Merge pull request #6 from discosat/dynamic-store-lazy-allocation

allocate memory lazily in dynamic proc store

README.md

@@ -87,8 +87,8 @@ proc run 1  # Run the procedure to log data points when the vehicle is within th
 
 One can then imagine an extended scenario where there is e.g. a third node responsible for some actuator that must react based on the sensor node, which adds another layer of coordination to the system - all this can be orchestrated using the DSL!
 
-### Utilizing reserved, pre-programmable procedure slots
-There is also support for pre-programmed procedures in reserved slots, which can be used to simplify the DSL code or take care of more complex operations. For example, one can write a function compiled into the application on node 1 that calculates the euclidean distance between points defined by (`lat`, `lon`) and (`target_lat`, `target_lon`) and stores the result in the `dist` parameter. For the sake of example, let's assumed this procedure is available in slot 0. Then the geo-fencing setup procedure can be simplified as follows:
+### Utilizing reserved, pre-programmable procedure slots (Not yet fully implemented)
+There is also (_planned_) support for pre-programmed procedures in reserved slots, which can be used to simplify the DSL code or take care of more complex operations. For example, one can write a function compiled into the application on node 1 that calculates the euclidean distance between points defined by (`lat`, `lon`) and (`target_lat`, `target_lon`) and stores the result in the `dist` parameter. For the sake of example, let's assumed this procedure is available in slot 0. Then the geo-fencing setup procedure can be simplified as follows:
 ```bash
 # procedure 1 (geo-fencing setup)
 proc new

include/csp_proc/proc_store.h

@@ -21,7 +21,7 @@ int __attribute__((weak)) delete_proc(uint8_t slot);
 /**
  * Reset the procedure storage.
  */
-void __attribute__((weak)) reset_proc_store();
+int __attribute__((weak)) reset_proc_store();
 
 /**
  * Initialize the procedure storage and any necessary resources.

src/store/proc_store_dynamic.c

@@ -2,17 +2,20 @@
 #include <csp_proc/proc_mutex.h>
 #include <csp_proc/proc_memory.h>
 
-proc_t * proc_store = NULL;
+proc_t * proc_store[MAX_PROC_SLOT + 1];
 proc_mutex_t * proc_store_mutex = NULL;
 
 int _delete_proc(uint8_t slot) {
 	if (slot < 0 || slot > MAX_PROC_SLOT) {
 		return -1;
 	}
-	for (int i = 0; i < proc_store[slot].instruction_count; i++) {
-		proc_free_instruction(&proc_store[slot].instructions[i]);
+	if (proc_store[slot] != NULL) {
+		for (int i = 0; i < proc_store[slot]->instruction_count; i++) {
+			proc_free_instruction(&proc_store[slot]->instructions[i]);
+		}
+		proc_free(proc_store[slot]);
+		proc_store[slot] = NULL;
 	}
-	proc_store[slot].instruction_count = 0;
 	return 0;
 }
 
@@ -25,7 +28,7 @@ int delete_proc(uint8_t slot) {
 	return ret;
 }
 
-void reset_proc_store() {
+int reset_proc_store() {
 	if (proc_mutex_take(proc_store_mutex) != PROC_MUTEX_OK) {
 		return PROC_MUTEX_ERR;
 	}
@@ -40,18 +43,14 @@ int proc_store_init() {
 	if (proc_store_mutex == NULL) {
 		return -1;
 	}
-	proc_store = (proc_t *)proc_calloc(MAX_PROC_SLOT + 1, sizeof(proc_t));
-	if (proc_store == NULL) {
-		proc_mutex_destroy(proc_store_mutex);
-		return -1;
-	}
 	return 0;
 }
 
 void destroy_proc_store() {
 	if (proc_store != NULL) {
-		proc_free(proc_store);
-		proc_store = NULL;
+		for (int i = 0; i < MAX_PROC_SLOT + 1; i++) {
+			_delete_proc(i);
+		}
 	}
 	if (proc_store_mutex != NULL) {
 		proc_mutex_destroy(proc_store_mutex);
@@ -60,43 +59,30 @@ void destroy_proc_store() {
 }
 
 int set_proc(proc_t * proc, uint8_t slot, int overwrite) {
-	if (slot < 0 || slot > MAX_PROC_SLOT) {
-		return -1;
-	}
-	if (proc_mutex_take(proc_store_mutex) != PROC_MUTEX_OK) {
-		return PROC_MUTEX_ERR;
-	}
+	// Free any existing procedure in the slot
+	if (proc_store[slot] != NULL) {
+		if (!overwrite) {
+			return -1;
+		}
 
-	int ret = -1;
-	if (proc_store[slot].instruction_count == 0) {
-		_delete_proc(slot);
-		proc_store[slot] = *proc;
-		ret = slot;
-	} else if (overwrite) {
-		_delete_proc(slot);
-		proc_store[slot] = *proc;
-		ret = slot;
+		proc_free(proc_store[slot]);
 	}
-	proc_mutex_give(proc_store_mutex);
-	return ret;
-}
 
-proc_t * get_proc(uint8_t slot) {
-	if (slot < 0 || slot > MAX_PROC_SLOT) {
-		return NULL;
+	proc_store[slot] = proc_malloc(sizeof(proc_t));
+	if (proc_store[slot] == NULL) {
+		return -1;
 	}
 
-	if (proc_mutex_take(proc_store_mutex) != PROC_MUTEX_OK) {
-		return PROC_MUTEX_ERR;
-	}
+	memcpy(proc_store[slot], proc, sizeof(proc_t));
+
+	return slot;
+}
 
-	if (proc_store[slot].instruction_count == 0) {
-		proc_mutex_give(proc_store_mutex);
+proc_t * get_proc(uint8_t slot) {
+	if (proc_store[slot] == NULL) {
 		return NULL;
 	}
-
-	proc_mutex_give(proc_store_mutex);
-	return &proc_store[slot];
+	return proc_store[slot];
 }
 
 int * get_proc_slots() {
@@ -107,7 +93,7 @@ int * get_proc_slots() {
 		return NULL;
 	}
 	for (int i = 0; i < MAX_PROC_SLOT + 1; i++) {
-		if (proc_store[i].instruction_count > 0) {
+		if (proc_store[i] != NULL) {
 			slots[count++] = i;
 		}
 	}

src/store/proc_store_static.c

@@ -25,7 +25,7 @@ int delete_proc(uint8_t slot) {
 	return ret;
 }
 
-void reset_proc_store() {
+int reset_proc_store() {
 	if (proc_mutex_take(proc_store_mutex) != PROC_MUTEX_OK) {
 		return PROC_MUTEX_ERR;
 	}