Module: wine Branch: master Commit: d1e02148b6f2ed7ffe3c57452aba9900f0434c9a URL: https://gitlab.winehq.org/wine/wine/-/commit/d1e02148b6f2ed7ffe3c57452aba990...
Author: Yuxuan Shui yshui@codeweavers.com Date: Mon Nov 6 16:05:38 2023 +0000
ntdll: Tweak the binary representation of SRWLOCK.
There are applications that uses SRWLOCK in an invalid way and then checks its binary representation. Tweak our representation a bit so they are happy.
---
dlls/kernel32/tests/sync.c | 17 +++++++++++++++++ dlls/ntdll/sync.c | 24 ++++++++++++++---------- 2 files changed, 31 insertions(+), 10 deletions(-)
diff --git a/dlls/kernel32/tests/sync.c b/dlls/kernel32/tests/sync.c index 10765765bc5..56a9d6e4859 100644 --- a/dlls/kernel32/tests/sync.c +++ b/dlls/kernel32/tests/sync.c @@ -2535,6 +2535,22 @@ static void test_srwlock_example(void) trace("number of total exclusive accesses is %ld\n", srwlock_protected_value); }
+static void test_srwlock_quirk(void) +{ + union { SRWLOCK *s; LONG *l; } u = { &srwlock_example }; + + if (!pInitializeSRWLock) { + /* function is not yet in XP, only in newer Windows */ + win_skip("no srw lock support.\n"); + return; + } + + /* WeCom 4.x checks releasing a lock with value 0x1 results in it becoming 0x0. */ + *u.l = 1; + pReleaseSRWLockExclusive(&srwlock_example); + ok(*u.l == 0, "expected 0x0, got %lx\n", *u.l); +} + static DWORD WINAPI alertable_wait_thread(void *param) { HANDLE *semaphores = param; @@ -2887,6 +2903,7 @@ START_TEST(sync) test_condvars_base(&unaligned_cv.cv); test_condvars_consumer_producer(); test_srwlock_base(&aligned_srwlock); + test_srwlock_quirk(); #if defined(__i386__) || defined(__x86_64__) /* unaligned locks only work on x86 platforms */ test_srwlock_base(&unaligned_srwlock.lock); diff --git a/dlls/ntdll/sync.c b/dlls/ntdll/sync.c index fa64917029a..bb5dcbb66e6 100644 --- a/dlls/ntdll/sync.c +++ b/dlls/ntdll/sync.c @@ -473,9 +473,10 @@ DWORD WINAPI RtlRunOnceExecuteOnce( RTL_RUN_ONCE *once, PRTL_RUN_ONCE_INIT_FN fu
struct srw_lock { + /* bit 0 - if the lock is held exclusive. bit 1.. - number of exclusive waiters. */ short exclusive_waiters;
- /* Number of shared owners, or -1 if owned exclusive. + /* Number of owners. * * Sadly Windows has no equivalent to FUTEX_WAIT_BITSET, so in order to wake * up *only* exclusive or *only* shared waiters (and thus avoid spurious @@ -486,7 +487,7 @@ struct srw_lock * the latter waits only on the "owners" member. Note then that "owners" * must not be the first element in the structure. */ - short owners; + unsigned short owners; }; C_ASSERT( sizeof(struct srw_lock) == 4 );
@@ -517,7 +518,7 @@ void WINAPI RtlAcquireSRWLockExclusive( RTL_SRWLOCK *lock ) { union { RTL_SRWLOCK *rtl; struct srw_lock *s; LONG *l; } u = { lock };
- InterlockedIncrement16( &u.s->exclusive_waiters ); + InterlockedExchangeAdd16( &u.s->exclusive_waiters, 2 );
for (;;) { @@ -532,8 +533,9 @@ void WINAPI RtlAcquireSRWLockExclusive( RTL_SRWLOCK *lock ) if (!old.s.owners) { /* Not locked exclusive or shared. We can try to grab it. */ - new.s.owners = -1; - --new.s.exclusive_waiters; + new.s.owners = 1; + new.s.exclusive_waiters -= 2; + new.s.exclusive_waiters |= 1; wait = FALSE; } else @@ -568,7 +570,7 @@ void WINAPI RtlAcquireSRWLockShared( RTL_SRWLOCK *lock ) old.s = *u.s; new = old;
- if (old.s.owners != -1 && !old.s.exclusive_waiters) + if (!old.s.exclusive_waiters) { /* Not locked exclusive, and no exclusive waiters. * We can try to grab it. */ @@ -599,9 +601,10 @@ void WINAPI RtlReleaseSRWLockExclusive( RTL_SRWLOCK *lock ) old.s = *u.s; new = old;
- if (old.s.owners != -1) ERR("Lock %p is not owned exclusive!\n", lock); + if (!(old.s.exclusive_waiters & 1)) ERR("Lock %p is not owned exclusive!\n", lock);
new.s.owners = 0; + new.s.exclusive_waiters &= ~1; } while (InterlockedCompareExchange( u.l, new.l, old.l ) != old.l);
if (new.s.exclusive_waiters) @@ -623,7 +626,7 @@ void WINAPI RtlReleaseSRWLockShared( RTL_SRWLOCK *lock ) old.s = *u.s; new = old;
- if (old.s.owners == -1) ERR("Lock %p is owned exclusive!\n", lock); + if (old.s.exclusive_waiters & 1) ERR("Lock %p is owned exclusive!\n", lock); else if (!old.s.owners) ERR("Lock %p is not owned shared!\n", lock);
--new.s.owners; @@ -654,7 +657,8 @@ BOOLEAN WINAPI RtlTryAcquireSRWLockExclusive( RTL_SRWLOCK *lock ) if (!old.s.owners) { /* Not locked exclusive or shared. We can try to grab it. */ - new.s.owners = -1; + new.s.owners = 1; + new.s.exclusive_waiters |= 1; ret = TRUE; } else @@ -680,7 +684,7 @@ BOOLEAN WINAPI RtlTryAcquireSRWLockShared( RTL_SRWLOCK *lock ) old.s = *u.s; new.s = old.s;
- if (old.s.owners != -1 && !old.s.exclusive_waiters) + if (!old.s.exclusive_waiters) { /* Not locked exclusive, and no exclusive waiters. * We can try to grab it. */
-
Alexandre Julliard