From 85f64f38517c81ba1387de2f672d41293e9e827b Mon Sep 17 00:00:00 2001 From: Justine Tunney Date: Tue, 3 Oct 2023 14:47:20 -0700 Subject: [PATCH] Make futexes 100x better on x86 MacOS Thanks to @autumnjolitz (in #876) the Cosmopolitan codebase is now acquainted with Apple's outstanding ulock system calls which offer something much closer to futexes than Grand Central Dispatch which wasn't quite as good, since its wait function can't be interrupted by signals (therefore necessitating a busy loop) and it also needs semaphore objects to be created and freed. Even though ulock is an internal Apple API, strictly speaking, the benefits of futexes are so great that it's worth the risk for now especially since we have the GCD implementation still as a quick escape hatch if it changes Here's why this change is important for x86 XNU users. Cosmo has a suboptimal polyfill when the operating system doesn't offer an API that let's us implement futexes properly. Sadly we had to use that on X86 XNU until now. The polyfill works using clock_nanosleep, to poll the futex in a busy loop with exponential backoff. On XNU x86 clock_nanosleep suffers from us not being able to use a fast clock gettime implementation, which had a compounding effect that's made the polyfill function even more poorly. On X86 XNU we also need to polyfill sched_yield() using select(), which made things even more troublesome. Now that we have futexes we don't have any busy loops anymore for both condition variables and thread joining so optimal performance is attained. To demonstrate, consider these benchmarks Before: $ ./lockscale_test.com -b consumed 38.8377 seconds real time and 0.087131 seconds cpu time After: $ ./lockscale_test.com -b consumed 0.007955 seconds real time and 0.011515 seconds cpu time Fixes #876 --- libc/calls/syscall_support-sysv.internal.h | 2 + libc/intrin/kprintf.greg.c | 52 +++++++++++++++------ libc/intrin/strace.internal.h | 4 +- libc/intrin/ulock.c | 54 ++++++++++++++++++++++ libc/intrin/ulock.h | 27 +++++++++++ libc/log/oncrash_arm64.c | 6 +++ libc/runtime/clone.c | 22 ++++++--- libc/runtime/enable_tls.c | 1 + libc/sysv/calls/sys_futex.S | 2 +- libc/sysv/calls/sys_futex_cp.S | 2 +- libc/sysv/syscall2.S | 2 + libc/sysv/syscall3.S | 2 + libc/sysv/syscall4.S | 53 +++++++++++++++++++++ libc/sysv/syscalls.sh | 4 +- libc/sysv/sysv.mk | 3 ++ libc/thread/pthread_exit.c | 2 +- libc/thread/pthread_timedjoin_np.c | 2 +- test/libc/calls/sigbus_test.c | 7 ++- third_party/nsync/README.cosmo | 2 + third_party/nsync/futex.c | 37 +++++++++++++++ third_party/nsync/mu_semaphore.c | 15 ++++-- 21 files changed, 267 insertions(+), 34 deletions(-) create mode 100644 libc/intrin/ulock.c create mode 100644 libc/intrin/ulock.h create mode 100644 libc/sysv/syscall4.S diff --git a/libc/calls/syscall_support-sysv.internal.h b/libc/calls/syscall_support-sysv.internal.h index 1f6be424ac0..ebf3103d7b4 100644 --- a/libc/calls/syscall_support-sysv.internal.h +++ b/libc/calls/syscall_support-sysv.internal.h @@ -10,6 +10,8 @@ long __syscall2(long, long, int); int __syscall2i(long, long, int) asm("__syscall2"); long __syscall3(long, long, long, int); int __syscall3i(long, long, long, int) asm("__syscall3"); +long __syscall4(long, long, long, long, int); +int __syscall4i(long, long, long, long, int) asm("__syscall4"); bool __is_linux_2_6_23(void); bool32 sys_isatty_metal(int); diff --git a/libc/intrin/kprintf.greg.c b/libc/intrin/kprintf.greg.c index fd434015dd6..05d7d654f8c 100644 --- a/libc/intrin/kprintf.greg.c +++ b/libc/intrin/kprintf.greg.c @@ -568,25 +568,37 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt, goto FormatUnsigned; case 'P': + if (!(tib && (tib->tib_flags & TIB_FLAG_VFORKED))) { + x = __pid; +#ifdef __x86_64__ + } else if (IsLinux()) { + asm volatile("syscall" + : "=a"(x) + : "0"(__NR_getpid) + : "rcx", "rdx", "r11", "memory"); +#endif + } else { + x = 666; + } + if (!__nocolor && p + 7 <= e) { + *p++ = '\e'; + *p++ = '['; + *p++ = '1'; + *p++ = ';'; + *p++ = '3'; + *p++ = '0' + x % 8; + *p++ = 'm'; + ansi = 1; + } + goto FormatDecimal; + + case 'H': if (!(tib && (tib->tib_flags & TIB_FLAG_VFORKED))) { if (tib) { x = atomic_load_explicit(&tib->tib_tid, memory_order_relaxed); - if (IsNetbsd() && x == 1) { - x = __pid; - } } else { x = __pid; } - if (!__nocolor && p + 7 <= e) { - *p++ = '\e'; - *p++ = '['; - *p++ = '1'; - *p++ = ';'; - *p++ = '3'; - *p++ = '0' + x % 8; - *p++ = 'm'; - ansi = 1; - } #ifdef __x86_64__ } else if (IsLinux()) { asm volatile("syscall" @@ -597,6 +609,17 @@ privileged static size_t kformat(char *b, size_t n, const char *fmt, } else { x = 666; } + if (!__nocolor && p + 7 <= e) { + // xnu thread ids are always divisible by 8 + *p++ = '\e'; + *p++ = '['; + *p++ = '1'; + *p++ = ';'; + *p++ = '3'; + *p++ = '0' + x % 7; + *p++ = 'm'; + ansi = 1; + } goto FormatDecimal; case 'u': @@ -1080,7 +1103,8 @@ privileged void kvprintf(const char *fmt, va_list v) { * - `X` uppercase * - `T` timestamp * - `x` hexadecimal - * - `P` PID (or TID if TLS is enabled) + * - `P` process id + * - `H` thread id * * Types: * diff --git a/libc/intrin/strace.internal.h b/libc/intrin/strace.internal.h index 60b17b3ad5b..92cc9101ea8 100644 --- a/libc/intrin/strace.internal.h +++ b/libc/intrin/strace.internal.h @@ -3,7 +3,7 @@ #include "libc/intrin/likely.h" #include "libc/runtime/runtime.h" -#define _NTTRACE 1 /* not configurable w/ flag yet */ +#define _NTTRACE 0 /* not configurable w/ flag yet */ #define _POLLTRACE 0 /* not configurable w/ flag yet */ #define _DATATRACE 1 /* not configurable w/ flag yet */ #define _LOCKTRACE 0 /* not configurable w/ flag yet */ @@ -11,7 +11,7 @@ #define _KERNTRACE 0 /* not configurable w/ flag yet */ #define _TIMETRACE 0 /* not configurable w/ flag yet */ -#define STRACE_PROLOGUE "%rSYS %6P %'18T " +#define STRACE_PROLOGUE "%rSYS %6P %6H %'18T " #if !