From 2c53ef1bfee7c7afea889f42b9ef13e1007ad228 Mon Sep 17 00:00:00 2001 From: Yorick van Pelt Date: Fri, 3 Feb 2023 17:50:01 +0100 Subject: [PATCH 1/4] Disable GC inside coroutines on mac OS --- src/libexpr/eval.cc | 20 ++++++++++++++++++++ src/libutil/serialise.cc | 38 +++++++++++++++++++++++++++++++++----- src/libutil/serialise.hh | 10 ++++++++++ 3 files changed, 63 insertions(+), 5 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 7f2065656..f7c056998 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -345,6 +345,20 @@ static Symbol getName(const AttrName & name, EvalState & state, Env & env) } +class BoehmDisableGC : public DisableGC { +public: + BoehmDisableGC() { +#if HAVE_BOEHMGC + GC_disable(); +#endif + }; + virtual ~BoehmDisableGC() override { +#if HAVE_BOEHMGC + GC_enable(); +#endif + }; +}; + static bool gcInitialised = false; void initGC() @@ -368,6 +382,12 @@ void initGC() StackAllocator::defaultAllocator = &boehmGCStackAllocator; + + /* Used to disable GC when entering coroutines on macOS */ + DisableGC::create = []() { + return std::dynamic_pointer_cast(std::make_shared()); + }; + /* Set the initial heap size to something fairly big (25% of physical RAM, up to a maximum of 384 MiB) so that in most cases we don't need to garbage collect at all. (Collection has a diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc index 7476e6f6c..fac2a0df8 100644 --- a/src/libutil/serialise.cc +++ b/src/libutil/serialise.cc @@ -186,6 +186,10 @@ static DefaultStackAllocator defaultAllocatorSingleton; StackAllocator *StackAllocator::defaultAllocator = &defaultAllocatorSingleton; +std::shared_ptr (*DisableGC::create)() = []() { + return std::dynamic_pointer_cast(std::make_shared()); +}; + std::unique_ptr sourceToSink(std::function fun) { struct SourceToSink : FinishSink @@ -206,7 +210,11 @@ std::unique_ptr sourceToSink(std::function fun) if (in.empty()) return; cur = in; - if (!coro) + if (!coro) { +#if __APPLE__ + /* Disable GC when entering the coroutine on macOS, since it doesn't find the main thread stack in this case */ + auto disablegc = DisableGC::create(); +#endif coro = coro_t::push_type(VirtualStackAllocator{}, [&](coro_t::pull_type & yield) { LambdaSource source([&](char *out, size_t out_len) { if (cur.empty()) { @@ -223,17 +231,28 @@ std::unique_ptr sourceToSink(std::function fun) }); fun(source); }); + } if (!*coro) { abort(); } - if (!cur.empty()) (*coro)(false); + if (!cur.empty()) { +#if __APPLE__ + auto disablegc = DisableGC::create(); +#endif + (*coro)(false); + } } void finish() override { if (!coro) return; if (!*coro) abort(); - (*coro)(true); + { +#if __APPLE__ + auto disablegc = DisableGC::create(); +#endif + (*coro)(true); + } if (*coro) abort(); } }; @@ -264,18 +283,27 @@ std::unique_ptr sinkToSource( size_t read(char * data, size_t len) override { - if (!coro) + if (!coro) { +#if __APPLE__ + auto disablegc = DisableGC::create(); +#endif coro = coro_t::pull_type(VirtualStackAllocator{}, [&](coro_t::push_type & yield) { LambdaSink sink([&](std::string_view data) { if (!data.empty()) yield(std::string(data)); }); fun(sink); }); + } if (!