Merge pull request #1395 from LudwigOrtmann/transceiver_unregister

sys/transceiver: add transceiver_unregister and refactor transceiver_register

sys/include/transceiver.h

@@ -228,5 +228,15 @@ int transceiver_start(void);
  */
 uint8_t transceiver_register(transceiver_type_t transceivers, int pid);
 
+/**
+ * @brief unregister a thread for events from certain transceivers
+ *
+ * @param transceivers  The transceiver types to register for
+ * @param pid           The pid of the thread to register
+ *
+ * @return              1 on success, 0 otherwise
+ */
+uint8_t transceiver_unregister(transceiver_type_t transceivers, int pid);
+
 #endif /* TRANSCEIVER_H */
 /** @} */

sys/transceiver/transceiver.c

@@ -233,22 +233,37 @@ int transceiver_start(void)
 /* Register an upper layer thread */
 uint8_t transceiver_register(transceiver_type_t t, int pid)
 {
-    uint8_t i;
-
-    /* find pid in registered threads or first unused space */
-    for (i = 0; ((i < TRANSCEIVER_MAX_REGISTERED) &&
-                 (reg[i].pid != pid) &&
-                 (reg[i].transceivers != TRANSCEIVER_NONE)); i++);
-
-    if (i >= TRANSCEIVER_MAX_REGISTERED) {
-        return ENOMEM;
+    int result = 0;
+    int state = disableIRQ();
+    for (size_t i = 0; i < TRANSCEIVER_MAX_REGISTERED; i++) {
+        if ((reg[i].pid == pid) || (reg[i].transceivers == TRANSCEIVER_NONE)) {
+            reg[i].transceivers |= t;
+            reg[i].pid = pid;
+            DEBUG("transceiver: Thread %i registered for %i\n", reg[i].pid, reg[i].transceivers);
+            restoreIRQ(state);
+            result = 1;
+            break;
+        }
     }
-    else {
-        reg[i].transceivers |= t;
-        reg[i].pid         = pid;
-        DEBUG("transceiver: Thread %i registered for %i\n", reg[i].pid, reg[i].transceivers);
-        return 1;
+    restoreIRQ(state);
+    return result;
+}
+
+/* Unregister an upper layer thread */
+uint8_t transceiver_unregister(transceiver_type_t t, int pid)
+{
+    int result = 0;
+    int state = disableIRQ();
+    for (size_t i = 0; i < TRANSCEIVER_MAX_REGISTERED; ++i) {
+        if (reg[i].pid == pid) {
+            reg[i].transceivers &= ~t;
+            restoreIRQ(state);
+            result = 1;
+            break;
+        }
     }
+    restoreIRQ(state);
+    return result;
 }
 
 /*------------------------------------------------------------------------------------*/
@@ -465,7 +480,7 @@ static void receive_packet(uint16_t type, uint8_t pos)
 
 #ifdef DBG_IGNORE
 
-        for (uint8_t i = 0; (i < TRANSCEIVER_MAX_IGNORED_ADDR) && (transceiver_ignored_addr[i]); i++) {
+        for (size_t i = 0; (i < TRANSCEIVER_MAX_IGNORED_ADDR) && (transceiver_ignored_addr[i]); i++) {
             DEBUG("check if source (%u) is ignored -> %u\n", transceiver_buffer[transceiver_buffer_pos].src, transceiver_ignored_addr[i]);
 
             if (transceiver_buffer[transceiver_buffer_pos].src == transceiver_ignored_addr[i]) {
@@ -1223,7 +1238,7 @@ static int16_t ignore_add(transceiver_type_t transceiver, void *address)
     (void) transceiver;
     radio_address_t addr = *((radio_address_t *)address);
 
-    for (uint8_t i = 0; i < TRANSCEIVER_MAX_IGNORED_ADDR; i++) {
+    for (size_t i = 0; i < TRANSCEIVER_MAX_IGNORED_ADDR; i++) {
         if (transceiver_ignored_addr[i] == 0) {
             transceiver_ignored_addr[i] = addr;
             DEBUG("addr %u will be ignored (%u)\n", addr, i);