[XRay][compiler-rt] Migrate basic mode logging to the XRay framework

Summary:
Before this patch, XRay's basic (naive mode) logging would be
initialised and installed in an adhoc manner. This patch ports the
implementation of the basic (naive mode) logging implementation to use
the common XRay framework.

We also make the following changes to reduce the variance between the
usage model of basic mode from FDR (flight data recorder) mode:

  - Allow programmatic control of the size of the buffers dedicated to
    per-thread records. This removes some hard-coded constants and turns
    them into runtime-controllable flags and through an Options
    structure.

  - Default the `xray_naive_log` option to false. For now, the only way
    to start basic mode is to set the environment variable, or set the
    default at build-time compiler options. Because of this change we've
    had to update a couple of tests relying on basic mode being always
    on.

  - Removed the reliance on a non-trivially destructible per-thread
    resource manager. We use a similar trick done in D39526 to use
    pthread_key_create() and pthread_setspecific() to ensure that the
    per-thread cleanup handling is performed at thread-exit time.

We also radically simplify the code structure for basic mode, to move
most of the implementation in the `__xray` namespace.

Reviewers: pelikan, eizan, kpw

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D40164

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@318734 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 2 deletions

diff --git a/lib/xray/xray_flags.inc b/lib/xray/xray_flags.inc
index 890f6fda2..470db45d7 100644
--- a/lib/xray/xray_flags.inc
+++ b/lib/xray/xray_flags.inc
@@ -16,10 +16,22 @@
 
 XRAY_FLAG(bool, patch_premain, false,
           "Whether to patch instrumentation points before main.")
-XRAY_FLAG(bool, xray_naive_log, true,
-          "Whether to install the naive log implementation.")
 XRAY_FLAG(const char *, xray_logfile_base, "xray-log.",
           "Filename base for the xray logfile.")
+
+// Basic (Naive) Mode logging options.
+XRAY_FLAG(bool, xray_naive_log, false,
+          "Whether to install the naive log implementation.")
+XRAY_FLAG(int, xray_naive_log_func_duration_threshold_us, 5,
+          "Naive logging will try to skip functions that execute for fewer "
+          "microseconds than this threshold.")
+XRAY_FLAG(int, xray_naive_log_max_stack_depth, 64,
+          "Naive logging will keep track of at most this deep a call stack, "
+          "any more and the recordings will be droppped.")
+XRAY_FLAG(int, xray_naive_log_thread_buffer_size, 1024,
+          "The number of entries to keep on a per-thread buffer.")
+
+// FDR (Flight Data Recorder) Mode logging options.
 XRAY_FLAG(bool, xray_fdr_log, false,
           "Whether to install the flight data recorder logging implementation.")
 XRAY_FLAG(int, xray_fdr_log_func_duration_threshold_us, 5,