[PATCH v27 0/9] MR3103: server: Create and use a desktop shared mapping for GetCursorPos.
First part of Proton shared memory series. The full branch can be seen at https://gitlab.winehq.org/rbernon/wine/-/commits/mr/shared-memories.
-- v27: win32u: Use the desktop shared data for GetCursorPos. server: Move the last cursor time to the desktop session object. server: Move the cursor position to the desktop session object. win32u: Open desktop shared objects from session mapping. server: Return the desktop object info in get_thread_desktop. server: Allocate shared session object for desktops. win32u: Open the global session shared mapping. include: Add ReadNoFence64 inline helpers. server: Create a global session shared mapping.
From: Rémi Bernon rbernon@codeweavers.com
--- server/directory.c | 7 +++++++ server/file.h | 19 +++++++++++++++++++ server/mapping.c | 33 +++++++++++++++++++++++++++++++++ server/protocol.def | 24 ++++++++++++++++++++++++ tools/make_requests | 1 + 5 files changed, 84 insertions(+)
diff --git a/server/directory.c b/server/directory.c index 23d7eb0a2b7..1ef645c2c2d 100644 --- a/server/directory.c +++ b/server/directory.c @@ -439,11 +439,14 @@ void init_directories( struct fd *intl_fd ) /* mappings */ static const WCHAR intlW[] = {'N','l','s','S','e','c','t','i','o','n','L','A','N','G','_','I','N','T','L'}; static const WCHAR user_dataW[] = {'_','_','w','i','n','e','_','u','s','e','r','_','s','h','a','r','e','d','_','d','a','t','a'}; + static const WCHAR sessionW[] = {'_','_','w','i','n','e','_','s','e','s','s','i','o','n'}; static const struct unicode_str intl_str = {intlW, sizeof(intlW)}; static const struct unicode_str user_data_str = {user_dataW, sizeof(user_dataW)}; + static const struct unicode_str session_str = {sessionW, sizeof(sessionW)};
struct directory *dir_driver, *dir_device, *dir_global, *dir_kernel, *dir_nls; struct object *named_pipe_device, *mailslot_device, *null_device; + struct mapping *session_mapping; unsigned int i;
root_directory = create_directory( NULL, NULL, OBJ_PERMANENT, HASH_SIZE, NULL ); @@ -491,6 +494,10 @@ void init_directories( struct fd *intl_fd ) release_object( create_user_data_mapping( &dir_kernel->obj, &user_data_str, OBJ_PERMANENT, NULL )); release_object( intl_fd );
+ session_mapping = create_session_mapping( &dir_kernel->obj, &session_str, OBJ_PERMANENT, NULL ); + set_session_mapping( session_mapping ); + release_object( session_mapping ); + release_object( named_pipe_device ); release_object( mailslot_device ); release_object( null_device ); diff --git a/server/file.h b/server/file.h index 7f2d1637863..3a288f0a212 100644 --- a/server/file.h +++ b/server/file.h @@ -188,6 +188,25 @@ extern struct mapping *create_fd_mapping( struct object *root, const struct unic unsigned int attr, const struct security_descriptor *sd ); extern struct object *create_user_data_mapping( struct object *root, const struct unicode_str *name, unsigned int attr, const struct security_descriptor *sd ); +extern struct mapping *create_session_mapping( struct object *root, const struct unicode_str *name, + unsigned int attr, const struct security_descriptor *sd ); +extern void set_session_mapping( struct mapping *mapping ); + + +#define SHARED_WRITE_BEGIN( object, type ) \ + do { \ + const type *__shared = (object); \ + type *shared = (type *)__shared; \ + LONG64 __seq = shared->obj.seq + 1, __end = __seq + 1; \ + assert( (__seq & 1) != 0 ); \ + __WINE_ATOMIC_STORE_RELEASE( &shared->obj.seq, &__seq ); \ + do + +#define SHARED_WRITE_END \ + while(0); \ + assert( __seq == shared->obj.seq ); \ + __WINE_ATOMIC_STORE_RELEASE( &shared->obj.seq, &__end ); \ + } while(0)
/* device functions */
diff --git a/server/mapping.c b/server/mapping.c index 6b0de1b8b94..b90a3e84723 100644 --- a/server/mapping.c +++ b/server/mapping.c @@ -225,6 +225,13 @@ static const mem_size_t granularity_mask = 0xffff; static struct addr_range ranges32; static struct addr_range ranges64;
+struct session +{ + const session_shm_t *shared; +}; +static struct mapping *session_mapping; +static struct session session; + #define ROUND_SIZE(size) (((size) + page_mask) & ~page_mask)
void init_memory(void) @@ -1256,6 +1263,32 @@ int get_page_size(void) return page_mask + 1; }
+struct mapping *create_session_mapping( struct object *root, const struct unicode_str *name, + unsigned int attr, const struct security_descriptor *sd ) +{ + static const unsigned int access = FILE_READ_DATA | FILE_WRITE_DATA; + mem_size_t size; + + size = max(offsetof(session_shm_t, objects[512]), 0x10000); + size = (size + page_mask) & ~((mem_size_t)page_mask); + + return create_mapping( root, name, attr, size, SEC_COMMIT, 0, access, sd ); +} + +void set_session_mapping( struct mapping *mapping ) +{ + session.shared = mmap( NULL, mapping->size, PROT_READ | PROT_WRITE, MAP_SHARED, get_unix_fd( mapping->fd ), 0 ); + if (session.shared == MAP_FAILED) return; + + session_mapping = mapping; + SHARED_WRITE_BEGIN( session.shared, session_shm_t ) + { + shared->obj.id = -1; /* use the last valid object id for the session */ + shared->object_capacity = (mapping->size - offsetof(session_shm_t, objects[0])) / sizeof(session_obj_t); + } + SHARED_WRITE_END; +} + struct object *create_user_data_mapping( struct object *root, const struct unicode_str *name, unsigned int attr, const struct security_descriptor *sd ) { diff --git a/server/protocol.def b/server/protocol.def index 13aea96e796..08f55aaeee2 100644 --- a/server/protocol.def +++ b/server/protocol.def @@ -45,6 +45,7 @@ typedef unsigned __int64 mem_size_t; typedef unsigned __int64 file_pos_t; typedef unsigned __int64 client_ptr_t; typedef unsigned __int64 affinity_t; +typedef unsigned __int64 object_id_t; typedef client_ptr_t mod_handle_t;
struct request_header @@ -874,6 +875,29 @@ typedef struct lparam_t info; } cursor_pos_t;
+/****************************************************************/ +/* shared session mapping structures */ + +typedef volatile struct +{ + LONG64 seq; /* sequence number - server updating if (seq & 1) != 0 */ + object_id_t id; /* object unique id, object data is valid if != 0 */ +} object_shm_t; + +typedef volatile union +{ + object_shm_t obj; +} session_obj_t; + +typedef volatile struct +{ + object_shm_t obj; + mem_size_t object_capacity; + session_obj_t objects[]; +} session_shm_t; + +C_ASSERT(sizeof(session_shm_t) == offsetof(session_shm_t, objects[0])); + /****************************************************************/ /* Request declarations */
