On supported platforms (as of this writing, only Linux), the runtime can take advantage of
perf map files
to make Python functions visible to an external profiling tool (such as
perf
). A running process may create a file in the
/tmp
directory, which contains entries that can map a section of executable code to a name. This interface is described in the
documentation of the Linux Perf tool
.
In Python, these helper APIs can be used by libraries and features that rely on generating machine code on the fly.
Note that holding the Global Interpreter Lock (GIL) is not required for these APIs.
打开
/tmp/perf-$pid.map
file, unless it’s already opened, and create a lock to ensure thread-safe writes to the file (provided the writes are done through
PyUnstable_WritePerfMapEntry()
). Normally, there’s no need to call this explicitly; just use
PyUnstable_WritePerfMapEntry()
and it will initialize the state on first call.
返回
0
当成功时，
-1
on failure to create/open the perf map file, or
-2
on failure to create a lock. Check
errno
for more information about the cause of a failure.
Write one single entry to the
/tmp/perf-$pid.map
file. This function is thread safe. Here is what an example entry looks like:
# address size name 7f3529fcf759 b py::bar:/run/t.py
Will call
PyUnstable_PerfMapState_Init()
before writing the entry, if the perf map file is not already opened. Returns
0
on success, or the same error codes as
PyUnstable_PerfMapState_Init()
当故障时。
Close the perf map file opened by
PyUnstable_PerfMapState_Init()
. This is called by the runtime itself during interpreter shut-down. In general, there shouldn’t be a reason to explicitly call this, except to handle specific scenarios such as forking.
