Adding upstream version 1.20.14.upstream/1.20.14upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/src/runtime/debug.go b/src/runtime/debug.go
new file mode 100644
index 0000000..669c36f
--- /dev/null
+++ b/src/runtime/debug.go
@@ -0,0 +1,115 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package runtime
+
+import (
+	"runtime/internal/atomic"
+	"unsafe"
+)
+
+// GOMAXPROCS sets the maximum number of CPUs that can be executing
+// simultaneously and returns the previous setting. It defaults to
+// the value of runtime.NumCPU. If n < 1, it does not change the current setting.
+// This call will go away when the scheduler improves.
+func GOMAXPROCS(n int) int {
+	if GOARCH == "wasm" && n > 1 {
+		n = 1 // WebAssembly has no threads yet, so only one CPU is possible.
+	}
+
+	lock(&sched.lock)
+	ret := int(gomaxprocs)
+	unlock(&sched.lock)
+	if n <= 0 || n == ret {
+		return ret
+	}
+
+	stopTheWorldGC("GOMAXPROCS")
+
+	// newprocs will be processed by startTheWorld
+	newprocs = int32(n)
+
+	startTheWorldGC()
+	return ret
+}
+
+// NumCPU returns the number of logical CPUs usable by the current process.
+//
+// The set of available CPUs is checked by querying the operating system
+// at process startup. Changes to operating system CPU allocation after
+// process startup are not reflected.
+func NumCPU() int {
+	return int(ncpu)
+}
+
+// NumCgoCall returns the number of cgo calls made by the current process.
+func NumCgoCall() int64 {
+	var n = int64(atomic.Load64(&ncgocall))
+	for mp := (*m)(atomic.Loadp(unsafe.Pointer(&allm))); mp != nil; mp = mp.alllink {
+		n += int64(mp.ncgocall)
+	}
+	return n
+}
+
+// NumGoroutine returns the number of goroutines that currently exist.
+func NumGoroutine() int {
+	return int(gcount())
+}
+
+//go:linkname debug_modinfo runtime/debug.modinfo
+func debug_modinfo() string {
+	return modinfo
+}
+
+// mayMoreStackPreempt is a maymorestack hook that forces a preemption
+// at every possible cooperative preemption point.
+//
+// This is valuable to apply to the runtime, which can be sensitive to
+// preemption points. To apply this to all preemption points in the
+// runtime and runtime-like code, use the following in bash or zsh:
+//
+//	X=(-{gc,asm}flags={runtime/...,reflect,sync}=-d=maymorestack=runtime.mayMoreStackPreempt) GOFLAGS=${X[@]}
+//
+// This must be deeply nosplit because it is called from a function
+// prologue before the stack is set up and because the compiler will
+// call it from any splittable prologue (leading to infinite
+// recursion).
+//
+// Ideally it should also use very little stack because the linker
+// doesn't currently account for this in nosplit stack depth checking.
+//
+// Ensure mayMoreStackPreempt can be called for all ABIs.
+//
+//go:nosplit
+//go:linkname mayMoreStackPreempt
+func mayMoreStackPreempt() {
+	// Don't do anything on the g0 or gsignal stack.
+	gp := getg()
+	if gp == gp.m.g0 || gp == gp.m.gsignal {
+		return
+	}
+	// Force a preemption, unless the stack is already poisoned.
+	if gp.stackguard0 < stackPoisonMin {
+		gp.stackguard0 = stackPreempt
+	}
+}
+
+// mayMoreStackMove is a maymorestack hook that forces stack movement
+// at every possible point.
+//
+// See mayMoreStackPreempt.
+//
+//go:nosplit
+//go:linkname mayMoreStackMove
+func mayMoreStackMove() {
+	// Don't do anything on the g0 or gsignal stack.
+	gp := getg()
+	if gp == gp.m.g0 || gp == gp.m.gsignal {
+		return
+	}
+	// Force stack movement, unless the stack is already poisoned.
+	if gp.stackguard0 < stackPoisonMin {
+		gp.stackguard0 = stackForceMove
+	}
+}