diff --git a/tools/make_requests b/tools/make_requests index e3eaaf45b6f..f22ad279b61 100755 --- a/tools/make_requests +++ b/tools/make_requests @@ -42,6 +42,7 @@ my %formats = "file_pos_t" => [ 8, 8, "&dump_uint64" ], "mem_size_t" => [ 8, 8, "&dump_uint64" ], "affinity_t" => [ 8, 8, "&dump_uint64" ], + "object_id_t" => [ 8, 8, "&dump_uint64" ], "timeout_t" => [ 8, 8, "&dump_timeout" ], "abstime_t" => [ 8, 8, "&dump_abstime" ], "rectangle_t" => [ 16, 4, "&dump_rectangle" ],
From: Rémi Bernon rbernon@codeweavers.com
--- include/winnt.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/include/winnt.h b/include/winnt.h index e7c322fd127..5ea908c97ad 100644 --- a/include/winnt.h +++ b/include/winnt.h @@ -7059,11 +7059,14 @@ static FORCEINLINE void MemoryBarrier(void) */ #if _MSC_VER >= 1700 #pragma intrinsic(__iso_volatile_load32) +#pragma intrinsic(__iso_volatile_load64) #pragma intrinsic(__iso_volatile_store32) #define __WINE_LOAD32_NO_FENCE(src) (__iso_volatile_load32(src)) +#define __WINE_LOAD64_NO_FENCE(src) (__iso_volatile_load64(src)) #define __WINE_STORE32_NO_FENCE(dest, value) (__iso_volatile_store32(dest, value)) #else /* _MSC_VER >= 1700 */ #define __WINE_LOAD32_NO_FENCE(src) (*(src)) +#define __WINE_LOAD64_NO_FENCE(src) (*(src)) #define __WINE_STORE32_NO_FENCE(dest, value) ((void)(*(dest) = (value))) #endif /* _MSC_VER >= 1700 */
@@ -7097,6 +7100,12 @@ static FORCEINLINE LONG ReadNoFence( LONG const volatile *src ) return value; }
+static FORCEINLINE LONG64 ReadNoFence64( LONG64 const volatile *src ) +{ + LONG64 value = __WINE_LOAD64_NO_FENCE( (__int64 const volatile *)src ); + return value; +} + static FORCEINLINE void WriteRelease( LONG volatile *dest, LONG value ) { __wine_memory_barrier_acq_rel(); @@ -7283,6 +7292,13 @@ static FORCEINLINE LONG ReadNoFence( LONG const volatile *src ) return value; }
+static FORCEINLINE LONG64 ReadNoFence64( LONG64 const volatile *src ) +{ + LONG64 value; + __WINE_ATOMIC_LOAD_RELAXED( src, &value ); + return value; +} + static FORCEINLINE void WriteRelease( LONG volatile *dest, LONG value ) { __WINE_ATOMIC_STORE_RELEASE( dest, &value );
On Mon Mar 18 15:39:59 2024 +0000, Jinoh Kang wrote:
Setting the ID to -1 works for me. (It's guaranteed to be distinct from any other ID, and stands out from the rest.)
Done.
From: Rémi Bernon rbernon@codeweavers.com
--- dlls/win32u/win32u_private.h | 23 ++++++++ dlls/win32u/winstation.c | 110 ++++++++++++++++++++++++++++++++++- 2 files changed, 132 insertions(+), 1 deletion(-)
diff --git a/dlls/win32u/win32u_private.h b/dlls/win32u/win32u_private.h index 0af6960a3eb..003d2fd5c24 100644 --- a/dlls/win32u/win32u_private.h +++ b/dlls/win32u/win32u_private.h @@ -364,4 +364,27 @@ static inline BOOL intersect_rect( RECT *dst, const RECT *src1, const RECT *src2 return !IsRectEmpty( dst ); }
+#if defined(__i386__) || defined(__x86_64__) +/* this prevents compilers from incorrectly reordering non-volatile reads (e.g., memcpy) from shared memory */ +#define __SHARED_READ_FENCE do { __asm__ __volatile__( "" ::: "memory" ); } while (0) +#else +#define __SHARED_READ_FENCE __atomic_thread_fence( __ATOMIC_ACQUIRE ) +#endif + +#define SHARED_READ_BEGIN( ptr, type ) \ + do { \ + const type *shared = (ptr); \ + LONG64 __seq; \ + do { \ + while ((__seq = ReadNoFence64( &shared->obj.seq )) & 1) \ + YieldProcessor(); \ + __SHARED_READ_FENCE; \ + do + +#define SHARED_READ_END \ + while (0); \ + __SHARED_READ_FENCE; \ + } while (ReadNoFence64( &shared->obj.seq ) != __seq); \ + } while(0) + #endif /* __WINE_WIN32U_PRIVATE */ diff --git a/dlls/win32u/winstation.c b/dlls/win32u/winstation.c index 6ddd5411f94..6b15ec3a560 100644 --- a/dlls/win32u/winstation.c +++ b/dlls/win32u/winstation.c @@ -22,9 +22,12 @@ #pragma makedep unix #endif
+#include <stdarg.h> +#include <stddef.h> +#include <pthread.h> + #include "ntstatus.h" #define WIN32_NO_STATUS -#include <stdarg.h> #include "windef.h" #include "winbase.h" #include "ntuser.h" @@ -40,6 +43,107 @@ WINE_DECLARE_DEBUG_CHANNEL(win);
#define DESKTOP_ALL_ACCESS 0x01ff
+struct shared_session +{ + LONG ref; + UINT object_capacity; + const session_shm_t *shared; +}; + +static pthread_mutex_t session_lock = PTHREAD_MUTEX_INITIALIZER; +static struct shared_session *shared_session; + +static struct shared_session *shared_session_acquire( struct shared_session *session ) +{ + int ref = InterlockedIncrement( &session->ref ); + TRACE( "session %p incrementing ref to %d\n", session, ref ); + return session; +} + +static void shared_session_release( struct shared_session *session ) +{ + int ref = InterlockedDecrement( &session->ref ); + TRACE( "session %p decrementing ref to %d\n", session, ref ); + if (!ref) + { + NtUnmapViewOfSection( GetCurrentProcess(), (void *)session->shared ); + free( session ); + } +} + +static NTSTATUS map_shared_session_section( struct shared_session *session, HANDLE handle ) +{ + NTSTATUS status; + SIZE_T size = 0; + + while (!(status = NtMapViewOfSection( handle, GetCurrentProcess(), (void **)&session->shared, 0, 0, + NULL, &size, ViewUnmap, 0, PAGE_READONLY ))) + { + BOOL valid; + session->object_capacity = (size - offsetof(session_shm_t, objects[0])) / sizeof(session_obj_t); + SHARED_READ_BEGIN( session->shared, session_shm_t ) + { + valid = session->object_capacity == shared->object_capacity; + } + SHARED_READ_END; + if (valid) break; + + NtUnmapViewOfSection( GetCurrentProcess(), (void *)session->shared ); + session->shared = NULL; + size = 0; + } + + return status; +} + +static struct shared_session *get_shared_session( BOOL force ) +{ + struct shared_session *session; + + pthread_mutex_lock( &session_lock ); + + if (force || !shared_session) + { + static const WCHAR nameW[] = + { + '\','K','e','r','n','e','l','O','b','j','e','c','t','s','\', + '_','_','w','i','n','e','_','s','e','s','s','i','o','n',0 + }; + UNICODE_STRING name = RTL_CONSTANT_STRING( nameW ); + OBJECT_ATTRIBUTES attr; + unsigned int status; + HANDLE handle; + + if (!(session = calloc( 1, sizeof(*session) ))) goto done; + session->ref = 1; + + InitializeObjectAttributes( &attr, &name, 0, NULL, NULL ); + if (!(status = NtOpenSection( &handle, SECTION_MAP_READ, &attr ))) + { + status = map_shared_session_section( session, handle ); + NtClose( handle ); + } + + if (status) + { + ERR( "Failed to map session mapping, status %#x\n", status ); + free( session ); + session = NULL; + goto done; + } + + if (shared_session) shared_session_release( shared_session ); + shared_session = session; + } + + session = shared_session_acquire( shared_session ); + +done: + pthread_mutex_unlock( &session_lock ); + + return session; +} + BOOL is_virtual_desktop(void) { HANDLE desktop = NtUserGetThreadDesktop( GetCurrentThreadId() ); @@ -630,12 +734,16 @@ void winstation_init(void) { RTL_USER_PROCESS_PARAMETERS *params = NtCurrentTeb()->Peb->ProcessParameters; WCHAR *winstation = NULL, *desktop = NULL, *buffer = NULL; + struct shared_session *session; HANDLE handle, dir = NULL; OBJECT_ATTRIBUTES attr; UNICODE_STRING str;
