This tool traces MySQL/PostgreSQL queries, including an optional
minimum duration threshold. This is based on `mysqld_qslower` but
adapted to automatically detect MySQL/PostgreSQL processes, and a
couple of other code fixes.

I believe at this time, `mysqld_qslower` can be retired, as this
tool completely supersedes it.

Revert "undo rebase"

This reverts commit a112514c.

The changes the commit reverted are legit and should not have been
reverted.

Move monotonic_time to BPF class, use CLOCK_MONOTONIC

Add pkg-config file to Debian packages.

filetop: Fix TypeError by not mixing bytes and str.

When executing the filetop command tool, the following message was
generated:

Traceback (most recent call last):
  File "/usr/share/bcc/tools/filetop", line 190, in <module>
    name = name[:-3] + "..."
TypeError: can't concat bytes to str

Also, by decoding the bytes we print the strings without a leading "b'"
making the output more readable.

Add optional kernel flags for running networking examples in INSTALL.md

tools/trace accepts abspath arguments to -I (and some doc tweaks)

Fix ucalls

fixes #962 - fix lambda on both py2 and py3

gethostlatency: Filter by process ID

u* tools: Gracefully handle missing probes

When the target process is missing the required USDT probes, it can
be a simple mistake (e.g. attaching a script as Java to a Python
process), or a runtime that is not instrumented with the required
probes. Attempt to gracefully handle the error and print a helpful
message instructing the user why the error might have occurred.

```
$ uthreads -l java $(pidof python)
Error attaching USDT probes: the specified pid might not contain
the given language's runtime, or the runtime was not built with the
required USDT probes. Look for a configure flag similar to
--with-dtrace or --enable-dtrace. To check which probes are present
in the process, use the tplist tool.
```

u* tools: PHP support

ugc: Add -M for minimum time and -F for text filtering

See: https://www.python.org/dev/peps/pep-3113/

$ ucalls
  File "./ucalls", line 239
    data = map(lambda (k, v): (k.clazz + "." + k.method,
                      ^
SyntaxError: invalid syntax

See: https://www.python.org/dev/peps/pep-3113/

On python3 map returns a generator instead of a list. This fixes the
following error:

Traceback (most recent call last):
  File "./ucalls", line 280, in <module>
    data = get_data()   # [(function, (num calls, latency in ns))]
  File "./ucalls", line 255, in get_data
    data.extend(syscalls)
AttributeError: 'map' object has no attribute 'extend'

Fix uobjnew and ustat on python3

Debian jessie .deb build config and automated test fixes.

$ ./ustat
  File "./ustat", line 242
    counts = sorted(counts.items(), key=lambda (_, v):
                                               ^
SyntaxError: invalid syntax

$ ./uobjnew
  File "./uobjnew", line 150
    data = sorted(data.items(), key=lambda (k, v): v.num_allocs)
                                           ^
SyntaxError: invalid syntax

This fixes a TypeError in python 3, e.g, when executing uobjnew

Traceback (most recent call last):
  File "./uobjnew", line 134, in <module>
    bpf = BPF(text=program, usdt_contexts=[usdt])
  File "/usr/lib/python3.5/site-packages/bcc/__init__.py", line 224, in __init__
    text = usdt_text + text
TypeError: can't concat bytes to str

Use fast compression in test deb builds

Builds on GCE/ubuntu image were taking a long time due to combination of
disk speed/single core, and the default dpkg-deb compression level
(-z9). The dpkg-deb alone step was taking up to 5 minutes. Reduce to ~1
minute by forcing -z1. Unfortunately, it was not obvious how to capture
the option in debuild command, so this is a bit hacky.
Signed-off-by: Brenden Blanco <bblanco@gmail.com>

Fixes for LLVM4+, python3

Signed-off-by: Brenden Blanco <bblanco@gmail.com>

Signed-off-by: Brenden Blanco <bblanco@gmail.com>

In python3, output needs to be converted from ascii to str before the
"error_msg in str" test will succeed. This change should be backwards
compatible with python2.
Signed-off-by: Brenden Blanco <bblanco@gmail.com>

Diff generated by clang-format
Signed-off-by: Brenden Blanco <bblanco@gmail.com>

Recent llvm changed the calling convention of setInvocation, breaking
3.9/4.0 compatibility. This new approach works for both.
Signed-off-by: Brenden Blanco <bblanco@gmail.com>

Without marking as nounwind, recent llvm started generating .eh_frame
section, which is invalid for bpf target jit.
Signed-off-by: Brenden Blanco <bblanco@gmail.com>

Signed-off-by: Brenden Blanco <bblanco@gmail.com>