privateenv: Use POSIX keys instead of task variables.

6 files changed, 71 insertions, 32 deletions

diff --git a/cpukit/include/rtems/userenv.h b/cpukit/include/rtems/userenv.h
index 8a9a4fcd32..631d773ae5 100644
--- a/cpukit/include/rtems/userenv.h
+++ b/cpukit/include/rtems/userenv.h
@@ -66,8 +66,17 @@ typedef struct {
   pid_t                            pgrp; /* process group id */
 } rtems_user_env_t;
 
-extern rtems_user_env_t * rtems_current_user_env;
-extern rtems_user_env_t   rtems_global_user_env;
+extern rtems_user_env_t rtems_global_user_env;
+
+/**
+ * @brief Fetch the pointer to the current user environment.
+ *
+ * If the task has a private user environment the pointer to it will be
+ * returned. Otherwise the pointer to rtems_global_user_env will be returned.
+ */
+rtems_user_env_t * rtems_current_user_env_get(void);
+
+#define rtems_current_user_env rtems_current_user_env_get()
 
 #define rtems_filesystem_current     (rtems_current_user_env->current_directory)
 #define rtems_filesystem_root        (rtems_current_user_env->root_directory)
@@ -86,6 +95,11 @@ extern rtems_user_env_t   rtems_global_user_env;
  * function must be called from normal thread context and may block on a mutex.
  * Thread dispatching is disabled to protect some critical sections.
  *
+ * The private environment internally uses a POSIX key. The key is added to the
+ * configuration implicitly. But for each thread that uses a private environment
+ * a key value pair has to be configured by the application. If only the global
+ * environment is used there is no need to configure a key value pair.
+ *
  * @retval RTEMS_SUCCESSFUL Successful operation.
  * @retval RTEMS_NO_MEMORY Not enough memory.
  * @retval RTEMS_UNSATISFIED Cloning of the current environment failed.
diff --git a/cpukit/libcsupport/include/rtems/libio_.h b/cpukit/libcsupport/include/rtems/libio_.h
index 9960288c20..d7f9034e3d 100644
--- a/cpukit/libcsupport/include/rtems/libio_.h
+++ b/cpukit/libcsupport/include/rtems/libio_.h
@@ -24,6 +24,7 @@
 #include <sys/uio.h>
 #include <errno.h>
 #include <limits.h>
+#include <pthread.h>
 
 #include <rtems.h>
 #include <rtems/libio.h>
@@ -238,6 +239,10 @@ void rtems_filesystem_location_free( rtems_filesystem_location_info_t *loc );
  */
 #include <rtems/userenv.h>
 
+void rtems_libio_free_user_env( void *env );
+
+extern pthread_key_t rtems_current_user_env_key;
+
 static inline void rtems_libio_lock( void )
 {
   rtems_semaphore_obtain( rtems_libio_semaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT );
diff --git a/cpukit/libcsupport/src/__usrenv.c b/cpukit/libcsupport/src/__usrenv.c
index 3ce6a2dfea..71efda9d7f 100644
--- a/cpukit/libcsupport/src/__usrenv.c
+++ b/cpukit/libcsupport/src/__usrenv.c
@@ -257,4 +257,4 @@ rtems_user_env_t rtems_global_user_env = {
   .umask = S_IWGRP | S_IWOTH
 };
 
-rtems_user_env_t *rtems_current_user_env = &rtems_global_user_env;
+pthread_key_t rtems_current_user_env_key;
diff --git a/cpukit/libcsupport/src/libio_init.c b/cpukit/libcsupport/src/libio_init.c
index 4d705fb8ee..e64ddd6e3a 100644
--- a/cpukit/libcsupport/src/libio_init.c
+++ b/cpukit/libcsupport/src/libio_init.c
@@ -46,6 +46,7 @@ void rtems_libio_init( void )
     rtems_status_code rc;
     uint32_t i;
     rtems_libio_t *iop;
+    int eno;
 
     if (rtems_libio_number_iops > 0)
     {
@@ -61,6 +62,17 @@ void rtems_libio_init( void )
     }
 
