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authorGravatar ctiller <ctiller@google.com>2014-12-23 08:53:43 -0800
committerGravatar Jan Tattermusch <jtattermusch@google.com>2014-12-29 17:26:55 -0800
commitd94ad10cf1ef0b4c94b7f53e4e823d5b14127365 (patch)
tree2318945b5e9f940fd13d4e506734a370414d9d50 /src/core
parent7e012cf4e062e2d0798c75f270188e04cd71523e (diff)
Provide a port of cpu related code to posix, and linux.
Properly set this up in our build environment. Change on 2014/12/23 by ctiller <ctiller@google.com> ------------- Created by MOE: http://code.google.com/p/moe-java MOE_MIGRATED_REVID=82725899
Diffstat (limited to 'src/core')
-rw-r--r--src/core/support/cpu_linux.c75
-rw-r--r--src/core/support/cpu_posix.c34
2 files changed, 93 insertions, 16 deletions
diff --git a/src/core/support/cpu_linux.c b/src/core/support/cpu_linux.c
new file mode 100644
index 0000000000..4d538a5b1b
--- /dev/null
+++ b/src/core/support/cpu_linux.c
@@ -0,0 +1,75 @@
+/*
+ *
+ * Copyright 2014, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_CPU_LINUX
+
+#include "src/core/support/cpu.h"
+
+#define _GNU_SOURCE
+#define __USE_GNU
+#define __USE_MISC
+#include <sched.h>
+#undef _GNU_SOURCE
+#undef __USE_GNU
+#undef __USE_MISC
+
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <grpc/support/log.h>
+
+int gpr_cpu_num_cores() {
+ static int ncpus = 0;
+ if (ncpus == 0) {
+ ncpus = sysconf(_SC_NPROCESSORS_ONLN);
+ if (ncpus < 1) {
+ gpr_log(GPR_ERROR, "Cannot determine number of CPUs: assuming 1");
+ ncpus = 1;
+ }
+ }
+ return ncpus;
+}
+
+int gpr_cpu_current_cpu() {
+ int cpu = sched_getcpu();
+ if (cpu < 0) {
+ gpr_log(GPR_ERROR, "Error determining current CPU: %s\n", strerror(errno));
+ return 0;
+ }
+ return cpu;
+}
+
+#endif /* GPR_CPU_LINUX */
diff --git a/src/core/support/cpu_posix.c b/src/core/support/cpu_posix.c
index 7f9cb8b4dd..3dd1c548b0 100644
--- a/src/core/support/cpu_posix.c
+++ b/src/core/support/cpu_posix.c
@@ -31,16 +31,11 @@
*
*/
-#include "src/core/support/cpu.h"
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_CPU_POSIX
-#ifdef __linux__
-#define _GNU_SOURCE
-#define __USE_GNU
-#define __USE_MISC
-#include <sched.h>
-#undef _GNU_SOURCE
-#undef __USE_GNU
-#undef __USE_MISC
+#include "src/core/support/cpu.h"
#include <errno.h>
#include <unistd.h>
@@ -48,6 +43,8 @@
#include <grpc/support/log.h>
+static __thread char magic_thread_local;
+
int gpr_cpu_num_cores() {
static int ncpus = 0;
if (ncpus == 0) {
@@ -60,13 +57,18 @@ int gpr_cpu_num_cores() {
return ncpus;
}
+/* This is a cheap, but good enough, pointer hash for sharding things: */
+static size_t shard_ptr(const void *info) {
+ size_t x = (size_t)info;
+ return ((x >> 4) ^ (x >> 9) ^ (x >> 14)) % gpr_cpu_num_cores();
+}
+
int gpr_cpu_current_cpu() {
- int cpu = sched_getcpu();
- if (cpu < 0) {
- gpr_log(GPR_ERROR, "Error determining current CPU: %s\n", strerror(errno));
- return 0;
- }
- return cpu;
+ /* NOTE: there's no way I know to return the actual cpu index portably...
+ most code that's using this is using it to shard across work queues though,
+ so here we use thread identity instead to achieve a similar though not
+ identical effect */
+ return shard_ptr(&magic_thread_local);
}
-#endif /* __linux__ */
+#endif /* GPR_CPU_LINUX */