*coro) { eof(); abort(); } if (pos == cur.size()) { - if (!cur.empty()) (*coro)(); + if (!cur.empty()) { +#if __APPLE__ + auto disablegc = DisableGC::create(); +#endif + (*coro)(); + } cur = coro->get(); pos = 0; } diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh index 2cf527023..612196fd2 100644 --- a/src/libutil/serialise.hh +++ b/src/libutil/serialise.hh @@ -551,4 +551,14 @@ struct StackAllocator { static StackAllocator *defaultAllocator; }; +/* Disabling GC when entering a coroutine (on macos). + ::create is to avoid boehm gc dependency in libutil. + */ +class DisableGC { +public: + DisableGC() {}; + virtual ~DisableGC() {}; + static std::shared_ptr (*create)(); +}; + } From 00bc34430b9e8e687cd3f1681e9f7b5baa7c717e Mon Sep 17 00:00:00 2001 From: Yorick van Pelt Date: Fri, 10 Feb 2023 15:04:17 +0100 Subject: [PATCH 2/4] DisableGC: replace by CoroutineContext, std::shared_ptr --- src/libexpr/eval.cc | 20 +++++++++++--------- src/libutil/serialise.cc | 38 ++++++++++++++++++++------------------ src/libutil/serialise.hh | 10 +++------- 3 files changed, 34 insertions(+), 34 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index f7c056998..e5e8d2b22 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -344,20 +344,22 @@ static Symbol getName(const AttrName & name, EvalState & state, Env & env) } } - -class BoehmDisableGC : public DisableGC { +#if HAVE_BOEHMGC +/* Disable GC while this object lives. Used by CoroutineContext. + * + * Boehm keeps a count of GC_disable() and GC_enable() calls, + * and only enables GC when the count matches. + */ +class BoehmDisableGC { public: BoehmDisableGC() { -#if HAVE_BOEHMGC GC_disable(); -#endif }; - virtual ~BoehmDisableGC() override { -#if HAVE_BOEHMGC + ~BoehmDisableGC() { GC_enable(); -#endif }; }; +#endif static bool gcInitialised = false; @@ -384,8 +386,8 @@ void initGC() /* Used to disable GC when entering coroutines on macOS */ - DisableGC::create = []() { - return std::dynamic_pointer_cast(std::make_shared()); + create_disable_gc = []() -> std::shared_ptr { + return std::make_shared(); }; /* Set the initial heap size to something fairly big (25% of diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc index fac2a0df8..0bdeec0cd 100644 --- a/src/libutil/serialise.cc +++ b/src/libutil/serialise.cc @@ -186,8 +186,21 @@ static DefaultStackAllocator defaultAllocatorSingleton; StackAllocator *StackAllocator::defaultAllocator = &defaultAllocatorSingleton; -std::shared_ptr (*DisableGC::create)() = []() { - return std::dynamic_pointer_cast(std::make_shared()); +std::shared_ptr (*create_disable_gc)() = []() -> std::shared_ptr { + return {}; +}; + +/* This class is used for entry and exit hooks on coroutines */ +class CoroutineContext { +#if __APPLE__ + /* Disable GC when entering the coroutine on macOS, since it doesn't find the main thread stack in this case. + * std::shared_ptr performs type-erasure, so it will call the right + * deleter. */ + const std::shared_ptr disable_gc = create_disable_gc(); +#endif +public: + CoroutineContext() {}; + ~CoroutineContext() {}; }; std::unique_ptr sourceToSink(std::function fun) @@ -211,10 +224,7 @@ std::unique_ptr sourceToSink(std::function fun) cur = in; if (!coro) { -#if __APPLE__ - /* Disable GC when entering the coroutine on macOS, since it doesn't find the main thread stack in this case */ - auto disablegc = DisableGC::create(); -#endif + CoroutineContext ctx; coro = coro_t::push_type(VirtualStackAllocator{}, [&](coro_t::pull_type & yield) { LambdaSource source([&](char *out, size_t out_len) { if (cur.empty()) { @@ -236,9 +246,7 @@ std::unique_ptr sourceToSink(std::function fun) if (!