kern/{log,shell}: use a bulletin for initial log dump notification

4 files changed, 49 insertions, 56 deletions

diff --git a/kern/log.c b/kern/log.c
index 0e988a60..2d2206ca 100644
--- a/kern/log.c
+++ b/kern/log.c
@@ -26,6 +26,7 @@
 #include <string.h>
 
 #include <kern/arg.h>
+#include <kern/bulletin.h>
 #include <kern/init.h>
 #include <kern/log.h>
 #include <kern/macros.h>
@@ -54,9 +55,8 @@ static char log_buffer[LOG_BUFFER_SIZE];
 
 static unsigned int log_nr_overruns;
 
-#ifdef CONFIG_SHELL
-static bool log_shell_started = false;
-#endif
+static bool log_bulletin_published;
+static struct bulletin log_bulletin;
 
 /*
  * Global lock.
@@ -141,25 +141,6 @@ log_print_record(const struct log_record *record, unsigned int level)
     }
 }
 
-#ifdef CONFIG_SHELL
-
-static void
-log_start_shell(unsigned long *flags)
-{
-    if (log_shell_started) {
-        return;
-    }
-
-    log_shell_started = true;
-    spinlock_unlock_intr_restore(&log_lock, *flags);
-    shell_start();
-    spinlock_lock_intr_save(&log_lock, flags);
-}
-
-#else /* CONFIG_SHELL */
-#define log_start_shell(flags)
-#endif /* CONFIG_SHELL */
-
 static void
 log_run(void *arg)
 {
@@ -191,12 +172,10 @@ log_run(void *arg)
                 break;
             }
 
-            /*
-             * Starting the shell when the log thread sleeps for the first
-             * time serializes log messages and shell prompt, resulting in
-             * a clean ordered output.
-             */
-            log_start_shell(&flags);
+            if (!log_bulletin_published) {
+                bulletin_publish(&log_bulletin, 0);
+                log_bulletin_published = true;
+            }
 
             thread_sleep(&log_lock, &log_mbuf, "log_mbuf");
         }
@@ -297,6 +276,7 @@ log_setup(void)
     mbuf_init(&log_mbuf, log_buffer, sizeof(log_buffer),
               sizeof(struct log_record));
     spinlock_init(&log_lock);
+    bulletin_init(&log_bulletin);
 
     boot_log_info();
     arg_log_info();
@@ -539,3 +519,9 @@ log_vdebug(const char *format, va_list ap)
 {
     return log_vmsg(LOG_DEBUG, format, ap);
 }
+
+struct bulletin *
+log_get_bulletin(void)
+{
+    return &log_bulletin;
+}
diff --git a/kern/log.h b/kern/log.h
index 2f7882bd..554dbb27 100644
--- a/kern/log.h
+++ b/kern/log.h
@@ -85,6 +85,12 @@ int log_vdebug(const char *format, va_list ap)
     __attribute__((format(printf, 1, 0)));
 
 /*
+ * The bulletin returned by this function is used to notify the initial log
+ * dump so that console output is well ordered.
+ */
+struct bulletin * log_get_bulletin(void);
+
+/*
  * This init operation provides :
  *  - message logging
  *
diff --git a/kern/shell.c b/kern/shell.c
index 1fff5d26..65c995d6 100644
--- a/kern/shell.c
+++ b/kern/shell.c
@@ -26,6 +26,7 @@
 #include <stdint.h>
 #include <string.h>
 
+#include <kern/bulletin.h>
 #include <kern/hash.h>
 #include <kern/init.h>
 #include <kern/log.h>
@@ -67,6 +68,8 @@ struct shell_esc_seq {
 #define SHELL_ERASE_BS  '\b'
 #define SHELL_ERASE_DEL '\x7f'
 
+static struct bulletin_sub shell_log_bulletin_sub;
+
 static const char *
 shell_find_word(const char *str)
 {
@@ -1114,7 +1117,7 @@ shell_process_ctrl_char(struct shell *shell, char c)
     return 0;
 }
 
-void
+static void
 shell_run(struct shell *shell)
 {
     int c, error, escape;
@@ -1204,12 +1207,37 @@ shell_main_vfprintf(void *io_object, const char *format, va_list ap)
     vprintf(format, ap);
 }
 
+static void
+shell_main_run(void *arg)
+{
+    shell_run(arg);
+}
+
+static void
+shell_start(uintptr_t value, void *arg)
+{
+    struct thread_attr attr;
+    struct thread *thread;
+    int error;
+
+    (void)value;
+    (void)arg;
+
+    thread_attr_init(&attr, THREAD_KERNEL_PREFIX "shell");
+    thread_attr_set_detached(&attr);
+    error = thread_create(&thread, &attr, shell_main_run, &shell_main);
+    error_check(error, "thread_create");
+}
+
 static int __init
 shell_setup(void)
 {
     shell_cmd_set_init(&shell_main_cmd_set);
     shell_init(&shell_main, &shell_main_cmd_set,
                shell_main_getc, shell_main_vfprintf, NULL);
+    bulletin_subscribe(log_get_bulletin(), &shell_log_bulletin_sub,
+                       shell_start, NULL);
+
     return 0;
 }
 
@@ -1223,22 +1251,3 @@ shell_get_main_cmd_set(void)
 {
     return &shell_main_cmd_set;
 }
-
-static void
-shell_main_run(void *arg)
-{
-    shell_run(arg);
-}
-
-void __init
-shell_start(void)
-{
-    struct thread_attr attr;
-    struct thread *thread;
-    int error;
-
-    thread_attr_init(&attr, THREAD_KERNEL_PREFIX "shell");
-    thread_attr_set_detached(&attr);
-    error = thread_create(&thread, &attr, shell_main_run, &shell_main);
-    error_check(error, "thread_create");
-}
diff --git a/kern/shell.h b/kern/shell.h
index bde2a341..c01c719d 100644
--- a/kern/shell.h
+++ b/kern/shell.h
@@ -115,13 +115,6 @@ void shell_init(struct shell *shell, struct shell_cmd_set *cmd_set,
                 void *io_object);
 
 /*
- * Run the shell.
- *
- * This function doesn't return.
- */
-void shell_run(struct shell *shell);
-
-/*
  * Obtain the command set associated with a shell.
  */
 struct shell_cmd_set * shell_get_cmd_set(struct shell *shell);
@@ -141,6 +134,5 @@ void shell_vprintf(struct shell *shell, const char *format, va_list ap)
 INIT_OP_DECLARE(shell_setup);
 
 struct shell_cmd_set * shell_get_main_cmd_set(void);
-void shell_start(void);
 
 #endif /* KERN_SHELL_H */