[PATCH v3] pkl: Add data payload param in IO device API

[Mohammad-Reza Nabipoor]

2021-12-23  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>

        * libpoke/ios-dev-file.c (ios_dev_file_open): Add new param `data`.
        * libpoke/ios-dev-mem.c (ios_dev_mem_open): Likewise.
        * libpoke/ios-dev-nbd.c (ios_dev_nbd_open): Likewise.
        * libpoke/ios-dev-proc.c (ios_dev_proc_open): Likewise.
        * libpoke/ios-dev-stream.c (ios_dev_stream_open): Likewise.
        * libpoke/ios-dev-zero.c (ios_dev_zero_open): Likewise.
        * libpoke/ios-dev-sub.c (ios_dev_sub_open): Likewise.
        * libpoke/ios-dev.h (struct ios_dev_if): Change `open` to accept new
        `data` param. Add new field `data`.
        * libpoke/libpoke.h (struct pk_iod_if): Likewise.
        * libpoke/ios.c (ios_open): Call `open` with IOD-specific data.
        * testsuite/poke.libpoke/foreign-iod.c (iod_op): Add new field
        `data`.
        (iod_open): Add new param `data`. Report success through `error`.
        (iod_if): Add user data.
        (USER_DATA): New constant.
        (main): Add test for user data.
---

Hi, Jose.

- I used __attribute__((unused)) to avoid warnings.
- Improved the doc string.
- In `libpoke/ios-dev.h`, we need an empty line to be consistent with
  the rest of fields.
  I removed the empty line in `libpoke/libpoke.h`.
- I changed the `user_data` to `data`. IMO it's a better name. As you
  said it's a IOD-specific data, not user data.


Regards,
Mohammad-Reza


 ChangeLog                            | 20 ++++++++++++++++++++
 libpoke/ios-dev-file.c               |  3 ++-
 libpoke/ios-dev-mem.c                |  3 ++-
 libpoke/ios-dev-nbd.c                |  3 ++-
 libpoke/ios-dev-proc.c               |  5 +++--
 libpoke/ios-dev-stream.c             |  3 ++-
 libpoke/ios-dev-sub.c                |  2 +-
 libpoke/ios-dev-zero.c               |  4 +++-
 libpoke/ios-dev.h                    | 13 ++++++++++---
 libpoke/ios.c                        |  2 +-
 libpoke/libpoke.c                    |  1 +
 libpoke/libpoke.h                    |  3 ++-
 testsuite/poke.libpoke/foreign-iod.c | 16 ++++++++++++++--
 13 files changed, 63 insertions(+), 15 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 1aa44925..74c40cdf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,23 @@
+2021-12-23  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
+
+       * libpoke/ios-dev-file.c (ios_dev_file_open): Add new param `data`.
+       * libpoke/ios-dev-mem.c (ios_dev_mem_open): Likewise.
+       * libpoke/ios-dev-nbd.c (ios_dev_nbd_open): Likewise.
+       * libpoke/ios-dev-proc.c (ios_dev_proc_open): Likewise.
+       * libpoke/ios-dev-stream.c (ios_dev_stream_open): Likewise.
+       * libpoke/ios-dev-zero.c (ios_dev_zero_open): Likewise.
+       * libpoke/ios-dev-sub.c (ios_dev_sub_open): Likewise.
+       * libpoke/ios-dev.h (struct ios_dev_if): Change `open` to accept new
+       `data` param. Add new field `data`.
+       * libpoke/libpoke.h (struct pk_iod_if): Likewise.
+       * libpoke/ios.c (ios_open): Call `open` with IOD-specific data.
+       * testsuite/poke.libpoke/foreign-iod.c (iod_op): Add new field
+       `data`.
+       (iod_open): Add new param `data`. Report success through `error`.
+       (iod_if): Add user data.
+       (USER_DATA): New constant.
+       (main): Add test for user data.
+
 2021-12-23  Jose E. Marchesi  <jemarch@gnu.org>
 
        * etc/poke.rec (.set with no arguments should give a summary of
diff --git a/libpoke/ios-dev-file.c b/libpoke/ios-dev-file.c
index d470c62e..31ea0de9 100644
--- a/libpoke/ios-dev-file.c
+++ b/libpoke/ios-dev-file.c
@@ -96,7 +96,8 @@ ios_dev_file_convert_flags (int mode_flags, char 
**mode_for_fdopen)
 }
 
 static void *
-ios_dev_file_open (const char *handler, uint64_t flags, int *error)
+ios_dev_file_open (const char *handler, uint64_t flags, int *error,
+                   void *data __attribute__ ((unused)))
 {
   struct ios_dev_file *fio = NULL;
   FILE *f = NULL;
diff --git a/libpoke/ios-dev-mem.c b/libpoke/ios-dev-mem.c
index c1757500..f2b8b042 100644
--- a/libpoke/ios-dev-mem.c
+++ b/libpoke/ios-dev-mem.c
@@ -56,7 +56,8 @@ ios_dev_mem_handler_normalize (const char *handler, uint64_t 
flags, int *error)
 }
 
