build on 32-bit platforms

configure.ac

@@ -32,6 +32,8 @@ AX_CHECK_COMPILE_FLAG([-fno-strict-aliasing], [TK_CFLAGS="$TK_CFLAGS -fno-strict
 dnl Apply TK_CFLAGS only for tcpkali sources, not third-party dependencies.
 AC_SUBST(TK_CFLAGS)
 
+AC_CHECK_SIZEOF([size_t])
+
 AC_CHECK_HEADERS(sched.h uv.h)
 AC_CHECK_FUNCS(sched_getaffinity)
 

deps/libcows/libcows.c

@@ -40,6 +40,7 @@
 #include "libcows_frame.h"
 
 #include "libcows.h"
+#include "config.h"
 
 /*
  * Kick off writing of the output chain.
@@ -357,10 +358,17 @@ static void libcows_queue_hdr(libcows_ctx *ctx, size_t size) {
     } else {
         fhdr_buf[0] = *(unsigned char *)&frame;
         fhdr_buf[1] = 127;
+#if SIZEOF_SIZE_T == 4
+        fhdr_buf[2] = 0;
+        fhdr_buf[3] = 0;
+        fhdr_buf[4] = 0;
+        fhdr_buf[5] = 0;
+#else
         fhdr_buf[2] = size >> 56;
         fhdr_buf[3] = size >> 48;
         fhdr_buf[4] = size >> 40;
         fhdr_buf[5] = size >> 32;
+#endif
         fhdr_buf[6] = size >> 24;
         fhdr_buf[7] = size >> 16;
         fhdr_buf[8] = size >> 8;

src/tcpkali_atomic.h

@@ -27,8 +27,23 @@
 #ifndef TCPKALI_ATOMIC_H
 #define TCPKALI_ATOMIC_H
 
+
+#if SIZEOF_SIZE_T == 4
+typedef uint32_t atomic_t;
+typedef uint32_t atomic_wide_t;
+
+static inline void __attribute__((unused)) atomic_add(atomic_wide_t *i, uint64_t v) {
+    asm volatile("lock addl %1, %0" : "+m" (*i) : "r" (v));
+}
+
+#elif SIZEOF_SIZE_T == 8
 typedef uint32_t atomic_t;
-typedef uint64_t atomic64_t;
+typedef uint64_t atomic_wide_t;
+
+static inline void __attribute__((unused)) atomic_add(atomic_wide_t *i, uint64_t v) {
+    asm volatile("lock addq %1, %0" : "+m" (*i) : "r" (v));
+}
+#endif  /* SIZEOF_SIZE_T */
 
 static inline void __attribute__((unused)) atomic_increment(atomic_t *i) {
     asm volatile("lock incl %0" : "+m" (*i));
@@ -38,8 +53,4 @@ static inline void __attribute__((unused)) atomic_decrement(atomic_t *i) {
     asm volatile("lock decl %0" : "+m" (*i));
 }
 
-static inline void __attribute__((unused)) atomic_add(atomic64_t *i, uint64_t v) {
-    asm volatile("lock addq %1, %0" : "+m" (*i) : "r" (v));
-}
-
 #endif  /* TCPKALI_ATOMIC_H */

src/tcpkali_engine.c

@@ -112,8 +112,8 @@ struct loop_arguments {
     int private_control_pipe_wr;    /* Private blocking pipe for this worker (write side). */
     int thread_no;
     /* The following atomic members are accessed outside of worker thread */
-    atomic64_t worker_data_sent;
-    atomic64_t worker_data_received;
+    atomic_wide_t worker_data_sent      __attribute__((aligned(sizeof(atomic_wide_t))));
+    atomic_wide_t worker_data_received  __attribute__((aligned(sizeof(atomic_wide_t))));
     atomic_t outgoing_connecting;
     atomic_t outgoing_established;
     atomic_t incoming_established;
@@ -228,6 +228,9 @@ static socklen_t sockaddr_len(struct sockaddr *sa) {
 struct engine *engine_start(struct engine_params params) {
     int fildes[2];
 
+    /* Check that worker_data_sent is properly aligned for atomicity */
+    assert(((long)(&((struct loop_arguments *)0)->worker_data_sent) & 7) == 0);
+
     /* Global control pipe. Engine -> workers. */
     int rc = pipe(fildes);
     assert(rc == 0);