static const WCHAR winsta0[] = {'W','i','n','S','t','a','0',0};
+ if ((session = get_shared_session( FALSE ))) + shared_session_release( session ); + if (params->Desktop.Length) { buffer = malloc( params->Desktop.Length + sizeof(WCHAR) );
From: Rémi Bernon rbernon@codeweavers.com
--- server/file.h | 4 +++ server/mapping.c | 76 +++++++++++++++++++++++++++++++++++++++++++++ server/protocol.def | 6 ++++ server/user.h | 1 + server/winstation.c | 8 +++++ 5 files changed, 95 insertions(+)
diff --git a/server/file.h b/server/file.h index 3a288f0a212..5380e1a6430 100644 --- a/server/file.h +++ b/server/file.h @@ -192,6 +192,10 @@ extern struct mapping *create_session_mapping( struct object *root, const struct unsigned int attr, const struct security_descriptor *sd ); extern void set_session_mapping( struct mapping *mapping );
+extern int alloc_shared_object(void); +extern void free_shared_object( int index ); +extern const desktop_shm_t *get_shared_desktop( int index ); +
#define SHARED_WRITE_BEGIN( object, type ) \ do { \ diff --git a/server/mapping.c b/server/mapping.c index b90a3e84723..392ce49cf5b 100644 --- a/server/mapping.c +++ b/server/mapping.c @@ -228,6 +228,8 @@ static struct addr_range ranges64; struct session { const session_shm_t *shared; + mem_size_t next_object_index; + object_id_t last_object_id; }; static struct mapping *session_mapping; static struct session session; @@ -1289,6 +1291,80 @@ void set_session_mapping( struct mapping *mapping ) SHARED_WRITE_END; }
+static int grow_session_mapping(void) +{ + unsigned int capacity; + mem_size_t size; + int unix_fd; + void *tmp; + + capacity = session.shared->object_capacity * 3 / 2; + assert( capacity > session.shared->object_capacity ); + size = offsetof(session_shm_t, objects[capacity]); + size = (size + page_mask) & ~((mem_size_t)page_mask); + + unix_fd = get_unix_fd( session_mapping->fd ); + if (!grow_file( unix_fd, size )) return -1; + + if ((tmp = mmap( NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, unix_fd, 0 )) == MAP_FAILED) + { + file_set_error(); + return -1; + } + munmap( (void *)session.shared, session_mapping->size ); + session.shared = tmp; + session_mapping->size = size; + + SHARED_WRITE_BEGIN( session.shared, session_shm_t ) + { + shared->object_capacity = (size - offsetof(session_shm_t, objects[0])) / sizeof(session_obj_t); + } + SHARED_WRITE_END; + + return 0; +} + +int alloc_shared_object(void) +{ + mem_size_t index, offset = session.next_object_index, capacity = session.shared->object_capacity; + + for (index = offset; index != offset + capacity; index++) + if (!session.shared->objects[index % capacity].obj.id) + break; + if (index != offset + capacity) index %= capacity; + else + { + if (grow_session_mapping()) return -1; + index = capacity; + } + + SHARED_WRITE_BEGIN( &session.shared->objects[index], session_obj_t ) + { + shared->obj.id = ++session.last_object_id; + } + SHARED_WRITE_END; + session.next_object_index = index + 1; + + return index; +} + +void free_shared_object( int index ) +{ + if (index < 0) return; + + SHARED_WRITE_BEGIN( &session.shared->objects[index], session_obj_t ) + { + shared->obj.id = 0; + } + SHARED_WRITE_END; +} + +const desktop_shm_t *get_shared_desktop( int index ) +{ + if (index < 0) return NULL; + return &session.shared->objects[index].desktop; +} + struct object *create_user_data_mapping( struct object *root, const struct unicode_str *name, unsigned int attr, const struct security_descriptor *sd ) { diff --git a/server/protocol.def b/server/protocol.def index 08f55aaeee2..258b1abb6ed 100644 --- a/server/protocol.def +++ b/server/protocol.def @@ -884,9 +884,15 @@ typedef volatile struct object_id_t id; /* object unique id, object data is valid if != 0 */ } object_shm_t;
+typedef volatile struct +{ + object_shm_t obj; +} desktop_shm_t; + typedef volatile union { object_shm_t obj; + desktop_shm_t desktop; } session_obj_t;
typedef volatile struct diff --git a/server/user.h b/server/user.h index 309a0966104..21d67656c9c 100644 --- a/server/user.h +++ b/server/user.h @@ -81,6 +81,7 @@ struct desktop unsigned int users; /* processes and threads using this desktop */ struct global_cursor cursor; /* global cursor information */ unsigned char keystate[256]; /* asynchronous key state */ + int session_index; /* desktop index in session shared memory */ };
/* user handles functions */ diff --git a/server/winstation.c b/server/winstation.c index 3af4c365ec3..d055a632dec 100644 --- a/server/winstation.c +++ b/server/winstation.c @@ -297,6 +297,13 @@ static struct desktop *create_desktop( const struct unicode_str *name, unsigned list_add_tail( &winstation->desktops, &desktop->entry ); list_init( &desktop->hotkeys ); list_init( &desktop->pointers ); + desktop->session_index = -1; + + if ((desktop->session_index = alloc_shared_object()) == -1) + { + release_object( desktop ); + return NULL; + } } else { @@ -366,6 +373,7 @@ static void desktop_destroy( struct object *obj ) if (desktop->global_hooks) release_object( desktop->global_hooks ); if (desktop->close_timeout) remove_timeout_user( desktop->close_timeout ); release_object( desktop->winstation ); + free_shared_object( desktop->session_index ); }
/* retrieve the thread desktop, checking the handle access rights */
From: Rémi Bernon rbernon@codeweavers.com
--- server/protocol.def | 2 ++ server/winstation.c | 12 ++++++++++++ 2 files changed, 14 insertions(+)
diff --git a/server/protocol.def b/server/protocol.def index 258b1abb6ed..1096df4c0ab 100644 --- a/server/protocol.def +++ b/server/protocol.def @@ -2813,6 +2813,8 @@ enum coords_relative thread_id_t tid; /* thread id */ @REPLY obj_handle_t handle; /* handle to the desktop */ + int index; /* index of desktop object in session shared memory */ + object_id_t object_id; /* id of the session object */ @END
diff --git a/server/winstation.c b/server/winstation.c index d055a632dec..54f422ddf60 100644 --- a/server/winstation.c +++ b/server/winstation.c @@ -737,10 +737,22 @@ DECL_HANDLER(close_desktop) /* get the thread current desktop */ DECL_HANDLER(get_thread_desktop) { + struct desktop *desktop; struct thread *thread;
if (!(thread = get_thread_from_id( req->tid ))) return; reply->handle = thread->desktop; + reply->index = -1; + + if (!(desktop = get_thread_desktop( thread, 0 ))) clear_error(); + else + { + const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index ); + reply->index = desktop->session_index; + reply->object_id = desktop_shm->obj.id; + release_object( desktop ); + } + release_object( thread ); }
