Shell threadless

include/zephyr/shell/shell.h

@@ -822,11 +822,10 @@
 };
 
 enum shell_signal {
-	SHELL_SIGNAL_RXRDY,
-	SHELL_SIGNAL_LOG_MSG,
-	SHELL_SIGNAL_KILL,
-	SHELL_SIGNAL_TXDONE, /* TXDONE must be last one before SHELL_SIGNALS */
-	SHELL_SIGNALS
+	SHELL_SIGNAL_RXRDY = BIT(0),
+	SHELL_SIGNAL_LOG_MSG = BIT(1),
+	SHELL_SIGNAL_KILL = BIT(2),
+	SHELL_SIGNAL_TXDONE = BIT(3),
 };
 
 /**
@@ -884,15 +883,11 @@
 	volatile union shell_backend_cfg cfg;
 	volatile union shell_backend_ctx ctx;
 
-	struct k_poll_signal signals[SHELL_SIGNALS];
-
-	/** Events that should be used only internally by shell thread.
-	 * Event for SHELL_SIGNAL_TXDONE is initialized but unused.
-	 */
-	struct k_poll_event events[SHELL_SIGNALS];
-
-	struct k_mutex wr_mtx;
+#if CONFIG_MULTITHREADING
+	struct k_event signal_event;
+	struct k_sem lock_sem;
 	k_tid_t tid;
+#endif
 	int ret_val;
 };
 
@@ -928,13 +923,29 @@
 	LOG_INSTANCE_PTR_DECLARE(log);
 
 	const char *name;
+
+#if CONFIG_MULTITHREADING
 	struct k_thread *thread;
 	k_thread_stack_t *stack;
+#endif
 };
 
 extern void z_shell_print_stream(const void *user_ctx, const char *data,
 				 size_t data_len);
 
+#if CONFIG_MULTITHREADING
+#define Z_SHELL_THREAD_DEFINE(_name)                                                               \
+	static K_KERNEL_STACK_DEFINE(_name##_stack, CONFIG_SHELL_STACK_SIZE);                      \
+	static struct k_thread _name##_thread
+
+#define Z_SHELL_THREAD_INIT(_name)                                                                 \
+	.thread = &_name##_thread,                                                                 \
+	.stack = _name##_stack,
+#else
+#define Z_SHELL_THREAD_DEFINE(_name)
+#define Z_SHELL_THREAD_INIT(_name)
+#endif
+
 /** @brief Internal macro for defining a shell instance.
  *
  * As it does not create the default shell logging backend it allows to use
@@ -955,8 +966,7 @@
 			       IS_ENABLED(CONFIG_SHELL_PRINTF_AUTOFLUSH), z_shell_print_stream);   \
 	LOG_INSTANCE_REGISTER(shell, _name, CONFIG_SHELL_LOG_LEVEL);                               \
 	Z_SHELL_STATS_DEFINE(_name);                                                               \
-	static K_KERNEL_STACK_DEFINE(_name##_stack, CONFIG_SHELL_STACK_SIZE);                      \
-	static struct k_thread _name##_thread;                                                     \
+	Z_SHELL_THREAD_DEFINE(_name);                                                              \
 	static const STRUCT_SECTION_ITERABLE(shell, _name) = {                                     \
 		.default_prompt = _prompt,                                                         \
 		.iface = _transport_iface,                                                         \
@@ -966,9 +976,10 @@
 		.fprintf_ctx = &_name##_fprintf,                                                   \
 		.stats = Z_SHELL_STATS_PTR(_name),                                                 \
 		.log_backend = _log_backend,                                                       \
-		LOG_INSTANCE_PTR_INIT(log, shell, _name).name =                                    \
-			STRINGIFY(_name), .thread = &_name##_thread, .stack = _name##_stack}
+		LOG_INSTANCE_PTR_INIT(log, shell, _name).name = STRINGIFY(_name),                  \
+		Z_SHELL_THREAD_INIT(_name)                                                         \
+	}
 
 /**
  * @brief Macro for defining a shell instance.
  *

subsys/shell/Kconfig

@@ -8,7 +8,7 @@
 menuconfig SHELL
 	bool "Shell"
 	imply LOG_RUNTIME_FILTERING
-	select POLL
+	select EVENTS if MULTITHREADING
 
 if SHELL
 
@@ -326,6 +326,16 @@ config SHELL_CUSTOM_HEADER
 	  extension of the shell APIs at the macro level. Please use cautiously!
 	  The internal shell API may change in future releases.
 
+config SHELL_TX_TIMEOUT_MS
+	int "Shell TX timeout in milliseconds"
+	default 500 if SHELL_LOG_BACKEND
+	default 50
+	help
+	  The timeout in milliseconds for the shell TX mutex. This is used to
+	  prevent deadlocks when called from other than the shell's processing thread.
+	  When using the shell log backend, the timeout should be longer to avoid
+	  timeouts due to log processing. A value of 0 means no timeout.
+
 source "subsys/shell/modules/Kconfig"
 
 endif # SHELL