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// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
#include "config.h"
#include "base/basictypes.h"
#include "gperftools/stacktrace.h"
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#if HAVE_LIBUNWIND_H
#include <libunwind.h>
#endif
#include "run_benchmark.h"
#if defined(__GNUC__) && defined(__has_attribute)
#if defined(__linux__) && defined(__x86_64__) && defined(_LP64) && __has_attribute(naked)
#include <stddef.h>
#include <ucontext.h>
#define BENCHMARK_UCONTEXT_STUFF 1
extern "C" void getcontext_light(ucontext_t *ctx);
#define R(r) offsetof(ucontext_t, uc_mcontext.gregs[r])
__attribute__((naked))
void getcontext_light(ucontext_t *ctx) {
__asm__ __volatile__(
"\tmovq %%rbx, %c0(%%rdi)\n"
"\tmovq %%rbp, %c1(%%rdi)\n"
"\tmovq %%r12, %c2(%%rdi)\n"
"\tmovq %%r13, %c3(%%rdi)\n"
"\tmovq %%r14, %c4(%%rdi)\n"
"\tmovq %%r15, %c5(%%rdi)\n"
"\tmovq (%%rsp), %%rcx\n"
"\tmovq %%rcx, %c6(%%rdi)\n"
"\tleaq 8(%%rsp), %%rcx\n" /* Exclude the return address. */
"\tmovq %%rcx, %c7(%%rdi)\n"
"\tret\n"
: : "i" (R(REG_RBX)),
"i" (R(REG_RBP)),
"i" (R(REG_R12)),
"i" (R(REG_R13)),
"i" (R(REG_R14)),
"i" (R(REG_R15)),
"i" (R(REG_RIP)),
"i" (R(REG_RSP)));
}
#undef R
#endif
#endif
#define MAX_FRAMES 2048
static void *frames[MAX_FRAMES];
enum measure_mode {
MODE_NOOP,
MODE_WITH_CONTEXT,
MODE_WITHOUT_CONTEXT
};
static int ATTRIBUTE_NOINLINE measure_unwind(int maxlevel, int mode) {
int n;
if (mode == MODE_NOOP)
return 0;
if (mode == MODE_WITH_CONTEXT) {
#if BENCHMARK_UCONTEXT_STUFF
ucontext_t uc;
getcontext_light(&uc);
n = GetStackTraceWithContext(frames, MAX_FRAMES, 0, &uc);
#else
abort();
#endif
} else {
n = GetStackTrace(frames, MAX_FRAMES, 0);
}
if (n < maxlevel) {
fprintf(stderr, "Expected at least %d frames, got %d\n", maxlevel, n);
abort();
}
return 0;
}
static int ATTRIBUTE_NOINLINE frame_forcer(int rv) {
#ifdef __GNUC__
// aargh, clang is too smart and it optimizes out f1 "loop" even
// despite frame_forcer trick. So lets resort to less portable asm
// volatile thingy.
__asm__ __volatile__ ("");
#endif
return rv;
}
static int ATTRIBUTE_NOINLINE f1(int level, int maxlevel, int mode) {
if (level == maxlevel)
return frame_forcer(measure_unwind(maxlevel, mode));
return frame_forcer(f1(level + 1, maxlevel, mode));
}
static void bench_unwind_no_op(long iterations, uintptr_t param) {
do {
f1(0, param, MODE_NOOP);
iterations -= param;
} while (iterations > 0);
}
#if BENCHMARK_UCONTEXT_STUFF
static void bench_unwind_context(long iterations, uintptr_t param) {
do {
f1(0, param, MODE_WITH_CONTEXT);
iterations -= param;
} while (iterations > 0);
}
#endif
static void bench_unwind_no_context(long iterations, uintptr_t param) {
do {
f1(0, param, MODE_WITHOUT_CONTEXT);
iterations -= param;
} while (iterations > 0);
}
int main(int argc, char **argv) {
init_benchmark(&argc, &argv);
#if BENCHMARK_UCONTEXT_STUFF
report_benchmark("unwind_context", bench_unwind_context, 1024);
#endif
report_benchmark("unwind_no_context", bench_unwind_no_context, 1024);
report_benchmark("unwind_no_op", bench_unwind_no_op, 1024);
//// TODO: somehow this fails at linking step. Figure out why this is missing
// #if HAVE_LIBUNWIND_H
// unw_set_caching_policy(unw_local_addr_space, UNW_CACHE_PER_THREAD);
// #endif
return 0;
}
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