   /*
+   *  Create the posix key for user environment.
+   */
+  eno = pthread_key_create(
+    &rtems_current_user_env_key,
+    rtems_libio_free_user_env
+  );
+  if (eno != 0) {
+    rtems_fatal_error_occurred( RTEMS_UNSATISFIED );
+  }
+
+  /*
    *  Create the binary semaphore used to provide mutual exclusion
    *  on the IOP Table.
    */
diff --git a/cpukit/libcsupport/src/privateenv.c b/cpukit/libcsupport/src/privateenv.c
index bee94c117f..60207b0815 100644
--- a/cpukit/libcsupport/src/privateenv.c
+++ b/cpukit/libcsupport/src/privateenv.c
@@ -29,7 +29,16 @@
  *  Instantiate a private user environment for the calling thread.
  */
 
-static void free_user_env(void *arg)
+rtems_user_env_t * rtems_current_user_env_get(void)
+{
+  void *ptr = pthread_getspecific(rtems_current_user_env_key);
+  if (ptr == NULL) {
+    ptr = &rtems_global_user_env;
+  }
+  return (rtems_user_env_t *) ptr;
+}
+
+void rtems_libio_free_user_env(void *arg)
 {
   rtems_user_env_t *env = arg;
   bool uses_global_env = env == &rtems_global_user_env;
@@ -44,7 +53,7 @@ static void free_user_env(void *arg)
 static void free_user_env_protected(rtems_user_env_t *env)
 {
   _Thread_Disable_dispatch();
-  free_user_env(env);
+  rtems_libio_free_user_env(env);
   _Thread_Enable_dispatch();
 }
 
@@ -68,14 +77,13 @@ rtems_status_code rtems_libio_set_private_env(void)
         !rtems_filesystem_global_location_is_null(new_env->root_directory)
           && !rtems_filesystem_global_location_is_null(new_env->current_directory)
       ) {
-        sc = rtems_task_variable_add(
-          RTEMS_SELF,
-          (void **) &rtems_current_user_env,
-          free_user_env
+        int eno = pthread_setspecific(
+          rtems_current_user_env_key,
+          new_env
         );
-        if (sc == RTEMS_SUCCESSFUL) {
+
+        if (eno == 0) {
           free_user_env_protected(old_env);
-          rtems_current_user_env = new_env;
         } else {
           sc = RTEMS_TOO_MANY;
         }
@@ -84,7 +92,7 @@ rtems_status_code rtems_libio_set_private_env(void)
       }
 
       if (sc != RTEMS_SUCCESSFUL) {
-        free_user_env(new_env);
+        rtems_libio_free_user_env(new_env);
       }
     } else {
       sc = RTEMS_NO_MEMORY;
@@ -101,14 +109,7 @@ void rtems_libio_use_global_env(void)
   bool uses_private_env = env != &rtems_global_user_env;
 
   if (uses_private_env) {
-    sc = rtems_task_variable_delete(
-      RTEMS_SELF,
-      (void **) &rtems_current_user_env
-    );
-    if (sc != RTEMS_SUCCESSFUL) {
-      rtems_fatal_error_occurred(0xdeadbeef);
-    }
-
-    rtems_current_user_env = &rtems_global_user_env;
+    free_user_env_protected(env);
+    pthread_setspecific(rtems_current_user_env_key, NULL);
   }
 }
diff --git a/cpukit/sapi/include/confdefs.h b/cpukit/sapi/include/confdefs.h
index b7317433d9..d8cf2af402 100644
--- a/cpukit/sapi/include/confdefs.h
+++ b/cpukit/sapi/include/confdefs.h
@@ -148,6 +148,11 @@ const rtems_libio_helper rtems_fs_init_helper =
  */
 #define CONFIGURE_LIBIO_SEMAPHORES 1
 
+/**
+ * POSIX key count used by the IO library.
+ */
+#define CONFIGURE_LIBIO_POSIX_KEYS 1
+
 #ifdef CONFIGURE_INIT
   /**
    * When instantiating the configuration tables, this variable is
@@ -1734,16 +1739,18 @@ const rtems_libio_helper rtems_fs_init_helper =
 #include <rtems/posix/key.h>
 
