Add thapi_start() and thapi_stop()

configure.ac

@@ -104,7 +104,10 @@ AX_COMPARE_VERSION([$H2YAML_VERSION], [ge], [$H2YAML_MIN_VERSION],
 
 PKG_CHECK_MODULES([LIBFFI], [libffi >= 3.2])
 PKG_CHECK_MODULES([BABELTRACE2], [babeltrace2 >= 2.0])
-PKG_CHECK_MODULES([LTTNG_UST], [lttng-ust >= 2.10])
+# Use of __attribute__((constructor)) requires `lttng-ust >= 2.12.8` to work properly.
+# Specifically, the following fix:
+# https://github.com/lttng/lttng-ust/commit/a8fafb675a9f580f6a889223e26664ea11cb0c99.
+PKG_CHECK_MODULES([LTTNG_UST], [lttng-ust >= 2.12.8])
 PKG_CHECK_MODULES([PROTOBUF], [protobuf >= 3.0])
 
 AX_RUBY_EXTENSION([nokogiri], [yes])
@@ -138,6 +141,8 @@ AC_FUNC_MMAP
 AC_FUNC_REALLOC
 AC_CHECK_FUNCS([clock_gettime ftruncate memmove memset strdup strstr strtoull strlen strchr])
 
+AX_GCC_FUNC_ATTRIBUTE(constructor)
+
 # Required for configuring thapi.pc.in
 PKG_PROG_PKG_CONFIG
 

integration_tests/setup_suite.bash

@@ -3,6 +3,7 @@
 setup_suite() {
   export MPIRUN=${MPIRUN:-mpirun}
 
+  # Set the path to find iprof, babeltrace_thapi, etc.
   export PATH=$(pkg-config --variable=bindir thapi):${PATH}
 
   missing_tools=()

integration_tests/toggle.bats

@@ -0,0 +1,97 @@
+#!/usr/bin/env bats
+
+setup_file() {
+  export THAPI_INCFLAGS="-I$(pkg-config --variable=includedir thapi)"
+  export THAPI_LDFLAGS="-Wl,-rpath,$(pkg-config --variable=libdir thapi) $(pkg-config --libs thapi)"
+  # needed for toggle api dlopen test.
+  export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:$(pkg-config --variable=libdir thapi)
+}
+
+get_unique_jobid() {
+  echo ${BATS_TEST_NAME}.${RANDOM}
+}
+
+@test "toggle_api" {
+  rm -rf toggle_traces 2>/dev/null
+
+  cc ${THAPI_INCFLAGS} ./integration_tests/toggle.c -o toggle ${THAPI_LDFLAGS}
+  iprof --trace-output toggle_traces --no-analysis -- ./toggle
+
+  # Make sure auto_stop comes before stop.
+  babeltrace_thapi ./toggle_traces | awk 'BEGIN { seen_auto = 0 }
+  $0 ~ /lttng_ust_toggle:auto_stop/ { seen_auto = 1 }
+  $0 ~ /lttng_ust_toggle:stop/ { if (seen_auto == 1) { exit 0 } else { exit 1 } }
+  '
+
+  # Check expected trace counts.
+  dir=$(ls -d -1 ./toggle_traces/*/)
+  start_count=$(babeltrace_thapi -c $dir | grep lttng_ust_toggle:start | wc -l)
+  [ "$start_count" -eq 1 ]
+
+  stop_count=$(babeltrace_thapi -c $dir | grep lttng_ust_toggle:stop | wc -l)
+  [ "$stop_count" -eq 1 ]
+
+  auto_stop_count=$(babeltrace_thapi -c $dir | grep lttng_ust_toggle:auto_stop | wc -l)
+  [ "$auto_stop_count" -eq 1 ]
+}
+
+@test "toggle_api_dlopen" {
+  rm -rf toggle_traces 2>/dev/null
+
+  cc ./integration_tests/toggle_dlopen.c -o toggle_dlopen -ldl
+  iprof --trace-output toggle_traces --no-analysis -- ./toggle_dlopen
+
+  # Check expected trace counts.
+  dir=$(ls -d -1 ./toggle_traces/*/)
+  start_count=$(babeltrace_thapi -c $dir | grep lttng_ust_toggle:start | wc -l)
+  [ "$start_count" -eq 2 ]
+
+  stop_count=$(babeltrace_thapi -c $dir | grep lttng_ust_toggle:stop | wc -l)
+  [ "$stop_count" -eq 2 ]
+
+  auto_stop_count=$(babeltrace_thapi -c $dir | grep lttng_ust_toggle:auto_stop | wc -l)
+  [ "$auto_stop_count" -eq 2 ]
+}
+
+# Trace and analyse in a single iprof call: `--toggle-on` gates the events on the
+# lttng_ust_toggle start/stop tracepoints, and iprof prints the tally to stdout.
+count_base() {
+  rm -rf toggle_traces 2>/dev/null
+
+  mpicc ${THAPI_INCFLAGS} ./integration_tests/toggle_mpi.c -o toggle_mpi ${THAPI_LDFLAGS}
+
+  THAPI_SYNC_DAEMON=fs THAPI_JOBID=$(get_unique_jobid) timeout 40s mpirun -n $1 \
+    iprof --toggle-on --trace-output toggle_traces -- ./toggle_mpi $2
+}
+
+# Count the number of traced API calls: the tally's `Total` row, whose 4th
+# `|`-separated column is the call count (see general.bats `default_summary`).
+count_traces() {
+  count_base $1 $2 | awk -F'|' '/Total/ {c = int($4)} END {print c + 0}'
+}
+
+@test "toggle_plugin_mpi_np_1" {
+  count_0=$(count_traces 1 0)
+  count_1=$(count_traces 1 1)
+  count_2=$(count_traces 1 2)
+
+  [ "$count_0" -eq 2 ]
+  [ "$count_1" -eq 1 ]
+  [ "$count_2" -eq 0 ]
+}
+
+# Count the number of processes that emitted traced API calls: the `Processes`
+# field of the tally header.
+count_processors() {
+  count_base $1 $2 | grep -oP '\d+(?= Processes)' || echo 0
+}
+
+@test "toggle_plugin_mpi_np_2" {
+  count_0=$(count_processors 2 0)
+  count_1=$(count_processors 2 1)
+  count_2=$(count_processors 2 2)
+
+  [ "$count_0" -eq 2 ]
+  [ "$count_1" -eq 1 ]
+  [ "$count_2" -eq 0 ]
+}