(__ASSEMBLER__ + __LINKER__ + 0) COSMOPOLITAN_C_START_ diff --git a/libc/intrin/ulock.c b/libc/intrin/ulock.c new file mode 100644 index 00000000000..6a6849eb962 --- /dev/null +++ b/libc/intrin/ulock.c @@ -0,0 +1,54 @@ +/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│ +│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│ +╞══════════════════════════════════════════════════════════════════════════════╡ +│ Copyright 2023 Justine Alexandra Roberts Tunney │ +│ │ +│ Permission to use, copy, modify, and/or distribute this software for │ +│ any purpose with or without fee is hereby granted, provided that the │ +│ above copyright notice and this permission notice appear in all copies. │ +│ │ +│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │ +│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │ +│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │ +│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │ +│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │ +│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │ +│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │ +│ PERFORMANCE OF THIS SOFTWARE. │ +╚─────────────────────────────────────────────────────────────────────────────*/ +#include "libc/intrin/ulock.h" +#include "libc/assert.h" +#include "libc/calls/calls.h" +#include "libc/calls/syscall_support-sysv.internal.h" +#include "libc/dce.h" +#include "libc/intrin/describeflags.internal.h" +#include "libc/intrin/strace.internal.h" + +// XNU futexes +// https://opensource.apple.com/source/xnu/xnu-7195.50.7.100.1/bsd/sys/ulock.h.auto.html +// https://opensource.apple.com/source/xnu/xnu-3789.41.3/bsd/kern/sys_ulock.c.auto.html + +int sys_ulock_wait(uint32_t operation, void *addr, uint64_t value, + uint32_t timeout_micros) asm("sys_futex_cp"); + +// returns -1 w/ errno +int ulock_wait(uint32_t operation, void *addr, uint64_t value, + uint32_t timeout_micros) { + int rc; + operation |= ULF_WAIT_CANCEL_POINT; + STRACE("ulock_wait(%#x, %p, %lx, %u) → ...", operation, addr, value, + timeout_micros); + rc = sys_ulock_wait(operation, addr, value, timeout_micros); + STRACE("ulock_wait(%#x, %p, %lx, %u) → %d% m", operation, addr, value, + timeout_micros, rc); + return rc; +} + +// returns -errno +int ulock_wake(uint32_t operation, void *addr, uint64_t wake_value) { + int rc; + rc = __syscall3i(operation, (long)addr, wake_value, 0x2000000 | 516); + STRACE("ulock_wake(%#x, %p, %lx) → %s", operation, addr, wake_value, + DescribeErrno(rc)); + return rc; +} diff --git a/libc/intrin/ulock.h b/libc/intrin/ulock.h new file mode 100644 index 00000000000..d76277a4ff3 --- /dev/null +++ b/libc/intrin/ulock.h @@ -0,0 +1,27 @@ +#ifndef COSMOPOLITAN_ULOCK_H_ +#define COSMOPOLITAN_ULOCK_H_ +#if !(__ASSEMBLER__ + __LINKER__ + 0) +COSMOPOLITAN_C_START_ + +/* both wake and wait take one of these */ +#define UL_COMPARE_AND_WAIT 1 /* multi-thread */ +#define UL_UNFAIR_LOCK 2 +#define UL_COMPARE_AND_WAIT_SHARED 3 /* multi-thread/process */ +#define UL_UNFAIR_LOCK64_SHARED 4 +#define UL_COMPARE_AND_WAIT64 5 +#define UL_COMPARE_AND_WAIT64_SHARED 6 + +#define ULF_WAKE_ALL 0x00000100 +#define ULF_WAKE_THREAD 0x00000200 /* takes wake_value */ +#define ULF_WAKE_ALLOW_NON_OWNER 0x00000400 + +#define ULF_WAIT_WORKQ_DATA_CONTENTION 0x00010000 +#define