Have Meson orchestrate the whole build rather than stack.

As a part of this, I changed the file layout to:

rt/ - the Montis runtime
plug/ - the Montis plugin
wlroots/ - wlroots

1 files changed, 266 insertions, 0 deletions

diff --git a/rt/src/plugin.c b/rt/src/plugin.c
new file mode 100644
index 0000000..37a6dd3
--- /dev/null
+++ b/rt/src/plugin.c
@@ -0,0 +1,266 @@
+#include "plugin.h"
+#include "foreign_intf.h"
+#include "wl.h"
+
+#include <sys/stat.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <dlfcn.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Utility function for showing the marshalled states as hex code */
+static void shx(uint8_t *state, uint32_t sz)
+{
+  uint32_t i = 0;
+  while (i < sz) {
+    for (int j = 0; j < 16; ++j) {
+      if (i < sz) {
+        printf("%02x ", (unsigned int)state[i]);
+      }
+      else {
+        printf("   ");
+      }
+      ++i;
+    }
+
+    i -= 16;
+
+    printf("   ");
+
+    for (int j = 0; j < 16; ++j) {
+      if (i < sz) {
+        if (isprint(state[i]) && !isspace(state[i])) {
+          printf("%c", state[i]);
+        }
+        else {
+          printf(".");
+        }
+      }
+      else {
+        printf(" ");
+      }
+      ++i;
+    }
+    printf("\n");
+  }
+}
+
+int load_plugin_from_dl_(dlhandle_t dl, plugin_t *plug);
+
+static void lock(plugin_t *plugin) { pthread_mutex_lock(&plugin->lock); };
+
+static void unlock(plugin_t *plugin) { pthread_mutex_unlock(&plugin->lock); };
+
+static int plugin_hot_reload_same_state_action_(plugin_t *plugin, void *ignore)
+{
+  return plugin_hot_reload_same_state(plugin);
+}
+
+void do_request_hot_reload(void *plugv)
+{
+  plugin_t *plugin = plugv;
+
+  size_t n = plugin->n_requested_actions++;
+  if (n < 8) {
+    plugin->requested_actions[n].action = plugin_hot_reload_same_state_action_;
+    plugin->requested_actions[n].arg_dtor = NULL;
+  }
+}
+
+static int plugin_do_log(plugin_t *plugin, void *chrs)
+{
+  char *str = chrs;
+  puts(str);
+  return 0;
+}
+
+void do_request_log(void *plugv, const char *str)
+{
+  plugin_t *plugin = plugv;
+
+  size_t n = plugin->n_requested_actions++;
+  if (n < 8) {
+    plugin->requested_actions[n].action = plugin_do_log;
+    plugin->requested_actions[n].str_arg = strdup(str);
+    plugin->requested_actions[n].arg_dtor = free;
+  }
+}
+
+static int plugin_do_exit(void *plugv, int ec)
+{
+  exit(ec);
+  return 0;
+}
+
+void do_request_exit(void *plugv, int ec)
+{
+  plugin_t *plugin = plugv;
+
+  size_t n = plugin->n_requested_actions++;
+  if (n < 8) {
+    plugin->requested_actions[n].action =
+        (int (*)(plugin_t *, void *))plugin_do_exit;
+    plugin->requested_actions[n].int_arg = ec;
+    plugin->requested_actions[n].arg_dtor = NULL;
+  }
+}
+
+static void* plugin_get_seat(void* ctx) {
+  struct montis_server* server = wl_container_of(ctx, server, plugin);
+  return server->seat;
+}
+
+static int load_plugin_from_file_(int argc, char **argv, const char *filename,
+                                  plugin_t *plugin)
+{
+  dlhandle_t lib = dlopen(filename, RTLD_LAZY);
+  int ec = 0;
+
+  if (!lib) {
+    fprintf(stderr, "Failed to open library: %s: %s\n", filename, dlerror());
+    ec = 1;
+    goto end;
+  }
+
+  printf("Loading file.\n");
+  ec = load_plugin_from_dl_(lib, plugin);
+
+  if (ec) {
+    goto end;
+  }
+
+  strncpy(plugin->filename, filename, sizeof(plugin->filename));
+  plugin->argc = argc;
+  plugin->argv = argv;
+
+  plugin->foreign_intf.ctx = plugin;
