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authorGravatar Mark D. Roth <roth@google.com>2016-07-01 14:17:38 -0700
committerGravatar Mark D. Roth <roth@google.com>2016-07-01 14:17:38 -0700
commit3c945ee2b3c3bf0fd01cc995332e252d1e10e51e (patch)
tree9bbd2d09cebc94133609932827b8fa7a71bb8365 /src/core/lib/iomgr
parentafa864244d921626480abc6e4408a2aa183396c3 (diff)
parent20caeb182cbc152e7e038306a9b01f438f79ca41 (diff)
Merge branch 'master' into filter_call_init_failure
Diffstat (limited to 'src/core/lib/iomgr')
-rw-r--r--src/core/lib/iomgr/error.c83
-rw-r--r--src/core/lib/iomgr/error.h15
-rw-r--r--src/core/lib/iomgr/ev_epoll_linux.c1872
-rw-r--r--src/core/lib/iomgr/ev_epoll_linux.h47
-rw-r--r--src/core/lib/iomgr/ev_posix.c15
-rw-r--r--src/core/lib/iomgr/ev_posix.h3
-rw-r--r--src/core/lib/iomgr/network_status_tracker.c121
-rw-r--r--src/core/lib/iomgr/network_status_tracker.h41
-rw-r--r--src/core/lib/iomgr/socket_utils_common_posix.c22
-rw-r--r--src/core/lib/iomgr/socket_utils_posix.h3
-rw-r--r--src/core/lib/iomgr/tcp_posix.c8
-rw-r--r--src/core/lib/iomgr/tcp_server.h3
-rw-r--r--src/core/lib/iomgr/tcp_server_posix.c123
-rw-r--r--src/core/lib/iomgr/tcp_server_windows.c3
-rw-r--r--src/core/lib/iomgr/tcp_windows.c5
-rw-r--r--src/core/lib/iomgr/udp_server.c4
-rw-r--r--src/core/lib/iomgr/wakeup_fd_eventfd.c6
17 files changed, 2319 insertions, 55 deletions
diff --git a/src/core/lib/iomgr/error.c b/src/core/lib/iomgr/error.c
index 1b15963e57..149c55663c 100644
--- a/src/core/lib/iomgr/error.c
+++ b/src/core/lib/iomgr/error.c
@@ -37,6 +37,7 @@
#include <stdbool.h>
#include <string.h>
+#include <grpc/status.h>
#include <grpc/support/alloc.h>
#include <grpc/support/avl.h>
#include <grpc/support/log.h>
@@ -47,6 +48,8 @@
#include <grpc/support/log_windows.h>
#endif
+#include "src/core/lib/profiling/timers.h"
+
static void destroy_integer(void *key) {}
static void *copy_integer(void *key) { return key; }
@@ -115,6 +118,8 @@ static const char *error_int_name(grpc_error_ints key) {
return "wsa_error";
case GRPC_ERROR_INT_HTTP_STATUS:
return "http_status";
+ case GRPC_ERROR_INT_LIMIT:
+ return "limit";
}
GPR_UNREACHABLE_CODE(return "unknown");
}
@@ -169,8 +174,8 @@ static bool is_special(grpc_error *err) {
grpc_error *grpc_error_ref(grpc_error *err, const char *file, int line,
const char *func) {
if (is_special(err)) return err;
- gpr_log(GPR_DEBUG, "%p: %d -> %d [%s:%d %s]", err, err->refs.count,
- err->refs.count + 1, file, line, func);
+ gpr_log(GPR_DEBUG, "%p: %" PRIdPTR " -> %" PRIdPTR " [%s:%d %s]", err,
+ err->refs.count, err->refs.count + 1, file, line, func);
gpr_ref(&err->refs);
return err;
}
@@ -195,8 +200,8 @@ static void error_destroy(grpc_error *err) {
void grpc_error_unref(grpc_error *err, const char *file, int line,
const char *func) {
if (is_special(err)) return;
- gpr_log(GPR_DEBUG, "%p: %d -> %d [%s:%d %s]", err, err->refs.count,
- err->refs.count - 1, file, line, func);
+ gpr_log(GPR_DEBUG, "%p: %" PRIdPTR " -> %" PRIdPTR " [%s:%d %s]", err,
+ err->refs.count, err->refs.count - 1, file, line, func);
if (gpr_unref(&err->refs)) {
error_destroy(err);
}
@@ -213,6 +218,7 @@ void grpc_error_unref(grpc_error *err) {
grpc_error *grpc_error_create(const char *file, int line, const char *desc,
grpc_error **referencing,
size_t num_referencing) {
+ GPR_TIMER_BEGIN("grpc_error_create", 0);
grpc_error *err = gpr_malloc(sizeof(*err));
if (err == NULL) { // TODO(ctiller): make gpr_malloc return NULL
return GRPC_ERROR_OOM;
@@ -238,63 +244,91 @@ grpc_error *grpc_error_create(const char *file, int line, const char *desc,
(void *)(uintptr_t)GRPC_ERROR_TIME_CREATED,
box_time(gpr_now(GPR_CLOCK_REALTIME)));
gpr_ref_init(&err->refs, 1);
+ GPR_TIMER_END("grpc_error_create", 0);
return err;
}
static grpc_error *copy_error_and_unref(grpc_error *in) {
+ GPR_TIMER_BEGIN("copy_error_and_unref", 0);
+ grpc_error *out;
if (is_special(in)) {
- if (in == GRPC_ERROR_NONE) return GRPC_ERROR_CREATE("no error");
- if (in == GRPC_ERROR_OOM) return GRPC_ERROR_CREATE("oom");
- if (in == GRPC_ERROR_CANCELLED) return GRPC_ERROR_CREATE("cancelled");
- return GRPC_ERROR_CREATE("unknown");
- }
- grpc_error *out = gpr_malloc(sizeof(*out));
+ if (in == GRPC_ERROR_NONE)
+ out = GRPC_ERROR_CREATE("no error");
+ else if (in == GRPC_ERROR_OOM)
+ out = GRPC_ERROR_CREATE("oom");
+ else if (in == GRPC_ERROR_CANCELLED)
+ out =
+ grpc_error_set_int(GRPC_ERROR_CREATE("cancelled"),
+ GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_CANCELLED);
+ else
+ out = GRPC_ERROR_CREATE("unknown");
+ } else {
+ out = gpr_malloc(sizeof(*out));
#ifdef GRPC_ERROR_REFCOUNT_DEBUG
- gpr_log(GPR_DEBUG, "%p create copying", out);
+ gpr_log(GPR_DEBUG, "%p create copying", out);
#endif
- out->ints = gpr_avl_ref(in->ints);
- out->strs = gpr_avl_ref(in->strs);
- out->errs = gpr_avl_ref(in->errs);
- out->times = gpr_avl_ref(in->times);
- out->next_err = in->next_err;
- gpr_ref_init(&out->refs, 1);
- GRPC_ERROR_UNREF(in);
+ out->ints = gpr_avl_ref(in->ints);
+ out->strs = gpr_avl_ref(in->strs);
+ out->errs = gpr_avl_ref(in->errs);
+ out->times = gpr_avl_ref(in->times);
+ out->next_err = in->next_err;
+ gpr_ref_init(&out->refs, 1);
+ GRPC_ERROR_UNREF(in);
+ }
+ GPR_TIMER_END("copy_error_and_unref", 0);
return out;
}
grpc_error *grpc_error_set_int(grpc_error *src, grpc_error_ints which,
intptr_t value) {
+ GPR_TIMER_BEGIN("grpc_error_set_int", 0);
grpc_error *new = copy_error_and_unref(src);
new->ints = gpr_avl_add(new->ints, (void *)(uintptr_t)which, (void *)value);
+ GPR_TIMER_END("grpc_error_set_int", 0);
return new;
}
bool grpc_error_get_int(grpc_error *err, grpc_error_ints which, intptr_t *p) {
+ GPR_TIMER_BEGIN("grpc_error_get_int", 0);
void *pp;
+ if (is_special(err)) {
+ if (err == GRPC_ERROR_CANCELLED && which == GRPC_ERROR_INT_GRPC_STATUS) {
+ *p = GRPC_STATUS_CANCELLED;
+ GPR_TIMER_END("grpc_error_get_int", 0);
+ return true;
+ }
+ GPR_TIMER_END("grpc_error_get_int", 0);
+ return false;
+ }
if (gpr_avl_maybe_get(err->ints, (void *)(uintptr_t)which, &pp)) {
if (p != NULL) *p = (intptr_t)pp;
+ GPR_TIMER_END("grpc_error_get_int", 0);
return true;
}
+ GPR_TIMER_END("grpc_error_get_int", 0);
return false;
}
grpc_error *grpc_error_set_str(grpc_error *src, grpc_error_strs which,
const char *value) {
+ GPR_TIMER_BEGIN("grpc_error_set_str", 0);
grpc_error *new = copy_error_and_unref(src);
new->strs =
gpr_avl_add(new->strs, (void *)(uintptr_t)which, gpr_strdup(value));
+ GPR_TIMER_END("grpc_error_set_str", 0);
return new;
}
-const char *grpc_error_get_str(grpc_error *error, grpc_error_strs which) {
- void *s = NULL;
- gpr_avl_maybe_get(error->strs, (void *)(uintptr_t)which, &s);
- return s;
+const char *grpc_error_get_str(grpc_error *err, grpc_error_strs which) {
+ if (is_special(err)) return NULL;
+ return gpr_avl_get(err->strs, (void *)(uintptr_t)which);
}
grpc_error *grpc_error_add_child(grpc_error *src, grpc_error *child) {
+ GPR_TIMER_BEGIN("grpc_error_add_child", 0);
grpc_error *new = copy_error_and_unref(src);
new->errs = gpr_avl_add(new->errs, (void *)(new->next_err++), child);
+ GPR_TIMER_END("grpc_error_add_child", 0);
return new;
}
@@ -486,6 +520,7 @@ void grpc_error_free_string(const char *str) {
}
const char *grpc_error_string(grpc_error *err) {
+ GPR_TIMER_BEGIN("grpc_error_string", 0);
if (err == GRPC_ERROR_NONE) return no_error_string;
if (err == GRPC_ERROR_OOM) return oom_error_string;
if (err == GRPC_ERROR_CANCELLED) return cancelled_error_string;
@@ -502,7 +537,9 @@ const char *grpc_error_string(grpc_error *err) {
qsort(kvs.kvs, kvs.num_kvs, sizeof(kv_pair), cmp_kvs);
- return finish_kvs(&kvs);
+ const char *out = finish_kvs(&kvs);
+ GPR_TIMER_END("grpc_error_string", 0);
+ return out;
}
grpc_error *grpc_os_error(const char *file, int line, int err,
diff --git a/src/core/lib/iomgr/error.h b/src/core/lib/iomgr/error.h
index 4bff591fe3..bc7781250e 100644
--- a/src/core/lib/iomgr/error.h
+++ b/src/core/lib/iomgr/error.h
@@ -92,6 +92,8 @@ typedef enum {
GRPC_ERROR_INT_FD,
/// HTTP status (i.e. 404)
GRPC_ERROR_INT_HTTP_STATUS,
+ /// context sensitive limit associated with the error
+ GRPC_ERROR_INT_LIMIT,
} grpc_error_ints;
typedef enum {
@@ -163,26 +165,27 @@ void grpc_error_unref(grpc_error *err);
#endif
grpc_error *grpc_error_set_int(grpc_error *src, grpc_error_ints which,
- intptr_t value);
+ intptr_t value) GRPC_MUST_USE_RESULT;
bool grpc_error_get_int(grpc_error *error, grpc_error_ints which, intptr_t *p);
grpc_error *grpc_error_set_time(grpc_error *src, grpc_error_times which,
- gpr_timespec value);
+ gpr_timespec value) GRPC_MUST_USE_RESULT;
grpc_error *grpc_error_set_str(grpc_error *src, grpc_error_strs which,
- const char *value);
+ const char *value) GRPC_MUST_USE_RESULT;
/// Returns NULL if the specified string is not set.