From: Rémi Bernon rbernon@codeweavers.com
--- dlls/win32u/ntuser_private.h | 1 + dlls/win32u/sysparams.c | 1 + dlls/win32u/win32u_private.h | 13 +++++ dlls/win32u/winstation.c | 102 +++++++++++++++++++++++++++++++++-- 4 files changed, 113 insertions(+), 4 deletions(-)
diff --git a/dlls/win32u/ntuser_private.h b/dlls/win32u/ntuser_private.h index 3b6cab5bdc9..27430c3478b 100644 --- a/dlls/win32u/ntuser_private.h +++ b/dlls/win32u/ntuser_private.h @@ -127,6 +127,7 @@ struct user_thread_info UINT spy_indent; /* Current spy indent */ BOOL clipping_cursor; /* thread is currently clipping */ DWORD clipping_reset; /* time when clipping was last reset */ + struct session_thread_data *session_data; /* shared session thread data */ };
C_ASSERT( sizeof(struct user_thread_info) <= sizeof(((TEB *)0)->Win32ClientInfo) ); diff --git a/dlls/win32u/sysparams.c b/dlls/win32u/sysparams.c index 6c4223f0cdb..cb9920bb4d5 100644 --- a/dlls/win32u/sysparams.c +++ b/dlls/win32u/sysparams.c @@ -6151,6 +6151,7 @@ static void thread_detach(void) destroy_thread_windows(); cleanup_imm_thread(); NtClose( thread_info->server_queue ); + free( thread_info->session_data );
exiting_thread_id = 0; } diff --git a/dlls/win32u/win32u_private.h b/dlls/win32u/win32u_private.h index 003d2fd5c24..4b7905639b7 100644 --- a/dlls/win32u/win32u_private.h +++ b/dlls/win32u/win32u_private.h @@ -193,6 +193,19 @@ extern void user_unlock(void); extern void user_check_not_lock(void);
/* winstation.c */ + +struct shared_session; + +struct object_lock +{ + UINT64 id; + const session_obj_t *shared; /* only valid when locked, read inside SHARED_READ_BEGIN */ + struct shared_session *session; /* only valid when locked */ +}; + +extern void object_lock_release( struct object_lock *lock ); +extern BOOL get_shared_desktop( struct object_lock *lock ); + extern BOOL is_virtual_desktop(void);
/* window.c */ diff --git a/dlls/win32u/winstation.c b/dlls/win32u/winstation.c index 6b15ec3a560..84eb20bda60 100644 --- a/dlls/win32u/winstation.c +++ b/dlls/win32u/winstation.c @@ -43,6 +43,17 @@ WINE_DECLARE_DEBUG_CHANNEL(win);
#define DESKTOP_ALL_ACCESS 0x01ff
+struct object_info +{ + UINT64 id; + UINT index; +}; + +struct session_thread_data +{ + struct object_info shared_desktop; /* thread desktop shared session object info */ +}; + struct shared_session { LONG ref; @@ -53,6 +64,13 @@ struct shared_session static pthread_mutex_t session_lock = PTHREAD_MUTEX_INITIALIZER; static struct shared_session *shared_session;
+static struct session_thread_data *get_session_thread_data(void) +{ + struct user_thread_info *thread_info = get_user_thread_info(); + if (!thread_info->session_data) thread_info->session_data = calloc(1, sizeof(*thread_info->session_data)); + return thread_info->session_data; +} + static struct shared_session *shared_session_acquire( struct shared_session *session ) { int ref = InterlockedIncrement( &session->ref ); @@ -144,6 +162,82 @@ done: return session; }
+void object_lock_release( struct object_lock *lock ) +{ + shared_session_release( lock->session ); + memset( lock, 0, sizeof(*lock) ); + lock->id = -1; /* force object to be refreshed when retrying lock */ +} + +enum object_type +{ + OBJECT_TYPE_DESKTOP = 1, +}; + +static NTSTATUS get_thread_session_object_info( UINT tid, enum object_type type, + struct object_info *info ) +{ + NTSTATUS status; + + switch (type) + { + case OBJECT_TYPE_DESKTOP: + SERVER_START_REQ( get_thread_desktop ) + { + req->tid = tid; + if (!(status = wine_server_call( req ))) + { + info->id = reply->object_id; + info->index = reply->index; + } + } + SERVER_END_REQ; + break; + } + + return status; +} + +/* return a locked session object for a thread id and type */ +static BOOL get_thread_session_object( UINT tid, enum object_type type, struct object_info *info, + struct object_lock *lock ) +{ + struct shared_session *session; + BOOL valid = TRUE; + + TRACE( "tid %04x, type %u\n", tid, type ); + + while ((session = get_shared_session( !valid ))) + { + if (!info->id && get_thread_session_object_info( tid, type, info )) break; + if ((valid = info->index < session->object_capacity)) + { + lock->id = info->id; + lock->session = session; + lock->shared = &session->shared->objects[info->index]; + return TRUE; + } + shared_session_release( session ); + memset( info, 0, sizeof(*info) ); + } + + WARN( "Failed to find object type %u for thread %04x\n", type, tid ); + if (session) shared_session_release( session ); + memset( info, 0, sizeof(*info) ); + return FALSE; +} + +BOOL get_shared_desktop( struct object_lock *lock ) +{ + struct session_thread_data *data = get_session_thread_data(); + struct object_info *info = &data->shared_desktop; + + TRACE( "lock %p\n", lock ); + + if (lock->id) info->id = 0; /* invalidate info if the lock was abandoned due to id mismatch */ + return get_thread_session_object( GetCurrentThreadId(), OBJECT_TYPE_DESKTOP, info, lock ); +} + BOOL is_virtual_desktop(void) { HANDLE desktop = NtUserGetThreadDesktop( GetCurrentThreadId() ); @@ -365,9 +459,13 @@ BOOL WINAPI NtUserSetThreadDesktop( HDESK handle ) { struct user_thread_info *thread_info = get_user_thread_info(); struct user_key_state_info *key_state_info = thread_info->key_state; + struct object_info *desktop_info = &get_session_thread_data()->shared_desktop; + struct object_lock lock = {0}; thread_info->client_info.top_window = 0; thread_info->client_info.msg_window = 0; if (key_state_info) key_state_info->time = 0; + memset( desktop_info, 0, sizeof(*desktop_info) ); + if (get_shared_desktop( &lock )) object_lock_release( &lock ); if (was_virtual_desktop != is_virtual_desktop()) update_display_cache( TRUE ); } return ret; @@ -734,16 +832,12 @@ void winstation_init(void) { RTL_USER_PROCESS_PARAMETERS *params = NtCurrentTeb()->Peb->ProcessParameters; WCHAR *winstation = NULL, *desktop = NULL, *buffer = NULL; - struct shared_session *session; HANDLE handle, dir = NULL; OBJECT_ATTRIBUTES attr; UNICODE_STRING str;
static const WCHAR winsta0[] = {'W','i','n','S','t','a','0',0};
- if ((session = get_shared_session( FALSE ))) - shared_session_release( session ); - if (params->Desktop.Length) { buffer = malloc( params->Desktop.Length + sizeof(WCHAR) );
From: Rémi Bernon rbernon@codeweavers.com
Based on a patch by Huw Davies huw@codeweavers.com. --- server/protocol.def | 7 ++++ server/queue.c | 78 ++++++++++++++++++++++++++++----------------- server/user.h | 2 -- 3 files changed, 55 insertions(+), 32 deletions(-)
