Support for Perf Maps ¶

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.

int PyUnstable_PerfMapState_Init ( void ) ¶

这为 Unstable API . It may change without warning in minor releases.

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.

int PyUnstable_WritePerfMapEntry ( const void * code_addr , unsigned int code_size , const char * entry_name ) ¶

这为 Unstable API . It may change without warning in minor releases.

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