/// Caller does NOT own return value.
const char *grpc_error_get_str(grpc_error *error, grpc_error_strs which);
/// Add a child error: an error that is believed to have contributed to this
/// error occurring. Allows root causing high level errors from lower level
/// errors that contributed to them.
-grpc_error *grpc_error_add_child(grpc_error *src, grpc_error *child);
+grpc_error *grpc_error_add_child(grpc_error *src,
+ grpc_error *child) GRPC_MUST_USE_RESULT;
grpc_error *grpc_os_error(const char *file, int line, int err,
- const char *call_name);
+ const char *call_name) GRPC_MUST_USE_RESULT;
/// create an error associated with errno!=0 (an 'operating system' error)
#define GRPC_OS_ERROR(err, call_name) \
grpc_os_error(__FILE__, __LINE__, err, call_name)
grpc_error *grpc_wsa_error(const char *file, int line, int err,
- const char *call_name);
+ const char *call_name) GRPC_MUST_USE_RESULT;
/// windows only: create an error associated with WSAGetLastError()!=0
#define GRPC_WSA_ERROR(err, call_name) \
grpc_wsa_error(__FILE__, __LINE__, err, call_name)
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
new file mode 100644
index 0000000000..cf0fe736a0
--- /dev/null
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -0,0 +1,1872 @@
+/*
+ *
+ * Copyright 2016, 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/grpc_posix.h>
+#include <grpc/support/port_platform.h>
+
+/* This polling engine is only relevant on linux kernels supporting epoll() */
+#ifdef GPR_LINUX_EPOLL
+
+#include "src/core/lib/iomgr/ev_epoll_linux.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <poll.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/tls.h>
+#include <grpc/support/useful.h>
+
+#include "src/core/lib/iomgr/ev_posix.h"
+#include "src/core/lib/iomgr/iomgr_internal.h"
+#include "src/core/lib/iomgr/wakeup_fd_posix.h"
+#include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/support/block_annotate.h"
+
+/* TODO: sreek - Move this to init.c and initialize this like other tracers. */
+static int grpc_polling_trace = 0; /* Disabled by default */
+#define GRPC_POLLING_TRACE(fmt, ...) \
+ if (grpc_polling_trace) { \
+ gpr_log(GPR_INFO, (fmt), __VA_ARGS__); \
+ }
+
+static int grpc_wakeup_signal = -1;
+static bool is_grpc_wakeup_signal_initialized = false;
+
+/* Implements the function defined in grpc_posix.h. This function might be
+ * called before even calling grpc_init() to set either a different signal to
+ * use. If signum == -1, then the use of signals is disabled */
+void grpc_use_signal(int signum) {
+ grpc_wakeup_signal = signum;
+ is_grpc_wakeup_signal_initialized = true;
+
+ if (grpc_wakeup_signal < 0) {
+ gpr_log(GPR_INFO,
+ "Use of signals is disabled. Epoll engine will not be used");
+ } else {
+ gpr_log(GPR_INFO, "epoll engine will be using signal: %d",
+ grpc_wakeup_signal);
+ }
+}
+
+struct polling_island;
+
+/*******************************************************************************
+ * Fd Declarations
+ */
+struct grpc_fd {
+ int fd;
+ /* refst format:
+ bit 0 : 1=Active / 0=Orphaned
+ bits 1-n : refcount
+ Ref/Unref by two to avoid altering the orphaned bit */
+ gpr_atm refst;
+
+ gpr_mu mu;
+
+ /* Indicates that the fd is shutdown and that any pending read/write closures
+ should fail */
+ bool shutdown;
+
+ /* The fd is either closed or we relinquished control of it. In either cases,
+ this indicates that the 'fd' on this structure is no longer valid */
+ bool orphaned;
+
+ /* TODO: sreek - Move this to a lockfree implementation */
+ grpc_closure *read_closure;
+ grpc_closure *write_closure;
+
+ /* The polling island to which this fd belongs to and the mutex protecting the
+ the field */
+ gpr_mu pi_mu;
+ struct polling_island *polling_island;
+
+ struct grpc_fd *freelist_next;
+ grpc_closure *on_done_closure;
+
+ /* The pollset that last noticed that the fd is readable */
+ grpc_pollset *read_notifier_pollset;
+
+ grpc_iomgr_object iomgr_object;
+};
+
+/* Reference counting for fds */
+// #define GRPC_FD_REF_COUNT_DEBUG
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+static void fd_ref(grpc_fd *fd, const char *reason, const char *file, int line);
+static void fd_unref(grpc_fd *fd, const char *reason, const char *file,
+ int line);
+#define GRPC_FD_REF(fd, reason) fd_ref(fd, reason, __FILE__, __LINE__)
+#define GRPC_FD_UNREF(fd, reason) fd_unref(fd, reason, __FILE__, __LINE__)
+#else
+static void fd_ref(grpc_fd *fd);
+static void fd_unref(grpc_fd *fd);
+#define GRPC_FD_REF(fd, reason) fd_ref(fd)
+#define GRPC_FD_UNREF(fd, reason) fd_unref(fd)
+#endif
+
+static void fd_global_init(void);
+static void fd_global_shutdown(void);
+
+#define CLOSURE_NOT_READY ((grpc_closure *)0)
+#define CLOSURE_READY ((grpc_closure *)1)
+
+/*******************************************************************************
+ * Polling island Declarations
+ */
+
+// #define GRPC_PI_REF_COUNT_DEBUG
+#ifdef GRPC_PI_REF_COUNT_DEBUG
+
+#define PI_ADD_REF(p, r) pi_add_ref_dbg((p), (r), __FILE__, __LINE__)
+#define PI_UNREF(p, r) pi_unref_dbg((p), (r), __FILE__, __LINE__)
+
+#else /* defined(GRPC_PI_REF_COUNT_DEBUG) */
+
+#define PI_ADD_REF(p, r) pi_add_ref((p))
+#define PI_UNREF(p, r) pi_unref((p))
+
+#endif /* !defined(GPRC_PI_REF_COUNT_DEBUG) */
+
+typedef struct polling_island {
+ gpr_mu mu;
+ /* Ref count. Use PI_ADD_REF() and PI_UNREF() macros to increment/decrement
+ the refcount.
+ Once the ref count becomes zero, this structure is destroyed which means
+ we should ensure that there is never a scenario where a PI_ADD_REF() is
+ racing with a PI_UNREF() that just made the ref_count zero. */
+ gpr_refcount ref_count;
+
+ /* Pointer to the polling_island this merged into.
+ * merged_to value is only set once in polling_island's lifetime (and that too
+ * only if the island is merged with another island). Because of this, we can
+ * use gpr_atm type here so that we can do atomic access on this and reduce
+ * lock contention on 'mu' mutex.
+ *
+ * Note that if this field is not NULL (i.e not 0), all the remaining fields
+ * (except mu and ref_count) are invalid and must be ignored. */
+ gpr_atm merged_to;
+
+ /* The fd of the underlying epoll set */
+ int epoll_fd;
+
+ /* The file descriptors in the epoll set */
+ size_t fd_cnt;
+ size_t fd_capacity;
+ grpc_fd **fds;
+
+ /* Polling islands that are no longer needed are kept in a freelist so that
+ they can be reused. This field points to the next polling island in the
+ free list */
+ struct polling_island *next_free;
+} polling_island;
+
+/*******************************************************************************
+ * Pollset Declarations
+ */
+struct grpc_pollset_worker {
+ /* Thread id of this worker */
+ pthread_t pt_id;
+
+ /* Used to prevent a worker from getting kicked multiple times */
+ gpr_atm is_kicked;
+ struct grpc_pollset_worker *next;
+ struct grpc_pollset_worker *prev;
+};
+
+struct grpc_pollset {
+ gpr_mu mu;
+ grpc_pollset_worker root_worker;
+ bool kicked_without_pollers;
+
+ bool shutting_down; /* Is the pollset shutting down ? */
+ bool finish_shutdown_called; /* Is the 'finish_shutdown_locked()' called ? */
+ grpc_closure *shutdown_done; /* Called after after shutdown is complete */
+
+ /* The polling island to which this pollset belongs to */
+ struct polling_island *polling_island;
+};
+
+/*******************************************************************************
+ * Pollset-set Declarations
+ */
+/* TODO: sreek - Change the pollset_set implementation such that a pollset_set
+ * directly points to a polling_island (and adding an fd/pollset/pollset_set to
+ * the current pollset_set would result in polling island merges. This would
+ * remove the need to maintain fd_count here. This will also significantly
+ * simplify the grpc_fd structure since we would no longer need to explicitly
+ * maintain the orphaned state */
+struct grpc_pollset_set {
+ gpr_mu mu;
+
+ size_t pollset_count;
+ size_t pollset_capacity;
+ grpc_pollset **pollsets;
+
+ size_t pollset_set_count;
+ size_t pollset_set_capacity;
+ struct grpc_pollset_set **pollset_sets;
+
+ size_t fd_count;
+ size_t fd_capacity;
+ grpc_fd **fds;
+};
+
+/*******************************************************************************
+ * Common helpers
+ */
+
+static void append_error(grpc_error **composite, grpc_error *error,
+ const char *desc) {
+ if (error == GRPC_ERROR_NONE) return;
+ if (*composite == GRPC_ERROR_NONE) {
+ *composite = GRPC_ERROR_CREATE(desc);
+ }
+ *composite = grpc_error_add_child(*composite, error);
+}
+
+/*******************************************************************************
+ * Polling island Definitions
+ */
+
+/* The wakeup fd that is used to wake up all threads in a Polling island. This
+ is useful in the polling island merge operation where we need to wakeup all
+ the threads currently polling the smaller polling island (so that they can
+ start polling the new/merged polling island)
+
+ NOTE: This fd is initialized to be readable and MUST NOT be consumed i.e the
+ threads that woke up MUST NOT call grpc_wakeup_fd_consume_wakeup() */
+static grpc_wakeup_fd polling_island_wakeup_fd;
+
+/* Polling island freelist */
+static gpr_mu g_pi_freelist_mu;
+static polling_island *g_pi_freelist = NULL;
+
+static void polling_island_delete(); /* Forward declaration */
+
+#ifdef GRPC_TSAN
+/* Currently TSAN may incorrectly flag data races between epoll_ctl and
+ epoll_wait for any grpc_fd structs that are added to the epoll set via
+ epoll_ctl and are returned (within a very short window) via epoll_wait().