diff --git a/server/protocol.def b/server/protocol.def index 1096df4c0ab..736d2b0232c 100644 --- a/server/protocol.def +++ b/server/protocol.def @@ -878,6 +878,12 @@ typedef struct /****************************************************************/ /* shared session mapping structures */
+struct shared_cursor +{ + int x; /* cursor position */ + int y; +}; + typedef volatile struct { LONG64 seq; /* sequence number - server updating if (seq & 1) != 0 */ @@ -887,6 +893,7 @@ typedef volatile struct typedef volatile struct { object_shm_t obj; + struct shared_cursor cursor; /* global cursor information */ } desktop_shm_t;
typedef volatile union diff --git a/server/queue.c b/server/queue.c index 0e8653bedf0..cba5514deef 100644 --- a/server/queue.c +++ b/server/queue.c @@ -418,6 +418,7 @@ static void queue_cursor_message( struct desktop *desktop, user_handle_t win, un lparam_t wparam, lparam_t lparam ) { static const struct hw_msg_source source = { IMDT_UNAVAILABLE, IMO_SYSTEM }; + const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index ); struct thread_input *input; struct message *msg;
@@ -426,8 +427,8 @@ static void queue_cursor_message( struct desktop *desktop, user_handle_t win, un msg->msg = message; msg->wparam = wparam; msg->lparam = lparam; - msg->x = desktop->cursor.x; - msg->y = desktop->cursor.y; + msg->x = desktop_shm->cursor.x; + msg->y = desktop_shm->cursor.y; if (!(msg->win = win) && (input = desktop->foreground_input)) msg->win = input->active; queue_hardware_message( desktop, msg, 1 ); } @@ -465,13 +466,20 @@ static int update_desktop_cursor_window( struct desktop *desktop, user_handle_t
static int update_desktop_cursor_pos( struct desktop *desktop, user_handle_t win, int x, int y ) { + const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index ); int updated;
x = max( min( x, desktop->cursor.clip.right - 1 ), desktop->cursor.clip.left ); y = max( min( y, desktop->cursor.clip.bottom - 1 ), desktop->cursor.clip.top ); - updated = (desktop->cursor.x != x || desktop->cursor.y != y); - desktop->cursor.x = x; - desktop->cursor.y = y; + + SHARED_WRITE_BEGIN( desktop_shm, desktop_shm_t ) + { + updated = shared->cursor.x != x || shared->cursor.y != y; + shared->cursor.x = x; + shared->cursor.y = y; + } + SHARED_WRITE_END; + desktop->cursor.last_change = get_tick_count();
if (!win || !is_window_visible( win ) || is_window_transparent( win )) @@ -517,15 +525,17 @@ static void set_cursor_pos( struct desktop *desktop, int x, int y ) static void get_message_defaults( struct msg_queue *queue, int *x, int *y, unsigned int *time ) { struct desktop *desktop = queue->input->desktop; + const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index );
- *x = desktop->cursor.x; - *y = desktop->cursor.y; + *x = desktop_shm->cursor.x; + *y = desktop_shm->cursor.y; *time = get_tick_count(); }
/* set the cursor clip rectangle */ void set_clip_rectangle( struct desktop *desktop, const rectangle_t *rect, unsigned int flags, int reset ) { + const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index ); rectangle_t top_rect; int x, y;
@@ -543,9 +553,9 @@ void set_clip_rectangle( struct desktop *desktop, const rectangle_t *rect, unsig else desktop->cursor.clip = top_rect;
/* warp the mouse to be inside the clip rect */ - x = max( min( desktop->cursor.x, desktop->cursor.clip.right - 1 ), desktop->cursor.clip.left ); - y = max( min( desktop->cursor.y, desktop->cursor.clip.bottom - 1 ), desktop->cursor.clip.top ); - if (x != desktop->cursor.x || y != desktop->cursor.y) set_cursor_pos( desktop, x, y ); + x = max( min( desktop_shm->cursor.x, desktop->cursor.clip.right - 1 ), desktop->cursor.clip.left ); + y = max( min( desktop_shm->cursor.y, desktop->cursor.clip.bottom - 1 ), desktop->cursor.clip.top ); + if (x != desktop_shm->cursor.x || y != desktop_shm->cursor.y) set_cursor_pos( desktop, x, y );
/* request clip cursor rectangle reset to the desktop thread */ if (reset) post_desktop_message( desktop, WM_WINE_CLIPCURSOR, flags, FALSE ); @@ -1668,6 +1678,7 @@ static void prepend_cursor_history( int x, int y, unsigned int time, lparam_t in /* queue a hardware message into a given thread input */ static void queue_hardware_message( struct desktop *desktop, struct message *msg, int always_queue ) { + const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index ); user_handle_t win; struct thread *thread; struct thread_input *input; @@ -1700,8 +1711,8 @@ static void queue_hardware_message( struct desktop *desktop, struct message *msg if (desktop->keystate[VK_XBUTTON2] & 0x80) msg->wparam |= MK_XBUTTON2; break; } - msg->x = desktop->cursor.x; - msg->y = desktop->cursor.y; + msg->x = desktop_shm->cursor.x; + msg->y = desktop_shm->cursor.y;
if (msg->win && (thread = get_window_thread( msg->win ))) { @@ -1983,6 +1994,7 @@ static void dispatch_rawinput_message( struct desktop *desktop, struct rawinput_ static int queue_mouse_message( struct desktop *desktop, user_handle_t win, const hw_input_t *input, unsigned int origin, struct msg_queue *sender ) { + const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index ); const struct rawinput_device *device; struct hardware_msg_data *msg_data; struct rawinput_message raw_msg; @@ -2021,19 +2033,19 @@ static int queue_mouse_message( struct desktop *desktop, user_handle_t win, cons x = input->mouse.x; y = input->mouse.y; if (flags & ~(MOUSEEVENTF_MOVE | MOUSEEVENTF_ABSOLUTE) && - x == desktop->cursor.x && y == desktop->cursor.y) + x == desktop_shm->cursor.x && y == desktop_shm->cursor.y) flags &= ~MOUSEEVENTF_MOVE; } else { - x = desktop->cursor.x + input->mouse.x; - y = desktop->cursor.y + input->mouse.y; + x = desktop_shm->cursor.x + input->mouse.x; + y = desktop_shm->cursor.y + input->mouse.y; } } else { - x = desktop->cursor.x; - y = desktop->cursor.y; + x = desktop_shm->cursor.x; + y = desktop_shm->cursor.y; }
if ((foreground = get_foreground_thread( desktop, win ))) @@ -2044,7 +2056,7 @@ static int queue_mouse_message( struct desktop *desktop, user_handle_t win, cons raw_msg.time = time; raw_msg.message = WM_INPUT; raw_msg.flags = flags; - rawmouse_init( &raw_msg.rawinput, &raw_msg.data.mouse, x - desktop->cursor.x, y - desktop->cursor.y, + rawmouse_init( &raw_msg.rawinput, &raw_msg.data.mouse, x - desktop_shm->cursor.x, y - desktop_shm->cursor.y, raw_msg.flags, input->mouse.data, input->mouse.info );
