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Merge pull request #353 from insertinterestingnamehere/threadpool
New Internal Threadpool Implementation
2 parents 3349459 + 3b63359 commit 1a74e0d

13 files changed

+824
-1
lines changed

‎.circleci/config.yml

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@@ -229,7 +229,7 @@ jobs:
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export REPO_HTTPS=`echo "$CIRCLE_REPOSITORY_URL" | sed "s|[email protected]:|https://github.com/|g"`
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git clone -b "$CIRCLE_BRANCH" "$REPO_HTTPS" . --depth=1
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- run: |
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apk add --no-cache --no-progress bash make musl-dev hwloc-dev cmake gcc g++
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apk add --no-cache --no-progress bash make musl-dev hwloc-dev cmake gcc g++ linux-headers
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if [ "<< parameters.compiler >>" == "clang" ]; then apk add clang; fi
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- run: |
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if [ "<< parameters.compiler >>" == "clang" ]; then export CC=clang && export CXX=clang++; fi

‎include/qt_arithmetic.h

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#ifndef QT_ARITHMETIC_H
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#define QT_ARITHMETIC_H
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// Miscellanious aritmetic utility macros.
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#define QTHREAD_MAX(a, b) (((a) > (b)) ? (a) : (b))
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#define QTHREAD_MIN(a, b) (((a) < (b)) ? (a) : (b))
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#endif

‎include/qt_asserts.h

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@@ -6,6 +6,12 @@
66

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#include <assert.h> /* for assert() */
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#if __STDC_VERSION__ < 202311L
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#define qt_static_assert _Static_assert
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#else
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#define qt_static_assert static_assert
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#endif
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#ifdef qassert
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#undef qassert
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#endif

