From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <4382F115.5010007@domain.hid>
Date: Tue, 22 Nov 2005 11:21:09 +0100
From: Jan Kiszka <kiszka@domain.hid>
MIME-Version: 1.0
Subject: Re: [Xenomai-core] [RFC] define your own pipe heap
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	<43825E4C.4030002@domain.hid>
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Jan Kiszka wrote:
> ...
> A patch says more than thousand words. ;)
>=20
> As a first approach, I picked the second variant and implemented a new
> function called rt_pipe_setpool. I also had to extend rt_pipe_alloc and=

> rt_pipe_free so that the right pool is used by them.
>=20

I thought about this variant again, and it seems to me rather unsafe in
case some buffer allocation takes place between rt_pipe_create and
rt_pipe_setpool. So, here is a patch which extends rt_pipe_create with a
new argument poolsize instead.

Still untested...

Jan

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 filename="rt_pipe_create-ext.patch"

Index: skins/native/pipe.h
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- skins/native/pipe.h	(revision 165)
+++ skins/native/pipe.h	(working copy)
@@ -37,6 +37,8 @@
=20
 #ifdef __KERNEL__
=20
+#include <nucleus/heap.h>
+
 #define XENO_PIPE_MAGIC 0x55550202
=20
 typedef xnpipe_mh_t RT_PIPE_MSG;
@@ -57,6 +59,10 @@
=20
     RT_PIPE_MSG *buffer;	/* !< Buffer used in byte stream mode. */
=20
+    xnheap_t *bufpool;		/* !< Current buffer pool. */
+
+    xnheap_t privpool;		/* !< Private buffer pool. */
+
     size_t fillsz;		/* !< Bytes written to the buffer.  */
=20
     u_long flushable;		/* !< Flush request flag. */
@@ -85,8 +91,12 @@
=20
 int rt_pipe_create(RT_PIPE *pipe,
 		   const char *name,
-		   int minor);
+		   int minor,
+		   size_t poolsize);
=20
+int rt_pipe_setpool(RT_PIPE *pipe,
+                    size_t poolsize);
+
 int rt_pipe_delete(RT_PIPE *pipe);
=20
 ssize_t rt_pipe_read(RT_PIPE *pipe,
@@ -113,9 +123,11 @@
 		     size_t size,
 		     int mode);
=20
-RT_PIPE_MSG *rt_pipe_alloc(size_t size);
+RT_PIPE_MSG *rt_pipe_alloc(RT_PIPE *pipe,
+                           size_t size);
=20
-int rt_pipe_free(RT_PIPE_MSG *msg);
+int rt_pipe_free(RT_PIPE *pipe,
+                 RT_PIPE_MSG *msg);
=20
 ssize_t rt_pipe_flush(RT_PIPE *pipe);
=20
Index: skins/native/syscall.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- skins/native/syscall.c	(revision 165)
+++ skins/native/syscall.c	(working copy)
@@ -3194,6 +3194,7 @@
     char name[XNOBJECT_NAME_LEN];
     RT_PIPE_PLACEHOLDER ph;
     int err, minor;
+    size_t poolsize;
     RT_PIPE *pipe;
=20
     if (!__xn_access_ok(curr,VERIFY_WRITE,__xn_reg_arg1(regs),sizeof(ph)=
))
@@ -3213,12 +3214,15 @@
     /* Device minor. */
     minor =3D (int)__xn_reg_arg3(regs);
=20
+    /* Buffer pool size. */
+    poolsize =3D (size_t)__xn_reg_arg4(regs);
+
     pipe =3D (RT_PIPE *)xnmalloc(sizeof(*pipe));
=20
     if (!pipe)
 	return -ENOMEM;
=20
-    err =3D rt_pipe_create(pipe,name,minor);
+    err =3D rt_pipe_create(pipe,name,minor,poolsize);
=20
     if (err =3D=3D 0)
 	{
@@ -3332,7 +3336,7 @@
     /* Zero-sized messages are allowed, so we still need to free the
        message buffer even if no data copy took place. */
=20
-    rt_pipe_free(msg);
+    rt_pipe_free(pipe,msg);
=20
     return err;
 }
@@ -3374,7 +3378,7 @@
     if (!__xn_access_ok(curr,VERIFY_READ,__xn_reg_arg2(regs),size))
 	return -EFAULT;
=20
-    msg =3D rt_pipe_alloc(size);
+    msg =3D rt_pipe_alloc(pipe,size);
 =09
     if (!msg)
 	return -ENOMEM;
@@ -3386,7 +3390,7 @@
     if (err !=3D size)
 	/* If the operation failed, we need to free the message buffer
 	   by ourselves. */
-	rt_pipe_free(msg);