+
+ To work-around this race, we establish a happens-before relation between
+ the code just-before epoll_ctl() and the code after epoll_wait() by using
+ this atomic */
+gpr_atm g_epoll_sync;
+#endif /* defined(GRPC_TSAN) */
+
+#ifdef GRPC_PI_REF_COUNT_DEBUG
+void pi_add_ref(polling_island *pi);
+void pi_unref(polling_island *pi);
+
+void pi_add_ref_dbg(polling_island *pi, char *reason, char *file, int line) {
+ long old_cnt = gpr_atm_acq_load(&(pi->ref_count.count));
+ pi_add_ref(pi);
+ gpr_log(GPR_DEBUG, "Add ref pi: %p, old: %ld -> new:%ld (%s) - (%s, %d)",
+ (void *)pi, old_cnt, old_cnt + 1, reason, file, line);
+}
+
+void pi_unref_dbg(polling_island *pi, char *reason, char *file, int line) {
+ long old_cnt = gpr_atm_acq_load(&(pi->ref_count.count));
+ pi_unref(pi);
+ gpr_log(GPR_DEBUG, "Unref pi: %p, old:%ld -> new:%ld (%s) - (%s, %d)",
+ (void *)pi, old_cnt, (old_cnt - 1), reason, file, line);
+}
+#endif
+
+void pi_add_ref(polling_island *pi) { gpr_ref(&pi->ref_count); }
+
+void pi_unref(polling_island *pi) {
+ /* If ref count went to zero, delete the polling island.
+ Note that this deletion not be done under a lock. Once the ref count goes
+ to zero, we are guaranteed that no one else holds a reference to the
+ polling island (and that there is no racing pi_add_ref() call either).
+
+ Also, if we are deleting the polling island and the merged_to field is
+ non-empty, we should remove a ref to the merged_to polling island
+ */
+ if (gpr_unref(&pi->ref_count)) {
+ polling_island *next = (polling_island *)gpr_atm_acq_load(&pi->merged_to);
+ polling_island_delete(pi);
+ if (next != NULL) {
+ PI_UNREF(next, "pi_delete"); /* Recursive call */
+ }
+ }
+}
+
+/* The caller is expected to hold pi->mu lock before calling this function */
+static void polling_island_add_fds_locked(polling_island *pi, grpc_fd **fds,
+ size_t fd_count, bool add_fd_refs,
+ grpc_error **error) {
+ int err;
+ size_t i;
+ struct epoll_event ev;
+ char *err_msg;
+ const char *err_desc = "polling_island_add_fds";
+
+#ifdef GRPC_TSAN
+ /* See the definition of g_epoll_sync for more context */
+ gpr_atm_rel_store(&g_epoll_sync, (gpr_atm)0);
+#endif /* defined(GRPC_TSAN) */
+
+ for (i = 0; i < fd_count; i++) {
+ ev.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET);
+ ev.data.ptr = fds[i];
+ err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_ADD, fds[i]->fd, &ev);
+
+ if (err < 0) {
+ if (errno != EEXIST) {
+ gpr_asprintf(
+ &err_msg,
+ "epoll_ctl (epoll_fd: %d) add fd: %d failed with error: %d (%s)",
+ pi->epoll_fd, fds[i]->fd, errno, strerror(errno));
+ append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
+ gpr_free(err_msg);
+ }
+
+ continue;
+ }
+
+ if (pi->fd_cnt == pi->fd_capacity) {
+ pi->fd_capacity = GPR_MAX(pi->fd_capacity + 8, pi->fd_cnt * 3 / 2);
+ pi->fds = gpr_realloc(pi->fds, sizeof(grpc_fd *) * pi->fd_capacity);
+ }
+
+ pi->fds[pi->fd_cnt++] = fds[i];
+ if (add_fd_refs) {
+ GRPC_FD_REF(fds[i], "polling_island");
+ }
+ }
+}
+
+/* The caller is expected to hold pi->mu before calling this */
+static void polling_island_add_wakeup_fd_locked(polling_island *pi,
+ grpc_wakeup_fd *wakeup_fd,
+ grpc_error **error) {
+ struct epoll_event ev;
+ int err;
+ char *err_msg;
+ const char *err_desc = "polling_island_add_wakeup_fd";
+
+ ev.events = (uint32_t)(EPOLLIN | EPOLLET);
+ ev.data.ptr = wakeup_fd;
+ err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_ADD,
+ GRPC_WAKEUP_FD_GET_READ_FD(wakeup_fd), &ev);
+ if (err < 0 && errno != EEXIST) {
+ gpr_asprintf(&err_msg,
+ "epoll_ctl (epoll_fd: %d) add wakeup fd: %d failed with "
+ "error: %d (%s)",
+ pi->epoll_fd,
+ GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd), errno,
+ strerror(errno));
+ append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
+ gpr_free(err_msg);
+ }
+}
+
+/* The caller is expected to hold pi->mu lock before calling this function */
+static void polling_island_remove_all_fds_locked(polling_island *pi,
+ bool remove_fd_refs,
+ grpc_error **error) {
+ int err;
+ size_t i;
+ char *err_msg;
+ const char *err_desc = "polling_island_remove_fds";
+
+ for (i = 0; i < pi->fd_cnt; i++) {
+ err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_DEL, pi->fds[i]->fd, NULL);
+ if (err < 0 && errno != ENOENT) {
+ gpr_asprintf(&err_msg,
+ "epoll_ctl (epoll_fd: %d) delete fds[%zu]: %d failed with "
+ "error: %d (%s)",
+ pi->epoll_fd, i, pi->fds[i]->fd, errno, strerror(errno));
+ append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
+ gpr_free(err_msg);
+ }
+
+ if (remove_fd_refs) {
+ GRPC_FD_UNREF(pi->fds[i], "polling_island");
+ }
+ }
+
+ pi->fd_cnt = 0;
+}
+
+/* The caller is expected to hold pi->mu lock before calling this function */
+static void polling_island_remove_fd_locked(polling_island *pi, grpc_fd *fd,
+ bool is_fd_closed,
+ grpc_error **error) {
+ int err;
+ size_t i;
+ char *err_msg;
+ const char *err_desc = "polling_island_remove_fd";
+
+ /* If fd is already closed, then it would have been automatically been removed
+ from the epoll set */
+ if (!is_fd_closed) {
+ err = epoll_ctl(pi->epoll_fd, EPOLL_CTL_DEL, fd->fd, NULL);
+ if (err < 0 && errno != ENOENT) {
+ gpr_asprintf(
+ &err_msg,
+ "epoll_ctl (epoll_fd: %d) del fd: %d failed with error: %d (%s)",
+ pi->epoll_fd, fd->fd, errno, strerror(errno));
+ append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
+ gpr_free(err_msg);
+ }
+ }
+
+ for (i = 0; i < pi->fd_cnt; i++) {
+ if (pi->fds[i] == fd) {
+ pi->fds[i] = pi->fds[--pi->fd_cnt];
+ GRPC_FD_UNREF(fd, "polling_island");
+ break;
+ }
+ }
+}
+
+/* Might return NULL in case of an error */
+static polling_island *polling_island_create(grpc_fd *initial_fd,
+ grpc_error **error) {
+ polling_island *pi = NULL;
+ char *err_msg;
+ const char *err_desc = "polling_island_create";
+
+ /* Try to get one from the polling island freelist */
+ gpr_mu_lock(&g_pi_freelist_mu);
+ if (g_pi_freelist != NULL) {
+ pi = g_pi_freelist;
+ g_pi_freelist = g_pi_freelist->next_free;
+ pi->next_free = NULL;
+ }
+ gpr_mu_unlock(&g_pi_freelist_mu);
+
+ /* Create new polling island if we could not get one from the free list */
+ if (pi == NULL) {
+ pi = gpr_malloc(sizeof(*pi));
+ gpr_mu_init(&pi->mu);
+ pi->fd_cnt = 0;
+ pi->fd_capacity = 0;
+ pi->fds = NULL;
+ }
+
+ gpr_ref_init(&pi->ref_count, 0);
+ gpr_atm_rel_store(&pi->merged_to, (gpr_atm)NULL);
+
+ pi->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
+
+ if (pi->epoll_fd < 0) {
+ gpr_asprintf(&err_msg, "epoll_create1 failed with error %d (%s)", errno,
+ strerror(errno));
+ append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
+ gpr_free(err_msg);
+ } else {
+ polling_island_add_wakeup_fd_locked(pi, &grpc_global_wakeup_fd, error);
+ pi->next_free = NULL;
+
+ if (initial_fd != NULL) {
+ /* Lock the polling island here just in case we got this structure from
+ the freelist and the polling island lock was not released yet (by the
+ code that adds the polling island to the freelist) */
+ gpr_mu_lock(&pi->mu);
+ polling_island_add_fds_locked(pi, &initial_fd, 1, true, error);
+ gpr_mu_unlock(&pi->mu);
+ }
+ }
+
+ return pi;
+}
+
+static void polling_island_delete(polling_island *pi) {
+ GPR_ASSERT(pi->fd_cnt == 0);
+
+ gpr_atm_rel_store(&pi->merged_to, (gpr_atm)NULL);
+
+ close(pi->epoll_fd);
+ pi->epoll_fd = -1;
+
+ gpr_mu_lock(&g_pi_freelist_mu);
+ pi->next_free = g_pi_freelist;
+ g_pi_freelist = pi;
+ gpr_mu_unlock(&g_pi_freelist_mu);
+}
+
+/* Attempts to gets the last polling island in the linked list (liked by the
+ * 'merged_to' field). Since this does not lock the polling island, there are no
+ * guarantees that the island returned is the last island */
+static polling_island *polling_island_maybe_get_latest(polling_island *pi) {
+ polling_island *next = (polling_island *)gpr_atm_acq_load(&pi->merged_to);
+ while (next != NULL) {
+ pi = next;
+ next = (polling_island *)gpr_atm_acq_load(&pi->merged_to);
+ }
+
+ return pi;
+}
+
+/* Gets the lock on the *latest* polling island i.e the last polling island in
+ the linked list (linked by the 'merged_to' field). Call gpr_mu_unlock on the
+ returned polling island's mu.
+ Usage: To lock/unlock polling island "pi", do the following:
+ polling_island *pi_latest = polling_island_lock(pi);
+ ...
