diff options
| author | Austin Clements <austin@google.com> | 2017-06-15 10:51:15 -0400 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2017-10-11 17:47:08 +0000 |
| commit | 2595fe7fb6f272f9204ca3ef0b0c55e66fb8d90f (patch) | |
| tree | 53c883492b86bf9313a11b78b038f431f7fe7ee6 /src/runtime/runtime2.go | |
| parent | 9a9780a20d6987d462d97fa191de3c4a66980022 (diff) | |
| download | go-2595fe7fb6f272f9204ca3ef0b0c55e66fb8d90f.tar.xz | |
runtime: don't start new threads from locked threads
Applications that need to manipulate kernel thread state are currently
on thin ice in Go: they can use LockOSThread to prevent other
goroutines from running on the manipulated thread, but Go may clone
this manipulated state into a new thread that's put into the runtime's
thread pool along with other threads.
Fix this by never starting a new thread from a locked thread or a
thread that may have been started by C. Instead, the runtime starts a
"template thread" with a known-good state. If it then needs to start a
new thread but doesn't know that the current thread is in a good
state, it forwards the thread creation to the template thread.
Fixes #20676.
Change-Id: I798137a56e04b7723d55997e9c5c085d1d910643
Reviewed-on: https://go-review.googlesource.com/46033
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/runtime/runtime2.go')
| -rw-r--r-- | src/runtime/runtime2.go | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go index f56876fc63..325152aea4 100644 --- a/src/runtime/runtime2.go +++ b/src/runtime/runtime2.go @@ -533,6 +533,7 @@ type schedt struct { nmidlelocked int32 // number of locked m's waiting for work mcount int32 // number of m's that have been created maxmcount int32 // maximum number of m's allowed (or die) + nmsys int32 // number of system m's not counted for deadlock ngsys uint32 // number of system goroutines; updated atomically |