Add sync_perf_output BCC example

Author: r41k0u

BCC-Examples/sync_perf_output.py

@@ -0,0 +1,78 @@
+from pythonbpf import bpf, map, struct, section, bpfglobal, BPF
+from pythonbpf.helper import ktime
+from pythonbpf.maps import HashMap
+from pythonbpf.maps import PerfEventArray
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@struct
+class data_t:
+    ts: c_int64
+    ms: c_int64
+
+
+@bpf
+@map
+def events() -> PerfEventArray:
+    return PerfEventArray(key_size=c_int64, value_size=c_int64)
+
+
+@bpf
+@map
+def last() -> HashMap:
+    return HashMap(key=c_int64, value=c_int64, max_entries=1)
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_sync")
+def do_trace(ctx: c_void_p) -> c_int64:
+    dat, dat.ts, key = data_t(), ktime(), 0
+    tsp = last.lookup(key)
+    if tsp:
+        delta = ktime() - tsp
+        if delta < 1000000000:
+            dat.ms = delta // 1000000
+            events.output(dat)
+        last.delete(key)
+    else:
+        last.update(key, ktime())
+    return 0  # type: ignore [return-value]
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+# Compile and load
+b = BPF()
+b.load()
+b.attach_all()
+
+print("Tracing for quick sync's... Ctrl-C to end")
+
+# format output
+start = 0
+
+
+def callback(cpu, event):
+    global start
+    if start == 0:
+        start = event.ts
+    event.ts -= start
+    print(
+        f"At time {event.ts / 1e9} s: Multiple sync detected, Last sync: {event.ms} ms ago"
+    )
+
+
+perf = b["events"].open_perf_buffer(callback, struct_name="data_t")
+print("Starting to poll... (Ctrl+C to stop)")
+print("Try running: fork() or clone() system calls to trigger events")
+
+try:
+    while True:
+        b["events"].poll(1000)
+except KeyboardInterrupt:
+    print("Stopping...")