Files
wazero/internal/engine/wazevo/wazevoapi/perfmap.go
2023-12-19 08:26:47 -08:00

97 lines
2.2 KiB
Go

package wazevoapi
import (
"fmt"
"os"
"strconv"
"sync"
)
var PerfMap *Perfmap
func init() {
if PerfMapEnabled {
pid := os.Getpid()
filename := "/tmp/perf-" + strconv.Itoa(pid) + ".map"
fh, err := os.OpenFile(filename, os.O_APPEND|os.O_RDWR|os.O_CREATE, 0o644)
if err != nil {
panic(err)
}
PerfMap = &Perfmap{fh: fh}
}
}
// Perfmap holds perfmap entries to be flushed into a perfmap file.
type Perfmap struct {
entries []entry
mux sync.Mutex
fh *os.File
}
type entry struct {
index int
offset int64
size uint64
name string
}
func (f *Perfmap) Lock() {
f.mux.Lock()
}
func (f *Perfmap) Unlock() {
f.mux.Unlock()
}
// AddModuleEntry adds a perfmap entry into the perfmap file.
// index is the index of the function in the module, offset is the offset of the function in the module,
// size is the size of the function, and name is the name of the function.
//
// Note that the entries are not flushed into the perfmap file until Flush is called,
// and the entries are module-scoped; Perfmap must be locked until Flush is called.
func (f *Perfmap) AddModuleEntry(index int, offset int64, size uint64, name string) {
e := entry{index: index, offset: offset, size: size, name: name}
if f.entries == nil {
f.entries = []entry{e}
return
}
f.entries = append(f.entries, e)
}
// Flush writes the perfmap entries into the perfmap file where the entries are adjusted by the given `addr` and `functionOffsets`.
func (f *Perfmap) Flush(addr uintptr, functionOffsets []int) {
defer func() {
_ = f.fh.Sync()
}()
for _, e := range f.entries {
if _, err := f.fh.WriteString(fmt.Sprintf("%x %s %s\n",
uintptr(e.offset)+addr+uintptr(functionOffsets[e.index]),
strconv.FormatUint(e.size, 16),
e.name,
)); err != nil {
panic(err)
}
}
f.entries = f.entries[:0]
}
// Clear clears the perfmap entries not yet flushed.
func (f *Perfmap) Clear() {
f.entries = f.entries[:0]
}
// AddEntry writes a perfmap entry directly into the perfmap file, not using the entries.
func (f *Perfmap) AddEntry(addr uintptr, size uint64, name string) {
_, err := f.fh.WriteString(fmt.Sprintf("%x %s %s\n",
addr,
strconv.FormatUint(size, 16),
name,
))
if err != nil {
panic(err)
}
}