 static void *
-ios_dev_mem_open (const char *handler, uint64_t flags, int *error)
+ios_dev_mem_open (const char *handler, uint64_t flags, int *error,
+                  void *data __attribute__ ((unused)))
 {
   int internal_error = IOD_ERROR;
   struct ios_dev_mem *mio = malloc (sizeof (struct ios_dev_mem));
diff --git a/libpoke/ios-dev-nbd.c b/libpoke/ios-dev-nbd.c
index 2c3fa6ab..00f74a1b 100644
--- a/libpoke/ios-dev-nbd.c
+++ b/libpoke/ios-dev-nbd.c
@@ -66,7 +66,8 @@ ios_dev_nbd_handler_normalize (const char *handler, uint64_t 
flags, int* error)
 }
 
 static void *
-ios_dev_nbd_open (const char *handler, uint64_t flags, int *error)
+ios_dev_nbd_open (const char *handler, uint64_t flags, int *error,
+                  void *data __attribute__ ((unused)))
 {
   struct ios_dev_nbd *nio = NULL;
   struct nbd_handle *nbd = NULL;
diff --git a/libpoke/ios-dev-proc.c b/libpoke/ios-dev-proc.c
index a6ad9247..67b5c616 100644
--- a/libpoke/ios-dev-proc.c
+++ b/libpoke/ios-dev-proc.c
@@ -71,7 +71,8 @@ ios_dev_proc_handler_normalize (const char *handler, uint64_t 
flags, int *error)
 }
 
 static void *
-ios_dev_proc_open (const char *handler, uint64_t flags, int *error)
+ios_dev_proc_open (const char *handler, uint64_t flags, int *error,
+                   void *data __attribute__ ((unused)))
 {
   struct ios_dev_proc *proc = malloc (sizeof (struct ios_dev_proc));
 
@@ -112,7 +113,7 @@ ios_dev_proc_open (const char *handler, uint64_t flags, int 
*error)
 
   proc->memfile = ios_dev_file.open (proc->memfile_path,
                                      IOS_F_READ | IOS_F_WRITE,
-                                     error);
+                                     error, NULL);
   if (proc->memfile == NULL)
     {
       free (proc);
diff --git a/libpoke/ios-dev-stream.c b/libpoke/ios-dev-stream.c
index 5a566657..64b15339 100644
--- a/libpoke/ios-dev-stream.c
+++ b/libpoke/ios-dev-stream.c
@@ -70,7 +70,8 @@ ios_dev_stream_handler_normalize (const char *handler, 
uint64_t flags, int *erro
 }
 
 static void *
-ios_dev_stream_open (const char *handler, uint64_t flags, int *error)
+ios_dev_stream_open (const char *handler, uint64_t flags, int *error,
+                     void *data __attribute__ ((unused)))
 {
   struct ios_dev_stream *sio;
   int internal_error = IOD_ERROR;
diff --git a/libpoke/ios-dev-sub.c b/libpoke/ios-dev-sub.c
index fe061511..f6646dab 100644
--- a/libpoke/ios-dev-sub.c
+++ b/libpoke/ios-dev-sub.c
@@ -68,7 +68,7 @@ ios_dev_sub_handler_normalize (const char *handler, uint64_t 
flags, int* error)
 }
 
 static void *
-ios_dev_sub_open (const char *handler, uint64_t flags, int *error)
+ios_dev_sub_open (const char *handler, uint64_t flags, int *error, void *data)
 {
   struct ios_dev_sub *sub = malloc (sizeof (struct ios_dev_sub));
   const char *p;
diff --git a/libpoke/ios-dev-zero.c b/libpoke/ios-dev-zero.c
index 2772c81d..3c8849b6 100644
--- a/libpoke/ios-dev-zero.c
+++ b/libpoke/ios-dev-zero.c
@@ -53,7 +53,9 @@ ios_dev_zero_handler_normalize (const char *handler, uint64_t 
flags, int *error)
 }
 
 static void *
-ios_dev_zero_open (const char *handler, uint64_t flags, int *error)
+ios_dev_zero_open (const char *handler __attribute__ ((unused)),
+                   uint64_t flags __attribute__ ((unused)), int *error,
+                   void *data __attribute__ ((unused)))
 {
   /* This IOD doesn't need to keep any state.  */
   if (error)
diff --git a/libpoke/ios-dev.h b/libpoke/ios-dev.h
index 2ffd5fea..f563a9b0 100644
--- a/libpoke/ios-dev.h
+++ b/libpoke/ios-dev.h
@@ -65,9 +65,10 @@ struct ios_dev_if
   /* Open a device using the provided HANDLER.  Return the opened
      device, or NULL in case of errors.  Set the ERROR to error code or to
      IOD_OK.  Note that this function assumes that HANDLER is recognized as a
-     handler by the backend.  */
+     handler by the backend.  DATA is the `data' pointer below, intended to be
+     used as an IOD-specific payload specified by the author of IOD.  */
 