+ ... critical section ..
+ ...
+ gpr_mu_unlock(&pi_latest->mu); // NOTE: use pi_latest->mu. NOT pi->mu */
+static polling_island *polling_island_lock(polling_island *pi) {
+ polling_island *next = NULL;
+
+ while (true) {
+ next = (polling_island *)gpr_atm_acq_load(&pi->merged_to);
+ if (next == NULL) {
+ /* Looks like 'pi' is the last node in the linked list but unless we check
+ this by holding the pi->mu lock, we cannot be sure (i.e without the
+ pi->mu lock, we don't prevent island merges).
+ To be absolutely sure, check once more by holding the pi->mu lock */
+ gpr_mu_lock(&pi->mu);
+ next = (polling_island *)gpr_atm_acq_load(&pi->merged_to);
+ if (next == NULL) {
+ /* pi is infact the last node and we have the pi->mu lock. we're done */
+ break;
+ }
+
+ /* pi->merged_to is not NULL i.e pi isn't the last node anymore. pi->mu
+ * isn't the lock we are interested in. Continue traversing the list */
+ gpr_mu_unlock(&pi->mu);
+ }
+
+ pi = next;
+ }
+
+ return pi;
+}
+
+/* Gets the lock on the *latest* polling islands in the linked lists pointed by
+ *p and *q (and also updates *p and *q to point to the latest polling islands)
+
+ This function is needed because calling the following block of code to obtain
+ locks on polling islands (*p and *q) is prone to deadlocks.
+ {
+ polling_island_lock(*p, true);
+ polling_island_lock(*q, true);
+ }
+
+ Usage/example:
+ polling_island *p1;
+ polling_island *p2;
+ ..
+ polling_island_lock_pair(&p1, &p2);
+ ..
+ .. Critical section with both p1 and p2 locked
+ ..
+ // Release locks: Always call polling_island_unlock_pair() to release locks
+ polling_island_unlock_pair(p1, p2);
+*/
+static void polling_island_lock_pair(polling_island **p, polling_island **q) {
+ polling_island *pi_1 = *p;
+ polling_island *pi_2 = *q;
+ polling_island *next_1 = NULL;
+ polling_island *next_2 = NULL;
+
+ /* The algorithm is simple:
+ - Go to the last polling islands in the linked lists *pi_1 and *pi_2 (and
+ keep updating pi_1 and pi_2)
+ - Then obtain locks on the islands by following a lock order rule of
+ locking polling_island with lower address first
+ Special case: Before obtaining the locks, check if pi_1 and pi_2 are
+ pointing to the same island. If that is the case, we can just call
+ polling_island_lock()
+ - After obtaining both the locks, double check that the polling islands
+ are still the last polling islands in their respective linked lists
+ (this is because there might have been polling island merges before
+ we got the lock)
+ - If the polling islands are the last islands, we are done. If not,
+ release the locks and continue the process from the first step */
+ while (true) {
+ next_1 = (polling_island *)gpr_atm_acq_load(&pi_1->merged_to);
+ while (next_1 != NULL) {
+ pi_1 = next_1;
+ next_1 = (polling_island *)gpr_atm_acq_load(&pi_1->merged_to);
+ }
+
+ next_2 = (polling_island *)gpr_atm_acq_load(&pi_2->merged_to);
+ while (next_2 != NULL) {
+ pi_2 = next_2;
+ next_2 = (polling_island *)gpr_atm_acq_load(&pi_2->merged_to);
+ }
+
+ if (pi_1 == pi_2) {
+ pi_1 = pi_2 = polling_island_lock(pi_1);
+ break;
+ }
+
+ if (pi_1 < pi_2) {
+ gpr_mu_lock(&pi_1->mu);
+ gpr_mu_lock(&pi_2->mu);
+ } else {
+ gpr_mu_lock(&pi_2->mu);
+ gpr_mu_lock(&pi_1->mu);
+ }
+
+ next_1 = (polling_island *)gpr_atm_acq_load(&pi_1->merged_to);
+ next_2 = (polling_island *)gpr_atm_acq_load(&pi_2->merged_to);
+ if (next_1 == NULL && next_2 == NULL) {
+ break;
+ }
+
+ gpr_mu_unlock(&pi_1->mu);
+ gpr_mu_unlock(&pi_2->mu);
+ }
+
+ *p = pi_1;
+ *q = pi_2;
+}
+
+static void polling_island_unlock_pair(polling_island *p, polling_island *q) {
+ if (p == q) {
+ gpr_mu_unlock(&p->mu);
+ } else {
+ gpr_mu_unlock(&p->mu);
+ gpr_mu_unlock(&q->mu);
+ }
+}
+
+static polling_island *polling_island_merge(polling_island *p,
+ polling_island *q,
+ grpc_error **error) {
+ /* Get locks on both the polling islands */
+ polling_island_lock_pair(&p, &q);
+
+ if (p != q) {
+ /* Make sure that p points to the polling island with fewer fds than q */
+ if (p->fd_cnt > q->fd_cnt) {
+ GPR_SWAP(polling_island *, p, q);
+ }
+
+ /* Merge p with q i.e move all the fds from p (The one with fewer fds) to q
+ Note that the refcounts on the fds being moved will not change here.
+ This is why the last param in the following two functions is 'false') */
+ polling_island_add_fds_locked(q, p->fds, p->fd_cnt, false, error);
+ polling_island_remove_all_fds_locked(p, false, error);
+
+ /* Wakeup all the pollers (if any) on p so that they pickup this change */
+ polling_island_add_wakeup_fd_locked(p, &polling_island_wakeup_fd, error);
+
+ /* Add the 'merged_to' link from p --> q */
+ gpr_atm_rel_store(&p->merged_to, (gpr_atm)q);
+ PI_ADD_REF(q, "pi_merge"); /* To account for the new incoming ref from p */
+ }
+ /* else if p == q, nothing needs to be done */
+
+ polling_island_unlock_pair(p, q);
+
+ /* Return the merged polling island (Note that no merge would have happened
+ if p == q which is ok) */
+ return q;
+}
+
+static grpc_error *polling_island_global_init() {
+ grpc_error *error = GRPC_ERROR_NONE;
+
+ gpr_mu_init(&g_pi_freelist_mu);
+ g_pi_freelist = NULL;
+
+ error = grpc_wakeup_fd_init(&polling_island_wakeup_fd);
+ if (error == GRPC_ERROR_NONE) {
+ error = grpc_wakeup_fd_wakeup(&polling_island_wakeup_fd);
+ }
+
+ return error;
+}
+
+static void polling_island_global_shutdown() {
+ polling_island *next;
+ gpr_mu_lock(&g_pi_freelist_mu);
+ gpr_mu_unlock(&g_pi_freelist_mu);
+ while (g_pi_freelist != NULL) {
+ next = g_pi_freelist->next_free;
+ gpr_mu_destroy(&g_pi_freelist->mu);
+ gpr_free(g_pi_freelist->fds);
+ gpr_free(g_pi_freelist);
+ g_pi_freelist = next;
+ }
+ gpr_mu_destroy(&g_pi_freelist_mu);
+
+ grpc_wakeup_fd_destroy(&polling_island_wakeup_fd);
+}
+
+/*******************************************************************************
+ * Fd Definitions
+ */
+
+/* We need to keep a freelist not because of any concerns of malloc performance
+ * but instead so that implementations with multiple threads in (for example)
+ * epoll_wait deal with the race between pollset removal and incoming poll
+ * notifications.
+ *
+ * The problem is that the poller ultimately holds a reference to this
+ * object, so it is very difficult to know when is safe to free it, at least
+ * without some expensive synchronization.
+ *
+ * If we keep the object freelisted, in the worst case losing this race just
+ * becomes a spurious read notification on a reused fd.
