Change to self allocation of shm buffers

include/screencast_common.h

@@ -107,6 +107,7 @@ struct xdpw_wlr_output {
 };
 
 void randname(char *buf);
+int anonymous_shm_open(void);
 enum spa_video_format xdpw_format_pw_from_wl_shm(
 	struct xdpw_screencast_instance *cast);
 enum spa_video_format xdpw_format_pw_strip_alpha(enum spa_video_format format);

src/screencast/pipewire_screencast.c

@@ -5,6 +5,8 @@
 #include <spa/param/props.h>
 #include <spa/param/format-utils.h>
 #include <spa/param/video/format-utils.h>
+#include <sys/mman.h>
+#include <unistd.h>
 
 #include "wlr_screencast.h"
 #include "xdpw.h"
@@ -148,18 +150,47 @@ static void pwr_handle_stream_add_buffer(void *data, struct pw_buffer *buffer) {
 
 	// Prepare buffer for choosen type
 	if (d[0].type == SPA_DATA_MemPtr) {
+		d[0].type = SPA_DATA_MemFd;
 		d[0].maxsize = cast->simple_frame.size;
 		d[0].mapoffset = 0;
 		d[0].chunk->size = cast->simple_frame.size;
 		d[0].chunk->stride = cast->simple_frame.stride;
 		d[0].chunk->offset = 0;
-		d[0].flags = 0;
-		d[0].fd = -1;
+		d[0].flags = SPA_DATA_FLAG_READWRITE;
+		d[0].fd = anonymous_shm_open();
+
+		if (d[0].fd == -1) {
+			logprint(ERROR, "pipewire: unable to create anonymous filedescriptor");
+			return;
+		}
+
+		if (ftruncate(d[0].fd, d[0].maxsize) < 0) {
+			logprint(ERROR, "pipewire: unable to truncate filedescriptor");
+			return;
+		}
+
+		d[0].data = mmap(NULL, d[0].maxsize, PROT_READ | PROT_WRITE, MAP_SHARED, d[0].fd, d[0].mapoffset);
+		if (d[0].data == MAP_FAILED) {
+			logprint(ERROR, "pipewire: unable to mmap memory");
+			return;
+		}
 	}
 }
 
 static void pwr_handle_stream_remove_buffer(void *data, struct pw_buffer *buffer) {
+	struct spa_data *d;
+
 	logprint(TRACE, "pipewire: remove buffer event handle");
+
+	d = buffer->buffer->datas;
+	switch (d[0].type) {
+	case SPA_DATA_MemFd:
+		munmap(d[0].data, d[0].maxsize);
+		close(d[0].fd);
+		break;
+	default:
+		break;
+	}
 }
 
 static const struct pw_stream_events pwr_stream_events = {
@@ -228,7 +259,7 @@ void xdpw_pwr_stream_init(struct xdpw_screencast_instance *cast) {
 	pw_stream_connect(cast->stream,
 		PW_DIRECTION_OUTPUT,
 		PW_ID_ANY,
-		PW_STREAM_FLAG_DRIVER,
+		PW_STREAM_FLAG_DRIVER | PW_STREAM_FLAG_ALLOC_BUFFERS,
 		&param, 1);
 
 }

src/screencast/screencast_common.c

@@ -1,5 +1,9 @@
 #include "screencast_common.h"
 #include <assert.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <unistd.h>
 
 void randname(char *buf) {
 	struct timespec ts;
@@ -12,6 +16,25 @@ void randname(char *buf) {
 	}
 }
 
+int anonymous_shm_open(void) {
+	char name[] = "/xdpw-shm-XXXXXX";
+	int retries = 100;
+
+	do {
+		randname(name + strlen(name) - 6);
+
+		--retries;
+		// shm_open guarantees that O_CLOEXEC is set
+		int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+		if (fd >= 0) {
+			shm_unlink(name);
+			return fd;
+		}
+	} while (retries > 0 && errno == EEXIST);
+
+	return -1;
+}
+
 enum spa_video_format xdpw_format_pw_from_wl_shm(
 		struct xdpw_screencast_instance *cast) {
 	switch (cast->simple_frame.format) {

src/screencast/wlr_screencast.c

@@ -54,25 +54,6 @@ void xdpw_wlr_frame_free(struct xdpw_screencast_instance *cast) {
 	xdpw_wlr_register_cb(cast);
 }
 
-static int anonymous_shm_open(void) {
-	char name[] = "/xdpw-shm-XXXXXX";
-	int retries = 100;
-
-	do {
-		randname(name + strlen(name) - 6);
-
-		--retries;
-		// shm_open guarantees that O_CLOEXEC is set
-		int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
-		if (fd >= 0) {
-			shm_unlink(name);
-			return fd;
-		}
-	} while (retries > 0 && errno == EEXIST);
-
-	return -1;
-}
-
 static struct wl_buffer *create_shm_buffer(struct xdpw_screencast_instance *cast,
 		enum wl_shm_format fmt, int width, int height, int stride,
 		void **data_out) {