‎include/qt_atomic_wait.h

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#ifndef QT_ATOMIC_WAIT_H
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#define QT_ATOMIC_WAIT_H
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#include <assert.h>
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#include <stdatomic.h>
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#include <stdint.h>
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#include "qt_asserts.h"
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#include "qt_os.h"
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// This header defines a cross-platform futex-like API.
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// It's somewhat like atomic_wait in c++20, however these constructs are
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// guaranteed to use the appropriate OS APIs directly. It's also somewhat like
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// Rust's https://github.com/m-ou-se/atomic-wait, except this is just a bunch of
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// C macros and it supports a few more OSs.
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// Linux only has 32-bit futexes so that's the only size that's possible to
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// standardize.
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#define qt_atomic_wait_t _Atomic uint32_t
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#define qt_atomic_wait_empty 0u
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#define qt_atomic_wait_full UINT32_MAX
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#define qt_atomic_wait_set_empty(a) \
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atomic_store_explicit((a), 0u, memory_order_relaxed)
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#define qt_atomic_wait_set_full(a) \
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atomic_store_explicit((a), UINT32_MAX, memory_order_relaxed)
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#define qt_atomic_wait_load(a) atomic_load_explicit((a), memory_order_relaxed)
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#define qt_atomic_wait_store(a, v) \
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atomic_store_explicit((a), v, memory_order_relaxed)
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// Futex-like atomic wait functionality that's guaranteed to use
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// the appropriate OS thread pausing functionality (e.g. futex).
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// Due to constraints between the various operating systems,
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// only 32-bit integers are supported.
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#ifdef QTHREADS_LINUX
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// Use Linux futexes
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#include <errno.h>
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#include <linux/futex.h>
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#include <sys/syscall.h>
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#include <unistd.h>
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#ifndef NDEBUG
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#define qt_wait_on_address(a, expected) \
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do { \
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long status = syscall(SYS_futex, \
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(a), \
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FUTEX_WAIT | FUTEX_PRIVATE_FLAG, \
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(expected), \
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NULL, \
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NULL, \
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0u); \
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/* EAGAIN means the value already changed so no sleep was necessary. */ \
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assert(!status || (status == -1 && errno == EAGAIN)); \
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} while (0)
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#else
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#define qt_wait_on_address(a, expected) \
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do { \
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syscall(SYS_futex, \
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(a), \
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FUTEX_WAIT | FUTEX_PRIVATE_FLAG, \
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(expected), \
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NULL, \
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NULL, \
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0u); \
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} while (0)
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#endif
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#define qt_wake_all(a) \
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do { \
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syscall(SYS_futex, \
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(a), \
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FUTEX_WAKE | FUTEX_PRIVATE_FLAG, \
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UINT32_MAX, \
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NULL, \
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NULL, \
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0u); \
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} while (0)
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#define qt_wake_one(a) \
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do { \
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syscall( \
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SYS_futex, (a), FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1u, NULL, NULL, 0u); \
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} while (0)
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#elif defined(QTHREADS_APPLE)
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// use __ulock_wait and __ulock_wake
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// NOTE! This isn't technically a stable API even though they export the
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// symbols, so watch for changes in OSX releases later. libc++ relies on them
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// though so changes seem very unlikely.
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// Can't directly include apple's sys/ulock.h but we only need these symbols.
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// They are exported from libSystem though, which also provides their libc.
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// Given that, presumably we're already linking to them.
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// See
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// https://github.com/apple/darwin-xnu/blob/2ff845c2e033bd0ff64b5b6aa6063a1f8f65aa32/bsd/sys/ulock.h#L64-L68
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extern int
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__ulock_wait(uint32_t operation, void *addr, uint64_t value, uint32_t timeout);
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extern int __ulock_wake(uint32_t operation, void *addr, uint64_t wake_value);
101+
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// Corresponding operation codes:
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// See
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// https://github.com/apple/darwin-xnu/blob/2ff845c2e033bd0ff64b5b6aa6063a1f8f65aa32/bsd/sys/ulock.h#L72-L137
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#define UL_COMPARE_AND_WAIT 1
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#define ULF_WAKE_ALL 0x00000100
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#define ULF_NO_ERRNO 0x01000000
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// Note: no need to check for the case where a wait operation
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// wakes because the flag was already changed.
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// In that case the return value ends up being the same.
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// See
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// https://github.com/apple/darwin-xnu/blob/2ff845c2e033bd0ff64b5b6aa6063a1f8f65aa32/osfmk/kern/waitq.c#L2819-L2820
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// See also
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// https://github.com/apple/darwin-xnu/blob/2ff845c2e033bd0ff64b5b6aa6063a1f8f65aa32/bsd/kern/sys_ulock.c#L424
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#define qt_wait_on_address(a, expected) \
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do { \
118+
qassert( \
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__ulock_wait(UL_COMPARE_AND_WAIT | ULF_NO_ERRNO, (a), (expected), 0ull), \
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0); \
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} while (0)
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#define qt_wake_all(a) \
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do { \
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qassert(__ulock_wake(UL_COMPARE_AND_WAIT | ULF_WAKE_ALL | ULF_NO_ERRNO, \
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(a), \
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0ull) >= 0, \
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1); \
129+
} while (0)
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#define qt_wake_one(a) \
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do { __ulock_wake(UL_COMPARE_AND_WAIT | ULF_NO_ERRNO, (a), 0ull); } while (0)
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#elif defined(QTHREADS_FREEBSD)
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// use _umtx_op
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#include <sys/types.h>
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#include <sys/umtx.h>
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#define qt_wait_on_address(a, expected) \
140+
do { \
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qassert(_umtx_op((a), UMTX_OP_WAIT_UINT_PRIVATE, (expected), NULL, NULL), \
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0); \
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} while (0)
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#define qt_wake_all(a) \
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do { \
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/* Docs say use INT32_MAX to specify all. */ \
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qassert( \
149+
_umtx_op( \
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(a), UMTX_OP_WAKE_PRIVATE, (unsigned long)INT32_MAX, NULL, NULL), \
151+
0); \
152+
} while (0)
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#define qt_wake_one(a) \
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do { \
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qassert(_umtx_op((a), UMTX_OP_WAKE_PRIVATE, 1ul, NULL, NULL), 0); \
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} while (0)
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#elif defined(QTHREADS_OPENBSD)
160+
// use futex syscall wrapper they provide: https://man.openbsd.org/futex
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#include <errno.h>
162+
#include <sys/futex.h>
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#include <sys/time.h>
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#ifndef NDEBUG
166+
#define qt_wait_on_address(a, expected) \
167+
do { \
168+
int status = \
169+
futex((a), FUTEX_WAIT | FUTEX_PRIVATE_FLAG, (expected), NULL, NULL); \
170+
assert(!status || (status == -1 && errno == EAGAIN));
171+
}
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while (0)
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#else
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#define qt_wait_on_address(a, expected) \
175+
do { \
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futex((a), FUTEX_WAIT | FUTEX_PRIVATE_FLAG, (expected), NULL, NULL); \
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} while (0)
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#endif
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#define qt_wake_all(a) \
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do { \
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/* For whatever reason they used a signed integer for the val parameter so \
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* use INT32_MAX.*/ \
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futex((a), FUTEX_WAKE | FUTEX_PRIVATE_FLAG, INT32_MAX, NULL, NULL); \
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} while (0)
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#define qt_wake_one(a) \
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do { futex((a), FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1, NULL, NULL); } while (0)
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#elif defined(QTHREADS_NETBSD)
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// use SYS___futex syscall
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#include <errno.h>
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#include <sys/futex.h>
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#include <sys/syscall.h>
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#include <sys/time.h>
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#ifndef NDEBUG
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#define qt_wait_on_address(a, expected) \
199+
do { \
200+
int status = syscall(SYS___futex, \
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(a), \
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FUTEX_WAIT | FUTEX_PRIVATE_FLAG, \
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(expected), \
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NULL, \
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NULL); \
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assert(!status || status == -1 && errno == EAGAIN); \
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} while (0)
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#else
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#define qt_wait_on_address(a, expected) \
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do { \
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syscall(SYS___futex, \
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(a), \
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FUTEX_WAIT | FUTEX_PRIVATE_FLAG, \
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(expected), \
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NULL, \
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NULL); \
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while (0)
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#endif
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#define qt_wake_all(a) \
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do { \
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syscall(SYS___futex, \
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(a), \
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FUTEX_WAKE | FUTEX_PRIVATE_FLAG, \
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UINT32_MAX, \
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NULL, \
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NULL); \
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} while (0)
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#define qt_wake_one(a) \
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do { \
232+
syscall( \
233+
SYS___futex, (a), FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1u, NULL, NULL); \
234+
} while (0)
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#elif defined(QTHREADS_DRAGONFLYBSD)
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// use umtx_sleep and umtx_wakeup
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#include <errno.h>
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#include <unistd.h>
240+
#ifndef NDEBUG
241+
#define qt_wait_on_address(a, expected) \
242+
do { \
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int status = umtx_sleep((a), (expected), 0); \
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assert(!status || (status == -1 && errno == EBUSY)); \
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} while (0)
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#else
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#define qt_wait_on_address(a, expected) \
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do { umtx_sleep((a), (expected), 0); } while (0)
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#endif
250+
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#define qt_wake_all(a) \
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do { \
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/* The interface uses signed integers, so use INT32_MAX here */ \
254+
qassert(umtx_wakeup((a), INT32_MAX), 0); \
255+
} while (0)
256+
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#define qt_wake_one(a) \
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do { qassert(umtx_wakeup((a), 1), 0); } while (0)
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#elif defined(QTHREADS_WINDOWS)
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// use WaitOnAddress/WakeByAddressSingle/WakeByAddressAll
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#include <synchapi.h>
263+
#define qt_wait_on_address(a, expected) \
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do { qassert(WaitOnAddress((a), (expected), 4, INFINITE), TRUE); } while (0)
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#define qt_wake_all(a) \
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do { WakeByAddressAll(a); } while (0)
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#define qt_wake_one(a) \
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do { WakeByAddressSingle(a); } while (0)
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#elif defined(__sun)
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// Solaris supposedly provides something futex-like via "user-level adaptive
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// spin mutexes".
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// TODO: implement that
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#error "futex equivalent not implemented for solaris."
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#else
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#error "no known futex equivalent for current OS"
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#endif
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#endif

