core: Support memfd transport; bump protocol version

Now that all layers in the stack support memfd blocks, add memfd
support for the daemon's global core mempool. Also introduce
"enable-memfd=" daemon argument and configuration option.

For now, memfd support is an opt-in feature to be activated only
when daemon's enable-memfd= is set to yes.

Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>

4 files changed, 18 insertions, 2 deletions

diff --git a/src/daemon/cmdline.c b/src/daemon/cmdline.c
index 117147dd8..0454b6d84 100644
--- a/src/daemon/cmdline.c
+++ b/src/daemon/cmdline.c
@@ -63,6 +63,7 @@ enum {
     ARG_CHECK,
     ARG_NO_CPU_LIMIT,
     ARG_DISABLE_SHM,
+    ARG_ENABLE_MEMFD,
     ARG_DUMP_RESAMPLE_METHODS,
     ARG_SYSTEM,
     ARG_CLEANUP_SHM,
@@ -100,6 +101,7 @@ static const struct option long_options[] = {
     {"system",                      2, 0, ARG_SYSTEM},
     {"no-cpu-limit",                2, 0, ARG_NO_CPU_LIMIT},
     {"disable-shm",                 2, 0, ARG_DISABLE_SHM},
+    {"enable-memfd",                2, 0, ARG_ENABLE_MEMFD},
     {"dump-resample-methods",       2, 0, ARG_DUMP_RESAMPLE_METHODS},
     {"cleanup-shm",                 2, 0, ARG_CLEANUP_SHM},
     {NULL, 0, 0, 0}
@@ -152,7 +154,8 @@ void pa_cmdline_help(const char *argv0) {
            "      --use-pid-file[=BOOL]             Create a PID file\n"
            "      --no-cpu-limit[=BOOL]             Do not install CPU load limiter on\n"
            "                                        platforms that support it.\n"
-           "      --disable-shm[=BOOL]              Disable shared memory support.\n\n"
+           "      --disable-shm[=BOOL]              Disable shared memory support.\n"
+           "      --enable-memfd[=BOOL]             Enable memfd shared memory support.\n\n"
 
            "STARTUP SCRIPT:\n"
            "  -L, --load=\"MODULE ARGUMENTS\"         Load the specified plugin module with\n"
@@ -389,6 +392,14 @@ int pa_cmdline_parse(pa_daemon_conf *conf, int argc, char *const argv [], int *d
                 conf->disable_shm = !!b;
                 break;
 
+            case ARG_ENABLE_MEMFD:
+                if ((b = optarg ? pa_parse_boolean(optarg) : 1) < 0) {
+                    pa_log(_("--enable-memfd expects boolean argument"));
+                    goto fail;
+                }
+                conf->disable_memfd = !b;
+                break;
+
             default:
                 goto fail;
         }
diff --git a/src/daemon/daemon-conf.c b/src/daemon/daemon-conf.c
index 288aed2b2..965a5c802 100644
--- a/src/daemon/daemon-conf.c
+++ b/src/daemon/daemon-conf.c
@@ -92,6 +92,7 @@ static const pa_daemon_conf default_conf = {
 #endif
     .no_cpu_limit = true,
     .disable_shm = false,
+    .disable_memfd = true,
     .lock_memory = false,
     .deferred_volume = true,
     .default_n_fragments = 4,
@@ -526,6 +527,7 @@ int pa_daemon_conf_load(pa_daemon_conf *c, const char *filename) {
         { "cpu-limit",                  pa_config_parse_not_bool, &c->no_cpu_limit, NULL },
         { "disable-shm",                pa_config_parse_bool,     &c->disable_shm, NULL },
         { "enable-shm",                 pa_config_parse_not_bool, &c->disable_shm, NULL },
+        { "enable-memfd",               pa_config_parse_not_bool, &c->disable_memfd, NULL },
         { "flat-volumes",               pa_config_parse_bool,     &c->flat_volumes, NULL },
         { "lock-memory",                pa_config_parse_bool,     &c->lock_memory, NULL },
         { "enable-deferred-volume",     pa_config_parse_bool,     &c->deferred_volume, NULL },
diff --git a/src/daemon/daemon-conf.h b/src/daemon/daemon-conf.h
index 458784c98..82b619fa6 100644
--- a/src/daemon/daemon-conf.h
+++ b/src/daemon/daemon-conf.h
@@ -66,6 +66,7 @@ typedef struct pa_daemon_conf {
         system_instance,
         no_cpu_limit,
         disable_shm,
+        disable_memfd,
         disable_remixing,
         disable_lfe_remixing,
         load_default_script_file,
diff --git a/src/daemon/main.c b/src/daemon/main.c
index c2f47b69a..ae1185d31 100644
--- a/src/daemon/main.c
+++ b/src/daemon/main.c
@@ -1017,7 +1017,9 @@ int main(int argc, char *argv[]) {
 
     pa_assert_se(mainloop = pa_mainloop_new());
 
-    if (!(c = pa_core_new(pa_mainloop_get_api(mainloop), !conf->disable_shm, conf->shm_size))) {
+    if (!(c = pa_core_new(pa_mainloop_get_api(mainloop), !conf->disable_shm,
+                          !conf->disable_shm && !conf->disable_memfd && pa_memfd_is_locally_supported(),
+                          conf->shm_size))) {
         pa_log(_("pa_core_new() failed."));
         goto finish;
     }