+ */
+
+/* The alarm system needs to be able to wakeup 'some poller' sometimes
+ * (specifically when a new alarm needs to be triggered earlier than the next
+ * alarm 'epoch'). This wakeup_fd gives us something to alert on when such a
+ * case occurs. */
+
+/* TODO: sreek: Right now, this wakes up all pollers. In future we should make
+ * sure to wake up one polling thread (which can wake up other threads if
+ * needed) */
+grpc_wakeup_fd grpc_global_wakeup_fd;
+
+static grpc_fd *fd_freelist = NULL;
+static gpr_mu fd_freelist_mu;
+
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+#define REF_BY(fd, n, reason) ref_by(fd, n, reason, __FILE__, __LINE__)
+#define UNREF_BY(fd, n, reason) unref_by(fd, n, reason, __FILE__, __LINE__)
+static void ref_by(grpc_fd *fd, int n, const char *reason, const char *file,
+ int line) {
+ gpr_log(GPR_DEBUG, "FD %d %p ref %d %ld -> %ld [%s; %s:%d]", fd->fd,
+ (void *)fd, n, gpr_atm_no_barrier_load(&fd->refst),
+ gpr_atm_no_barrier_load(&fd->refst) + n, reason, file, line);
+#else
+#define REF_BY(fd, n, reason) ref_by(fd, n)
+#define UNREF_BY(fd, n, reason) unref_by(fd, n)
+static void ref_by(grpc_fd *fd, int n) {
+#endif
+ GPR_ASSERT(gpr_atm_no_barrier_fetch_add(&fd->refst, n) > 0);
+}
+
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+static void unref_by(grpc_fd *fd, int n, const char *reason, const char *file,
+ int line) {
+ gpr_atm old;
+ gpr_log(GPR_DEBUG, "FD %d %p unref %d %ld -> %ld [%s; %s:%d]", fd->fd,
+ (void *)fd, n, gpr_atm_no_barrier_load(&fd->refst),
+ gpr_atm_no_barrier_load(&fd->refst) - n, reason, file, line);
+#else
+static void unref_by(grpc_fd *fd, int n) {
+ gpr_atm old;
+#endif
+ old = gpr_atm_full_fetch_add(&fd->refst, -n);
+ if (old == n) {
+ /* Add the fd to the freelist */
+ gpr_mu_lock(&fd_freelist_mu);
+ fd->freelist_next = fd_freelist;
+ fd_freelist = fd;
+ grpc_iomgr_unregister_object(&fd->iomgr_object);
+
+ gpr_mu_unlock(&fd_freelist_mu);
+ } else {
+ GPR_ASSERT(old > n);
+ }
+}
+
+/* Increment refcount by two to avoid changing the orphan bit */
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+static void fd_ref(grpc_fd *fd, const char *reason, const char *file,
+ int line) {
+ ref_by(fd, 2, reason, file, line);
+}
+
+static void fd_unref(grpc_fd *fd, const char *reason, const char *file,
+ int line) {
+ unref_by(fd, 2, reason, file, line);
+}
+#else
+static void fd_ref(grpc_fd *fd) { ref_by(fd, 2); }
+static void fd_unref(grpc_fd *fd) { unref_by(fd, 2); }
+#endif
+
+static void fd_global_init(void) { gpr_mu_init(&fd_freelist_mu); }
+
+static void fd_global_shutdown(void) {
+ gpr_mu_lock(&fd_freelist_mu);
+ gpr_mu_unlock(&fd_freelist_mu);
+ while (fd_freelist != NULL) {
+ grpc_fd *fd = fd_freelist;
+ fd_freelist = fd_freelist->freelist_next;
+ gpr_mu_destroy(&fd->mu);
+ gpr_free(fd);
+ }
+ gpr_mu_destroy(&fd_freelist_mu);
+}
+
+static grpc_fd *fd_create(int fd, const char *name) {
+ grpc_fd *new_fd = NULL;
+
+ gpr_mu_lock(&fd_freelist_mu);
+ if (fd_freelist != NULL) {
+ new_fd = fd_freelist;
+ fd_freelist = fd_freelist->freelist_next;
+ }
+ gpr_mu_unlock(&fd_freelist_mu);
+
+ if (new_fd == NULL) {
+ new_fd = gpr_malloc(sizeof(grpc_fd));
+ gpr_mu_init(&new_fd->mu);
+ gpr_mu_init(&new_fd->pi_mu);
+ }
+
+ /* Note: It is not really needed to get the new_fd->mu lock here. If this is a
+ newly created fd (or an fd we got from the freelist), no one else would be
+ holding a lock to it anyway. */
+ gpr_mu_lock(&new_fd->mu);
+
+ gpr_atm_rel_store(&new_fd->refst, (gpr_atm)1);
+ new_fd->fd = fd;
+ new_fd->shutdown = false;
+ new_fd->orphaned = false;
+ new_fd->read_closure = CLOSURE_NOT_READY;
+ new_fd->write_closure = CLOSURE_NOT_READY;
+ new_fd->polling_island = NULL;
+ new_fd->freelist_next = NULL;
+ new_fd->on_done_closure = NULL;
+ new_fd->read_notifier_pollset = NULL;
+
+ gpr_mu_unlock(&new_fd->mu);
+
+ char *fd_name;
+ gpr_asprintf(&fd_name, "%s fd=%d", name, fd);
+ grpc_iomgr_register_object(&new_fd->iomgr_object, fd_name);
+#ifdef GRPC_FD_REF_COUNT_DEBUG
+ gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, (void *)new_fd, fd_name);
+#endif
+ gpr_free(fd_name);
+ return new_fd;
+}
+
+static bool fd_is_orphaned(grpc_fd *fd) {
+ return (gpr_atm_acq_load(&fd->refst) & 1) == 0;
+}
+
+static int fd_wrapped_fd(grpc_fd *fd) {
+ int ret_fd = -1;
+ gpr_mu_lock(&fd->mu);
+ if (!fd->orphaned) {
+ ret_fd = fd->fd;
+ }
+ gpr_mu_unlock(&fd->mu);
+
+ return ret_fd;
+}
+
+static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+ grpc_closure *on_done, int *release_fd,
+ const char *reason) {
+ bool is_fd_closed = false;
+ grpc_error *error = GRPC_ERROR_NONE;
+
+ gpr_mu_lock(&fd->mu);
+ fd->on_done_closure = on_done;
+
+ /* If release_fd is not NULL, we should be relinquishing control of the file
+ descriptor fd->fd (but we still own the grpc_fd structure). */
+ if (release_fd != NULL) {
+ *release_fd = fd->fd;
+ } else {
+ close(fd->fd);
+ is_fd_closed = true;
+ }
+
+ fd->orphaned = true;
+
+ /* Remove the active status but keep referenced. We want this grpc_fd struct
+ to be alive (and not added to freelist) until the end of this function */
+ REF_BY(fd, 1, reason);
+
+ /* Remove the fd from the polling island:
+ - Get a lock on the latest polling island (i.e the last island in the
+ linked list pointed by fd->polling_island). This is the island that
+ would actually contain the fd
+ - Remove the fd from the latest polling island
+ - Unlock the latest polling island
+ - Set fd->polling_island to NULL (but remove the ref on the polling island
+ before doing this.) */
+ gpr_mu_lock(&fd->pi_mu);
+ if (fd->polling_island != NULL) {
+ polling_island *pi_latest = polling_island_lock(fd->polling_island);
+ polling_island_remove_fd_locked(pi_latest, fd, is_fd_closed, &error);
+ gpr_mu_unlock(&pi_latest->mu);
+
+ PI_UNREF(fd->polling_island, "fd_orphan");
+ fd->polling_island = NULL;
+ }
+ gpr_mu_unlock(&fd->pi_mu);
+
+ grpc_exec_ctx_sched(exec_ctx, fd->on_done_closure, error, NULL);
+
+ gpr_mu_unlock(&fd->mu);
+ UNREF_BY(fd, 2, reason); /* Drop the reference */
+ GRPC_LOG_IF_ERROR("fd_orphan", GRPC_ERROR_REF(error));
+}
+
+static grpc_error *fd_shutdown_error(bool shutdown) {
+ if (!shutdown) {
+ return GRPC_ERROR_NONE;
+ } else {
+ return GRPC_ERROR_CREATE("FD shutdown");
+ }
+}
+
+static void notify_on_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+ grpc_closure **st, grpc_closure *closure) {
+ if (fd->shutdown) {
+ grpc_exec_ctx_sched(exec_ctx, closure, GRPC_ERROR_CREATE("FD shutdown"),
+ NULL);
+ } else if (*st == CLOSURE_NOT_READY) {
+ /* not ready ==> switch to a waiting state by setting the closure */
+ *st = closure;
+ } else if (*st == CLOSURE_READY) {
+ /* already ready ==> queue the closure to run immediately */
+ *st = CLOSURE_NOT_READY;
+ grpc_exec_ctx_sched(exec_ctx, closure, fd_shutdown_error(fd->shutdown),
+ NULL);
+ } else {
+ /* upcallptr was set to a different closure. This is an error! */
+ gpr_log(GPR_ERROR,
+ "User called a notify_on function with a previous callback still "
+ "pending");
+ abort();
+ }
+}
+
+/* returns 1 if state becomes not ready */
+static int set_ready_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+ grpc_closure **st) {
+ if (*st == CLOSURE_READY) {
+ /* duplicate ready ==> ignore */
+ return 0;
+ } else if (*st == CLOSURE_NOT_READY) {
+ /* not ready, and not waiting ==> flag ready */
+ *st = CLOSURE_READY;
+ return 0;
+ } else {
+ /* waiting ==> queue closure */
+ grpc_exec_ctx_sched(exec_ctx, *st, fd_shutdown_error(fd->shutdown), NULL);
+ *st = CLOSURE_NOT_READY;
+ return 1;
+ }
+}
+
+static grpc_pollset *fd_get_read_notifier_pollset(grpc_exec_ctx *exec_ctx,
+ grpc_fd *fd) {
+ grpc_pollset *notifier = NULL;
+
+ gpr_mu_lock(&fd->mu);
+ notifier = fd->read_notifier_pollset;
+ gpr_mu_unlock(&fd->mu);
+
+ return notifier;
+}
+
+static bool fd_is_shutdown(grpc_fd *fd) {
+ gpr_mu_lock(&fd->mu);
+ const bool r = fd->shutdown;
+ gpr_mu_unlock(&fd->mu);
+ return r;
+}
+
+/* Might be called multiple times */
+static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
+ gpr_mu_lock(&fd->mu);
+ /* Do the actual shutdown only once */
+ if (!fd->shutdown) {
+ fd->shutdown = true;
+
+ shutdown(fd->fd, SHUT_RDWR);
+ /* Flush any pending read and write closures. Since fd->shutdown is 'true'
+ at this point, the closures would be called with 'success = false' */
+ set_ready_locked(exec_ctx, fd, &fd->read_closure);
+ set_ready_locked(exec_ctx, fd, &fd->write_closure);
+ }
+ gpr_mu_unlock(&fd->mu);
+}
+
+static void fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+ grpc_closure *closure) {
+ gpr_mu_lock(&fd->mu);
+ notify_on_locked(exec_ctx, fd, &fd->read_closure, closure);
+ gpr_mu_unlock(&fd->mu);
+}
+
+static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+ grpc_closure *closure) {
+ gpr_mu_lock(&fd->mu);
+ notify_on_locked(exec_ctx, fd, &fd->write_closure, closure);
+ gpr_mu_unlock(&fd->mu);
+}
+
+/*******************************************************************************
+ * Pollset Definitions
+ */
+GPR_TLS_DECL(g_current_thread_pollset);
+GPR_TLS_DECL(g_current_thread_worker);
+static __thread bool g_initialized_sigmask;
+static __thread sigset_t g_orig_sigmask;
+
+static void sig_handler(int sig_num) {
+#ifdef GRPC_EPOLL_DEBUG
+ gpr_log(GPR_INFO, "Received signal %d", sig_num);
+#endif
+}
+
+static void poller_kick_init() { signal(grpc_wakeup_signal, sig_handler); }
+
+/* Global state management */
+static grpc_error *pollset_global_init(void) {
+ gpr_tls_init(&g_current_thread_pollset);
+ gpr_tls_init(&g_current_thread_worker);
+ poller_kick_init();
+ return grpc_wakeup_fd_init(&grpc_global_wakeup_fd);
+}
+
+static void pollset_global_shutdown(void) {
+ grpc_wakeup_fd_destroy(&grpc_global_wakeup_fd);
+ gpr_tls_destroy(&g_current_thread_pollset);
+ gpr_tls_destroy(&g_current_thread_worker);
+}
+
+static grpc_error *pollset_worker_kick(grpc_pollset_worker *worker) {
+ grpc_error *err = GRPC_ERROR_NONE;
+
+ /* Kick the worker only if it was not already kicked */
+ if (gpr_atm_no_barrier_cas(&worker->is_kicked, (gpr_atm)0, (gpr_atm)1)) {
+ GRPC_POLLING_TRACE(
+ "pollset_worker_kick: Kicking worker: %p (thread id: %ld)",
+ (void *)worker, worker->pt_id);
+ int err_num = pthread_kill(worker->pt_id, grpc_wakeup_signal);
+ if (err_num != 0) {
+ err = GRPC_OS_ERROR(err_num, "pthread_kill");
+ }
+ }
+ return err;
+}
+
+/* Return 1 if the pollset has active threads in pollset_work (pollset must
+ * be locked) */
+static int pollset_has_workers(grpc_pollset *p) {
+ return p->root_worker.next != &p->root_worker;
+}
+
+static void remove_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
+ worker->prev->next = worker->next;
+ worker->next->prev = worker->prev;
+}
+
+static grpc_pollset_worker *pop_front_worker(grpc_pollset *p) {
+ if (pollset_has_workers(p)) {
+ grpc_pollset_worker *w = p->root_worker.next;
+ remove_worker(p, w);
+ return w;
+ } else {
+ return NULL;
+ }
+}
+
+static void push_back_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