*coro) { abort(); } if (!cur.empty()) { -#if __APPLE__ - auto disablegc = DisableGC::create(); -#endif + CoroutineContext ctx; (*coro)(false); } } @@ -248,9 +256,7 @@ std::unique_ptr sourceToSink(std::function fun) if (!coro) return; if (!*coro) abort(); { -#if __APPLE__ - auto disablegc = DisableGC::create(); -#endif + CoroutineContext ctx; (*coro)(true); } if (*coro) abort(); @@ -284,9 +290,7 @@ std::unique_ptr sinkToSource( size_t read(char * data, size_t len) override { if (!coro) { -#if __APPLE__ - auto disablegc = DisableGC::create(); -#endif + CoroutineContext ctx; coro = coro_t::pull_type(VirtualStackAllocator{}, [&](coro_t::push_type & yield) { LambdaSink sink([&](std::string_view data) { if (!data.empty()) yield(std::string(data)); @@ -299,9 +303,7 @@ std::unique_ptr sinkToSource( if (pos == cur.size()) { if (!cur.empty()) { -#if __APPLE__ - auto disablegc = DisableGC::create(); -#endif + CoroutineContext ctx; (*coro)(); } cur = coro->get(); diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh index 612196fd2..b895db779 100644 --- a/src/libutil/serialise.hh +++ b/src/libutil/serialise.hh @@ -552,13 +552,9 @@ struct StackAllocator { }; /* Disabling GC when entering a coroutine (on macos). - ::create is to avoid boehm gc dependency in libutil. + mutable to avoid boehm gc dependency in libutil. */ -class DisableGC { -public: - DisableGC() {}; - virtual ~DisableGC() {}; - static std::shared_ptr (*create)(); -}; +extern std::shared_ptr (*create_disable_gc)(); + } From 58d24a4cb630a6162d6f7d2a85e41949fdf2ad36 Mon Sep 17 00:00:00 2001 From: Yorick van Pelt Date: Wed, 1 Mar 2023 15:07:00 +0100 Subject: [PATCH 3/4] Always disable GC in a coroutine unless the patch is applied --- boehmgc-coroutine-sp-fallback.diff | 22 +++++++++++++++++++--- src/libexpr/eval.cc | 4 +++- src/libutil/serialise.cc | 9 ++++----- src/libutil/serialise.hh | 4 ++-- 4 files changed, 28 insertions(+), 11 deletions(-) diff --git a/boehmgc-coroutine-sp-fallback.diff b/boehmgc-coroutine-sp-fallback.diff index 2826486fb..5066d8278 100644 --- a/boehmgc-coroutine-sp-fallback.diff +++ b/boehmgc-coroutine-sp-fallback.diff @@ -1,8 +1,8 @@ diff --git a/darwin_stop_world.c b/darwin_stop_world.c -index 3dbaa3fb..36a1d1f7 100644 +index 0468aaec..b348d869 100644 --- a/darwin_stop_world.c +++ b/darwin_stop_world.c -@@ -352,6 +352,7 @@ GC_INNER void GC_push_all_stacks(void) +@@ -356,6 +356,7 @@ GC_INNER void GC_push_all_stacks(void) int nthreads = 0; word total_size = 0; mach_msg_type_number_t listcount = (mach_msg_type_number_t)THREAD_TABLE_SZ; @@ -10,7 +10,7 @@ index 3dbaa3fb..36a1d1f7 100644 if (!EXPECT(GC_thr_initialized, TRUE)) GC_thr_init(); -@@ -407,6 +408,19 @@ GC_INNER void GC_push_all_stacks(void) +@@ -411,6 +412,19 @@ GC_INNER void GC_push_all_stacks(void) GC_push_all_stack_sections(lo, hi, p->traced_stack_sect); } if (altstack_lo) { @@ -30,6 +30,22 @@ index 3dbaa3fb..36a1d1f7 100644 total_size += altstack_hi - altstack_lo; GC_push_all_stack(altstack_lo, altstack_hi); } +diff --git a/include/gc.h b/include/gc.h +index edab6c22..f2c61282 100644 +--- a/include/gc.h ++++ b/include/gc.h +@@ -2172,6 +2172,11 @@ GC_API void GC_CALL GC_win32_free_heap(void); + (*GC_amiga_allocwrapper_do)(a,GC_malloc_atomic_ignore_off_page) + #endif /* _AMIGA && !GC_AMIGA_MAKINGLIB */ + ++#if !