cpukit/shell: Replace task variables with posix keys.

Use posix keys for current shell environment instead of task variables. With
this patch the shell needs one posix-key and one posix-key-value-pair
configured.

Update documentation for the shell.

Adapt samples/fileio:
- Add necessary objects.
- Add login function and custom device name for better testing of the shell.

5 files changed, 49 insertions, 22 deletions

diff --git a/cpukit/libmisc/shell/shell.c b/cpukit/libmisc/shell/shell.c
index 90bb51253e..9fa56b6081 100644
--- a/cpukit/libmisc/shell/shell.c
+++ b/cpukit/libmisc/shell/shell.c
@@ -37,8 +37,10 @@
 #include <unistd.h>
 #include <errno.h>
 #include <pwd.h>
+#include <pthread.h>
+#include <assert.h>
 
-rtems_shell_env_t rtems_global_shell_env = {
+static rtems_shell_env_t rtems_global_shell_env = {
   .magic         = rtems_build_name('S', 'E', 'N', 'V'),
   .devname       = CONSOLE_DEVICE_NAME,
   .taskname      = "SHGL",
@@ -54,7 +56,8 @@ rtems_shell_env_t rtems_global_shell_env = {
   .login_check   = NULL
 };
 
-rtems_shell_env_t *rtems_current_shell_env = &rtems_global_shell_env;
+static pthread_once_t rtems_shell_current_env_once = PTHREAD_ONCE_INIT;
+static pthread_key_t rtems_shell_current_env_key;
 
 /*
  *  Initialize the shell user/process environment information
@@ -99,6 +102,24 @@ static void rtems_shell_env_free(
 }
 
 /*
+ *  Create the posix key.
+ */
+static void rtems_shell_current_env_make_key(void)
+{
+  (void) pthread_key_create(&rtems_shell_current_env_key, rtems_shell_env_free);
+}
+
+/*
+ *  Return the current shell environment
+ */
+rtems_shell_env_t *rtems_shell_get_current_env(void)
+{
+  void *ptr = pthread_getspecific(rtems_shell_current_env_key);
+  assert (ptr != NULL);
+  return (rtems_shell_env_t *) ptr;
+}
+
+/*
  *  Get a line of user input with modest features
  */
 static int rtems_shell_line_editor(
@@ -650,6 +671,7 @@ bool rtems_shell_main_loop(
   rtems_shell_env_t *shell_env;
   rtems_shell_cmd_t *shell_cmd;
   rtems_status_code  sc;
+  int                eno;
   struct termios     term;
   struct termios     previous_term;
   char              *prompt = NULL;
@@ -667,23 +689,21 @@ bool rtems_shell_main_loop(
 
   rtems_shell_initialize_command_set();
 
-  shell_env =
-  rtems_current_shell_env = rtems_shell_init_env( shell_env_arg );
-
-  /*
-   * @todo chrisj
-   * Remove the use of task variables. Change to have a single
-   * allocation per shell and then set into a notepad register
-   * in the TCB. Provide a function to return the pointer.
-   * Task variables are a virus to embedded systems software.
-   */
-  sc = rtems_task_variable_add(
-    RTEMS_SELF,
-    (void*)&rtems_current_shell_env,
-    rtems_shell_env_free
+  eno = pthread_once(
+    &rtems_shell_current_env_once,
+    rtems_shell_current_env_make_key
   );
-  if (sc != RTEMS_SUCCESSFUL) {
-    rtems_error(sc,"rtems_task_variable_add(current_shell_env):");
+  assert(eno == 0);
+
+  shell_env = rtems_shell_init_env(shell_env_arg);
+  if (shell_env == NULL) {
+    rtems_error(0, "rtems_shell_init_env");
+    return false;
+  }
+
+  eno = pthread_setspecific(rtems_shell_current_env_key, shell_env);
+  if (eno != 0) {
+    rtems_error(0, "pthread_setspecific(shell_current_env_key)");
     return false;
   }
 
diff --git a/cpukit/libmisc/shell/shell.h b/cpukit/libmisc/shell/shell.h
index 079ef667af..af09ac3a38 100644
--- a/cpukit/libmisc/shell/shell.h
+++ b/cpukit/libmisc/shell/shell.h
@@ -205,8 +205,8 @@ bool rtems_shell_main_loop(
   rtems_shell_env_t *rtems_shell_env
 );
 
-extern rtems_shell_env_t  rtems_global_shell_env;
-extern rtems_shell_env_t *rtems_current_shell_env;
+rtems_shell_env_t *rtems_shell_get_current_env(void);
+#define rtems_current_shell_env rtems_shell_get_current_env()
 
 /*
  * The types of file systems we can mount. We have them broken out
diff --git a/doc/shell/confinit.t b/doc/shell/confinit.t
index 6c8a23bd58..eb85fe18cb 100644
--- a/doc/shell/confinit.t
+++ b/doc/shell/confinit.t
@@ -252,3 +252,6 @@ This method invokes the @code{rtems_task_create} and @code{rtems_task_start}
 directives and as such may return any status code that those directives
 may return.
 
+There is one POSIX key necessary for all shell instances together and one POSIX
+key value pair per instance. You should make sure that your RTEMS configuration
+accounts for these resources.
diff --git a/testsuites/samples/fileio/init.c b/testsuites/samples/fileio/init.c
index 80da4ab0a6..2a0f9db1c3 100644
--- a/testsuites/samples/fileio/init.c
+++ b/testsuites/samples/fileio/init.c
@@ -708,10 +708,11 @@ static void fileio_start_shell(void)
     "SHLL",                          /* task_name */
     RTEMS_MINIMUM_STACK_SIZE * 4,    /* task_stacksize */
     100,                             /* task_priority */
-    "/dev/console",                  /* devname */
+    "/dev/foobar",                   /* devname */
+    /* device is currently ignored by the shell if it is not a pty */
     false,                           /* forever */
     true,                            /* wait */
-    NULL                             /* login */
+    rtems_shell_login_check          /* login */
   );
 }
 #endif /* USE_SHELL */
diff --git a/testsuites/samples/fileio/system.h b/testsuites/samples/fileio/system.h
index 726a507b46..654f7275c2 100644
--- a/testsuites/samples/fileio/system.h
+++ b/testsuites/samples/fileio/system.h
@@ -47,6 +47,9 @@ rtems_task Init(
 #define CONFIGURE_ATA_DRIVER_TASK_PRIORITY  14
 #endif
 
+#define CONFIGURE_MAXIMUM_POSIX_KEYS             1
+#define CONFIGURE_MAXIMUM_POSIX_KEY_VALUE_PAIRS  1
+
 #if FILEIO_BUILD
   #define CONFIGURE_APPLICATION_NEEDS_LIBBLOCK
   #define CONFIGURE_BDBUF_MAX_READ_AHEAD_BLOCKS  2