+ worker->next = &p->root_worker;
+ worker->prev = worker->next->prev;
+ worker->prev->next = worker->next->prev = worker;
+}
+
+static void push_front_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
+ worker->prev = &p->root_worker;
+ worker->next = worker->prev->next;
+ worker->prev->next = worker->next->prev = worker;
+}
+
+/* p->mu must be held before calling this function */
+static grpc_error *pollset_kick(grpc_pollset *p,
+ grpc_pollset_worker *specific_worker) {
+ GPR_TIMER_BEGIN("pollset_kick", 0);
+ grpc_error *error = GRPC_ERROR_NONE;
+ const char *err_desc = "Kick Failure";
+ grpc_pollset_worker *worker = specific_worker;
+ if (worker != NULL) {
+ if (worker == GRPC_POLLSET_KICK_BROADCAST) {
+ if (pollset_has_workers(p)) {
+ GPR_TIMER_BEGIN("pollset_kick.broadcast", 0);
+ for (worker = p->root_worker.next; worker != &p->root_worker;
+ worker = worker->next) {
+ if (gpr_tls_get(&g_current_thread_worker) != (intptr_t)worker) {
+ append_error(&error, pollset_worker_kick(worker), err_desc);
+ }
+ }
+ GPR_TIMER_END("pollset_kick.broadcast", 0);
+ } else {
+ p->kicked_without_pollers = true;
+ }
+ } else {
+ GPR_TIMER_MARK("kicked_specifically", 0);
+ if (gpr_tls_get(&g_current_thread_worker) != (intptr_t)worker) {
+ append_error(&error, pollset_worker_kick(worker), err_desc);
+ }
+ }
+ } else if (gpr_tls_get(&g_current_thread_pollset) != (intptr_t)p) {
+ /* Since worker == NULL, it means that we can kick "any" worker on this
+ pollset 'p'. If 'p' happens to be the same pollset this thread is
+ currently polling (i.e in pollset_work() function), then there is no need
+ to kick any other worker since the current thread can just absorb the
+ kick. This is the reason why we enter this case only when
+ g_current_thread_pollset is != p */
+
+ GPR_TIMER_MARK("kick_anonymous", 0);
+ worker = pop_front_worker(p);
+ if (worker != NULL) {
+ GPR_TIMER_MARK("finally_kick", 0);
+ push_back_worker(p, worker);
+ append_error(&error, pollset_worker_kick(worker), err_desc);
+ } else {
+ GPR_TIMER_MARK("kicked_no_pollers", 0);
+ p->kicked_without_pollers = true;
+ }
+ }
+
+ GPR_TIMER_END("pollset_kick", 0);
+ GRPC_LOG_IF_ERROR("pollset_kick", GRPC_ERROR_REF(error));
+ return error;
+}
+
+static grpc_error *kick_poller(void) {
+ return grpc_wakeup_fd_wakeup(&grpc_global_wakeup_fd);
+}
+
+static void pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
+ gpr_mu_init(&pollset->mu);
+ *mu = &pollset->mu;
+
+ pollset->root_worker.next = pollset->root_worker.prev = &pollset->root_worker;
+ pollset->kicked_without_pollers = false;
+
+ pollset->shutting_down = false;
+ pollset->finish_shutdown_called = false;
+ pollset->shutdown_done = NULL;
+
+ pollset->polling_island = NULL;
+}
+
+/* Convert a timespec to milliseconds:
+ - Very small or negative poll times are clamped to zero to do a non-blocking
+ poll (which becomes spin polling)
+ - Other small values are rounded up to one millisecond
+ - Longer than a millisecond polls are rounded up to the next nearest
+ millisecond to avoid spinning
+ - Infinite timeouts are converted to -1 */
+static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
+ gpr_timespec now) {
+ gpr_timespec timeout;
+ static const int64_t max_spin_polling_us = 10;
+ if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
+ return -1;
+ }
+
+ if (gpr_time_cmp(deadline, gpr_time_add(now, gpr_time_from_micros(
+ max_spin_polling_us,
+ GPR_TIMESPAN))) <= 0) {
+ return 0;
+ }
+ timeout = gpr_time_sub(deadline, now);
+ return gpr_time_to_millis(gpr_time_add(
+ timeout, gpr_time_from_nanos(GPR_NS_PER_MS - 1, GPR_TIMESPAN)));
+}
+
+static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
+ grpc_pollset *notifier) {
+ /* Need the fd->mu since we might be racing with fd_notify_on_read */
+ gpr_mu_lock(&fd->mu);
+ set_ready_locked(exec_ctx, fd, &fd->read_closure);
+ fd->read_notifier_pollset = notifier;
+ gpr_mu_unlock(&fd->mu);
+}
+
+static void fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
+ /* Need the fd->mu since we might be racing with fd_notify_on_write */
+ gpr_mu_lock(&fd->mu);
+ set_ready_locked(exec_ctx, fd, &fd->write_closure);
+ gpr_mu_unlock(&fd->mu);
+}
+
+static void pollset_release_polling_island(grpc_pollset *ps, char *reason) {
+ if (ps->polling_island != NULL) {
+ PI_UNREF(ps->polling_island, reason);
+ }
+ ps->polling_island = NULL;
+}
+
+static void finish_shutdown_locked(grpc_exec_ctx *exec_ctx,
+ grpc_pollset *pollset) {
+ /* The pollset cannot have any workers if we are at this stage */
+ GPR_ASSERT(!pollset_has_workers(pollset));
+
+ pollset->finish_shutdown_called = true;
+
+ /* Release the ref and set pollset->polling_island to NULL */
+ pollset_release_polling_island(pollset, "ps_shutdown");
+ grpc_exec_ctx_sched(exec_ctx, pollset->shutdown_done, GRPC_ERROR_NONE, NULL);
+}
+
+/* pollset->mu lock must be held by the caller before calling this */
+static void pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+ grpc_closure *closure) {
+ GPR_TIMER_BEGIN("pollset_shutdown", 0);
+ GPR_ASSERT(!pollset->shutting_down);
+ pollset->shutting_down = true;
+ pollset->shutdown_done = closure;
+ pollset_kick(pollset, GRPC_POLLSET_KICK_BROADCAST);
+
+ /* If the pollset has any workers, we cannot call finish_shutdown_locked()
+ because it would release the underlying polling island. In such a case, we
+ let the last worker call finish_shutdown_locked() from pollset_work() */
+ if (!pollset_has_workers(pollset)) {
+ GPR_ASSERT(!pollset->finish_shutdown_called);
+ GPR_TIMER_MARK("pollset_shutdown.finish_shutdown_locked", 0);
+ finish_shutdown_locked(exec_ctx, pollset);
+ }
+ GPR_TIMER_END("pollset_shutdown", 0);
+}
+
+/* pollset_shutdown is guaranteed to be called before pollset_destroy. So other
+ * than destroying the mutexes, there is nothing special that needs to be done
+ * here */
+static void pollset_destroy(grpc_pollset *pollset) {
+ GPR_ASSERT(!pollset_has_workers(pollset));
+ gpr_mu_destroy(&pollset->mu);
+}
+
+static void pollset_reset(grpc_pollset *pollset) {
+ GPR_ASSERT(pollset->shutting_down);
+ GPR_ASSERT(!pollset_has_workers(pollset));
+ pollset->shutting_down = false;
+ pollset->finish_shutdown_called = false;
+ pollset->kicked_without_pollers = false;
+ pollset->shutdown_done = NULL;
+ pollset_release_polling_island(pollset, "ps_reset");
+}
+
+#define GRPC_EPOLL_MAX_EVENTS 1000
+/* Note: sig_mask contains the signal mask to use *during* epoll_wait() */
+static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
+ grpc_pollset *pollset,
+ grpc_pollset_worker *worker, int timeout_ms,
+ sigset_t *sig_mask, grpc_error **error) {
+ struct epoll_event ep_ev[GRPC_EPOLL_MAX_EVENTS];
+ int epoll_fd = -1;
+ int ep_rv;
+ polling_island *pi = NULL;
+ char *err_msg;
+ const char *err_desc = "pollset_work_and_unlock";
+ GPR_TIMER_BEGIN("pollset_work_and_unlock", 0);
+
+ /* We need to get the epoll_fd to wait on. The epoll_fd is in inside the
+ latest polling island pointed by pollset->polling_island.
+
+ Since epoll_fd is immutable, we can read it without obtaining the polling
+ island lock. There is however a possibility that the polling island (from
+ which we got the epoll_fd) got merged with another island while we are
+ in this function. This is still okay because in such a case, we will wakeup
+ right-away from epoll_wait() and pick up the latest polling_island the next
+ this function (i.e pollset_work_and_unlock()) is called */
+
+ if (pollset->polling_island == NULL) {
+ pollset->polling_island = polling_island_create(NULL, error);
+ if (pollset->polling_island == NULL) {
+ GPR_TIMER_END("pollset_work_and_unlock", 0);
+ return; /* Fatal error. We cannot continue */
+ }
+
+ PI_ADD_REF(pollset->polling_island, "ps");
+ GRPC_POLLING_TRACE("pollset_work: pollset: %p created new pi: %p",
+ (void *)pollset, (void *)pollset->polling_island);
+ }
+
+ pi = polling_island_maybe_get_latest(pollset->polling_island);
+ epoll_fd = pi->epoll_fd;
+
+ /* Update the pollset->polling_island since the island being pointed by
+ pollset->polling_island maybe older than the one pointed by pi) */
+ if (pollset->polling_island != pi) {
+ /* Always do PI_ADD_REF before PI_UNREF because PI_UNREF may cause the
+ polling island to be deleted */
+ PI_ADD_REF(pi, "ps");
+ PI_UNREF(pollset->polling_island, "ps");
+ pollset->polling_island = pi;
+ }
+
+ /* Add an extra ref so that the island does not get destroyed (which means
+ the epoll_fd won't be closed) while we are are doing an epoll_wait() on the
+ epoll_fd */
+ PI_ADD_REF(pi, "ps_work");
+ gpr_mu_unlock(&pollset->mu);
+
+ do {
+ ep_rv = epoll_pwait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, timeout_ms,
+ sig_mask);
+ if (ep_rv < 0) {
+ if (errno != EINTR) {
+ gpr_asprintf(&err_msg,
+ "epoll_wait() epoll fd: %d failed with error: %d (%s)",
+ epoll_fd, errno, strerror(errno));
+ append_error(error, GRPC_OS_ERROR(errno, err_msg), err_desc);
+ } else {
+ /* We were interrupted. Save an interation by doing a zero timeout
+ epoll_wait to see if there are any other events of interest */
+ GRPC_POLLING_TRACE(
+ "pollset_work: pollset: %p, worker: %p received kick",
+ (void *)pollset, (void *)worker);
+ ep_rv = epoll_wait(epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, 0);
+ }
+ }
+
+#ifdef GRPC_TSAN
+ /* See the definition of g_poll_sync for more details */
+ gpr_atm_acq_load(&g_epoll_sync);
+#endif /* defined(GRPC_TSAN) */
+
+ for (int i = 0; i < ep_rv; ++i) {
+ void *data_ptr = ep_ev[i].data.ptr;
+ if (data_ptr == &grpc_global_wakeup_fd) {
+ append_error(error,
+ grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd),
+ err_desc);
+ } else if (data_ptr == &polling_island_wakeup_fd) {
+ GRPC_POLLING_TRACE(
+ "pollset_work: pollset: %p, worker: %p polling island (epoll_fd: "
+ "%d) got merged",
+ (void *)pollset, (void *)worker, epoll_fd);
+ /* This means that our polling island is merged with a different
+ island. We do not have to do anything here since the subsequent call
+ to the function pollset_work_and_unlock() will pick up the correct
+ epoll_fd */
+ } else {
+ grpc_fd *fd = data_ptr;
+ int cancel = ep_ev[i].events & (EPOLLERR | EPOLLHUP);
+ int read_ev = ep_ev[i].events & (EPOLLIN | EPOLLPRI);
+ int write_ev = ep_ev[i].events & EPOLLOUT;
+ if (read_ev || cancel) {
+ fd_become_readable(exec_ctx, fd, pollset);
+ }
+ if (write_ev || cancel) {
+ fd_become_writable(exec_ctx, fd);
+ }
+ }
+ }
+ } while (ep_rv == GRPC_EPOLL_MAX_EVENTS);
+
+ GPR_ASSERT(pi != NULL);
+
+ /* Before leaving, release the extra ref we added to the polling island. It
+ is important to use "pi" here (i.e our old copy of pollset->polling_island
+ that we got before releasing the polling island lock). This is because
+ pollset->polling_island pointer might get udpated in other parts of the
+ code when there is an island merge while we are doing epoll_wait() above */
+ PI_UNREF(pi, "ps_work");
+
+ GPR_TIMER_END("pollset_work_and_unlock", 0);
+}
+
+/* pollset->mu lock must be held by the caller before calling this.