__APPLE__ ++/* Patch doesn't work on apple */ ++#define NIX_BOEHM_PATCH_VERSION 1 ++#endif ++ + #ifdef __cplusplus + } /* extern "C" */ + #endif diff --git a/pthread_stop_world.c b/pthread_stop_world.c index b5d71e62..aed7b0bf 100644 --- a/pthread_stop_world.c diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index e5e8d2b22..7dcd10d50 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -385,10 +385,12 @@ void initGC() StackAllocator::defaultAllocator = &boehmGCStackAllocator; +#if NIX_BOEHM_PATCH_VERSION != 1 /* Used to disable GC when entering coroutines on macOS */ - create_disable_gc = []() -> std::shared_ptr { + create_coro_gc_hook = []() -> std::shared_ptr { return std::make_shared(); }; +#endif /* Set the initial heap size to something fairly big (25% of physical RAM, up to a maximum of 384 MiB) so that in most cases diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc index 0bdeec0cd..6e53239f5 100644 --- a/src/libutil/serialise.cc +++ b/src/libutil/serialise.cc @@ -186,18 +186,17 @@ static DefaultStackAllocator defaultAllocatorSingleton; StackAllocator *StackAllocator::defaultAllocator = &defaultAllocatorSingleton; -std::shared_ptr (*create_disable_gc)() = []() -> std::shared_ptr { +std::shared_ptr (*create_coro_gc_hook)() = []() -> std::shared_ptr { return {}; }; /* This class is used for entry and exit hooks on coroutines */ class CoroutineContext { -#if __APPLE__ - /* Disable GC when entering the coroutine on macOS, since it doesn't find the main thread stack in this case. + /* Disable GC when entering the coroutine without the boehm patch, + * since it doesn't find the main thread stack in this case. * std::shared_ptr performs type-erasure, so it will call the right * deleter. */ - const std::shared_ptr disable_gc = create_disable_gc(); -#endif + const std::shared_ptr coro_gc_hook = create_coro_gc_hook(); public: CoroutineContext() {}; ~CoroutineContext() {}; diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh index b895db779..ba6dbf619 100644 --- a/src/libutil/serialise.hh +++ b/src/libutil/serialise.hh @@ -551,10 +551,10 @@ struct StackAllocator { static StackAllocator *defaultAllocator; }; -/* Disabling GC when entering a coroutine (on macos). +/* Disabling GC when entering a coroutine (without the boehm patch). mutable to avoid boehm gc dependency in libutil. */ -extern std::shared_ptr (*create_disable_gc)(); +extern std::shared_ptr (*create_coro_gc_hook)(); } From 62ddd8633c06c32baad71b72ce4c82c54c2df512 Mon Sep 17 00:00:00 2001 From: Yorick van Pelt Date: Fri, 3 Mar 2023 11:43:47 +0100 Subject: [PATCH 4/4] Add talkative msg for coro gc debug --- src/libexpr/eval.cc | 1 + 1 file changed, 1 insertion(+) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 7dcd10d50..18cfd9531 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -386,6 +386,7 @@ void initGC() #if NIX_BOEHM_PATCH_VERSION != 1 + printTalkative("Unpatched BoehmGC, disabling GC inside coroutines"); /* Used to disable GC when entering coroutines on macOS */ create_coro_gc_hook = []() -> std::shared_ptr { return std::make_shared();