git/trace.c, branch v2.2.0

Merge branch 'bw/trace-no-inline-getnanotime'

2014-10-16T21:16:45Z

No file-scope static variables in an inlined function, please. * bw/trace-no-inline-getnanotime: trace.c: do not mark getnanotime() as "inline"

trace.c: do not mark getnanotime() as "inline"

2014-09-29T23:13:58Z

Oracle Studio compilers don't allow for static variables in functions that are defined to be inline. GNU C does permit this. Let's reference the C99 standard though, which doesn't allow for inline functions to contain modifiable static variables. Signed-off-by: Ben Walton Signed-off-by: Junio C Hamano

Merge branch 'kb/perf-trace'

2014-09-19T18:38:39Z

Compilation fix for some compilers. * kb/perf-trace: trace: correct trace_strbuf() parameter type for !HAVE_VARIADIC_MACROS

trace: correct trace_strbuf() parameter type for !HAVE_VARIADIC_MACROS

2014-09-08T18:08:04Z

Reported-by: dev Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

Merge branch 'rs/strbuf-getcwd'

2014-09-02T20:28:44Z

Reduce the use of fixed sized buffer passed to getcwd() calls by introducing xgetcwd() helper. * rs/strbuf-getcwd: use strbuf_add_absolute_path() to add absolute paths abspath: convert absolute_path() to strbuf use xgetcwd() to set $GIT_DIR use xgetcwd() to get the current directory or die wrapper: add xgetcwd() abspath: convert real_path_internal() to strbuf abspath: use strbuf_getcwd() to remember original working directory setup: convert setup_git_directory_gently_1 et al. to strbuf unix-sockets: use strbuf_getcwd() strbuf: add strbuf_getcwd()

use xgetcwd() to get the current directory or die

2014-08-26T18:06:06Z

Convert several calls of getcwd() and die() to use xgetcwd() instead. This way we get rid of fixed-size buffers (which can be too small depending on the used file system) and gain consistent error messages. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

git: add performance tracing for git's main() function to debug scripts

2014-07-14T04:25:21Z

Use trace_performance to measure and print execution time and command line arguments of the entire main() function. In constrast to the shell's 'time' utility, which measures total time of the parent process, this logs all involved git commands recursively. This is particularly useful to debug performance issues of scripted commands (i.e. which git commands were called with which parameters, and how long did they execute). Due to git's deliberate use of exit(), the implementation uses an atexit routine rather than just adding trace_performance_since() at the end of main(). Usage example: > GIT_TRACE_PERFORMANCE=~/git-trace.log git stash list Creates a log file like this: 23:57:38.638765 trace.c:405 performance: 0.000310107 s: git command: 'git' 'rev-parse' '--git-dir' 23:57:38.644387 trace.c:405 performance: 0.000261759 s: git command: 'git' 'rev-parse' '--show-toplevel' 23:57:38.646207 trace.c:405 performance: 0.000304468 s: git command: 'git' 'config' '--get-colorbool' 'color.interactive' 23:57:38.648491 trace.c:405 performance: 0.000241667 s: git command: 'git' 'config' '--get-color' 'color.interactive.help' 'red bold' 23:57:38.650465 trace.c:405 performance: 0.000243063 s: git command: 'git' 'config' '--get-color' '' 'reset' 23:57:38.654850 trace.c:405 performance: 0.025126313 s: git command: 'git' 'stash' 'list' Signed-off-by: Karsten Blees Signed-off-by: Junio C Hamano

trace: add trace_performance facility to debug performance issues

2014-07-14T04:25:20Z

Add trace_performance and trace_performance_since macros that print a duration and an optional printf-formatted text to the file specified in environment variable GIT_TRACE_PERFORMANCE. These macros, in conjunction with getnanotime(), are intended to simplify performance measurements from within the application (i.e. profiling via manual instrumentation, rather than using an external profiling tool). Unless enabled via GIT_TRACE_PERFORMANCE, these macros have no noticeable impact on performance, so that test code for well known time killers may be shipped in release builds. Alternatively, a developer could provide an additional performance patch (not meant for master) that allows reviewers to reproduce performance tests more easily, e.g. on other platforms or using their own repositories. Usage examples: Simple use case (measure one code section): uint64_t start = getnanotime(); /* code section to measure */ trace_performance_since(start, "foobar"); Complex use case (measure repetitive code sections): uint64_t t = 0; for (;;) { /* ignore */ t -= getnanotime(); /* code section to measure */ t += getnanotime(); /* ignore */ } trace_performance(t, "frotz"); Signed-off-by: Karsten Blees Signed-off-by: Junio C Hamano

trace: add high resolution timer function to debug performance issues

2014-07-14T04:25:20Z

Add a getnanotime() function that returns nanoseconds since 01/01/1970 as unsigned 64-bit integer (i.e. overflows in july 2554). This is easier to work with than e.g. struct timeval or struct timespec. Basing the timer on the epoch allows using the results with other time-related APIs. To simplify adaption to different platforms, split the implementation into a common getnanotime() and a platform-specific highres_nanos() function. The common getnanotime() function handles errors, falling back to gettimeofday() if highres_nanos() isn't implemented or doesn't work. getnanotime() is also responsible for normalizing to the epoch. The offset to the system clock is calculated only once on initialization, i.e. manually setting the system clock has no impact on the timer (except if the fallback gettimeofday() is in use). Git processes are typically short lived, so we don't need to handle clock drift. The highres_nanos() function returns monotonically increasing nanoseconds relative to some arbitrary point in time (e.g. system boot), or 0 on failure. Providing platform-specific implementations should be relatively easy, e.g. adapting to clock_gettime() as defined by the POSIX realtime extensions is seven lines of code. This version includes highres_nanos() implementations for: * Linux: using clock_gettime(CLOCK_MONOTONIC) * Windows: using QueryPerformanceCounter() Todo: * enable clock_gettime() on more platforms * add Mac OSX version, e.g. using mach_absolute_time + mach_timebase_info Signed-off-by: Karsten Blees Signed-off-by: Junio C Hamano

trace: add 'file:line' to all trace output

2014-07-14T04:25:20Z

This is useful to see where trace output came from. Add 'const char *file, int line' parameters to the printing functions and rename them to *_fl. Add trace_printf* and trace_strbuf macros resolving to the *_fl functions and let the preprocessor fill in __FILE__ and __LINE__. As the trace_printf* functions take a variable number of arguments, this requires variadic macros (i.e. '#define foo(...) foo_impl(__VA_ARGS__)'. Though part of C99, it is unclear whether older compilers support this. Thus keep the old functions and only enable variadic macros for GNUC and MSVC 2005+ (_MSC_VER 1400). This has the nice side effect that the old C-style declarations serve as documentation how the macros are to be used. Print 'file:line ' as prefix to each trace line. Align the remaining trace output at column 40 to accommodate 18 char file names + 4 digit line number (currently there are 30 *.c files of length 18 and just 11 of 19). Trace output from longer source files (e.g. builtin/receive-pack.c) will not be aligned. Signed-off-by: Karsten Blees Signed-off-by: Junio C Hamano