Changeset fbcdeb8 in mainline for uspace/lib/c/include/async.h

Timestamp:

2011-12-19T17:30:39Z (13 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

58f6229

Parents:

24cf31f1

Message:

Remove the two-phase way of creating virtual memory areas (first asking for a mappable address and then mapping it) which was prone to race conditions when two or more calls to as_get_mappable_page() and as_area_create() were interleaved. This for example caused the e1k driver to randomly fail.

The memory area related syscalls and IPC calls have all been altered to accept a special value (void *) -1, representing a demand to atomically search for a mappable address space "hole" and map to it.

Individual changes:

• IPC_M_SHARE_OUT: the destination address space area is supplied by the kernel, the callee only specifies the lower bound

(the address is returned to the callee via a pointer in an IPC reply argument)

• IPC_M_SHARE_IN: the destination address space ares is supplied by the kernel, the callee only specifies the lower bound

(the address is returned to the caller as usual via an IPC argument)

• SYS_AS_GET_UNMAPPED_AREA was removed
• dummy implementations of SYS_PHYSMEM_UNMAP and SYS_IOSPACE_DISABLE were added for the sake of symmetry (they do nothing yet)
• SYS_PHYSMEM_MAP and SYS_DMAMEM_MAP were altered to accept (void *) -1 as address space area base and a lower bound
• kernel as_area_create() and as_area_share() were altered to accept (void *) -1 as address space area base and a lower bound
• uspace libraries and programs were altered to reflect the new API

File:

• uspace/lib/c/include/async.h (modified) (2 diffs)

uspace/lib/c/include/async.h

@@ -346 +346 @@
  */
 
-#define async_share_in_start_0_0(exch, dst, size) \
-        async_share_in_start(exch, dst, size, 0, NULL)
-#define async_share_in_start_0_1(exch, dst, size, flags) \
-        async_share_in_start(exch, dst, size, 0, flags)
-#define async_share_in_start_1_0(exch, dst, size, arg) \
-        async_share_in_start(exch, dst, size, arg, NULL)
-#define async_share_in_start_1_1(exch, dst, size, arg, flags) \
-        async_share_in_start(exch, dst, size, arg, flags)
-
-extern int async_share_in_start(async_exch_t *, void *, size_t, sysarg_t,
-    unsigned int *);
+#define async_share_in_start_0_0(exch, size, dst) \
+        async_share_in_start(exch, size, 0, NULL, dst)
+#define async_share_in_start_0_1(exch, size, flags, dst) \
+        async_share_in_start(exch, size, 0, flags, dst)
+#define async_share_in_start_1_0(exch, size, arg, dst) \
+        async_share_in_start(exch, size, arg, NULL, dst)
+#define async_share_in_start_1_1(exch, size, arg, flags, dst) \
+        async_share_in_start(exch, size, arg, flags, dst)
+
+extern int async_share_in_start(async_exch_t *, size_t, sysarg_t,
+    unsigned int *, void **);
 extern bool async_share_in_receive(ipc_callid_t *, size_t *);
 extern int async_share_in_finalize(ipc_callid_t, void *, unsigned int);
@@ -362 +362 @@
 extern int async_share_out_start(async_exch_t *, void *, unsigned int);
 extern bool async_share_out_receive(ipc_callid_t *, size_t *, unsigned int *);
-extern int async_share_out_finalize(ipc_callid_t, void *);
+extern int async_share_out_finalize(ipc_callid_t, void **);
 
 /*