+ The function pollset_work() may temporarily release the lock (pollset->mu)
+ during the course of its execution but it will always re-acquire the lock and
+ ensure that it is held by the time the function returns */
+static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+ grpc_pollset_worker **worker_hdl,
+ gpr_timespec now, gpr_timespec deadline) {
+ GPR_TIMER_BEGIN("pollset_work", 0);
+ grpc_error *error = GRPC_ERROR_NONE;
+ int timeout_ms = poll_deadline_to_millis_timeout(deadline, now);
+
+ sigset_t new_mask;
+
+ grpc_pollset_worker worker;
+ worker.next = worker.prev = NULL;
+ worker.pt_id = pthread_self();
+ gpr_atm_no_barrier_store(&worker.is_kicked, (gpr_atm)0);
+
+ *worker_hdl = &worker;
+
+ gpr_tls_set(&g_current_thread_pollset, (intptr_t)pollset);
+ gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker);
+
+ if (pollset->kicked_without_pollers) {
+ /* If the pollset was kicked without pollers, pretend that the current
+ worker got the kick and skip polling. A kick indicates that there is some
+ work that needs attention like an event on the completion queue or an
+ alarm */
+ GPR_TIMER_MARK("pollset_work.kicked_without_pollers", 0);
+ pollset->kicked_without_pollers = 0;
+ } else if (!pollset->shutting_down) {
+ /* We use the posix-signal with number 'grpc_wakeup_signal' for waking up
+ (i.e 'kicking') a worker in the pollset. A 'kick' is a way to inform the
+ worker that there is some pending work that needs immediate attention
+ (like an event on the completion queue, or a polling island merge that
+ results in a new epoll-fd to wait on) and that the worker should not
+ spend time waiting in epoll_pwait().
+
+ A worker can be kicked anytime from the point it is added to the pollset
+ via push_front_worker() (or push_back_worker()) to the point it is
+ removed via remove_worker().
+ If the worker is kicked before/during it calls epoll_pwait(), it should
+ immediately exit from epoll_wait(). If the worker is kicked after it
+ returns from epoll_wait(), then nothing really needs to be done.
+
+ To accomplish this, we mask 'grpc_wakeup_signal' on this thread at all
+ times *except* when it is in epoll_pwait(). This way, the worker never
+ misses acting on a kick */
+
+ if (!g_initialized_sigmask) {
+ sigemptyset(&new_mask);
+ sigaddset(&new_mask, grpc_wakeup_signal);
+ pthread_sigmask(SIG_BLOCK, &new_mask, &g_orig_sigmask);
+ sigdelset(&g_orig_sigmask, grpc_wakeup_signal);
+ g_initialized_sigmask = true;
+ /* new_mask: The new thread mask which blocks 'grpc_wakeup_signal'.
+ This is the mask used at all times *except during
+ epoll_wait()*"
+ g_orig_sigmask: The thread mask which allows 'grpc_wakeup_signal' and
+ this is the mask to use *during epoll_wait()*
+
+ The new_mask is set on the worker before it is added to the pollset
+ (i.e before it can be kicked) */
+ }
+
+ push_front_worker(pollset, &worker); /* Add worker to pollset */
+
+ pollset_work_and_unlock(exec_ctx, pollset, &worker, timeout_ms,
+ &g_orig_sigmask, &error);
+ grpc_exec_ctx_flush(exec_ctx);
+
+ gpr_mu_lock(&pollset->mu);
+
+ /* Note: There is no need to reset worker.is_kicked to 0 since we are no
+ longer going to use this worker */
+ remove_worker(pollset, &worker);
+ }
+
+ /* If we are the last worker on the pollset (i.e pollset_has_workers() is
+ false at this point) and the pollset is shutting down, we may have to
+ finish the shutdown process by calling finish_shutdown_locked().
+ See pollset_shutdown() for more details.
+
+ Note: Continuing to access pollset here is safe; it is the caller's
+ responsibility to not destroy a pollset when it has outstanding calls to
+ pollset_work() */
+ if (pollset->shutting_down && !pollset_has_workers(pollset) &&
+ !pollset->finish_shutdown_called) {
+ GPR_TIMER_MARK("pollset_work.finish_shutdown_locked", 0);
+ finish_shutdown_locked(exec_ctx, pollset);
+
+ gpr_mu_unlock(&pollset->mu);
+ grpc_exec_ctx_flush(exec_ctx);
+ gpr_mu_lock(&pollset->mu);
+ }
+
+ *worker_hdl = NULL;
+
+ gpr_tls_set(&g_current_thread_pollset, (intptr_t)0);
+ gpr_tls_set(&g_current_thread_worker, (intptr_t)0);
+
+ GPR_TIMER_END("pollset_work", 0);
+
+ GRPC_LOG_IF_ERROR("pollset_work", GRPC_ERROR_REF(error));
+ return error;
+}
+
+static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+ grpc_fd *fd) {
+ grpc_error *error = GRPC_ERROR_NONE;
+
+ gpr_mu_lock(&pollset->mu);
+ gpr_mu_lock(&fd->pi_mu);
+
+ polling_island *pi_new = NULL;
+
+ /* 1) If fd->polling_island and pollset->polling_island are both non-NULL and
+ * equal, do nothing.
+ * 2) If fd->polling_island and pollset->polling_island are both NULL, create
+ * a new polling island (with a refcount of 2) and make the polling_island
+ * fields in both fd and pollset to point to the new island
+ * 3) If one of fd->polling_island or pollset->polling_island is NULL, update
+ * the NULL polling_island field to point to the non-NULL polling_island
+ * field (ensure that the refcount on the polling island is incremented by
+ * 1 to account for the newly added reference)
+ * 4) Finally, if fd->polling_island and pollset->polling_island are non-NULL
+ * and different, merge both the polling islands and update the
+ * polling_island fields in both fd and pollset to point to the merged
+ * polling island.
