cpu/native: use async read for stdio_read()

[benpicco]

Contribution description

The real_read() function will block the thread but won't preempt it.
That means all other threads on the same (or higher) priority level are blocked as RIOT still considers the thread that called stdio_read() as running.

Use async_read/isrpipe to properly block the thread when reading from stdin.

Testing procedure

Run a 2nd thread with the same priority as the main thread:

--- a/tests/shell/main.c
+++ b/tests/shell/main.c
@@ -132,10 +132,28 @@ static int _xfa_test2(int argc, char **argv)
 SHELL_COMMAND(xfa_test2, "xfa test command 2", _xfa_test2);
 SHELL_COMMAND(xfa_test1, "xfa test command 1", _xfa_test1);
 
+#include "thread.h"
+#include "ztimer.h"
+
+static char _stack[1024];
+
+static void *_func(void *arg)
+{
+    while (1) {
+        ztimer_sleep(ZTIMER_MSEC, 1000);
+        puts(arg);
+    }
+
+    return NULL;
+}
+
 int main(void)
 {
     printf("test_shell.\n");
 
+    thread_create(_stack, sizeof(_stack), THREAD_PRIORITY_MAIN, THREAD_CREATE_STACKTEST,
+                  _func, "Hello shell", "periodic");
+
     /* define own shell commands */
     shell_run_once(shell_commands, line_buf, sizeof(line_buf));

On master the periodic "Hello shell" message is never printed.

Issues/PRs references

fixes #16834

[riot-ci]

Murdock results

❌ FAILED

41ce809 sys/net/telnet: align API with stdio API

Build failures (10)

Application	Target	Toolchain	Runtime (s)	Worker
tests/pkg/libschc	native64	llvm	290.08	comsys-minion-0
tests/pkg/libschc	native	llvm	290.10	mobi7
tests/pkg/libschc	native	gnu	290.01	mobi7
tests/pkg/libschc	native64	gnu	290.11	sarajevo
tests/sys/congure_quic	native64	gnu	290.01	breeze
tests/sys/congure_quic	native	llvm	290.01	mobi3
tests/sys/congure_quic	native64	llvm	290.10	mobi6
tests/sys/congure_quic	native	gnu	290.08	comsys-minion-0
tests/sys/congure_test	native	gnu	290.10	mobi6
tests/sys/congure_test	native64	llvm	290.10	mobi6

Test failures (21)

Application	Target	Toolchain	Runtime (s)	Worker
tests/periph/flashpage	native64	gnu	0.00	mobi6
tests/periph/gpio	native64	gnu	0.00	mobi6
tests/periph/gpio	native	llvm	0.00	mobi6
tests/pkg/flatbuffers	native	gnu	0.00	mobi6
tests/pkg/uzlib	native64	gnu	0.00	mobi6
tests/pkg/uzlib	native64	llvm	0.00	mobi3
tests/sys/atomic_utils	native	gnu	0.00	mobi6
tests/sys/atomic_utils	native64	gnu	0.00	mobi6
tests/sys/atomic_utils	native	llvm	0.00	mobi6
tests/sys/cpp11_mutex	native	gnu	0.00	comsys-minion-0
tests/sys/rng	native	gnu	0.00	breeze
tests/sys/rng	native	llvm	0.00	comsys-minion-0
tests/sys/rng	native64	gnu	0.00	mobi6
tests/sys/senml_cbor	native64	llvm	0.00	sarajevo
tests/sys/senml_cbor	native64	gnu	0.00	mobi3
tests/sys/senml_cbor	native	gnu	0.00	mobi6
tests/sys/senml_cbor	native	llvm	0.00	mobi6
tests/sys/senml_phydat	native	gnu	0.00	mobi6
tests/sys/senml_phydat	native	llvm	0.00	breeze
tests/sys/struct_tm_utility	native64	gnu	0.00	mobi6

and 57 more test failures...

Artifacts

[benpicco]

@leandrolanzieri do you have an idea how to solve the Kconfig issue?

[gschorcht]

Looks good and works as expected.

[gschorcht]

Please squash.

[benpicco]

CI will still fail as some tests that use float will now preempt, which triggers #495