ULF_WAIT_CANCEL_POINT 0x00020000 /* raises eintr */ +#define ULF_WAIT_ADAPTIVE_SPIN 0x00040000 + +int ulock_wake(uint32_t, void *, uint64_t); +int ulock_wait(uint32_t, void *, uint64_t, uint32_t); + +COSMOPOLITAN_C_END_ +#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */ +#endif /* COSMOPOLITAN_ULOCK_H_ */ diff --git a/libc/log/oncrash_arm64.c b/libc/log/oncrash_arm64.c index 1ab35736795..89743cfd6d6 100644 --- a/libc/log/oncrash_arm64.c +++ b/libc/log/oncrash_arm64.c @@ -230,6 +230,11 @@ static relegated void __oncrash_impl(int sig, struct siginfo *si, } Append(b, " %s %s %s %s\n", names.sysname, names.version, names.nodename, names.release); + Append( + b, " cosmoaddr2line %s%s %lx %s\n", __argv[0], + endswith(__argv[0], ".com") ? ".dbg" : "", ctx ? ctx->uc_mcontext.PC : 0, + DescribeBacktrace(ctx ? (struct StackFrame *)ctx->uc_mcontext.BP + : (struct StackFrame *)__builtin_frame_address(0))); if (ctx) { long pc; char *mem = 0; @@ -240,6 +245,7 @@ static relegated void __oncrash_impl(int sig, struct siginfo *si, struct StackFrame *fp; struct SymbolTable *st; struct fpsimd_context *vc; + st = GetSymbolTable(); debugbin = FindDebugBinary(); addr2line = GetAddr2linePath(); diff --git a/libc/runtime/clone.c b/libc/runtime/clone.c index a771817afcc..a88b3d8da5a 100644 --- a/libc/runtime/clone.c +++ b/libc/runtime/clone.c @@ -30,6 +30,7 @@ #include "libc/intrin/atomic.h" #include "libc/intrin/describeflags.internal.h" #include "libc/intrin/strace.internal.h" +#include "libc/intrin/ulock.h" #include "libc/intrin/weaken.h" #include "libc/limits.h" #include "libc/macros.internal.h" @@ -197,12 +198,20 @@ XnuThreadMain(void *pthread, // rdi // %rsi = size_t freesize, // %rdx = uint32_t port, // %r10 = uint32_t sem); - asm volatile("movl\t$0,%0\n\t" // *wt->ztid = 0 - "xor\t%%r10d,%%r10d\n\t" // sem = 0 - "syscall" // __bsdthread_terminate() - : "=m"(*wt->ztid) - : "a"(0x2000000 | 361), "D"(0), "S"(0), "d"(0L) - : "rcx", "r10", "r11", "memory"); + asm volatile("movl\t$0,(%%rsi)\n\t" // *wt->ztid = 0 + "mov\t$0x101,%%edi\n\t" // wake all + "xor\t%%edx,%%edx\n\t" // wake_value + "mov\t$0x02000204,%%eax\n\t" // ulock_wake() + "syscall\n\t" // + "xor\t%%edi,%%edi\n\t" // freeaddr + "xor\t%%esi,%%esi\n\t" // freesize + "xor\t%%edx,%%edx\n\t" // kport + "xor\t%%r10d,%%r10d\n\t" // joinsem + "mov\t$0x02000169,%%eax\n\t" // bsdthread_terminate() + "syscall" + : /* no outputs */ + : "S"(wt->ztid) + : "rax", "rcx", "r10", "r11", "memory"); __builtin_unreachable(); } @@ -443,6 +452,7 @@ static void *SiliconThreadMain(void *arg) { *wt->ctid = wt->this; __stack_call(wt->arg, wt->this, 0, 0, wt->func, wt); *wt->ztid = 0; + ulock_wake(UL_COMPARE_AND_WAIT | ULF_WAKE_ALL, wt->ztid, 0); return 0; } diff --git a/libc/runtime/enable_tls.c b/libc/runtime/enable_tls.c index 77f1bef2f49..e8f3e315942 100644 --- a/libc/runtime/enable_tls.c +++ b/libc/runtime/enable_tls.c @@ -206,6 +206,7 @@ textstartup void __enable_tls(void) { tid = sys_gettid(); } atomic_store_explicit(&tib->tib_tid, tid, memory_order_relaxed); + // TODO(jart): set_tid_address? // initialize