[fuchsia] Expose runtime threads
Exposes all runtime threads through the channel signaling mechanism and
not only worker threads.
Bug: 122472
Change-Id: I2718617b3782ff0bda25912fcfe21587b2a14cb2
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/go/+/808487
Reviewed-by: Tamir Duberstein <tamird@google.com>
Fuchsia-Auto-Submit: Bruno Dal Bo <brunodalbo@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>
(cherry picked from commit 1e1d3be4725fcd1ea756acccdb7dff1206e312f3)
diff --git a/src/runtime/os_fuchsia.go b/src/runtime/os_fuchsia.go
index 853d1ff..232ee1c 100644
--- a/src/runtime/os_fuchsia.go
+++ b/src/runtime/os_fuchsia.go
@@ -73,7 +73,7 @@
func zx_set_namespace(m map[string]uint32)
//go:linkname zx_notify_new_thread syscall/zx.notify_new_thread
-func zx_notify_new_thread(h uint32)
+func zx_notify_new_thread(h uint32, w byte)
//go:linkname zx_init_threads_channel syscall/zx.init_threads_channel
func zx_init_threads_channel()
@@ -279,6 +279,18 @@
_cgo_write1 unsafe.Pointer
)
+type ThreadType byte
+
+const (
+ _ ThreadType = iota
+ WorkerThread
+ UnknownRuntimeThread
+ SysmonThread
+ WatchExceptionsThread
+ ProfileLoopThread
+ TemplateThread
+)
+
//go:nosplit
func minit() {
_g_ := getg()
@@ -291,8 +303,11 @@
mp.thread = h
+ // NB: Write barrier restrictions in this function disallow a nicer pattern
+ // to assign these variables.
isWorker := mp.p != 0 || mp.nextp != 0
threadName := []byte("go-worker")
+ threadType := WorkerThread
if !isWorker {
// There are some known functions that we can compare against,
// unfortunately we can't use FuncForPC here because of the write
@@ -300,14 +315,19 @@
switch abi.FuncPCABIInternal(mp.mstartfn) {
case abi.FuncPCABIInternal(sysmon):
threadName = []byte("sysmon")
+ threadType = SysmonThread
case abi.FuncPCABIInternal(watchexceptions):
threadName = []byte("watchexceptions")
+ threadType = WatchExceptionsThread
case abi.FuncPCABIInternal(profileLoop):
threadName = []byte("profileLoop")
+ threadType = ProfileLoopThread
case abi.FuncPCABIInternal(templateThread):
threadName = []byte("templateThread")
+ threadType = TemplateThread
default:
threadName = []byte("unknown-runtime-thread")
+ threadType = UnknownRuntimeThread
}
}
@@ -325,10 +345,7 @@
mp.threadKoid = info.koid
}
- if isWorker {
- // Don't notifiy users of runtime threads.
- zx_notify_new_thread(h)
- }
+ zx_notify_new_thread(h, byte(threadType))
unlock(&mp.threadLock)
}
diff --git a/src/syscall/zx/threads_fuchsia.go b/src/syscall/zx/threads_fuchsia.go
index d300090..1bc6f03 100644
--- a/src/syscall/zx/threads_fuchsia.go
+++ b/src/syscall/zx/threads_fuchsia.go
@@ -4,6 +4,8 @@
package zx
+import "unsafe"
+
var threadQueue struct {
writer, reader Channel
}
@@ -25,8 +27,11 @@
// this because minit is a very restricted environment where we can't allocate
// or do much else.
//
+// h is the thread handle. w is a constant exported from the runtime package
+// saying which thread type this is.
+//
//go:nosplit
-func notify_new_thread(h int32) {
+func notify_new_thread(h uint32, w byte) {
var dup Handle
// Duplicate the handle with the minimum set of rights to accomplish
// exposing the threads to applications and installing thread profiles.
@@ -34,14 +39,17 @@
// NB: Can't allocate here to provide status in panic.
panic("failed to duplicate thread handle")
}
- if status := Sys_channel_write(threadQueue.writer.Handle().Load(), 0, nil, 0, &dup, 1); status != ErrOk {
+
+ if status := Sys_channel_write(threadQueue.writer.Handle().Load(), 0, unsafe.Pointer(&w), 1, &dup, 1); status != ErrOk {
// NB: Can't allocate here to provide status in panic.
panic("failed to write thread to channel")
}
}
// GetThreadsChannel returns a reference to a channel that will be enqueued with
-// a zero-byte single-handle message for every thread that the runtime creates.
+// a single-byte single-handle message for every thread that the runtime
+// creates. The single byte encodes the thread type. See runtime.ThreadType.
+//
// Applications may read from this channel to retrieve handles to the runtime
// threads.
//
