[PATCH 2/2] ios: combine all global states into a single struct

[Mohammad-Reza Nabipoor]

2022-08-10  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>

        * libpoke/ios-dev.h (struct ios_dev_if): Remove `data' field.
        * libpoke/ios.h (ios_register_foreign_iod): Add new param: `data'.
        * libpoke/ios.c (struct ios_context): New struct to put all
        global states in one place.
        (IOS_DEV_IF_DATA): New macro.
        (ios_ctx): An instance of `struct ios_context' which contains
        all global states.
        (ios_shutdown): Adapt to use `ios_ctx' global variable.
        (ios_open): Likewise.
        (ios_close): Likewise.
        (ios_cur): Likewise.
        (ios_set_cur): Likewise.
        (ios_search): Likewise.
        (ios_search_by_id): Likewise.
        (ios_set_bias): Likewise.
        (ios_map): Likewise.
        (ios_register_foreign_iod): Use new param.
        * libpoke/libpoke.c (pk_register_iod): Update.
---

Hello Jose.

This is a step toward removing global state from libpoke.


Regards,
Mohammad-Reza

 
 ChangeLog         | 21 +++++++++++++++
 libpoke/ios-dev.h |  1 -
 libpoke/ios.c     | 66 ++++++++++++++++++++++++++---------------------
 libpoke/ios.h     |  2 +-
 libpoke/libpoke.c |  3 +--
 5 files changed, 60 insertions(+), 33 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 834441ee..9d700d13 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,24 @@
+2022-08-10  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
+
+       * libpoke/ios-dev.h (struct ios_dev_if): Remove `data' field.
+       * libpoke/ios.h (ios_register_foreign_iod): Add new param: `data'.
+       * libpoke/ios.c (struct ios_context): New struct to put all
+       global states in one place.
+       (IOS_DEV_IF_DATA): New macro.
+       (ios_ctx): An instance of `struct ios_context' which contains
+       all global states.
+       (ios_shutdown): Adapt to use `ios_ctx' global variable.
+       (ios_open): Likewise.
+       (ios_close): Likewise.
+       (ios_cur): Likewise.
+       (ios_set_cur): Likewise.
+       (ios_search): Likewise.
+       (ios_search_by_id): Likewise.
+       (ios_set_bias): Likewise.
+       (ios_map): Likewise.
+       (ios_register_foreign_iod): Use new param.
+       * libpoke/libpoke.c (pk_register_iod): Update.
+
 2022-08-10  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
 
        * bootstrap.conf (libpoke_modules): Add `array-list'.
diff --git a/libpoke/ios-dev.h b/libpoke/ios-dev.h
index 3be1c295..71628504 100644
--- a/libpoke/ios-dev.h
+++ b/libpoke/ios-dev.h
@@ -63,7 +63,6 @@ struct ios_dev_if
   uint64_t (*get_flags) (void *dev);
   ios_dev_off (*size) (void *dev);
   int (*flush) (void *dev, ios_dev_off offset);
-  void *data;
 };
 
 #define IOS_FILE_HANDLER_NORMALIZE(handler, new_handler)                \
diff --git a/libpoke/ios.c b/libpoke/ios.c
index 464a75b4..a79ff4d8 100644
--- a/libpoke/ios.c
+++ b/libpoke/ios.c
@@ -80,14 +80,17 @@ struct ios
   struct ios *next;
 };
 
-/* Next available IOS id.  */
-
-static int ios_next_id = 0;
-
-/* List of IO spaces, and pointer to the current one.  */
+struct ios_context
+{
+  int next_id;         /* Next available IOS id.  */
+  struct ios *io_list; /* List of all IO spaces.  */
+  struct ios *cur_io;  /* Pointer to the current IOS.  */
+  void *foreign_dev_if_data; /* User-defined data for foreign device.  */
+};
 
-static struct ios *io_list;
-static struct ios *cur_io;
+/* Only foreign device supports user-defined data.  */
+#define IOS_DEV_IF_DATA(dev_if)                                               \
+  ((dev_if) == ios_dev_ifs[0] ? ios_ctx.foreign_dev_if_data : NULL)
 
 /* The available backends are implemented in their own files, and
    provide the following interfaces.  */
@@ -122,6 +125,8 @@ static struct ios_dev_if *ios_dev_ifs[] =
    NULL,
   };
 
+static struct ios_context ios_ctx;
+
 void
 ios_init (void)
 {
@@ -132,8 +137,8 @@ void
 ios_shutdown (void)
 {
   /* Close and free all open IO spaces.  */
-  while (io_list)
-    ios_close (io_list);
+  while (ios_ctx.io_list)
+    ios_close (ios_ctx.io_list);
 }
 
 int
@@ -181,7 +186,7 @@ ios_open (const char *handler, uint64_t flags, int set_cur)
   io->dev_if = *dev_if;
 
   /* Do not re-open an already-open IO space.  */
-  for (ios i = io_list; i; i = i->next)
+  for (ios i = ios_ctx.io_list; i; i = i->next)
     if (STREQ (i->handler, io->handler))
       {
         error = IOS_EOPEN;
@@ -189,20 +194,21 @@ ios_open (const char *handler, uint64_t flags, int 
set_cur)
       }
 
