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[XRay][compiler-rt] Profiling: No files when empty 

This change makes it so that the profiling mode implementation will only
write files when there are buffers to write. Before this change, we'd
always open a file even if there were no profiles collected when
flushing.

llvm-svn: 337443
This commit is contained in:
Dean Michael Berris 2018-07-19 09:20:19 +00:00
parent dd7bf598cc
commit 41cea19b4f
3 changed files with 28 additions and 24 deletions
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48
compiler-rt/lib/xray/xray_profiling.cc
View File

@ -132,31 +132,35 @@ XRayLogFlushStatus profilingFlush() XRAY_NEVER_INSTRUMENT {
// At this point, we'll create the file that will contain the profile, but
// only if the options say so.
if (!profilingFlags()->no_flush) {
int Fd = -1;
Fd = getLogFD();
if (Fd == -1) {
if (__sanitizer::Verbosity())
Report(
"profiler: Failed to acquire a file descriptor, dropping data.\n");
// First check whether we have data in the profile collector service
// before we try and write anything down.
XRayBuffer B = profileCollectorService::nextBuffer({nullptr, 0});
if (B.Data == nullptr) {
if (Verbosity())
Report("profiling: No data to flush.\n");
} else {
XRayProfilingFileHeader Header;
Header.Timestamp = NanoTime();
Header.PID = internal_getpid();
retryingWriteAll(Fd, reinterpret_cast<const char *>(&Header),
reinterpret_cast<const char *>(&Header) +
sizeof(Header));
int Fd = getLogFD();
if (Fd == -1) {
if (Verbosity())
Report("profiling: Failed to flush to file, dropping data.\n");
} else {
XRayProfilingFileHeader Header;
Header.Timestamp = NanoTime();
Header.PID = internal_getpid();
retryingWriteAll(Fd, reinterpret_cast<const char *>(&Header),
reinterpret_cast<const char *>(&Header) +
sizeof(Header));
// Now for each of the threads, write out the profile data as we would see
// it in memory, verbatim.
XRayBuffer B = profileCollectorService::nextBuffer({nullptr, 0});
while (B.Data != nullptr && B.Size != 0) {
retryingWriteAll(Fd, reinterpret_cast<const char *>(B.Data),
reinterpret_cast<const char *>(B.Data) + B.Size);
B = profileCollectorService::nextBuffer(B);
// Now for each of the threads, write out the profile data as we would
// see it in memory, verbatim.
while (B.Data != nullptr && B.Size != 0) {
retryingWriteAll(Fd, reinterpret_cast<const char *>(B.Data),
reinterpret_cast<const char *>(B.Data) + B.Size);
B = profileCollectorService::nextBuffer(B);
}
// Then we close out the file.
internal_close(Fd);
}
// Then we close out the file.
internal_close(Fd);
}
}

2
compiler-rt/test/xray/TestCases/Posix/profiling-multi-threaded.cc
View File

@ -8,7 +8,7 @@
// RUN: XRAY_PROFILING_OPTIONS=no_flush=1 %run %t
// RUN: XRAY_OPTIONS=verbosity=1 %run %t
// RUN: PROFILES=`ls xray-log.profiling-multi-* | wc -l`
// RUN: [ $PROFILES -ge 1 ]
// RUN: [ $PROFILES -eq 1 ]
// RUN: rm -f xray-log.profiling-multi-*
//
// REQUIRES: x86_64-target-arch

2
compiler-rt/test/xray/TestCases/Posix/profiling-single-threaded.cc
View File

@ -8,7 +8,7 @@
// RUN: XRAY_PROFILING_OPTIONS=no_flush=true %run %t
// RUN: XRAY_OPTIONS=verbosity=1 %run %t
// RUN: PROFILES=`ls xray-log.profiling-single-* | wc -l`
// RUN: [ $PROFILES -ge 2 ]
// RUN: [ $PROFILES -eq 2 ]
// RUN: rm -f xray-log.profiling-single-*
//
// REQUIRES: x86_64-target-arch