-  void * (*open) (const char *handler, uint64_t flags, int *error);
+  void * (*open) (const char *handler, uint64_t flags, int *error, void *data);
 
   /* Close the given device.  Return the error code if there was an error
      during the operation, IOD_OK otherwise.  */
@@ -94,9 +95,15 @@ struct ios_dev_if
 
   /* If called on a in-stream, free the buffer before OFFSET.  If called on
      an out-stream, flush the data till OFFSET and free the buffer before
-     OFFSET.  Otherwise, do not do anything.  Return IOS_OK ın success and
+     OFFSET.  Otherwise, do not do anything.  Return IOS_OK in success and
      an error code on failure.  */
+
   int (*flush) (void *dev, ios_dev_off offset);
+
+  /* IOD-specific data payload that will be passed to OPEN function.  If not
+     used, it should be NULL.  */
+
+  void *data;
 };
 
 #define IOS_FILE_HANDLER_NORMALIZE(handler, new_handler)                \
diff --git a/libpoke/ios.c b/libpoke/ios.c
index b12f5e57..6bc5bd12 100644
--- a/libpoke/ios.c
+++ b/libpoke/ios.c
@@ -186,7 +186,7 @@ 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 = io->dev_if->open (handler, flags, &iod_error, io->dev_if->data);
   if (iod_error || io->dev == NULL)
     goto error;
 
diff --git a/libpoke/libpoke.c b/libpoke/libpoke.c
index 072205cf..6ae3ee41 100644
--- a/libpoke/libpoke.c
+++ b/libpoke/libpoke.c
@@ -974,6 +974,7 @@ 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);
diff --git a/libpoke/libpoke.h b/libpoke/libpoke.h
index 6332eef2..394c2794 100644
--- a/libpoke/libpoke.h
+++ b/libpoke/libpoke.h
@@ -1074,13 +1074,14 @@ struct pk_iod_if
 {
   const char *(*get_if_name) ();
   char *(*handler_normalize) (const char *handler, uint64_t flags, int *error);
-  void * (*open) (const char *handler, uint64_t flags, int *error);
+  void * (*open) (const char *handler, uint64_t flags, int *error, void *data);
   int (*close) (void *dev);
   int (*pread) (void *dev, void *buf, size_t count, pk_iod_off offset);
   int (*pwrite) (void *dev, const void *buf, size_t count, pk_iod_off offset);
   uint64_t (*get_flags) (void *dev);
   pk_iod_off (*size) (void *dev);
   int (*flush) (void *dev, pk_iod_off offset);
+  void *data;
 };
 
 /* Register a foreign IO device in the Poke compiler.
diff --git a/testsuite/poke.libpoke/foreign-iod.c 
b/testsuite/poke.libpoke/foreign-iod.c
index 0c97ae44..57f01d0e 100644
--- a/testsuite/poke.libpoke/foreign-iod.c
+++ b/testsuite/poke.libpoke/foreign-iod.c
@@ -51,6 +51,7 @@ struct
   int type; /* IOD_OP_READ or IOD_OP_WRITE */
   pk_iod_off offset;
   size_t count;
+  void *data;
 } iod_op;
 
 int iod_opened_p = 0;
@@ -81,9 +82,12 @@ iod_handler_normalize (const char *handler, uint64_t flags, 
int *error)
 }
 
 void *
-iod_open (const char *handler, uint64_t flags, int *error)
+iod_open (const char *handler, uint64_t flags, int *error, void *data)
 {
   iod_opened_p = 1;
+  iod_op.data = data;
+  if (error)
+    *error = PK_IOD_OK;
   return &iod_opened_p;
 }
 
@@ -136,6 +140,8 @@ iod_close (void *dev)
   return PK_OK;
 }
 
+static uint32_t USER_DATA = 0x706f6b65u; /* "poke" */
+
 struct pk_iod_if iod_if =
   {
     iod_get_if_name,
@@ -146,7 +152,8 @@ struct pk_iod_if iod_if =
     iod_pwrite,
     iod_get_flags,
     iod_size,
-    iod_flush
+    iod_flush,
+    (void*)&USER_DATA,
   };
 
 int
@@ -183,6 +190,11 @@ main (int argc, char *argv[])
         fail ("open not reflected in foreign IOD");
         return 1;
       }
+    if (*(uint32_t*)iod_op.data != USER_DATA)
+      {
+        fail ("user data not reflected in foreign IOD");
+        return 1;
+      }
 
     pass ("open foreign IOD");
   }
-- 
2.34.1