add examples/perf

Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>

.gitignore

@@ -40,6 +40,7 @@ examples/basic
 examples/bot
 examples/complex
 examples/component
+examples/perf
 examples/register
 examples/roster
 examples/uuid

Makefile.am

@@ -125,10 +125,11 @@ noinst_PROGRAMS = \
 	examples/bot \
 	examples/complex \
 	examples/component \
+	examples/perf \
+	examples/register \
 	examples/roster \
 	examples/uuid \
-	examples/vcard \
-	examples/register
+	examples/vcard
 
 examples_active_SOURCES = examples/active.c
 examples_active_CFLAGS = $(STROPHE_FLAGS)
@@ -145,6 +146,12 @@ examples_complex_LDADD = $(STROPHE_LIBS)
 examples_component_SOURCES = examples/component.c
 examples_component_CFLAGS = $(STROPHE_FLAGS)
 examples_component_LDADD = $(STROPHE_LIBS)
+examples_perf_SOURCES = examples/perf.c
+examples_perf_CFLAGS = $(STROPHE_FLAGS)
+examples_perf_LDADD = $(STROPHE_LIBS)
+examples_register_SOURCES = examples/register.c
+examples_register_CFLAGS = $(STROPHE_FLAGS)
+examples_register_LDADD = $(STROPHE_LIBS)
 examples_roster_SOURCES = examples/roster.c
 examples_roster_CFLAGS = $(STROPHE_FLAGS)
 examples_roster_LDADD = $(STROPHE_LIBS)
@@ -154,9 +161,6 @@ examples_uuid_LDADD = $(STROPHE_LIBS)
 examples_vcard_SOURCES = examples/vcard.c
 examples_vcard_CFLAGS = $(STROPHE_FLAGS)
 examples_vcard_LDADD = $(STROPHE_LIBS)
-examples_register_SOURCES = examples/register.c
-examples_register_CFLAGS = $(STROPHE_FLAGS)
-examples_register_LDADD = $(STROPHE_LIBS)
 
 
 ## Tests

examples/perf.c

@@ -0,0 +1,163 @@
+/* perf.c
+ * strophe XMPP client library -- performance measure
+ *
+ * Copyright (C) 2022 Steffen Jaeckel <jaeckel-floss@eyet-services.de>
+ *
+ *  This software is provided AS-IS with no warranty, either express
+ *  or implied.
+ *
+ *  This program is dual licensed under the MIT and GPLv3 licenses.
+ */
+
+/** @file
+ *  performance measure
+ *
+ *  Timing code shamelessly borrowed from libtomcrypt/demos/timing.c
+ */
+
+#include <strophe.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <inttypes.h>
+
+static void init_timer(void);
+static void t_start(void);
+static uint64_t t_read(void);
+
+static void perf_rand(xmpp_ctx_t *ctx)
+{
+    xmpp_rand_t *rng = xmpp_rand_new(ctx);
+
+    uint64_t t1, t2;
+    unsigned int n;
+    const size_t alloc_sz = 0x1000u;
+    unsigned char *buf = malloc(alloc_sz);
+
+    /* pre-heat */
+    for (n = 1; n < 4; ++n) {
+        xmpp_rand_bytes(rng, buf, n * 10);
+    }
+
+    for (size_t sz = 2; sz <= alloc_sz; sz <<= 1) {
+        t2 = 0;
+        for (n = 0; n < 1000u; ++n) {
+
+            t_start();
+            t1 = t_read();
+
+            xmpp_rand_bytes(rng, buf, sz);
+
+            t1 = t_read() - t1;
+            t2 += t1;
+        }
+        t2 /= 1000;
+        fprintf(stderr,
+                "Reading %6zu bytes from PRNG took %8" PRIu64 " cycles\n", sz,
+                t2);
+    }
+    free(buf);
+    xmpp_rand_free(ctx, rng);
+}
+
+int main()
+{
+    /* pass NULL instead to silence output */
+    xmpp_log_t *log = xmpp_get_default_logger(XMPP_LEVEL_DEBUG);
+    /* create a context */
+    xmpp_ctx_t *ctx = xmpp_ctx_new(NULL, log);
+
+    init_timer();
+
+    perf_rand(ctx);
+
+    return 0;
+}
+
+#define TIMES 100000
+static uint64_t timer, skew = 0;
+
+/* RDTSC from Scott Duplichan */
+static uint64_t rdtsc(void)
+{
+#if defined __GNUC__ && !defined(LTC_NO_ASM)
+#if defined(__i386__) || defined(__x86_64__)
+    /* version from http://www.mcs.anl.gov/~kazutomo/rdtsc.html
+     * the old code always got a warning issued by gcc, clang did not
+     * complain...
+     */
+    unsigned hi, lo;
+    __asm__ __volatile__("rdtsc" : "=a"(lo), "=d"(hi));
+    return ((uint64_t)lo) | (((uint64_t)hi) << 32);
+#elif defined(LTC_PPC32) || defined(TFM_PPC32)
+    unsigned long a, b;
+    __asm__ __volatile__("mftbu %1 \nmftb %0\n" : "=r"(a), "=r"(b));
+    return (((uint64_t)b) << 32ULL) | ((uint64_t)a);
+#elif defined(__ia64__) /* gcc-IA64 version */
+    unsigned long result;
+    __asm__ __volatile__("mov %0=ar.itc" : "=r"(result)::"memory");
+    while (__builtin_expect((int)result == -1, 0))
+        __asm__ __volatile__("mov %0=ar.itc" : "=r"(result)::"memory");
+    return result;
+#elif defined(__sparc__)
+#if defined(__arch64__)
+    uint64_t a;
+    asm volatile("rd %%tick,%0" : "=r"(a));
+    return a;
+#else
+    register unsigned long x, y;
+    __asm__ __volatile__("rd %%tick, %0; clruw %0, %1; srlx %0, 32, %0"
+                         : "=r"(x), "=r"(y)
+                         : "0"(x), "1"(y));
+    return ((unsigned long long)x << 32) | y;
+#endif
+#elif defined(__aarch64__)
+    uint64_t CNTVCT_EL0;
+    __asm__ __volatile__("mrs %0, cntvct_el0" : "=r"(CNTVCT_EL0));
+    return CNTVCT_EL0;
+#else
+    return XCLOCK();
+#endif
+
+/* Microsoft and Intel Windows compilers */
+#elif defined _M_IX86 && !defined(LTC_NO_ASM)
+    __asm rdtsc
+#elif defined _M_AMD64 && !defined(LTC_NO_ASM)
+    return __rdtsc();
+#elif defined _M_IA64 && !defined(LTC_NO_ASM)
+#if defined __INTEL_COMPILER
+#include <ia64intrin.h>
+#endif
+    return __getReg(3116);
+#else
+    return XCLOCK();
+#endif
+}
+
+static void t_start(void)
+{
+    timer = rdtsc();
+}
+
+static uint64_t t_read(void)
+{
+    return rdtsc() - timer;
+}
+
+static void init_timer(void)
+{
+    uint64_t c1, c2, t1, t2;
+    unsigned long y1;
+
+    c1 = c2 = (uint64_t)-1;
+    for (y1 = 0; y1 < TIMES * 100; y1++) {
+        t_start();
+        t1 = t_read();
+        t2 = (t_read() - t1) >> 1;
+
+        c1 = (t1 > c1) ? t1 : c1;
+        c2 = (t2 > c2) ? t2 : c2;
+    }
+    skew = c2 - c1;
+    fprintf(stderr, "Clock Skew: %lu\n", (unsigned long)skew);
+}