MINOR: cpuset: define a platform-independent cpuset type

This module can be used to manipulate a cpu sets in a platform agnostic
way. Use the type cpu_set_t/cpuset_t if available on the platform, or
fallback to unsigned long, which limits de facto the maximum cpu index
to LONGBITS.

Makefile

@@ -563,6 +563,10 @@ ifneq ($(USE_BACKTRACE),)
 OPTIONS_LDFLAGS += -Wl,$(if $(EXPORT_SYMBOL),$(EXPORT_SYMBOL),--export-dynamic)
 endif
 
+ifneq ($(USE_CPU_AFFINITY),)
+OPTIONS_OBJS   += src/cpuset.o
+endif
+
 ifneq ($(USE_OPENSSL),)
 SSL_INC =
 SSL_LIB =

include/haproxy/cpuset-t.h

@@ -0,0 +1,40 @@
+#define _GNU_SOURCE
+#include <sched.h>
+
+#if defined(__FreeBSD__) || defined(__DragonFly__) || defined(__NetBSD__)
+#include <sys/param.h>
+#ifdef __FreeBSD__
+#include <sys/_cpuset.h>
+#include <sys/cpuset.h>
+#endif
+#endif
+
+#ifndef _HAPROXY_CPUSET_T_H
+#define _HAPROXY_CPUSET_T_H
+
+#if defined(__linux__) || defined(__DragonFly__)
+
+# define CPUSET_REPR cpu_set_t
+# define CPUSET_USE_CPUSET
+
+#elif defined(__FreeBSD__) || defined(__NetBSD__)
+
+# define CPUSET_REPR cpuset_t
+# define CPUSET_USE_FREEBSD_CPUSET
+
+#elif defined(__APPLE__)
+
+# define CPUSET_REPR unsigned long
+# define CPUSET_USE_ULONG
+
+#else
+
+# error "No cpuset support implemented on this platform"
+
+#endif
+
+struct hap_cpuset {
+	CPUSET_REPR cpuset;
+};
+
+#endif /* _HAPROXY_CPUSET_T_H */

include/haproxy/cpuset.h

@@ -0,0 +1,42 @@
+#ifndef _HAPROXY_CPUSET_H
+#define _HAPROXY_CPUSET_H
+
+#include <haproxy/cpuset-t.h>
+
+/* Unset all indexes in <set>.
+ */
+void ha_cpuset_zero(struct hap_cpuset *set);
+
+/* Set <cpu> index in <set> if not present.
+ * Returns 0 on success otherwise non-zero.
+ */
+int ha_cpuset_set(struct hap_cpuset *set, int cpu);
+
+/* Clear <cpu> index in <set> if present.
+ * Returns 0 on success otherwise non-zero.
+ */
+int ha_cpuset_clr(struct hap_cpuset *set, int cpu);
+
+/* Bitwise and equivalent operation between <src> and <dst> stored in <dst>.
+ */
+void ha_cpuset_and(struct hap_cpuset *dst, const struct hap_cpuset *src);
+
+/* Returns the count of set index in <set>.
+ */
+int ha_cpuset_count(const struct hap_cpuset *set);
+
+/* Returns the first index set plus one in <set> starting from the lowest.
+ * Returns 0 if no index set.
+ * Do not forget to substract the result by one if using it for set/clr.
+ */
+int ha_cpuset_ffs(const struct hap_cpuset *set);
+
+/* Copy <src> set into <dst>.
+ */
+void ha_cpuset_assign(struct hap_cpuset *dst, const struct hap_cpuset *src);
+
+/* Returns the biggest index plus one usable on the platform.
+ */
+int ha_cpuset_size();
+
+#endif /* _HAPROXY_CPUSET_H */