   /* Open the device using the interface found above.  */
-  io->dev = io->dev_if->open (handler, flags, &iod_error, io->dev_if->data);
+  io->dev = io->dev_if->open (handler, flags, &iod_error,
+                              IOS_DEV_IF_DATA (io->dev_if));
   if (iod_error || io->dev == NULL)
     goto error;
 
   /* Increment the id counter after all possible errors are avoided.  */
-  io->id = ios_next_id++;
+  io->id = ios_ctx.next_id++;
 
   /* Add the newly created space to the list, and update the current
      space.  */
-  io->next = io_list;
-  io_list = io;
+  io->next = ios_ctx.io_list;
+  ios_ctx.io_list = io;
 
-  if (!cur_io || set_cur == 1)
-    cur_io = io;
+  if (!ios_ctx.cur_io || set_cur == 1)
+    ios_ctx.cur_io = io;
 
   return io->id;
 
@@ -230,19 +236,20 @@ ios_close (ios io)
   ret = io->dev_if->close (io->dev);
 
   /* Unlink the IOS from the list.  */
-  assert (io_list != NULL); /* The list contains at least this IO space.  */
-  if (io_list == io)
-    io_list = io_list->next;
+  /* The list contains at least this IO space.  */
+  assert (ios_ctx.io_list != NULL);
+  if (ios_ctx.io_list == io)
+    ios_ctx.io_list = ios_ctx.io_list->next;
   else
     {
-      for (tmp = io_list; tmp->next != io; tmp = tmp->next)
+      for (tmp = ios_ctx.io_list; tmp->next != io; tmp = tmp->next)
         ;
       tmp->next = io->next;
     }
 
   /* Set the new current IO.  */
-  if (io == cur_io)
-    cur_io = io_list;
+  if (io == ios_ctx.cur_io)
+    ios_ctx.cur_io = ios_ctx.io_list;
 
   /* Invalidate the sub-devices.  */
   {
@@ -274,13 +281,13 @@ ios_handler (ios io)
 ios
 ios_cur (void)
 {
-  return cur_io;
+  return ios_ctx.cur_io;
 }
 
 void
 ios_set_cur (ios io)
 {
-  cur_io = io;
+  ios_ctx.cur_io = io;
 }
 
 ios
@@ -288,7 +295,7 @@ ios_search (const char *handler)
 {
   ios io;
 
-  for (io = io_list; io; io = io->next)
+  for (io = ios_ctx.io_list; io; io = io->next)
     if (STREQ (io->handler, handler))
       break;
 
@@ -300,7 +307,7 @@ ios_search_by_id (int id)
 {
   ios io;
 
-  for (io = io_list; io; io = io->next)
+  for (io = ios_ctx.io_list; io; io = io->next)
     if (io->id == id)
       break;
 
@@ -334,7 +341,7 @@ ios_set_bias (ios io, ios_off bias)
 ios
 ios_begin (void)
 {
-  return io_list;
+  return ios_ctx.io_list;
 }
 
 bool
@@ -355,7 +362,7 @@ ios_map (ios_map_fn cb, void *data)
   ios io;
   ios io_next;
 
-  for (io = io_list; io; io = io_next)
+  for (io = ios_ctx.io_list; io; io = io_next)
     {
       /* Note that the handler may close IO.  */
       io_next = io->next;
@@ -1648,12 +1655,13 @@ ios_foreign_iod (void)
 }
 
 int
-ios_register_foreign_iod (struct ios_dev_if *iod_if)
+ios_register_foreign_iod (struct ios_dev_if *iod_if, void *data)
 {
   if (ios_dev_ifs[0] != NULL)
     return IOS_ERROR;
 
   ios_dev_ifs[0] = iod_if;
+  ios_ctx.foreign_dev_if_data = data;
   return IOS_OK;
 }
 
diff --git a/libpoke/ios.h b/libpoke/ios.h
index 478cf030..dda3b737 100644
--- a/libpoke/ios.h
+++ b/libpoke/ios.h
@@ -364,7 +364,7 @@ struct ios_dev_if *ios_foreign_iod (void);
    Return IOS_OK otherwise.  */
 
 struct ios_dev_if;
-int ios_register_foreign_iod (struct ios_dev_if *iod_if);
+int ios_register_foreign_iod (struct ios_dev_if *iod_if, void *data);
 
 /* **************** Sub IO space **************** */
 
diff --git a/libpoke/libpoke.c b/libpoke/libpoke.c
index f169becb..69c511a3 100644
--- a/libpoke/libpoke.c
+++ b/libpoke/libpoke.c
@@ -1097,9 +1097,8 @@ pk_register_iod (pk_compiler pkc, struct pk_iod_if 
*iod_if)
   CF (get_flags);
   CF (size);
   CF (flush);
-  CF (data);
 #undef CF
 
-  (void) ios_register_foreign_iod (&foreign_iod_if);
+  (void) ios_register_foreign_iod (&foreign_iod_if, iod_if->data);
   return pkc->status;
 }
-- 
2.37.1