diff options
Diffstat (limited to 'src/runtime/proc.go')
| -rw-r--r-- | src/runtime/proc.go | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/runtime/proc.go b/src/runtime/proc.go index 727c991a57..a0fddd0052 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -3000,6 +3000,8 @@ func _ExternalCode() { _ExternalCode() } func _GC() { _GC() } // Called if we receive a SIGPROF signal. +// Called by the signal handler, may run during STW. +//go:nowritebarrierrec func sigprof(pc, sp, lr uintptr, gp *g, mp *m) { if prof.hz == 0 { return @@ -3159,6 +3161,36 @@ func sigprof(pc, sp, lr uintptr, gp *g, mp *m) { mp.mallocing-- } +// If the signal handler receives a SIGPROF signal on a non-Go thread, +// it tries to collect a traceback into sigprofCallers. +// sigprofCallersUse is set to non-zero while sigprofCallers holds a traceback. +var sigprofCallers cgoCallers +var sigprofCallersUse uint32 + +// Called if we receive a SIGPROF signal on a non-Go thread. +// When this is called, sigprofCallersUse will be non-zero. +// g is nil, and what we can do is very limited. +//go:nosplit +//go:nowritebarrierrec +func sigprofNonGo() { + if prof.hz != 0 { + n := 0 + for n < len(sigprofCallers) && sigprofCallers[n] != 0 { + n++ + } + + // Simple cas-lock to coordinate with setcpuprofilerate. + if atomic.Cas(&prof.lock, 0, 1) { + if prof.hz != 0 { + cpuprof.addNonGo(sigprofCallers[:n]) + } + atomic.Store(&prof.lock, 0) + } + } + + atomic.Store(&sigprofCallersUse, 0) +} + // Reports whether a function will set the SP // to an absolute value. Important that // we don't traceback when these are at the bottom |