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author | Indrajith K L | 2022-12-03 17:00:20 +0530 |
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committer | Indrajith K L | 2022-12-03 17:00:20 +0530 |
commit | f5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch) | |
tree | 2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/old/vlib/sync/sync_windows.c.v | |
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Diffstat (limited to 'v_windows/v/old/vlib/sync/sync_windows.c.v')
-rw-r--r-- | v_windows/v/old/vlib/sync/sync_windows.c.v | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/v_windows/v/old/vlib/sync/sync_windows.c.v b/v_windows/v/old/vlib/sync/sync_windows.c.v new file mode 100644 index 0000000..d0942b7 --- /dev/null +++ b/v_windows/v/old/vlib/sync/sync_windows.c.v @@ -0,0 +1,212 @@ +// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved. +// Use of this source code is governed by an MIT license +// that can be found in the LICENSE file. +module sync + +import time + +#include <synchapi.h> +#include <time.h> + +fn C.GetSystemTimeAsFileTime(lpSystemTimeAsFileTime &C._FILETIME) +fn C.InitializeConditionVariable(voidptr) +fn C.WakeConditionVariable(voidptr) +fn C.SleepConditionVariableSRW(voidptr, voidptr, u32, u32) int + +// TODO: The suggestion of using CriticalSection instead of mutex +// was discussed. Needs consideration. + +// Mutex HANDLE +type MHANDLE = voidptr + +// Semaphore HANDLE +type SHANDLE = voidptr + +//[init_with=new_mutex] // TODO: implement support for this struct attribute, and disallow Mutex{} from outside the sync.new_mutex() function. + +// `SRWLOCK` is much more performant that `Mutex` on Windows, so use that in both cases since we don't want to share with other processes +[heap] +pub struct Mutex { +mut: + mx C.SRWLOCK // mutex handle +} + +[heap] +pub struct RwMutex { +mut: + mx C.SRWLOCK // mutex handle +} + +[heap] +struct Semaphore { + mtx C.SRWLOCK + cond C.CONDITION_VARIABLE +mut: + count u32 +} + +pub fn new_mutex() &Mutex { + mut m := &Mutex{} + m.init() + return m +} + +pub fn new_rwmutex() &RwMutex { + mut m := &RwMutex{} + m.init() + return m +} + +pub fn (mut m Mutex) init() { + C.InitializeSRWLock(&m.mx) +} + +pub fn (mut m RwMutex) init() { + C.InitializeSRWLock(&m.mx) +} + +pub fn (mut m Mutex) @lock() { + C.AcquireSRWLockExclusive(&m.mx) +} + +pub fn (mut m Mutex) unlock() { + C.ReleaseSRWLockExclusive(&m.mx) +} + +// RwMutex has separate read- and write locks +pub fn (mut m RwMutex) @rlock() { + C.AcquireSRWLockShared(&m.mx) +} + +pub fn (mut m RwMutex) @lock() { + C.AcquireSRWLockExclusive(&m.mx) +} + +// Windows SRWLocks have different function to unlock +// So provide two functions here, too, to have a common interface +pub fn (mut m RwMutex) runlock() { + C.ReleaseSRWLockShared(&m.mx) +} + +pub fn (mut m RwMutex) unlock() { + C.ReleaseSRWLockExclusive(&m.mx) +} + +pub fn (mut m Mutex) destroy() { + // nothing to do +} + +[inline] +pub fn new_semaphore() &Semaphore { + return new_semaphore_init(0) +} + +pub fn new_semaphore_init(n u32) &Semaphore { + mut sem := &Semaphore{} + sem.init(n) + return sem +} + +pub fn (mut sem Semaphore) init(n u32) { + C.atomic_store_u32(&sem.count, n) + C.InitializeSRWLock(&sem.mtx) + C.InitializeConditionVariable(&sem.cond) +} + +pub fn (mut sem Semaphore) post() { + mut c := C.atomic_load_u32(&sem.count) + for c > 1 { + if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c + 1) { + return + } + } + C.AcquireSRWLockExclusive(&sem.mtx) + c = C.atomic_fetch_add_u32(&sem.count, 1) + if c == 0 { + C.WakeConditionVariable(&sem.cond) + } + C.ReleaseSRWLockExclusive(&sem.mtx) +} + +pub fn (mut sem Semaphore) wait() { + mut c := C.atomic_load_u32(&sem.count) + for c > 0 { + if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) { + return + } + } + C.AcquireSRWLockExclusive(&sem.mtx) + c = C.atomic_load_u32(&sem.count) + + outer: for { + if c == 0 { + C.SleepConditionVariableSRW(&sem.cond, &sem.mtx, C.INFINITE, 0) + c = C.atomic_load_u32(&sem.count) + } + for c > 0 { + if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) { + if c > 1 { + C.WakeConditionVariable(&sem.cond) + } + break outer + } + } + } + C.ReleaseSRWLockExclusive(&sem.mtx) +} + +pub fn (mut sem Semaphore) try_wait() bool { + mut c := C.atomic_load_u32(&sem.count) + for c > 0 { + if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) { + return true + } + } + return false +} + +pub fn (mut sem Semaphore) timed_wait(timeout time.Duration) bool { + mut c := C.atomic_load_u32(&sem.count) + for c > 0 { + if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) { + return true + } + } + mut ft_start := C._FILETIME{} + C.GetSystemTimeAsFileTime(&ft_start) + time_end := ((u64(ft_start.dwHighDateTime) << 32) | ft_start.dwLowDateTime) + + u64(timeout / (100 * time.nanosecond)) + mut t_ms := timeout.sys_milliseconds() + C.AcquireSRWLockExclusive(&sem.mtx) + mut res := 0 + c = C.atomic_load_u32(&sem.count) + + outer: for { + if c == 0 { + res = C.SleepConditionVariableSRW(&sem.cond, &sem.mtx, t_ms, 0) + if res == 0 { + break outer + } + c = C.atomic_load_u32(&sem.count) + } + for c > 0 { + if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) { + if c > 1 { + C.WakeConditionVariable(&sem.cond) + } + break outer + } + } + C.GetSystemTimeAsFileTime(&ft_start) + time_now := ((u64(ft_start.dwHighDateTime) << 32) | ft_start.dwLowDateTime) // in 100ns + if time_now > time_end { + break outer // timeout exceeded + } + t_ms = u32((time_end - time_now) / 10000) + } + C.ReleaseSRWLockExclusive(&sem.mtx) + return res != 0 +} + +pub fn (s Semaphore) destroy() { +} |