From 29140608b5ac2842941ab684749f1a97b4d6c5f7 Mon Sep 17 00:00:00 2001 From: Ismael Luceno Date: Wed, 23 Sep 2026 12:31:10 +0200 Subject: [PATCH 1/2] screencast: warn when no PipeWire session manager is running Without a session manager, the stream is never linked or activated, it stays in the "paused" state and clients silently fail to capture, while the log looks perfectly healthy. This is hard to diagnose. Watch the PipeWire registry for the "default" metadata object that the session manager publishes. If it is missing when a stream is created, log a warning pointing at the likely cause. Also log at INFO level when the session manager appears, and warn if it goes away. Upstream-Status: Submitted [https://github.com/emersion/xdg-desktop-portal-wlr/pull/402] Signed-off-by: Ismael Luceno --- include/screencast_common.h | 4 ++ src/screencast/pipewire_screencast.c | 58 ++++++++++++++++++++++++++++ 2 files changed, 62 insertions(+) diff --git a/include/screencast_common.h b/include/screencast_common.h index 113c44f..6f2b7f5 100644 --- a/include/screencast_common.h +++ b/include/screencast_common.h @@ -109,6 +109,10 @@ struct xdpw_screencast_context { // pipewire struct pw_context *pwr_context; struct pw_core *core; + struct pw_registry *pwr_registry; + struct spa_hook pwr_registry_listener; + uint32_t pwr_metadata_id; + bool pwr_session_manager; // wlroots struct wl_list output_list; diff --git a/src/screencast/pipewire_screencast.c b/src/screencast/pipewire_screencast.c index 1f24760..2adf668 100644 --- a/src/screencast/pipewire_screencast.c +++ b/src/screencast/pipewire_screencast.c @@ -1,6 +1,7 @@ #include "pipewire_screencast.h" #include +#include #include #include #include @@ -10,6 +11,7 @@ #include #include #include +#include #include #include "screencast.h" @@ -668,6 +670,12 @@ void xdpw_pwr_stream_create(struct xdpw_screencast_instance *cast) { pw_loop_enter(state->pw_loop); + if (!ctx->pwr_session_manager) { + logprint(WARN, "pipewire: no session manager detected (no 'default' " + "metadata found); the stream will most likely stay paused and " + "clients will fail to capture. Is WirePlumber running?"); + } + uint8_t buffer[2 * 1024]; struct spa_pod_dynamic_builder builder;; spa_pod_dynamic_builder_init(&builder, buffer, sizeof(buffer), 2048); @@ -731,6 +739,38 @@ static const struct pw_core_events core_events = { static struct spa_hook core_listener; +// A session manager (e.g. WirePlumber) is what links and activates streams. +// Without one the stream stays paused and no error is reported anywhere, so +// track the "default" metadata object it publishes to be able to say so. +static void pwr_registry_global(void *data, uint32_t id, uint32_t permissions, + const char *type, uint32_t version, const struct spa_dict *props) { + struct xdpw_screencast_context *ctx = data; + if (props == NULL || strcmp(type, PW_TYPE_INTERFACE_Metadata) != 0) { + return; + } + const char *name = spa_dict_lookup(props, PW_KEY_METADATA_NAME); + if (name == NULL || strcmp(name, "default") != 0) { + return; + } + ctx->pwr_metadata_id = id; + ctx->pwr_session_manager = true; + logprint(INFO, "pipewire: session manager detected ('default' metadata, id %u)", id); +} + +static void pwr_registry_global_remove(void *data, uint32_t id) { + struct xdpw_screencast_context *ctx = data; + if (ctx->pwr_session_manager && id == ctx->pwr_metadata_id) { + ctx->pwr_session_manager = false; + logprint(WARN, "pipewire: session manager went away ('default' metadata removed)"); + } +} + +static const struct pw_registry_events registry_events = { + PW_VERSION_REGISTRY_EVENTS, + .global = pwr_registry_global, + .global_remove = pwr_registry_global_remove, +}; + int xdpw_pwr_context_create(struct xdpw_state *state) { struct xdpw_screencast_context *ctx = &state->screencast; @@ -755,6 +795,17 @@ int xdpw_pwr_context_create(struct xdpw_state *state) { // (i.e. in case the pipewire daemon is restarted). spa_zero(core_listener); pw_core_add_listener(ctx->core, &core_listener, &core_events, state); + + ctx->pwr_session_manager = false; + ctx->pwr_registry = pw_core_get_registry(ctx->core, PW_VERSION_REGISTRY, 0); + if (ctx->pwr_registry) { + spa_zero(ctx->pwr_registry_listener); + pw_registry_add_listener(ctx->pwr_registry, + &ctx->pwr_registry_listener, ®istry_events, ctx); + } else { + logprint(WARN, "pipewire: failed to get registry, " + "can't detect a missing session manager"); + } } return 0; } @@ -764,6 +815,13 @@ void xdpw_pwr_context_destroy(struct xdpw_state *state) { logprint(DEBUG, "pipewire: disconnecting fom core"); + if (ctx->pwr_registry) { + spa_hook_remove(&ctx->pwr_registry_listener); + pw_proxy_destroy((struct pw_proxy *)ctx->pwr_registry); + ctx->pwr_registry = NULL; + ctx->pwr_session_manager = false; + } + if (ctx->core) { pw_core_disconnect(ctx->core); ctx->core = NULL; -- 2.43.0