src/cpuset.c

@@ -0,0 +1,121 @@
+#define _GNU_SOURCE
+#include <sched.h>
+
+#include <haproxy/compat.h>
+#include <haproxy/cpuset.h>
+#include <haproxy/intops.h>
+
+void ha_cpuset_zero(struct hap_cpuset *set)
+{
+#if defined(CPUSET_USE_CPUSET) || defined(CPUSET_USE_FREEBSD_CPUSET)
+	CPU_ZERO(&set->cpuset);
+
+#elif defined(CPUSET_USE_ULONG)
+	set->cpuset = 0;
+#endif
+}
+
+int ha_cpuset_set(struct hap_cpuset *set, int cpu)
+{
+	if (cpu >= ha_cpuset_size())
+		return 1;
+
+#if defined(CPUSET_USE_CPUSET) || defined(CPUSET_USE_FREEBSD_CPUSET)
+	CPU_SET(cpu, &set->cpuset);
+	return 0;
+
+#elif defined(CPUSET_USE_ULONG)
+	set->cpuset |= (0x1 << cpu);
+	return 0;
+#endif
+}
+
+int ha_cpuset_clr(struct hap_cpuset *set, int cpu)
+{
+	if (cpu >= ha_cpuset_size())
+		return 1;
+
+#if defined(CPUSET_USE_CPUSET) || defined(CPUSET_USE_FREEBSD_CPUSET)
+	CPU_CLR(cpu, &set->cpuset);
+	return 0;
+
+#elif defined(CPUSET_USE_ULONG)
+	set->cpuset &= ~(0x1 << cpu);
+	return 0;
+#endif
+}
+
+void ha_cpuset_and(struct hap_cpuset *dst, const struct hap_cpuset *src)
+{
+#if defined(CPUSET_USE_CPUSET)
+	CPU_AND(&dst->cpuset, &dst->cpuset, &src->cpuset);
+
+#elif defined(CPUSET_USE_FREEBSD_CPUSET)
+	CPU_AND(&dst->cpuset, &src->cpuset);
+
+#elif defined(CPUSET_USE_ULONG)
+	dst->cpuset &= src->cpuset;
+#endif
+}
+
+int ha_cpuset_count(const struct hap_cpuset *set)
+{
+#if defined(CPUSET_USE_CPUSET) || defined(CPUSET_USE_FREEBSD_CPUSET)
+	return CPU_COUNT(&set->cpuset);
+
+#elif defined(CPUSET_USE_ULONG)
+	return my_popcountl(set->cpuset);
+#endif
+}
+
+int ha_cpuset_ffs(const struct hap_cpuset *set)
+{
+#if defined(CPUSET_USE_CPUSET)
+	int n;
+
+	if (!CPU_COUNT(&set->cpuset))
+		return 0;
+
+	for (n = 0; !CPU_ISSET(n, &set->cpuset); ++n)
+		;
+
+	return n + 1;
+
+#elif defined(CPUSET_USE_FREEBSD_CPUSET)
+	return CPU_FFS(&set->cpuset);
+
+#elif defined(CPUSET_USE_ULONG)
+	if (!set->cpuset)
+		return 0;
+
+	return my_ffsl(set->cpuset);
+#endif
+}
+
+void ha_cpuset_assign(struct hap_cpuset *dst, const struct hap_cpuset *src)
+{
+#if defined(CPUSET_USE_CPUSET)
+	CPU_ZERO(&dst->cpuset);
+	CPU_OR(&dst->cpuset, &dst->cpuset, &src->cpuset);
+
+#elif defined(CPUSET_USE_FREEBSD_CPUSET)
+	CPU_COPY(&src->cpuset, &dst->cpuset);
+
+#elif defined(CPUSET_USE_ULONG)
+	dst->cpuset = src->cpuset;
+#endif
+}
+
+int ha_cpuset_size()
+{
+#if defined(CPUSET_USE_CPUSET)
+	return CPU_SETSIZE;
+
+#elif defined(CPUSET_USE_FREEBSD_CPUSET)
+	return MAXCPU;
+
+#elif defined(CPUSET_USE_ULONG)
+	return LONGBITS;
+
+#endif
+}