dispatch_rawinput_message( desktop, &raw_msg ); @@ -2246,6 +2258,7 @@ static void queue_pointer_message( struct pointer *pointer, int repeated ) }; struct hw_msg_source source = { IMDT_UNAVAILABLE, IMDT_TOUCH }; struct desktop *desktop = pointer->desktop; + const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index ); const hw_input_t *input = &pointer->input; unsigned int i, wparam = input->hw.wparam; timeout_t time = get_tick_count(); @@ -2268,8 +2281,8 @@ static void queue_pointer_message( struct pointer *pointer, int repeated ) msg->msg = messages[input->hw.msg - WM_POINTERUPDATE][i]; msg->wparam = wparam; msg->lparam = MAKELONG(x, y); - msg->x = desktop->cursor.x; - msg->y = desktop->cursor.y; + msg->x = desktop_shm->cursor.x; + msg->y = desktop_shm->cursor.y;
queue_hardware_message( desktop, msg, 1 ); } @@ -2324,6 +2337,7 @@ static struct pointer *find_pointer_from_id( struct desktop *desktop, unsigned i static void queue_custom_hardware_message( struct desktop *desktop, user_handle_t win, unsigned int origin, const hw_input_t *input ) { + const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index ); struct hw_msg_source source = { IMDT_UNAVAILABLE, origin }; struct thread *foreground; struct pointer *pointer; @@ -2368,8 +2382,8 @@ static void queue_custom_hardware_message( struct desktop *desktop, user_handle_ msg->msg = input->hw.msg; msg->wparam = input->hw.wparam; msg->lparam = input->hw.lparam; - msg->x = desktop->cursor.x; - msg->y = desktop->cursor.y; + msg->x = desktop_shm->cursor.x; + msg->y = desktop_shm->cursor.y;
queue_hardware_message( desktop, msg, 1 ); } @@ -2917,6 +2931,7 @@ DECL_HANDLER(send_hardware_message) struct desktop *desktop; unsigned int origin = (req->flags & SEND_HWMSG_INJECTED ? IMO_INJECTED : IMO_HARDWARE); struct msg_queue *sender = req->flags & SEND_HWMSG_INJECTED ? get_current_queue() : NULL; + const desktop_shm_t *desktop_shm; int wait = 0;
if (!(desktop = get_hardware_input_desktop( req->win ))) return; @@ -2927,9 +2942,10 @@ DECL_HANDLER(send_hardware_message) set_error( STATUS_ACCESS_DENIED ); return; } + desktop_shm = get_shared_desktop( desktop->session_index );
- reply->prev_x = desktop->cursor.x; - reply->prev_y = desktop->cursor.y; + reply->prev_x = desktop_shm->cursor.x; + reply->prev_y = desktop_shm->cursor.y;
switch (req->input.type) { @@ -2947,8 +2963,8 @@ DECL_HANDLER(send_hardware_message) }
reply->wait = sender ? wait : 0; - reply->new_x = desktop->cursor.x; - reply->new_y = desktop->cursor.y; + reply->new_x = desktop_shm->cursor.x; + reply->new_y = desktop_shm->cursor.y; release_object( desktop ); }
@@ -3633,15 +3649,17 @@ DECL_HANDLER(set_cursor) struct msg_queue *queue = get_current_queue(); struct thread_input *input; struct desktop *desktop; + const desktop_shm_t *desktop_shm;
if (!queue) return; input = queue->input; desktop = input->desktop; + desktop_shm = get_shared_desktop( desktop->session_index );
reply->prev_handle = input->cursor; reply->prev_count = input->cursor_count; - reply->prev_x = desktop->cursor.x; - reply->prev_y = desktop->cursor.y; + reply->prev_x = desktop_shm->cursor.x; + reply->prev_y = desktop_shm->cursor.y;
if (req->flags & SET_CURSOR_HANDLE) { @@ -3664,8 +3682,8 @@ DECL_HANDLER(set_cursor) if (req->flags & (SET_CURSOR_HANDLE | SET_CURSOR_COUNT)) update_desktop_cursor_handle( desktop, input );
- reply->new_x = desktop->cursor.x; - reply->new_y = desktop->cursor.y; + reply->new_x = desktop_shm->cursor.x; + reply->new_y = desktop_shm->cursor.y; reply->new_clip = desktop->cursor.clip; reply->last_change = desktop->cursor.last_change; } diff --git a/server/user.h b/server/user.h index 21d67656c9c..94c107116ed 100644 --- a/server/user.h +++ b/server/user.h @@ -56,8 +56,6 @@ struct winstation
struct global_cursor { - int x; /* cursor position */ - int y; rectangle_t clip; /* cursor clip rectangle */ unsigned int last_change; /* time of last position change */ user_handle_t win; /* window that contains the cursor */
From: Rémi Bernon rbernon@codeweavers.com
Based on a patch by Huw Davies huw@codeweavers.com. --- server/protocol.def | 1 + server/queue.c | 17 +++++++++++------ server/user.h | 1 - 3 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/server/protocol.def b/server/protocol.def index 736d2b0232c..32e94d02f28 100644 --- a/server/protocol.def +++ b/server/protocol.def @@ -882,6 +882,7 @@ struct shared_cursor { int x; /* cursor position */ int y; + unsigned int last_change; /* time of last position change */ };
typedef volatile struct diff --git a/server/queue.c b/server/queue.c index cba5514deef..85b2254ad12 100644 --- a/server/queue.c +++ b/server/queue.c @@ -468,6 +468,7 @@ static int update_desktop_cursor_pos( struct desktop *desktop, user_handle_t win { const desktop_shm_t *desktop_shm = get_shared_desktop( desktop->session_index ); int updated; + unsigned int time = get_tick_count();
x = max( min( x, desktop->cursor.clip.right - 1 ), desktop->cursor.clip.left ); y = max( min( y, desktop->cursor.clip.bottom - 1 ), desktop->cursor.clip.top ); @@ -477,11 +478,10 @@ static int update_desktop_cursor_pos( struct desktop *desktop, user_handle_t win updated = shared->cursor.x != x || shared->cursor.y != y; shared->cursor.x = x; shared->cursor.y = y; + shared->cursor.last_change = time; } SHARED_WRITE_END;
- desktop->cursor.last_change = get_tick_count(); - if (!win || !is_window_visible( win ) || is_window_transparent( win )) win = shallow_window_from_point( desktop, x, y ); if (update_desktop_cursor_window( desktop, win )) updated = 1; @@ -2000,7 +2000,7 @@ static int queue_mouse_message( struct desktop *desktop, user_handle_t win, cons struct rawinput_message raw_msg; struct message *msg; struct thread *foreground; - unsigned int i, time, flags; + unsigned int i, time = get_tick_count(), flags; struct hw_msg_source source = { IMDT_MOUSE, origin }; int wait = 0, x, y;
@@ -2021,10 +2021,15 @@ static int queue_mouse_message( struct desktop *desktop, user_handle_t win, cons WM_MOUSEHWHEEL /* 0x1000 = MOUSEEVENTF_HWHEEL */ };
- desktop->cursor.last_change = get_tick_count(); + SHARED_WRITE_BEGIN( desktop_shm, desktop_shm_t ) + { + shared->cursor.last_change = time; + } + SHARED_WRITE_END; + flags = input->mouse.flags; time = input->mouse.time; - if (!time) time = desktop->cursor.last_change; + if (!time) time = desktop_shm->cursor.last_change;
if (flags & MOUSEEVENTF_MOVE) { @@ -3685,7 +3690,7 @@ DECL_HANDLER(set_cursor) reply->new_x = desktop_shm->cursor.x; reply->new_y = desktop_shm->cursor.y; reply->new_clip = desktop->cursor.clip; - reply->last_change = desktop->cursor.last_change; + reply->last_change = desktop_shm->cursor.last_change; }
/* Get the history of the 64 last cursor positions */ diff --git a/server/user.h b/server/user.h index 94c107116ed..4f98ce46ffa 100644 --- a/server/user.h +++ b/server/user.h @@ -57,7 +57,6 @@ struct winstation struct global_cursor { rectangle_t clip; /* cursor clip rectangle */ - unsigned int last_change; /* time of last position change */ user_handle_t win; /* window that contains the cursor */ };
