Muse
92dfdc542c
LazyProc.Call must-finds and panics on a missing export; the trimmed Tianyi cloud-PC image has no FreeMibIfTable2 in iphlpapi.dll, which killed the agent on its first collection after a successful register. Optional procs (GetSystemTimes/GlobalMemoryStatusEx/GetIfTable2Ex+ FreeMibIfTable2 as one gated pair) now resolve through sourceGate (Find once, missing = source disabled with one warning); the iface pair is gated together so a missing free proc never leaks the system table. collectMetrics additionally runs every source through guardedCall so any residual panic zeroes that source alone. Pure gate/guard logic lives in probe_guard.go (no build tag) with Linux-runnable regression tests.
64 lines
1.6 KiB
Go
64 lines
1.6 KiB
Go
package agent
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import (
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"errors"
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"testing"
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)
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// The degrade-don't-die mechanics behind V2.2.1 ①: on the trimmed
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// Tianyi cloud-PC image the Windows sampler died on its first
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// collection because a missing iphlpapi export made LazyProc.Call
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// panic. These tests pin the two layers that replace that failure
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// mode — a failed availability probe disables the source (probed
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// once, not per poll), and a panicking source is zeroed, never
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// propagated.
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func TestSourceGateDisablesFailedProbeOnce(t *testing.T) {
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var g sourceGate
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calls := 0
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probe := func() error {
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calls++
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return errors.New("procedure not found")
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}
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for i := range 3 {
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if g.enabled("test-source", probe) {
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t.Fatalf("call %d: gate enabled despite failed probe", i)
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}
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}
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if calls != 1 {
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t.Fatalf("probe ran %d times, want exactly 1 (cached verdict)", calls)
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}
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}
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func TestSourceGateEnablesSuccessfulProbeOnce(t *testing.T) {
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var g sourceGate
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calls := 0
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probe := func() error {
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calls++
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return nil
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}
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for i := range 3 {
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if !g.enabled("test-source", probe) {
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t.Fatalf("call %d: gate disabled despite successful probe", i)
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}
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}
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if calls != 1 {
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t.Fatalf("probe ran %d times, want exactly 1 (cached verdict)", calls)
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}
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}
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func TestGuardedCallRecoversPanicToZero(t *testing.T) {
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got := guardedCall("test-source", func() uint64 {
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panic("Failed to find FreeMibIfTable2 procedure in iphlpapi.dll")
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})
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if got != 0 {
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t.Fatalf("guardedCall after panic = %d, want zero value", got)
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}
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}
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func TestGuardedCallPassesValueThrough(t *testing.T) {
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if got := guardedCall("test-source", func() string { return "ok" }); got != "ok" {
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t.Fatalf("guardedCall = %q, want %q", got, "ok")
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}
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}
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