Obey timeout value on SerialUART.read/.peek (earlephilhower#211)

earlephilhower · web-flow · commit 30704a7c5e43 · 2021-06-13T14:11:23.000-07:00
Fixes a hang when reading from the Serial UART ports because before the core would pause indefinitely for the next character. Now, wait up to Serial.setTimeout() milliseconds and if it times out return -1 to the app. Fixes earlephilhower#210
diff --git a/cores/rp2040/SerialUART.cpp b/cores/rp2040/SerialUART.cpp
@@ -115,7 +115,11 @@ int SerialUART::peek() {
     if (_peek >= 0) {
         return _peek;
     }
-    _peek = uart_getc(_uart);
+    if (uart_is_readable_within_us(_uart, _timeout * 1000)) {
+        _peek = uart_getc(_uart);
+    } else {
+        _peek = -1; // Timeout
+    }
     return _peek;
 }
 
@@ -129,7 +133,11 @@ int SerialUART::read() {
         _peek = -1;
         return ret;
     }
-    return uart_getc(_uart);
+    if (uart_is_readable_within_us(_uart, _timeout * 1000)) {
+        return uart_getc(_uart);
+    } else {
+        return -1; // Timeout
+    }
 }
 
 int SerialUART::available() {

Original file line number	Diff line number	Diff line change
`@@ -115,7 +115,11 @@ int SerialUART::peek() {`
`115`	`115`	`if (_peek >= 0) {`
`116`	`116`	`return _peek;`
`117`	`117`	`}`
`118`		`- _peek = uart_getc(_uart);`
	`118`	`+ if (uart_is_readable_within_us(_uart, _timeout * 1000)) {`
	`119`	`+ _peek = uart_getc(_uart);`
	`120`	`+ } else {`
	`121`	`+ _peek = -1; // Timeout`
	`122`	`+ }`
`119`	`123`	`return _peek;`
`120`	`124`	`}`
`121`	`125`
`@@ -129,7 +133,11 @@ int SerialUART::read() {`
`129`	`133`	`_peek = -1;`
`130`	`134`	`return ret;`
`131`	`135`	`}`
`132`		`- return uart_getc(_uart);`
	`136`	`+ if (uart_is_readable_within_us(_uart, _timeout * 1000)) {`
	`137`	`+ return uart_getc(_uart);`
	`138`	`+ } else {`
	`139`	`+ return -1; // Timeout`
	`140`	`+ }`
`133`	`141`	`}`
`134`	`142`
`135`	`143`	`int SerialUART::available() {`