‎include/qt_branching.h

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#ifndef QT_BRANCHING_H
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#define QT_BRANCHING_H
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#define likely(x) (__builtin_expect(!!(x), 1))
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#define unlikely(x) (__builtin_expect(!!(x), 0))
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#endif

‎include/qt_macros.h

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#define QTHREAD_MSAN
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#endif
2525
#endif
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#ifdef QTHREAD_MSAN
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#define QTHREAD_SUPPRESS_MSAN __attribute__((no_sanitize("memory")))
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#else
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#define QTHREAD_SUPPRESS_MSAN
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#endif
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2732
#define TLS_DECL(type, name) thread_local type name
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#define TLS_DECL_INIT(type, name) thread_local type name = 0

‎include/qt_os.h

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#ifndef QT_OS_H
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#define QT_OS_H
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// Not all Operating systems listed here are actually supported.
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#if defined(__linux__) || defined(QTHREADS_LINUX)
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#ifndef QTHREADS_LINUX
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#define QTHREADS_LINUX
9+
#endif
10+
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#elif defined(__APPLE__) || defined(QTHREADS_APPLE)
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#ifndef QTHREADS_APPLE
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#define QTHREADS_APPLE
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#endif
15+
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#elif defined(_WIN32) || defined(QTHREADS_WINDOWS)
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#ifndef QTHREADS_WINDOWS
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#define QTHREADS_WINDOWS
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#endif
20+
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#elif defined(__FreeBSD__) || defined(QTHREADS_FREEBSD)
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#ifndef QTHREADS_FREEBSD
23+
#define QTHREADS_FREEBSD
24+
#endif
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#elif defined(__NetBSD__) || defined(QTHREADS_NETBSD)
27+
#ifndef QTHREADS_NETBSD
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#define QTHREADS_NETBSD
29+
#endif
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#elif defined(__OpenBSD__) || defined(QTHREADS_OPENBSD)
32+
#ifndef QTHREADS_OPENBSD
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#define QTHREADS_OPENBSD
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#endif
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#elif defined(__DragonFly__) || defined(QTHREADS_DRAGONFLYBSD)
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#ifndef QTHREADS_DRAGONFLYBSD
38+
#define QTHREADS_DRAGONFLYBSD
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#endif
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#elif defined(__sun)
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#error "Sun OS not currently supported."
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#else
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#error "Unrecognized OS"
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#endif
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#endif

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