integration_tests/toggle.c

@@ -0,0 +1,7 @@
+#include <thapi.h>
+
+int main(void) {
+  thapi_start();
+  thapi_stop();
+  return 0;
+}

integration_tests/toggle_dlopen.c

@@ -0,0 +1,35 @@
+#include <dlfcn.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define check_error(ptr_)                                                                          \
+  {                                                                                                \
+    void *ptr = (void *)ptr_;                                                                      \
+    if (!ptr) {                                                                                    \
+      fprintf(stderr, "%s:%d -- %s\n", __FILE__, __LINE__, dlerror());                             \
+      return 1;                                                                                    \
+    }                                                                                              \
+  }
+
+int main(void) {
+  dlerror();
+
+  for (int i = 0; i < 2; i++) {
+    void *thapi = dlopen("libThapi.so", RTLD_NOW | RTLD_LOCAL);
+    check_error(thapi);
+
+    void (*start)(void) = (void (*)(void))dlsym(thapi, "thapi_start");
+    check_error(start);
+
+    void (*stop)(void) = (void (*)(void))dlsym(thapi, "thapi_stop");
+    check_error(stop);
+
+    (*start)(), (*stop)();
+
+    dlclose(thapi);
+  }
+
+  return 0;
+}
+
+#undef check_error

integration_tests/toggle_mpi.c

@@ -0,0 +1,31 @@
+#include <mpi.h>
+#include <stdlib.h>
+
+#include <thapi.h>
+
+int main(int argc, char *argv[]) {
+  int variant = (argc > 1) ? atoi(argv[1]) : 0;
+
+  MPI_Init(&argc, &argv);
+
+  int rank, size;
+
+  switch (variant) {
+  case 0:
+    thapi_start();
+  case 1:
+    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+    if (rank == 0)
+      thapi_start();
+    MPI_Comm_size(MPI_COMM_WORLD, &size);
+    break;
+  default:
+    break;
+  }
+
+  thapi_stop();
+
+  MPI_Finalize();
+
+  return 0;
+}