+	rt_pipe_free(pipe,msg);
=20
     return err;
 }
@@ -3436,7 +3440,7 @@
 	}
     else
 	{
-	msg =3D rt_pipe_alloc(size);
+	msg =3D rt_pipe_alloc(pipe,size);
 =09
 	if (!msg)
 	    return -ENOMEM;
@@ -3449,7 +3453,7 @@
     err =3D rt_pipe_stream(pipe,buf,size);
=20
     if (msg)
-	rt_pipe_free(msg);
+	rt_pipe_free(pipe,msg);
=20
     return err;
 }
Index: skins/native/lib/pipe.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- skins/native/lib/pipe.c	(revision 165)
+++ skins/native/lib/pipe.c	(working copy)
@@ -23,7 +23,8 @@
=20
 int rt_pipe_create (RT_PIPE *pipe,
 		    const char *name,
-		    int minor)
+		    int minor,
+		    size_t poolsize)
 {
     return XENOMAI_SKINCALL3(__xeno_muxid,
 			     __xeno_pipe_create,
Index: skins/native/pipe.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- skins/native/pipe.c	(revision 165)
+++ skins/native/pipe.c	(working copy)
@@ -50,8 +50,6 @@
 #include <native/registry.h>
 #include <native/pipe.h>
=20
-static xnheap_t *__pipe_heap =3D &kheap;
-
 static int __pipe_flush_apc;
=20
 static DECLARE_XNQUEUE(__pipe_flush_q);
@@ -83,6 +81,14 @@
=20
 #endif /* CONFIG_XENO_NATIVE_EXPORT_REGISTRY */
=20
+static void __pipe_flush_pool (xnheap_t *heap,
+                               void *poolmem,
+                               u_long poolsize,
+                               void *cookie)
+{
+    xnarch_sysfree(poolmem,poolsize);
+}
+
 static inline ssize_t __pipe_flush (RT_PIPE *pipe)
=20
 {
@@ -122,8 +128,10 @@
 				   size_t size,
 				   void *cookie)
 {
+    RT_PIPE *pipe =3D (RT_PIPE *)cookie;
+
     /* Allocate memory for the incoming message. */
-    return xnheap_alloc(__pipe_heap,size);
+    return xnheap_alloc(pipe->bufpool,size);
 }
=20
 static int __pipe_output_handler (int bminor,
@@ -131,8 +139,10 @@
 				  int retval,
 				  void *cookie)
 {
+    RT_PIPE *pipe =3D (RT_PIPE *)cookie;
+
     /* Free memory from output/discarded message. */
-    xnheap_free(__pipe_heap,mh);
+    xnheap_free(pipe->bufpool,mh);
     return retval;
 }
=20
@@ -154,7 +164,7 @@
 }
=20
 /**
- * @fn int rt_pipe_create(RT_PIPE *pipe,const char *name,int minor)
+ * @fn int rt_pipe_create(RT_PIPE *pipe,const char *name,int minor, size=
_t poolsize)
  * @brief Create a message pipe.
  *
  * This service opens a bi-directional communication channel allowing
@@ -232,20 +242,55 @@
=20
 int rt_pipe_create (RT_PIPE *pipe,
 		    const char *name,
-		    int minor)
+		    int minor,
+		    size_t poolsize)
 {
     int err =3D 0;
+    void *poolmem;
=20
-    if (xnpod_asynch_p())
+    if (!xnpod_root_p())
 	return -EPERM;
=20
     pipe->buffer =3D NULL;
+    pipe->bufpool =3D &kheap;
     pipe->fillsz =3D 0;
     pipe->flushable =3D 0;
     pipe->handle =3D 0;    /* i.e. (still) unregistered pipe. */
     pipe->magic =3D XENO_PIPE_MAGIC;
     xnobject_copy_name(pipe->name,name);
=20
+    if (poolsize > 0)
+	{
+	/* Make sure we won't hit trivial argument errors when calling
+	   xnheap_init(). */
+
+	if (poolsize < 2 * PAGE_SIZE)
+	    poolsize =3D 2 * PAGE_SIZE;
+
+	/* Account for the overhead so that the actual free space is large
+	   enough to match the requested size. */
+
+	poolsize +=3D xnheap_overhead(poolsize,PAGE_SIZE);
+	poolsize =3D PAGE_ALIGN(poolsize);
+
+	poolmem =3D xnarch_sysalloc(poolsize);
+
+	if (!poolmem)
+	    return -ENOMEM;
+
+	err =3D xnheap_init(&pipe->privpool,
+	                  poolmem,
+	                  poolsize,
+	                  PAGE_SIZE); /* Use natural page size */
+	if (err)
+	    {
+	    xnarch_sysfree(poolmem,poolsize);
+	    return err;
+	    }
+
+	pipe->bufpool =3D &pipe->privpool;
+	}
+
     minor =3D xnpipe_connect(minor,
 			 &__pipe_output_handler,
 			 NULL,