From: Rémi Bernon rbernon@codeweavers.com
Based on a patch by Huw Davies huw@codeweavers.com. --- dlls/win32u/input.c | 21 +++++++++++++-------- dlls/win32u/winstation.c | 2 -- 2 files changed, 13 insertions(+), 10 deletions(-)
diff --git a/dlls/win32u/input.c b/dlls/win32u/input.c index 4a7c04f66c5..6728dbc5b24 100644 --- a/dlls/win32u/input.c +++ b/dlls/win32u/input.c @@ -739,22 +739,27 @@ BOOL WINAPI NtUserSetCursorPos( INT x, INT y ) */ BOOL get_cursor_pos( POINT *pt ) { - BOOL ret; - DWORD last_change; + struct object_lock lock = {0}; + BOOL ret = FALSE; + DWORD last_change = 0; UINT dpi;
if (!pt) return FALSE;
- SERVER_START_REQ( set_cursor ) + while (get_shared_desktop( &lock )) { - if ((ret = !wine_server_call( req ))) + BOOL valid; + SHARED_READ_BEGIN( &lock.shared->desktop, desktop_shm_t ) { - pt->x = reply->new_x; - pt->y = reply->new_y; - last_change = reply->last_change; + valid = lock.id == shared->obj.id; + pt->x = shared->cursor.x; + pt->y = shared->cursor.y; + last_change = shared->cursor.last_change; } + SHARED_READ_END; + object_lock_release( &lock ); + if ((ret = valid)) break; } - SERVER_END_REQ;
/* query new position from graphics driver if we haven't updated recently */ if (ret && NtGetTickCount() - last_change > 100) ret = user_driver->pGetCursorPos( pt ); diff --git a/dlls/win32u/winstation.c b/dlls/win32u/winstation.c index 84eb20bda60..e7bcc8ce1fc 100644 --- a/dlls/win32u/winstation.c +++ b/dlls/win32u/winstation.c @@ -460,12 +460,10 @@ BOOL WINAPI NtUserSetThreadDesktop( HDESK handle ) struct user_thread_info *thread_info = get_user_thread_info(); struct user_key_state_info *key_state_info = thread_info->key_state; struct object_info *desktop_info = &get_session_thread_data()->shared_desktop; - struct object_lock lock = {0}; thread_info->client_info.top_window = 0; thread_info->client_info.msg_window = 0; if (key_state_info) key_state_info->time = 0; memset( desktop_info, 0, sizeof(*desktop_info) ); - if (get_shared_desktop( &lock )) object_lock_release( &lock ); if (was_virtual_desktop != is_virtual_desktop()) update_display_cache( TRUE ); } return ret;
Jinoh Kang (@iamahuman) commented about dlls/win32u/winstation.c:
- NTSTATUS status;
- switch (type)
- {
- case OBJECT_TYPE_DESKTOP:
SERVER_START_REQ( get_thread_desktop ){req->tid = tid;if (!(status = wine_server_call( req ))){info->id = reply->object_id;info->index = reply->index;}}SERVER_END_REQ;break;
Uninitialized `status` on unrecognized object type.
```suggestion:-0+0 break; default: ERR( "unknown object type %d\n", type ); status = STATUS_UNSUCCESSFUL; break; ```
Jinoh Kang (@iamahuman) commented about server/mapping.c:
return page_mask + 1;}
+struct mapping *create_session_mapping( struct object *root, const struct unicode_str *name,
unsigned int attr, const struct security_descriptor *sd )+{
- static const unsigned int access = FILE_READ_DATA | FILE_WRITE_DATA;
- mem_size_t size;
- size = max(offsetof(session_shm_t, objects[512]), 0x10000);
- size = (size + page_mask) & ~((mem_size_t)page_mask);
(nit) this is unnecessary since `create_mapping` already rounds up the size in `/* Anonymous mapping (no associated file) */` case.
```suggestion:-0+0 ```
Note that `create_user_data_mapping` already relies on the round-up behavior: it passes `sizeof(KSHARED_USER_DATA)` directly to `create_mapping`.
Jinoh Kang (@iamahuman) commented about server/mapping.c:
struct session { const session_shm_t *shared;
- mem_size_t next_object_index;
```suggestion:-0+0
/* This index may be greater than capacity or already occupied. */ mem_size_t next_object_index;
```
Jinoh Kang (@iamahuman) commented about server/mapping.c:
- {
shared->obj.id = ++session.last_object_id;- }
- SHARED_WRITE_END;
- session.next_object_index = index + 1;
- return index;
+}
+void free_shared_object( int index ) +{
- if (index < 0) return;
- SHARED_WRITE_BEGIN( &session.shared->objects[index], session_obj_t )
- {
shared->obj.id = 0;
We're releasing the object unscrubbed. A future `alloc_shared_object()` call will return uninitialized memory, with leftover contents from previous allocation.[^1]
```suggestion:-0+0 memset( (char *)shared + offsetof(session_obj_t, obj.id), 0, sizeof(*shared) - offsetof(session_obj_t, obj.id) ); ```
[^1]: This means that e.g., queues will reuse memory from inputs, once we introduce other kinds of shared objects.
Jinoh Kang (@iamahuman) commented about dlls/win32u/win32u_private.h:
return !IsRectEmpty( dst );}
+#if defined(__i386__) || defined(__x86_64__) +/* this prevents compilers from incorrectly reordering non-volatile reads (e.g., memcpy) from shared memory */ +#define __SHARED_READ_FENCE do { __asm__ __volatile__( "" ::: "memory" ); } while (0) +#else +#define __SHARED_READ_FENCE __atomic_thread_fence( __ATOMIC_ACQUIRE ) +#endif
+#define SHARED_READ_BEGIN( ptr, type ) \
```suggestion:-0+0 /* Begin a reader critical section of a seqlock. * * Due to how seqlock works, a read may (transiently) fail when it races with * the writer side. On such a failure, this macro attempts to iterate multiple * times until the read succeeds. * * This leads to the following anomalies: * * - Variables ever written by the section may not have initially set values. * - Conditionally written variables may have corrupted values on section exit. * * To prevent such anomalies from causing bugs, the body should be *idempotent*. * Specifically, you should keep in mind the following rules: * * 1. Avoid if()s, loops, and other kinds of conditional execution. If they're * needed for some reason, make sure that the conditions don't depend on * values from the shared memory at all. * * 2. A variable should only ever be *either* read *or* written in a critical * section, but *not both*. An exception to this rule is when the variable * has been already written before (in the same iteration). * * 3. In general, if you want to perform computation, I/O or a blocking * operation, do so outside (before or after) the critical section. * * Any (unavoidable) violation of the rules above should be reviewed carefully * so that it maintains the property of idempotence (the section body only reads * from the latest values in the face of multiple retries.) */ #define SHARED_READ_BEGIN( ptr, type ) \ ```
After discovery of certain bugs like [^x] [^y] [^z], I wonder if the new code should be sufficiently tested before we move on to implement queues and inputs. Not an approval blocker, but would make future patches easier to review I think.
