 255);
-        *target++ = (unsigned char) alpha;
-    }
-
-    buffer =
-        wl_shm_pool_create_buffer(pool, 0,
-                                  image->width,
-                                  image->height,
-                                  stride, WL_SHM_FORMAT_ARGB8888);
-    munmap(data, length);
-    wl_shm_pool_destroy(pool);
-
-    return buffer;
-}
-
 static void createDecoration(_GLFWdecorationWayland* decoration,
                              struct wl_surface* parent,
                              struct wl_buffer* buffer, bool opaque,