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Let the CloudABI futex code use umtx_keys.

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The CloudABI kernel still passes all of the cloudlibc unit tests.

Reviewed by:	vangyzen
Differential Revision:	https://reviews.freebsd.org/D3286
This commit is contained in:
Ed Schouten 2015-08-04 06:02:03 +00:00
parent dc4b532479
commit 0c0964844e
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=286278
1 changed files with 11 additions and 72 deletions
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83
sys/compat/cloudabi/cloudabi_futex.c
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@ -35,13 +35,7 @@ __FBSDID("$FreeBSD$");
#include <sys/proc.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <sys/umtx.h>
#include <compat/cloudabi/cloudabi_proto.h>
#include <compat/cloudabi/cloudabi_syscalldefs.h>
@ -105,13 +99,7 @@ struct futex_waiter;
/* Identifier of a location in memory. */
struct futex_address {
/* For process-private objects: address space of the process. */
struct vmspace * fa_vmspace;
/* For process-shared objects: VM object containing the object. */
struct vm_object * fa_vmobject;
/* Memory address within address space or offset within VM object. */
uintptr_t fa_offset;
struct umtx_key fa_key;
};
/* A set of waiting threads. */
@ -225,61 +213,16 @@ static int
futex_address_create(struct futex_address *fa, struct thread *td,
const void *object, cloudabi_mflags_t scope)
{
struct vmspace *vs;
struct vm_object *vo;
vm_map_t map;
vm_map_entry_t entry;
vm_pindex_t pindex;
vm_prot_t prot;
boolean_t wired;
/*
* Most of the time objects are stored in privately mapped
* anonymous memory. For these objects we wouldn't need to look
* up the corresponding VM object. The scope hint provided by
* userspace allows us to skip the VM map lookup for the common
* case.
*
* POSIX does permit enabling PTHREAD_PROCESS_SHARED on a lock
* stored in a private mapping, at the cost of additional
* performance overhead. Fall back to identifying the object by
* virtual memory address if the mapping isn't shared.
*/
vs = td->td_proc->p_vmspace;
KASSERT(td == curthread,
("Can only create umtx keys for the current thread"));
switch (scope) {
case CLOUDABI_MAP_SHARED:
map = &vs->vm_map;
if (vm_map_lookup(&map, (vm_offset_t)object,
VM_PROT_COPY | VM_PROT_WRITE, &entry, &vo, &pindex, &prot,
&wired) != KERN_SUCCESS)
return (EFAULT);
if (entry->inheritance == VM_INHERIT_SHARE) {
/*
* Address corresponds to a shared mapping.
* Identify the address by its VM object.
*/
fa->fa_vmspace = NULL;
fa->fa_vmobject = vo;
vm_object_reference(vo);
fa->fa_offset = entry->offset - entry->start +
(vm_offset_t)object;
vm_map_lookup_done(map, entry);
return (0);
}
vm_map_lookup_done(map, entry);
/* FALLTHROUGH */
case CLOUDABI_MAP_PRIVATE:
/*
* Address corresponds to a private mapping. Never
* identify the address by its VM object, as shadow
* objects may get inserted if another thread forks.
* Simply use the VM space instead.
*/
fa->fa_vmspace = vs;
fa->fa_vmobject = NULL;
fa->fa_offset = (uintptr_t)object;
return (0);
return (umtx_key_get(object, TYPE_FUTEX, THREAD_SHARE,
&fa->fa_key));
case CLOUDABI_MAP_SHARED:
return (umtx_key_get(object, TYPE_FUTEX, AUTO_SHARE,
&fa->fa_key));
default:
return (EINVAL);
}
@ -289,8 +232,7 @@ static void
futex_address_free(struct futex_address *fa)
{
if (fa->fa_vmobject != NULL)
vm_object_deallocate(fa->fa_vmobject);
umtx_key_release(&fa->fa_key);
}
static bool
@ -298,10 +240,7 @@ futex_address_match(const struct futex_address *fa1,
const struct futex_address *fa2)
{
/* Either fa_vmspace or fa_vmobject is NULL. */
return (fa1->fa_vmspace == fa2->fa_vmspace &&
fa1->fa_vmobject == fa2->fa_vmobject &&
fa1->fa_offset == fa2->fa_offset);
return (umtx_key_match(&fa1->fa_key, &fa2->fa_key));
}
/*