Emitting a signpost for the first time can trigger lazy setup of the logging system, and doing this in the wrong context can cause deadlocks. Check to see if the logging system is already set up, and only emit signposts if it has been to avoid triggering this.
As it's hard to determine if the "is it set up?" function is available in the SDK we're building against, only do this in OS builds, as it's not particularly useful in local builds.
rdar://124620772
We can't use os_log functionality in logd, diagnosticd, or notifyd. Check for them and disable tracing in those processes.
Add a new TracingCommon.h for common code shared between swiftCore and swift_Concurrency tracing. Add a single function that checks if tracing should be enabled, which now checks if os_signpost_enabled is available, and if the process is one of these. Modify the tracing code to check this before creating os_log objects.
rdar://124226334
Moved all the threading code to one place. Added explicit support for
Darwin, Linux, Pthreads, C11 threads and Win32 threads, including new
implementations of Once for Linux, Pthreads, C11 and Win32.
rdar://90776105
Moved all the threading code to one place. Added explicit support for
Darwin, Linux, Pthreads, C11 threads and Win32 threads, including new
implementations of Once for Linux, Pthreads, C11 and Win32.
rdar://90776105
Concurrency tracing was enabled depending on the presence of a header
file, but if a similarly named header was found somewhere in the path
that didn't do the same thing, that might cause problems.
Instead, we should have a build time configuration option.
rdar://89787540
Each trace point is declared as a function in the new `Tracing.h` header. These functions are called from the appropriate places in the concurrency runtime.
On Darwin, an implementation of these functions is provided which uses the `os/signpost.h` API to emit signpost events/intervals.
When the signpost API is not available, no-op stub implementations are provided. Implementations for other OSes can be provided by providing implementations of the trace functions for that OS.
rdar://81858487