 #ifndef CONFIGURE_MAXIMUM_POSIX_KEYS
-  #define CONFIGURE_MAXIMUM_POSIX_KEYS            0
-  #define CONFIGURE_MAXIMUM_POSIX_KEY_VALUE_PAIRS 0
-#else
-  #ifndef CONFIGURE_MAXIMUM_POSIX_KEY_VALUE_PAIRS
-    #define CONFIGURE_MAXIMUM_POSIX_KEY_VALUE_PAIRS \
-      (CONFIGURE_MAXIMUM_POSIX_KEYS * \
-       (CONFIGURE_MAXIMUM_POSIX_THREADS + CONFIGURE_MAXIMUM_TASKS))
-  #endif
+  #define CONFIGURE_MAXIMUM_POSIX_KEYS 0
+#endif
+
+#ifndef CONFIGURE_MAXIMUM_POSIX_KEY_VALUE_PAIRS
+  #define CONFIGURE_MAXIMUM_POSIX_KEY_VALUE_PAIRS \
+    (CONFIGURE_MAXIMUM_POSIX_KEYS * \
+     (CONFIGURE_MAXIMUM_POSIX_THREADS + CONFIGURE_MAXIMUM_TASKS))
 #endif
 
+#define CONFIGURE_POSIX_KEYS \
+  (CONFIGURE_MAXIMUM_POSIX_KEYS + CONFIGURE_LIBIO_POSIX_KEYS)
+
 #define CONFIGURE_MEMORY_FOR_POSIX_KEYS(_keys, _key_value_pairs) \
    (_Configure_Object_RAM(_keys, sizeof(POSIX_Keys_Control) ) \
     + _Configure_From_workspace( \
@@ -2222,7 +2229,7 @@ const rtems_libio_helper rtems_fs_init_helper =
      CONFIGURE_TOTAL_TASKS_AND_THREADS, CONFIGURE_TOTAL_TASKS_AND_THREADS) + \
    CONFIGURE_MEMORY_FOR_CLASSIC + \
    CONFIGURE_MEMORY_FOR_POSIX_KEYS( \
-      CONFIGURE_MAXIMUM_POSIX_KEYS, \
+      CONFIGURE_POSIX_KEYS, \
       CONFIGURE_MAXIMUM_POSIX_KEY_VALUE_PAIRS ) + \
    CONFIGURE_MEMORY_FOR_POSIX + \
    CONFIGURE_MEMORY_FOR_STATIC_EXTENSIONS + \
@@ -2397,7 +2404,7 @@ const rtems_libio_helper rtems_fs_init_helper =
     CONFIGURE_EXECUTIVE_RAM_SIZE,             /* required RTEMS workspace */
     CONFIGURE_STACK_SPACE_SIZE,               /* required stack space */
     CONFIGURE_MAXIMUM_USER_EXTENSIONS,        /* maximum dynamic extensions */
-    CONFIGURE_MAXIMUM_POSIX_KEYS,             /* POSIX keys are always */
+    CONFIGURE_POSIX_KEYS,                     /* POSIX keys are always */
     CONFIGURE_MAXIMUM_POSIX_KEY_VALUE_PAIRS,  /*   enabled */
     CONFIGURE_MICROSECONDS_PER_TICK,          /* microseconds per clock tick */
     1000 * CONFIGURE_MICROSECONDS_PER_TICK,   /* nanoseconds per clock tick */
@@ -2592,7 +2599,7 @@ const rtems_libio_helper rtems_fs_init_helper =
     CONFIGURE_MEMORY_FOR_PERIODS(CONFIGURE_MAXIMUM_PERIODS),
     CONFIGURE_MEMORY_FOR_BARRIERS(CONFIGURE_BARRIERS),
     CONFIGURE_MEMORY_FOR_USER_EXTENSIONS(CONFIGURE_MAXIMUM_USER_EXTENSIONS),
-    CONFIGURE_MEMORY_FOR_POSIX_KEYS( CONFIGURE_MAXIMUM_POSIX_KEYS, \
+    CONFIGURE_MEMORY_FOR_POSIX_KEYS( CONFIGURE_POSIX_KEYS, \
                                      CONFIGURE_MAXIMUM_POSIX_KEY_VALUE_PAIRS ),
 
 #ifdef RTEMS_POSIX_API