@@ -253,7 +298,12 @@
 			 pipe);
=20
     if (minor < 0)
+	{
+	if (pipe->bufpool =3D=3D &pipe->privpool)
+	    xnheap_destroy(&pipe->privpool,__pipe_flush_pool,NULL);
+
 	return minor;
+	}
=20
     pipe->minor =3D minor;
=20
@@ -337,14 +387,15 @@
     if (!pipe)
 	{
 	err =3D xeno_handle_error(pipe,XENO_PIPE_MAGIC,RT_PIPE);
-	goto unlock_and_exit;
+	xnlock_put_irqrestore(&nklock,s);
+	return err;
 	}
=20
     if (__test_and_clear_bit(0,&pipe->flushable))
 	{
 	/* Purge data waiting for flush. */
 	removeq(&__pipe_flush_q,&pipe->link);
-	rt_pipe_free(pipe->buffer);
+	rt_pipe_free(pipe,pipe->buffer);
 	}
=20
     err =3D xnpipe_disconnect(pipe->minor);
@@ -356,10 +407,11 @@
=20
     xeno_mark_deleted(pipe);
=20
- unlock_and_exit:
-
     xnlock_put_irqrestore(&nklock,s);
=20
+    if (pipe->bufpool =3D=3D &pipe->privpool)
+	xnheap_destroy(&pipe->privpool,__pipe_flush_pool,NULL);
+
     return err;
 }
=20
@@ -572,7 +624,7 @@
     /* Zero-sized messages are allowed, so we still need to free the
        message buffer even if no data copy took place. */
=20
-    rt_pipe_free(msg);
+    rt_pipe_free(pipe,msg);
=20
     return nbytes;
 }
@@ -767,7 +819,7 @@
 	/* Try flushing the streaming buffer in any case. */
 	return rt_pipe_send(pipe,NULL,0,mode);
=20
-    msg =3D rt_pipe_alloc(size);
+    msg =3D rt_pipe_alloc(pipe,size);
 =09
     if (!msg)
 	return -ENOMEM;
@@ -779,7 +831,7 @@
     if (nbytes !=3D size)
 	/* If the operation failed, we need to free the message buffer
 	   by ourselves. */
-	rt_pipe_free(msg);
+	rt_pipe_free(pipe,msg);
=20
     return nbytes;
 }
@@ -886,7 +938,7 @@
=20
 	if (pipe->buffer =3D=3D NULL)
 	    {
-	    pipe->buffer =3D rt_pipe_alloc(CONFIG_XENO_OPT_NATIVE_PIPE_BUFSZ);
+	    pipe->buffer =3D rt_pipe_alloc(pipe,CONFIG_XENO_OPT_NATIVE_PIPE_BUF=
SZ);
=20
 	    if (pipe->buffer =3D=3D NULL)
 		{
@@ -984,7 +1036,7 @@
 }
=20
 /**
- * @fn RT_PIPE_MSG *rt_pipe_alloc(size_t size)
+ * @fn RT_PIPE_MSG *rt_pipe_alloc(RT_PIPE *pipe,size_t size)
  *
  * @brief Allocate a message pipe buffer.
  *
@@ -1010,10 +1062,11 @@
  * Rescheduling: never.
  */
=20
-RT_PIPE_MSG *rt_pipe_alloc (size_t size)
+RT_PIPE_MSG *rt_pipe_alloc (RT_PIPE *pipe,
+                            size_t size)
=20
 {
-    RT_PIPE_MSG *msg =3D (RT_PIPE_MSG *)xnheap_alloc(__pipe_heap,size + =
sizeof(RT_PIPE_MSG));
+    RT_PIPE_MSG *msg =3D (RT_PIPE_MSG *)xnheap_alloc(pipe->bufpool,size =
+ sizeof(RT_PIPE_MSG));
=20
     if (msg)
 	{
@@ -1025,7 +1078,7 @@
 }
=20
 /**
- * @fn int rt_pipe_free(RT_PIPE_MSG *msg)
+ * @fn int rt_pipe_free(RT_PIPE *pipe,RT_PIPE_MSG *msg)
  *
  * @brief Free a message pipe buffer.
  *
@@ -1049,9 +1102,9 @@
  * Rescheduling: never.
  */
=20
-int rt_pipe_free (RT_PIPE_MSG *msg)
+int rt_pipe_free (RT_PIPE *pipe,RT_PIPE_MSG *msg)
 {
-    return xnheap_free(__pipe_heap,msg);
+    return xnheap_free(pipe->bufpool,msg);
 }
=20
 /*@}*/
Index: testsuite/klatency/latency-module.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- testsuite/klatency/latency-module.c	(revision 165)
+++ testsuite/klatency/latency-module.c	(working copy)
@@ -83,7 +83,7 @@
 	maxjitter =3D maxj;
 	avgjitter =3D sumj / sample_count;
=20
-	msg =3D rt_pipe_alloc(sizeof(struct latency_stat));
+	msg =3D rt_pipe_alloc(&pipe,sizeof(struct latency_stat));
=20
 	if (!msg)
 	    {
@@ -103,7 +103,7 @@
 	   ourselves. */
=20
 	if (rt_pipe_send(&pipe,msg,sizeof(*s),0) !=3D sizeof(*s))
-	    rt_pipe_free(msg);
+	    rt_pipe_free(&pipe,msg);
 	}
 }
=20
@@ -128,7 +128,7 @@
 	return 2;
 	}
=20
-    err =3D rt_pipe_create(&pipe,"klatency",0);
+    err =3D rt_pipe_create(&pipe,"klatency",0,0);
=20
     if (err)
 	{

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