Merge pull request #8179 from tweag/disable-gc-on-coroutine

disable gc on coroutine
This commit is contained in:
Robert Hensing 2023-04-07 18:21:11 +02:00 committed by GitHub
commit 4411c7d7e0
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4 changed files with 84 additions and 8 deletions

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@ -1,8 +1,8 @@
diff --git a/darwin_stop_world.c b/darwin_stop_world.c 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 --- a/darwin_stop_world.c
+++ b/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; int nthreads = 0;
word total_size = 0; word total_size = 0;
mach_msg_type_number_t listcount = (mach_msg_type_number_t)THREAD_TABLE_SZ; 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)) if (!EXPECT(GC_thr_initialized, TRUE))
GC_thr_init(); 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); GC_push_all_stack_sections(lo, hi, p->traced_stack_sect);
} }
if (altstack_lo) { if (altstack_lo) {
@ -30,6 +30,22 @@ index 3dbaa3fb..36a1d1f7 100644
total_size += altstack_hi - altstack_lo; total_size += altstack_hi - altstack_lo;
GC_push_all_stack(altstack_lo, altstack_hi); 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 diff --git a/pthread_stop_world.c b/pthread_stop_world.c
index b5d71e62..aed7b0bf 100644 index b5d71e62..aed7b0bf 100644
--- a/pthread_stop_world.c --- a/pthread_stop_world.c

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@ -344,6 +344,22 @@ static Symbol getName(const AttrName & name, EvalState & state, Env & env)
} }
} }
#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() {
GC_disable();
};
~BoehmDisableGC() {
GC_enable();
};
};
#endif
static bool gcInitialised = false; static bool gcInitialised = false;
@ -368,6 +384,15 @@ void initGC()
StackAllocator::defaultAllocator = &boehmGCStackAllocator; StackAllocator::defaultAllocator = &boehmGCStackAllocator;
#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<void> {
return std::make_shared<BoehmDisableGC>();
};
#endif
/* Set the initial heap size to something fairly big (25% of /* 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 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 we don't need to garbage collect at all. (Collection has a

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@ -186,6 +186,22 @@ static DefaultStackAllocator defaultAllocatorSingleton;
StackAllocator *StackAllocator::defaultAllocator = &defaultAllocatorSingleton; StackAllocator *StackAllocator::defaultAllocator = &defaultAllocatorSingleton;
std::shared_ptr<void> (*create_coro_gc_hook)() = []() -> std::shared_ptr<void> {
return {};
};
/* This class is used for entry and exit hooks on coroutines */
class CoroutineContext {
/* 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<void> performs type-erasure, so it will call the right
* deleter. */
const std::shared_ptr<void> coro_gc_hook = create_coro_gc_hook();
public:
CoroutineContext() {};
~CoroutineContext() {};
};
std::unique_ptr<FinishSink> sourceToSink(std::function<void(Source &)> fun) std::unique_ptr<FinishSink> sourceToSink(std::function<void(Source &)> fun)
{ {
struct SourceToSink : FinishSink struct SourceToSink : FinishSink
@ -206,7 +222,8 @@ std::unique_ptr<FinishSink> sourceToSink(std::function<void(Source &)> fun)
if (in.empty()) return; if (in.empty()) return;
cur = in; cur = in;
if (!coro) if (!coro) {
CoroutineContext ctx;
coro = coro_t::push_type(VirtualStackAllocator{}, [&](coro_t::pull_type & yield) { coro = coro_t::push_type(VirtualStackAllocator{}, [&](coro_t::pull_type & yield) {
LambdaSource source([&](char *out, size_t out_len) { LambdaSource source([&](char *out, size_t out_len) {
if (cur.empty()) { if (cur.empty()) {
@ -223,17 +240,24 @@ std::unique_ptr<FinishSink> sourceToSink(std::function<void(Source &)> fun)
}); });
fun(source); fun(source);
}); });
}
if (!*coro) { abort(); } if (!*coro) { abort(); }
if (!cur.empty()) (*coro)(false); if (!cur.empty()) {
CoroutineContext ctx;
(*coro)(false);
}
} }
void finish() override void finish() override
{ {
if (!coro) return; if (!coro) return;
if (!*coro) abort(); if (!*coro) abort();
(*coro)(true); {
CoroutineContext ctx;
(*coro)(true);
}
if (*coro) abort(); if (*coro) abort();
} }
}; };
@ -264,18 +288,23 @@ std::unique_ptr<Source> sinkToSource(
size_t read(char * data, size_t len) override size_t read(char * data, size_t len) override
{ {
if (!coro) if (!coro) {
CoroutineContext ctx;
coro = coro_t::pull_type(VirtualStackAllocator{}, [&](coro_t::push_type & yield) { coro = coro_t::pull_type(VirtualStackAllocator{}, [&](coro_t::push_type & yield) {
LambdaSink sink([&](std::string_view data) { LambdaSink sink([&](std::string_view data) {
if (!data.empty()) yield(std::string(data)); if (!data.empty()) yield(std::string(data));
}); });
fun(sink); fun(sink);
}); });
}
if (!*coro) { eof(); abort(); } if (!*coro) { eof(); abort(); }
if (pos == cur.size()) { if (pos == cur.size()) {
if (!cur.empty()) (*coro)(); if (!cur.empty()) {
CoroutineContext ctx;
(*coro)();
}
cur = coro->get(); cur = coro->get();
pos = 0; pos = 0;
} }

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@ -551,4 +551,10 @@ struct StackAllocator {
static StackAllocator *defaultAllocator; static StackAllocator *defaultAllocator;
}; };
/* Disabling GC when entering a coroutine (without the boehm patch).
mutable to avoid boehm gc dependency in libutil.
*/
extern std::shared_ptr<void> (*create_coro_gc_hook)();
} }