posix threads _pthread_static.tib = tib; diff --git a/libc/sysv/calls/sys_futex.S b/libc/sysv/calls/sys_futex.S index 46135802836..98b3d2eef1f 100644 --- a/libc/sysv/calls/sys_futex.S +++ b/libc/sysv/calls/sys_futex.S @@ -1,2 +1,2 @@ #include "libc/sysv/macros.internal.h" -.scall sys_futex,0x0a60531c6ffff0ca,98,4095,globl,hidden +.scall sys_futex,0x0a60531c622030ca,98,515,globl,hidden diff --git a/libc/sysv/calls/sys_futex_cp.S b/libc/sysv/calls/sys_futex_cp.S index 32bafc3fd0e..8915061af2e 100644 --- a/libc/sysv/calls/sys_futex_cp.S +++ b/libc/sysv/calls/sys_futex_cp.S @@ -1,2 +1,2 @@ #include "libc/sysv/macros.internal.h" -.scall sys_futex_cp,0x8a68539c6ffff8ca,2146,4095,globl,hidden +.scall sys_futex_cp,0x8a68539c62a038ca,2146,2563,globl,hidden diff --git a/libc/sysv/syscall2.S b/libc/sysv/syscall2.S index 04de25d079e..9ee8b7d183b 100644 --- a/libc/sysv/syscall2.S +++ b/libc/sysv/syscall2.S @@ -26,6 +26,8 @@ // // The returned value follows the Linux kernel convention ie // errors are returned as `-errno`, rather than -1 w/ errno. +// +// This helper should not be used to do cancelation points. __syscall2: #ifdef __aarch64__ mov x8,x2 // syscall number (linux) diff --git a/libc/sysv/syscall3.S b/libc/sysv/syscall3.S index 8316971b951..8041b2f04aa 100644 --- a/libc/sysv/syscall3.S +++ b/libc/sysv/syscall3.S @@ -26,6 +26,8 @@ // // The return value follows the Linux Kernel (System V) ABI // where -errno is returned, rather than doing -1 w/ errno. +// +// This helper should not be used to do cancelation points. __syscall3: #ifdef __aarch64__ mov x8,x3 // syscall number (linux) diff --git a/libc/sysv/syscall4.S b/libc/sysv/syscall4.S new file mode 100644 index 00000000000..9c2d9b7f405 --- /dev/null +++ b/libc/sysv/syscall4.S @@ -0,0 +1,53 @@ +/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│ +│vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi│ +╞══════════════════════════════════════════════════════════════════════════════╡ +│ Copyright 2023 Justine Alexandra Roberts Tunney │ +│ │ +│ Permission to use, copy, modify, and/or distribute this software for │ +│ any purpose with or without fee is hereby granted, provided that the │ +│ above copyright notice and this permission notice appear in all copies. │ +│ │ +│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │ +│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │ +│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │ +│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │ +│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │ +│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │ +│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │ +│ PERFORMANCE OF THIS SOFTWARE. │ +╚─────────────────────────────────────────────────────────────────────────────*/ +#include "libc/macros.internal.h" + +// Invokes system call w/ arity of four. +// +// This function takes four params. The first four, are for +// args passed along to the system call. The 5th is for the +// the magic number, indicating