[^x]: https://gitlab.winehq.org/wine/wine/-/merge_requests/3103#note_63262 [^y]: https://gitlab.winehq.org/wine/wine/-/merge_requests/3103#note_64975 [^z]: https://gitlab.winehq.org/wine/wine/-/merge_requests/3103#note_65575
On Thu Mar 21 10:14:29 2024 +0000, Jinoh Kang wrote:
/* Begin a reader critical section of a seqlock. * * Due to how seqlock works, a read may (transiently) fail when it races with * the writer side. On such a failure, this macro attempts to iterate multiple * times until the read succeeds. * * This leads to the following anomalies: * * - Variables ever written by the section may not have initially set values. * - Conditionally written variables may have corrupted values on section exit. * * To prevent such anomalies from causing bugs, the body should be *idempotent*. * Specifically, you should keep the following rules in mind: * * 1. Avoid if()s, loops, and other kinds of conditional execution. If they're * needed for some reason, make sure that the conditions don't depend on * values from the shared memory at all. * * 2. A variable should only ever be *either* read *or* written in a critical * section, but *not both*. An exception to this rule is when the variable * has been already written before (in the same iteration). * * 3. In general, if you want to perform computation, I/O or a blocking * operation, do so outside (before or after) the critical section. * * Any (unavoidable) violation of the rules above should be reviewed carefully * so that it maintains the property of idempotence (the section body only reads * from the latest values in the face of multiple retries.) */ #define SHARED_READ_BEGIN( ptr, type ) \
EDIT: s/keep in mind the following rules/keep the following rules in mind/
On Thu Mar 21 10:15:00 2024 +0000, Jinoh Kang wrote:
EDIT: s/keep in mind the following rules/keep the following rules in mind/
IMHO this nicely summaries why the macro is ugly (and an explicit loop that I suggested earlier would make it much more obvious in client code).
On Thu Mar 21 11:23:26 2024 +0000, Jacek Caban wrote:
IMHO this nicely summaries why the macro is ugly (and an explicit loop that I suggested earlier would make it much more obvious in client code).
@rbernon said on this matter "I personally like that it looks like server requests, it makes wineserver communication stand out compared to other function calls."
I don't have strong opinions either way. Even if we *do* get rid of the macro, though, I'd propose that we keep this documentation no matter what since people can write bad code (emphasis on the "conditional" part).
*Personally* I'd go even further and just have a function that does everything: receive field offsets, and have an internal loop that fills out the out pointers (so that the user doesn't have to write the loop).
On Thu Mar 21 11:56:13 2024 +0000, Jinoh Kang wrote:
@rbernon said on this matter "I personally like that it looks like server requests, it makes wineserver communication stand out compared to other function calls." I don't have strong opinions either way. Even if we *do* get rid of the macro, though, I'd propose that we keep this documentation no matter what since people can write bad code (emphasis on the "conditional" part). *Personally* I'd go even further and just have a function that does everything: receive field offsets, and have an internal loop that fills out the out pointers (so that the user doesn't have to write the loop).
FWIW we do read user shared data (which counts as "wineserver communication") without a macro. In addition, our session shared mapping is quite similar to `gSharedInfo`, which also exists on Windows (which doesn't involve a "wineserver"). Also, the "wineserver communication" is unidirectional (client doesn't send to server), so maybe not using macro could be ok-ish?
Regardless, I think `SHARED_WRITE_BEGIN` is still useful though.
On Thu Mar 21 12:03:47 2024 +0000, Jinoh Kang wrote:
FWIW we do read user shared data (which counts as "wineserver communication") without a macro. In addition, our session shared mapping is quite similar to `gSharedInfo`, which also exists on Windows (which doesn't involve a "wineserver"). Also, the "wineserver communication" is unidirectional (client doesn't send to server), so maybe not using macro could be ok-ish? Regardless, I think `SHARED_WRITE_BEGIN` is still useful though.
Right, well as things have changed a lot since then as we now have loops anyway everywhere, what about merging the seq lock within it, like this: https://gitlab.winehq.org/rbernon/wine/-/commit/6897f75798835c3a0bf2e2c7f428...
Right, well as things have changed a lot since then as we now have loops anyway everywhere, what about merging the seq lock within it, like this: https://gitlab.winehq.org/rbernon/wine/-/commit/6897f75798835c3a0bf2e2c7f428...
Looks fine, although I'd use `STATUS_PENDING` instead of `STATUS_RETRY /* return STATUS_RETRY to enter reader loops */`. Also perhaps we want to pass-through NTSTATUS from `get_thread_session_object_info` instead of discarding it, so that we can return things like `0xc0010000 | ERROR_INVALID_WINDOW_HANDLE`.
On Thu Mar 21 15:24:43 2024 +0000, Jinoh Kang wrote:
Right, well as things have changed a lot since then as we now have
loops anyway everywhere, what about merging the seq lock within it, like this: https://gitlab.winehq.org/rbernon/wine/-/commit/6897f75798835c3a0bf2e2c7f428... Looks fine, although I'd use `STATUS_PENDING` instead of `STATUS_RETRY /* return STATUS_RETRY to enter reader loops */`. Also perhaps we want to pass-through NTSTATUS from `get_thread_session_object_info` instead of discarding it, so that we can return things like `0xc0010000 | ERROR_INVALID_WINDOW_HANDLE`.
You mean STATUS_PENDING all the time, or both STATUS_PENDING / STATUS_RETRY depending on the case? I'd prefer not to have two different statuses, so that caller loops can be simpler.
You mean STATUS_PENDING all the time,
Yes.
(Also, I guess `object_lock_acquire_seqlock` should accept `LONG64 *seq` pointer instead of full-blown `struct object_lock *`. Other than that, it seems good to go.)
On Thu Mar 21 05:16:45 2024 +0000, Jinoh Kang wrote:
We're releasing the object unscrubbed. A future `alloc_shared_object()` call will return uninitialized memory, with leftover contents from previous allocation.[^1]
memset( (char *)shared + offsetof(session_obj_t, obj.id), 0, sizeof(*shared) - offsetof(session_obj_t, obj.id) );(Although a cleaner approach would be appreciated if possible) [^1]: This means that e.g., queues will reuse memory from inputs (once we introduce other kinds of shared objects).
I think in wineserver memory is left uncleared and uninitialized, on purpose, and up to the allocer to initialize? I will add `mark_block_uninitialized( ptr, size );` on the allocation side instead.
On Thu Mar 21 17:06:57 2024 +0000, Rémi Bernon wrote:
I think in wineserver memory is left uncleared and uninitialized, on purpose, and up to the allocer to initialize? I will add `mark_block_uninitialized( ptr, size );` on the allocation side instead.
It is, but `create_desktop` memset()s cursor to zero. We pulled (x,y,last_change) out of the cursor, leaving them uninitialized.
On Thu Mar 21 17:14:56 2024 +0000, Jinoh Kang wrote:
It is, but `create_desktop` memset()s cursor to zero. We pulled (x,y,last_change) out of the cursor, leaving them uninitialized.
So you have two options: fix `create_desktop` to properly initialize (x,y,last_change), or zero objects on free. I personally prefer the latter since we can rely on the fact that the shared memory is always zero after allocation, reduces risk of garbage data read, and enables opportinuities for THP or KSM (if it grows big enough).
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Jacek Caban (＠jacek) -
Jinoh Kang (＠iamahuman)
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Rémi Bernon
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Rémi Bernon (＠rbernon)