+  plugin->foreign_intf.request_hot_reload = do_request_hot_reload;
+  plugin->foreign_intf.do_log = do_request_log;
+  plugin->foreign_intf.request_exit = do_request_exit;
+  plugin->foreign_intf.get_seat = plugin_get_seat;
+
+  plugin->plugin_load(plugin->argc, plugin->argv, &plugin->foreign_intf);
+end:
+  return ec;
+}
+
+static void maybe_run_metaload(int argc, char **argv, plugin_t *plugin)
+{
+  static char *loaded_plugins[12];
+  int i;
+  for (i = 0; i < 12 && loaded_plugins[i]; ++i) {
+    if (strcmp(loaded_plugins[i], plugin->plugin_name) == 0) {
+      return; // Plugin is already loaded
+    }
+  }
+  loaded_plugins[i] = strdup(plugin->plugin_name);
+
+  printf("First time loading %s, running metaload.\n", plugin->plugin_name);
+  if (plugin->plugin_metaload) {
+    plugin->plugin_metaload(argc, argv);
+  }
+}
+
+int load_plugin_from_file(int argc, char **argv, const char *filename,
+                          plugin_t *plugin)
+{
+  memset(plugin, 0, sizeof(*plugin));
+
+  pthread_mutexattr_t attr;
+  if (pthread_mutexattr_init(&attr)) {
+    perror("pthread_mutexattr_init");
+    return 1;
+  }
+
+  if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
+    perror("pthread_mutexattr_settype");
+    return 1;
+  }
+
+  if (pthread_mutex_init(&plugin->lock, &attr)) {
+    pthread_mutexattr_destroy(&attr);
+    perror("pthread_mutexattr_init");
+    return 1;
+  }
+  pthread_mutexattr_destroy(&attr);
+  int rc = load_plugin_from_file_(argc, argv, filename, plugin);
+
+  if (rc == 0) {
+    maybe_run_metaload(argc, argv, plugin);
+  }
+
+  return rc;
+}
+
+int plugin_hot_reload_same_state(plugin_t *plugin)
+{
+  char filename_cpy[PATH_MAX];
+  strncpy(filename_cpy, plugin->filename, sizeof(filename_cpy));
+  return plugin_hot_reload(plugin->argc, plugin->argv, filename_cpy, plugin);
+}
+
+int plugin_hot_reload(int argc, char **argv, const char *filepath,
+                      plugin_t *plugin)
+{
+  int ec = 0;
+  uint32_t sz = 0;
+  uint8_t *marshalled_state = NULL;
+
+  printf("Hot Reloading %s\n", plugin->plugin_name);
+  lock(plugin);
+
+  printf("Marshalling state ...\n");
+  marshalled_state = plugin->plugin_marshal_state(plugin->state, &sz);
+
+  printf("Calling teardown ...\n");
+  plugin->plugin_teardown(plugin->state);
+
+  printf("State Marshalled:\n");
+  shx(marshalled_state, sz);
+
+  printf("Unloading old library handle.\n");
+  if (dlclose(plugin->library_handle)) {
+    printf("Could not close library handle: %s\n", dlerror());
+  }
+
+  if ((ec = load_plugin_from_file_(argc, argv, filepath, plugin))) {
+    goto fail;
+  }
+
+  printf("Hot starting plugin ...\n");
+  plugin->state = plugin->plugin_hot_start(marshalled_state, sz);
+
+fail:
+  free(marshalled_state);
+  unlock(plugin);
+  return ec;
+}
+
+void plugin_run_requested_actions(plugin_t *plugin)
+{
+  lock(plugin);
+  requested_action_t requested_actions[MAX_QUEUED_ACTIONS];
+  size_t n_requested_actions = plugin->n_requested_actions;
+  memcpy(&requested_actions, plugin->requested_actions,
+         sizeof(requested_actions));
+  plugin->n_requested_actions = 0;
+  unlock(plugin);
+
+  size_t i;
+  for (i = 0; i < n_requested_actions; ++i) {
+    requested_actions[i].action(plugin, requested_actions[i].str_arg);
+    if (requested_actions[i].arg_dtor) {
+      requested_actions[i].arg_dtor(requested_actions[i].ptr_arg);
+    }
+  }
+}
+
+void plugin_cold_start(plugin_t *plugin)
+{
+  lock(plugin);
+  plugin->state = plugin->plugin_cold_start();
+  unlock(plugin);
+}