AP_Scripting: Support libraries holding the scheduler lock

libraries/AP_Scripting/generator/description/bindings.desc

@@ -144,6 +144,7 @@ singleton GCS method set_message_interval MAV_RESULT'enum uint8_t 0 MAVLINK_COMM
 
 include AP_Vehicle/AP_Vehicle.h
 singleton AP_Vehicle alias vehicle
+singleton AP_Vehicle scheduler-semaphore
 singleton AP_Vehicle method set_mode boolean uint8_t 0 UINT8_MAX ModeReason::SCRIPTING'literal
 singleton AP_Vehicle method get_mode uint8_t
 singleton AP_Vehicle method get_likely_flying boolean

libraries/AP_Scripting/generator/src/main.c

@@ -7,20 +7,21 @@
 #include <unistd.h>
 #include <getopt.h>
 
-char keyword_alias[]     = "alias";
-char keyword_ap_object[] = "ap_object";
-char keyword_comment[]   = "--";
-char keyword_depends[]   = "depends";
-char keyword_enum[]      = "enum";
-char keyword_field[]     = "field";
-char keyword_include[]   = "include";
-char keyword_method[]    = "method";
-char keyword_operator[]  = "operator";
-char keyword_read[]      = "read";
-char keyword_semaphore[] = "semaphore";
-char keyword_singleton[] = "singleton";
-char keyword_userdata[]  = "userdata";
-char keyword_write[]     = "write";
+char keyword_alias[]               = "alias";
+char keyword_ap_object[]           = "ap_object";
+char keyword_comment[]             = "--";
+char keyword_depends[]             = "depends";
+char keyword_enum[]                = "enum";
+char keyword_field[]               = "field";
+char keyword_include[]             = "include";
+char keyword_method[]              = "method";
+char keyword_operator[]            = "operator";
+char keyword_read[]                = "read";
+char keyword_scheduler_semaphore[] = "scheduler-semaphore";
+char keyword_semaphore[]           = "semaphore";
+char keyword_singleton[]           = "singleton";
+char keyword_userdata[]            = "userdata";
+char keyword_write[]               = "write";
 
 // attributes (should include the leading ' )
 char keyword_attr_enum[]    = "'enum";
@@ -298,7 +299,8 @@ struct userdata_field {
 };
 
 enum userdata_flags {
-  UD_FLAG_SEMAPHORE = (1U << 0),
+  UD_FLAG_SEMAPHORE         = (1U << 0),
+  UD_FLAG_SCHEDULER_SEMAPHORE = (1U << 1),
 };
 
 struct userdata_enum {
@@ -788,6 +790,8 @@ void handle_singleton(void) {
 
   } else if (strcmp(type, keyword_semaphore) == 0) {
     node->flags |= UD_FLAG_SEMAPHORE;
+  } else if (strcmp(type, keyword_scheduler_semaphore) == 0) {
+    node->flags |= UD_FLAG_SCHEDULER_SEMAPHORE;
   } else if (strcmp(type, keyword_method) == 0) {
     handle_method(node->name, &(node->methods));
   } else if (strcmp(type, keyword_enum) == 0) {
@@ -845,12 +849,19 @@ void handle_ap_object(void) {
 
   } else if (strcmp(type, keyword_semaphore) == 0) {
     node->flags |= UD_FLAG_SEMAPHORE;
+  } else if (strcmp(type, keyword_scheduler_semaphore) == 0) {
+    node->flags |= UD_FLAG_SCHEDULER_SEMAPHORE;
   } else if (strcmp(type, keyword_method) == 0) {
     handle_method(node->name, &(node->methods));
   } else {
     error(ERROR_SINGLETON, "AP_Objects only support aliases, methods or semaphore keyowrds (got %s)", type);
   }
 
+  // check that we didn't just add 2 singleton flags
+  if ((node->flags & UD_FLAG_SEMAPHORE) && (node->flags & UD_FLAG_SCHEDULER_SEMAPHORE)) {
+    error(ERROR_SINGLETON, "Taking both a library semaphore and scheduler semaphore is prohibited");
+  }
+
   // ensure no more tokens on the line
   if (next_token()) {
     error(ERROR_HEADER, "Singleton contained an unexpected extra token: %s", state.token);
@@ -1345,6 +1356,10 @@ void emit_userdata_method(const struct userdata *data, const struct method *meth
     fprintf(source, "    ud->get_semaphore().take_blocking();\n");
   }
 
+  if (data->flags & UD_FLAG_SCHEDULER_SEMAPHORE) {
+    fprintf(source, "    AP::scheduler().get_semaphore().take_blocking();\n");
+  }
+
   switch (method->return_type.type) {
     case TYPE_BOOLEAN:
       fprintf(source, "    const bool data = ud->%s(", method->name);
@@ -1433,6 +1448,10 @@ void emit_userdata_method(const struct userdata *data, const struct method *meth
     fprintf(source, "    ud->get_semaphore().give();\n");
   }
 
+  if (data->flags & UD_FLAG_SCHEDULER_SEMAPHORE) {
+    fprintf(source, "    AP::scheduler().get_semaphore().give();\n");
+  }
+
   int return_count = 1; // number of arguments to return
   switch (method->return_type.type) {
     case TYPE_BOOLEAN:

libraries/AP_Scripting/lua_generated_bindings.cpp

@@ -735,8 +735,10 @@ static int AP_Vehicle_get_time_flying_ms(lua_State *L) {
     }
 
     binding_argcheck(L, 1);
+    AP::scheduler().get_semaphore().take_blocking();
     const uint32_t data = ud->get_time_flying_ms();
 
+    AP::scheduler().get_semaphore().give();
         new_uint32_t(L);
         *static_cast<uint32_t *>(luaL_checkudata(L, -1, "uint32_t")) = data;
     return 1;
@@ -749,8 +751,10 @@ static int AP_Vehicle_get_likely_flying(lua_State *L) {
     }
 
     binding_argcheck(L, 1);
+    AP::scheduler().get_semaphore().take_blocking();
     const bool data = ud->get_likely_flying();
 
+    AP::scheduler().get_semaphore().give();
     lua_pushboolean(L, data);
     return 1;
 }
@@ -762,8 +766,10 @@ static int AP_Vehicle_get_mode(lua_State *L) {
     }
 
     binding_argcheck(L, 1);
+    AP::scheduler().get_semaphore().take_blocking();
     const uint8_t data = ud->get_mode();
 
+    AP::scheduler().get_semaphore().give();
     lua_pushinteger(L, data);
     return 1;
 }
@@ -778,10 +784,12 @@ static int AP_Vehicle_set_mode(lua_State *L) {
     const lua_Integer raw_data_2 = luaL_checkinteger(L, 2);
     luaL_argcheck(L, ((raw_data_2 >= MAX(0, 0)) && (raw_data_2 <= MIN(UINT8_MAX, UINT8_MAX))), 2, "argument out of range");
     const uint8_t data_2 = static_cast<uint8_t>(raw_data_2);
+    AP::scheduler().get_semaphore().take_blocking();
     const bool data = ud->set_mode(
             data_2,
             ModeReason::SCRIPTING);
 
+    AP::scheduler().get_semaphore().give();
     lua_pushboolean(L, data);
     return 1;
 }