which system call is called +// +// The return value follows the Linux Kernel (System V) ABI +// where -errno is returned, rather than doing -1 w/ errno. +// +// This helper should not be used to do cancelation points. +__syscall4: +#ifdef __aarch64__ + mov x8,x4 // syscall number (linux) + mov x16,x4 // syscall number (xnu) + mov x9,0 // clear carry flag + adds x9,x9,0 // clear carry flag + svc 0 + bcs 1f + ret +1: neg x0,x0 + ret +#elif defined(__x86_64__) + mov %rcx,%r10 // avoid intel cx clobber + mov %r8d,%eax // arg5 -> syscall number + clc // linux saves carry flag + syscall // bsds set carry on errs + jnc 1f + neg %rax // normalizes to system v +1: ret +#else +#error "unsupported architecture" +#endif + .endfn __syscall4,globl diff --git a/libc/sysv/syscalls.sh b/libc/sysv/syscalls.sh index cfe3afb2a6c..41639145828 100755 --- a/libc/sysv/syscalls.sh +++ b/libc/sysv/syscalls.sh @@ -100,8 +100,8 @@ scall sys_killpg 0x092fff092fffffff 0xfff globl hidden scall sys_clone 0x11fffffffffff038 0x0dc globl hidden scall sys_tkill 0x13e0771b121480c8 0x082 globl hidden # thr_kill() on FreeBSD; _lwp_kill() on NetBSD; thrkill() on OpenBSD where arg3 should be 0 or tcb; __pthread_kill() on XNU scall sys_tgkill 0xffffff1e1ffff0ea 0x083 globl hidden # thr_kill2() on FreeBSD -scall sys_futex 0x0a60531c6ffff0ca 0x062 globl hidden # raises SIGSYS on NetBSD; _umtx_op() on FreeBSD -scall sys_futex_cp 0x8a68539c6ffff8ca 0x862 globl hidden # intended for futex wait ops +scall sys_futex 0x0a60531c622030ca 0x062 globl hidden # raises SIGSYS on NetBSD; _umtx_op() on FreeBSD +scall sys_futex_cp 0x8a68539c62a038ca 0x862 globl hidden # intended for futex wait ops scall sys_set_robust_list 0x0a7ffffffffff111 0x063 globl # no wrapper scall sys_get_robust_list 0x0a8ffffffffff112 0x064 globl # no wrapper scall sys_uname 0x0a4fff0a4ffff03f 0x0a0 globl hidden diff --git a/libc/sysv/sysv.mk b/libc/sysv/sysv.mk index 9ea8e042ae6..ac1063d35ba 100644 --- a/libc/sysv/sysv.mk +++ b/libc/sysv/sysv.mk @@ -40,6 +40,7 @@ LIBC_SYSV_A_FILES := \ libc/sysv/restorert.S \ libc/sysv/syscall2.S \ libc/sysv/syscall3.S \ + libc/sysv/syscall4.S \ libc/sysv/systemfive.S \ libc/sysv/sysret.c \ libc/sysv/sysv.c \ @@ -170,6 +171,8 @@ o/$(MODE)/libc/sysv/syscall2.o: libc/sysv/syscall2.S @$(COMPILE) -AOBJECTIFY.S $(OBJECTIFY.S) $(OUTPUT_OPTION) $< o/$(MODE)/libc/sysv/syscall3.o: libc/sysv/syscall3.S @$(COMPILE) -AOBJECTIFY.S $(OBJECTIFY.S) $(OUTPUT_OPTION) $< +o/$(MODE)/libc/sysv/syscall4.o: libc/sysv/syscall4.S + @$(COMPILE) -AOBJECTIFY.S $(OBJECTIFY.S) $(OUTPUT_OPTION) $< o/$(MODE)/libc/sysv/restorert.o: libc/sysv/restorert.S @$(COMPILE) -AOBJECTIFY.S $(OBJECTIFY.S) $(OUTPUT_OPTION) $< o/$(MODE)/libc/sysv/calls/%.o: libc/sysv/calls/%.S diff --git a/libc/thread/pthread_exit.c b/libc/thread/pthread_exit.c index f1c46ebad08..10c6a440b28 100644 --- a/libc/thread/pthread_exit.c +++ b/libc/thread/pthread_exit.c @@ -155,7 +155,7 @@ wontreturn void pthread_exit(void *rc) { // note that the main thread is joinable by child threads if (pt->pt_flags & PT_STATIC) { atomic_store_explicit(&tib->tib_tid, 0, memory_order_release); - nsync_futex_wake_(&tib->tib_tid, INT_MAX, !IsWindows()); + nsync_futex_wake_(&tib->tib_tid, INT_MAX, !IsWindows() && !IsXnu()); _Exit1(0); } diff --git a/libc/thread/pthread_timedjoin_np.c b/libc/thread/pthread_timedjoin_np.c index ceb68d9c073..c37fcfb7b4d 100644 --- a/libc/thread/pthread_timedjoin_np.c +++ b/libc/thread/pthread_timedjoin_np.c @@ -65,7 +65,7 @@ static errno_t _pthread_wait(atomic_int *ctid, struct timespec *abstime) { if (!(rc = pthread_testcancel_np())) { BEGIN_CANCELLATION_POINT; while ((x = atomic_load_explicit(ctid, memory_order_acquire))) { - e = nsync_futex_wait_(ctid, x, !IsWindows(), abstime); + e = nsync_futex_wait_(ctid, x, !IsWindows() && !IsXnu(), abstime); if (e == -ECANCELED) { rc = ECANCELED; break; diff --git a/test/libc/calls/sigbus_test.c b/test/libc/calls/sigbus_test.c index 4bb852b7dc8..b7f69311f63 100644 --- a/test/libc/calls/sigbus_test.c +++ b/test/libc/calls/sigbus_test.c @@ -100,7 +100,12 @@ TEST(sigbus, test) { // verify the signal was raised EXPECT_EQ(SIGBUS, gotsig); - EXPECT_EQ(BUS_ADRERR, gotcode); + if (IsXnuSilicon()) { + // TODO: Why does it say it's an alignment error? + EXPECT_EQ(BUS_ADRALN, gotcode); + } else { + EXPECT_EQ(BUS_ADRERR, gotcode); + } // clean up sigaction(SIGBUS, &oldsa, 0); diff --git a/third_party/nsync/README.cosmo b/third_party/nsync/README.cosmo index d1d0eb4d744..29f2f8ec168 100644 --- a/third_party/nsync/README.cosmo +++ b/third_party/nsync/README.cosmo @@ -19,6 +19,8 @@ LOCAL CHANGES - Double linked list API was so good that it's now in libc + - Support Apple's ulock futexes which are internal but nicer than GCD + - Ensure resources such as POSIX semaphores are are released on fork. - Modified *NSYNC to allocate waiter objects on the stack. We need it diff --git a/third_party/nsync/futex.c b/third_party/nsync/futex.c index 227d9604403..83b7ac44b7d 100644 --- a/third_party/nsync/futex.c +++ b/third_party/nsync/futex.c @@ -32,6 +32,7 @@ #include "libc/intrin/atomic.h" #include "libc/intrin/describeflags.internal.h" #include "libc/intrin/strace.internal.h" +#include "libc/intrin/ulock.h" #include "libc/intrin/weaken.h" #include "libc/limits.h" #include "libc/nexgen32e/vendor.internal.h" @@ -75,6 +76,12 @@ static void nsync_futex_init_ (void) { return; } + if (IsXnu ()) { + nsync_futex_.is_supported = true; + nsync_futex_.timeout_is_relative = true; + return; + } + if (IsFreebsd ()) { nsync_futex_.is_supported = true; nsync_futex_.FUTEX_PRIVATE_FLAG_ = FUTEX_PRIVATE_FLAG; @@ -256,6 +263,20 @@ int nsync_futex_wait_ (atomic_int *w, int expect, char pshare, const struct time // Windows 8 futexes don't support multiple processes :( if (pshare) goto Polyfill; rc = nsync_futex_wait_win32_ (w, expect, pshare, timeout, pt); + } else if (IsXnu ()) { + uint32_t op, us; + if (pshare) { + op = UL_COMPARE_AND_WAIT_SHARED; + } else { + op = UL_COMPARE_AND_WAIT; + } + if (timeout) { + us = timespec_tomicros (*timeout); + } else { + us = -1u; + } + rc = ulock_wait (op, w, expect, us); + if (rc > 0) rc = 0; // TODO(jart): What does it mean? } else if (IsFreebsd ()) { rc = sys_umtx_timedwait_uint (w, expect, pshare, timeout); } else { @@ -326,6 +347,22 @@ int nsync_futex_wake_ (atomic_int *w, int count, char pshare) { WakeByAddressAll (w); } rc = 0; + } else if (IsXnu ()) { + uint32_t op; + if (pshare) { + op = UL_COMPARE_AND_WAIT_SHARED; + } else { + op = UL_COMPARE_AND_WAIT; + } + if (count > 1) { + op |= ULF_WAKE_ALL; + } + rc = ulock_wake (op, w, 0); + if (!rc) { + rc = 1; + } else if (rc == -ENOENT) { + rc = 0; + } } else if (IsFreebsd ()) { if (pshare) { fop = UMTX_OP_WAKE; diff --git a/third_party/nsync/mu_semaphore.c b/third_party/nsync/mu_semaphore.c index 6341b5c5c02..28570cc31b4 100644 --- a/third_party/nsync/mu_semaphore.c +++ b/third_party/nsync/mu_semaphore.c @@ -20,6 +20,11 @@ #include "libc/dce.h" #include "third_party/nsync/mu_semaphore.internal.h" +/* Apple's ulock (part by Cosmo futexes) is an internal API, but: + 1. Unlike GCD it's cancellable, i.e. can be EINTR'd by signals + 2. We currently always use ulock anyway for joining threads */ +#define PREFER_GCD_OVER_ULOCK 0 + asm(".ident\t\"\\n\\n\ *NSYNC (Apache 2.0)\\n\ Copyright 2016 Google, Inc.\\n\ @@ -28,7 +33,7 @@ Copyright 2016 Google, Inc.\\n\ /* Initialize *s; the initial value is 0. */ void nsync_mu_semaphore_init (nsync_semaphore *s) { - if (IsXnuSilicon ()) { + if (PREFER_GCD_OVER_ULOCK && IsXnuSilicon ()) { return nsync_mu_semaphore_init_gcd (s); } else if (IsNetbsd ()) { return nsync_mu_semaphore_init_sem (s); @@ -39,7 +44,7 @@ void nsync_mu_semaphore_init (nsync_semaphore *s) { /* Releases system resources associated with *s. */ void nsync_mu_semaphore_destroy (nsync_semaphore *s) { - if (IsXnuSilicon ()) { + if (PREFER_GCD_OVER_ULOCK && IsXnuSilicon ()) { return nsync_mu_semaphore_destroy_gcd (s); } else if (IsNetbsd ()) { return nsync_mu_semaphore_destroy_sem (s); @@ -53,7 +58,7 @@ void nsync_mu_semaphore_destroy (nsync_semaphore *s) { errno_t nsync_mu_semaphore_p (nsync_semaphore *s) { errno_t err; BEGIN_CANCELLATION_POINT; - if (IsXnuSilicon ()) { + if (PREFER_GCD_OVER_ULOCK && IsXnuSilicon ()) { err = nsync_mu_semaphore_p_gcd (s); } else if (IsNetbsd ()) { err = nsync_mu_semaphore_p_sem (s); @@ -71,7 +76,7 @@ errno_t nsync_mu_semaphore_p (nsync_semaphore *s) { errno_t nsync_mu_semaphore_p_with_deadline (nsync_semaphore *s, nsync_time abs_deadline) { errno_t err; BEGIN_CANCELLATION_POINT; - if (IsXnuSilicon ()) { + if (PREFER_GCD_OVER_ULOCK && IsXnuSilicon ()) { err = nsync_mu_semaphore_p_with_deadline_gcd (s, abs_deadline); } else if (IsNetbsd ()) { err = nsync_mu_semaphore_p_with_deadline_sem (s, abs_deadline); @@ -84,7 +89,7 @@ errno_t nsync_mu_semaphore_p_with_deadline (nsync_semaphore *s, nsync_time abs_d /* Ensure that the count of *s is at least 1. */ void nsync_mu_semaphore_v (nsync_semaphore *s) { - if (IsXnuSilicon ()) { + if (PREFER_GCD_OVER_ULOCK && IsXnuSilicon ()) { return nsync_mu_semaphore_v_gcd (s); } else if (IsNetbsd ()) { return nsync_mu_semaphore_v_sem (s);