+ */
+ if (fd->polling_island == pollset->polling_island) {
+ pi_new = fd->polling_island;
+ if (pi_new == NULL) {
+ pi_new = polling_island_create(fd, &error);
+
+ GRPC_POLLING_TRACE(
+ "pollset_add_fd: Created new polling island. pi_new: %p (fd: %d, "
+ "pollset: %p)",
+ (void *)pi_new, fd->fd, (void *)pollset);
+ }
+ } else if (fd->polling_island == NULL) {
+ pi_new = polling_island_lock(pollset->polling_island);
+ polling_island_add_fds_locked(pi_new, &fd, 1, true, &error);
+ gpr_mu_unlock(&pi_new->mu);
+
+ GRPC_POLLING_TRACE(
+ "pollset_add_fd: fd->pi was NULL. pi_new: %p (fd: %d, pollset: %p, "
+ "pollset->pi: %p)",
+ (void *)pi_new, fd->fd, (void *)pollset,
+ (void *)pollset->polling_island);
+ } else if (pollset->polling_island == NULL) {
+ pi_new = polling_island_lock(fd->polling_island);
+ gpr_mu_unlock(&pi_new->mu);
+
+ GRPC_POLLING_TRACE(
+ "pollset_add_fd: pollset->pi was NULL. pi_new: %p (fd: %d, pollset: "
+ "%p, fd->pi: %p",
+ (void *)pi_new, fd->fd, (void *)pollset, (void *)fd->polling_island);
+ } else {
+ pi_new = polling_island_merge(fd->polling_island, pollset->polling_island,
+ &error);
+ GRPC_POLLING_TRACE(
+ "pollset_add_fd: polling islands merged. pi_new: %p (fd: %d, pollset: "
+ "%p, fd->pi: %p, pollset->pi: %p)",
+ (void *)pi_new, fd->fd, (void *)pollset, (void *)fd->polling_island,
+ (void *)pollset->polling_island);
+ }
+
+ /* At this point, pi_new is the polling island that both fd->polling_island
+ and pollset->polling_island must be pointing to */
+
+ if (fd->polling_island != pi_new) {
+ PI_ADD_REF(pi_new, "fd");
+ if (fd->polling_island != NULL) {
+ PI_UNREF(fd->polling_island, "fd");
+ }
+ fd->polling_island = pi_new;
+ }
+
+ if (pollset->polling_island != pi_new) {
+ PI_ADD_REF(pi_new, "ps");
+ if (pollset->polling_island != NULL) {
+ PI_UNREF(pollset->polling_island, "ps");
+ }
+ pollset->polling_island = pi_new;
+ }
+
+ gpr_mu_unlock(&fd->pi_mu);
+ gpr_mu_unlock(&pollset->mu);
+}
+
+/*******************************************************************************
+ * Pollset-set Definitions
+ */
+
+static grpc_pollset_set *pollset_set_create(void) {
+ grpc_pollset_set *pollset_set = gpr_malloc(sizeof(*pollset_set));
+ memset(pollset_set, 0, sizeof(*pollset_set));
+ gpr_mu_init(&pollset_set->mu);
+ return pollset_set;
+}
+
+static void pollset_set_destroy(grpc_pollset_set *pollset_set) {
+ size_t i;
+ gpr_mu_destroy(&pollset_set->mu);
+ for (i = 0; i < pollset_set->fd_count; i++) {
+ GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
+ }
+ gpr_free(pollset_set->pollsets);
+ gpr_free(pollset_set->pollset_sets);
+ gpr_free(pollset_set->fds);
+ gpr_free(pollset_set);
+}
+
+static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
+ grpc_pollset_set *pollset_set, grpc_fd *fd) {
+ size_t i;
+ gpr_mu_lock(&pollset_set->mu);
+ if (pollset_set->fd_count == pollset_set->fd_capacity) {
+ pollset_set->fd_capacity = GPR_MAX(8, 2 * pollset_set->fd_capacity);
+ pollset_set->fds = gpr_realloc(
+ pollset_set->fds, pollset_set->fd_capacity * sizeof(*pollset_set->fds));
+ }
+ GRPC_FD_REF(fd, "pollset_set");
+ pollset_set->fds[pollset_set->fd_count++] = fd;
+ for (i = 0; i < pollset_set->pollset_count; i++) {
+ pollset_add_fd(exec_ctx, pollset_set->pollsets[i], fd);
+ }
+ for (i = 0; i < pollset_set->pollset_set_count; i++) {
+ pollset_set_add_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
+ }
+ gpr_mu_unlock(&pollset_set->mu);
+}
+
+static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
+ grpc_pollset_set *pollset_set, grpc_fd *fd) {
+ size_t i;
+ gpr_mu_lock(&pollset_set->mu);
+ for (i = 0; i < pollset_set->fd_count; i++) {
+ if (pollset_set->fds[i] == fd) {
+ pollset_set->fd_count--;
+ GPR_SWAP(grpc_fd *, pollset_set->fds[i],
+ pollset_set->fds[pollset_set->fd_count]);
+ GRPC_FD_UNREF(fd, "pollset_set");
+ break;
+ }
+ }
+ for (i = 0; i < pollset_set->pollset_set_count; i++) {
+ pollset_set_del_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
+ }
+ gpr_mu_unlock(&pollset_set->mu);
+}
+
+static void pollset_set_add_pollset(grpc_exec_ctx *exec_ctx,
+ grpc_pollset_set *pollset_set,
+ grpc_pollset *pollset) {
+ size_t i, j;
+ gpr_mu_lock(&pollset_set->mu);
+ if (pollset_set->pollset_count == pollset_set->pollset_capacity) {
+ pollset_set->pollset_capacity =
+ GPR_MAX(8, 2 * pollset_set->pollset_capacity);
+ pollset_set->pollsets =
+ gpr_realloc(pollset_set->pollsets, pollset_set->pollset_capacity *
+ sizeof(*pollset_set->pollsets));
+ }
+ pollset_set->pollsets[pollset_set->pollset_count++] = pollset;
+ for (i = 0, j = 0; i < pollset_set->fd_count; i++) {
+ if (fd_is_orphaned(pollset_set->fds[i])) {
+ GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
+ } else {
+ pollset_add_fd(exec_ctx, pollset, pollset_set->fds[i]);
+ pollset_set->fds[j++] = pollset_set->fds[i];
+ }
+ }
+ pollset_set->fd_count = j;
+ gpr_mu_unlock(&pollset_set->mu);
+}
+
+static void pollset_set_del_pollset(grpc_exec_ctx *exec_ctx,
+ grpc_pollset_set *pollset_set,
+ grpc_pollset *pollset) {
+ size_t i;
+ gpr_mu_lock(&pollset_set->mu);
+ for (i = 0; i < pollset_set->pollset_count; i++) {
+ if (pollset_set->pollsets[i] == pollset) {
+ pollset_set->pollset_count--;
+ GPR_SWAP(grpc_pollset *, pollset_set->pollsets[i],
+ pollset_set->pollsets[pollset_set->pollset_count]);
+ break;
+ }
+ }
+ gpr_mu_unlock(&pollset_set->mu);
+}
+
+static void pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx,
+ grpc_pollset_set *bag,
+ grpc_pollset_set *item) {
+ size_t i, j;
+ gpr_mu_lock(&bag->mu);
+ if (bag->pollset_set_count == bag->pollset_set_capacity) {
+ bag->pollset_set_capacity = GPR_MAX(8, 2 * bag->pollset_set_capacity);
+ bag->pollset_sets =
+ gpr_realloc(bag->pollset_sets,
+ bag->pollset_set_capacity * sizeof(*bag->pollset_sets));
+ }
+ bag->pollset_sets[bag->pollset_set_count++] = item;
+ for (i = 0, j = 0; i < bag->fd_count; i++) {
+ if (fd_is_orphaned(bag->fds[i])) {
+ GRPC_FD_UNREF(bag->fds[i], "pollset_set");
+ } else {
+ pollset_set_add_fd(exec_ctx, item, bag->fds[i]);
+ bag->fds[j++] = bag->fds[i];
+ }
+ }
+ bag->fd_count = j;
+ gpr_mu_unlock(&bag->mu);
+}
+
+static void pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
+ grpc_pollset_set *bag,
+ grpc_pollset_set *item) {
+ size_t i;
+ gpr_mu_lock(&bag->mu);
+ for (i = 0; i < bag->pollset_set_count; i++) {
+ if (bag->pollset_sets[i] == item) {
+ bag->pollset_set_count--;
+ GPR_SWAP(grpc_pollset_set *, bag->pollset_sets[i],
+ bag->pollset_sets[bag->pollset_set_count]);
+ break;
+ }
+ }
+ gpr_mu_unlock(&bag->mu);
+}
+
+/* Test helper functions
+ * */
+void *grpc_fd_get_polling_island(grpc_fd *fd) {
+ polling_island *pi;
+
+ gpr_mu_lock(&fd->pi_mu);
+ pi = fd->polling_island;
+ gpr_mu_unlock(&fd->pi_mu);
+
+ return pi;
+}
+
+void *grpc_pollset_get_polling_island(grpc_pollset *ps) {
+ polling_island *pi;
+
+ gpr_mu_lock(&ps->mu);
+ pi = ps->polling_island;
+ gpr_mu_unlock(&ps->mu);
+
+ return pi;
+}
+
+bool grpc_are_polling_islands_equal(void *p, void *q) {
+ polling_island *p1 = p;
+ polling_island *p2 = q;
+
+ /* Note: polling_island_lock_pair() may change p1 and p2 to point to the
+ latest polling islands in their respective linked lists */
+ polling_island_lock_pair(&p1, &p2);
+ polling_island_unlock_pair(p1, p2);
+
+ return p1 == p2;
+}
+
+/*******************************************************************************
+ * Event engine binding
+ */
+
+static void shutdown_engine(void) {
+ fd_global_shutdown();
+ pollset_global_shutdown();
+ polling_island_global_shutdown();
+}
+
+static const grpc_event_engine_vtable vtable = {
+ .pollset_size = sizeof(grpc_pollset),
+
+ .fd_create = fd_create,
+ .fd_wrapped_fd = fd_wrapped_fd,
+ .fd_orphan = fd_orphan,
+ .fd_shutdown = fd_shutdown,
+ .fd_is_shutdown = fd_is_shutdown,
+ .fd_notify_on_read = fd_notify_on_read,
+ .fd_notify_on_write = fd_notify_on_write,
+ .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset,
+
+ .pollset_init = pollset_init,
+ .pollset_shutdown = pollset_shutdown,
+ .pollset_reset = pollset_reset,
+ .pollset_destroy = pollset_destroy,
+ .pollset_work = pollset_work,
+ .pollset_kick = pollset_kick,
+ .pollset_add_fd = pollset_add_fd,
+
+ .pollset_set_create = pollset_set_create,
+ .pollset_set_destroy = pollset_set_destroy,
+ .pollset_set_add_pollset = pollset_set_add_pollset,
+ .pollset_set_del_pollset = pollset_set_del_pollset,
+ .pollset_set_add_pollset_set = pollset_set_add_pollset_set,
+ .pollset_set_del_pollset_set = pollset_set_del_pollset_set,
+ .pollset_set_add_fd = pollset_set_add_fd,
+ .pollset_set_del_fd = pollset_set_del_fd,
+
+ .kick_poller = kick_poller,
+
+ .shutdown_engine = shutdown_engine,
+};
+
+/* It is possible that GLIBC has epoll but the underlying kernel doesn't.
+ * Create a dummy epoll_fd to make sure epoll support is available */
+static bool is_epoll_available() {
+ int fd = epoll_create1(EPOLL_CLOEXEC);
+ if (fd < 0) {
+ gpr_log(
+ GPR_ERROR,
+ "epoll_create1 failed with error: %d. Not using epoll polling engine",
+ fd);
+ return false;
+ }
+ close(fd);
+ return true;
+}
+
+const grpc_event_engine_vtable *grpc_init_epoll_linux(void) {
+ /* If use of signals is disabled, we cannot use epoll engine*/
+ if (is_grpc_wakeup_signal_initialized && grpc_wakeup_signal < 0) {
+ return NULL;
+ }
+
+ if (!is_epoll_available()) {
+ return NULL;
+ }
+
+ if (!is_grpc_wakeup_signal_initialized) {
+ grpc_use_signal(SIGRTMIN + 2);
+ }
+
+ fd_global_init();
+
+ if (!GRPC_LOG_IF_ERROR("pollset_global_init", pollset_global_init())) {
+ return NULL;
+ }
+
+ if (!GRPC_LOG_IF_ERROR("polling_island_global_init",
+ polling_island_global_init())) {
+ return NULL;
+ }
+
+ return &vtable;
+}
+
+#else /* defined(GPR_LINUX_EPOLL) */
+#if defined(GPR_POSIX_SOCKET)
+#include "src/core/lib/iomgr/ev_posix.h"
+/* If GPR_LINUX_EPOLL is not defined, it means epoll is not available. Return
+ * NULL */
+const grpc_event_engine_vtable *grpc_init_epoll_linux(void) { return NULL; }
+#endif /* defined(GPR_POSIX_SOCKET) */
+
+void grpc_use_signal(int signum) {}
+#endif /* !defined(GPR_LINUX_EPOLL) */
diff --git a/src/core/lib/iomgr/ev_epoll_linux.h b/src/core/lib/iomgr/ev_epoll_linux.h
new file mode 100644
index 0000000000..7a494aba19
--- /dev/null
+++ b/src/core/lib/iomgr/ev_epoll_linux.h
@@ -0,0 +1,47 @@
+/*
+ *
+ * Copyright 2015, 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.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_EV_EPOLL_LINUX_H
+#define GRPC_CORE_LIB_IOMGR_EV_EPOLL_LINUX_H
+
+#include "src/core/lib/iomgr/ev_posix.h"
+
+const grpc_event_engine_vtable *grpc_init_epoll_linux(void);
+
+#ifdef GPR_LINUX_EPOLL
+void *grpc_fd_get_polling_island(grpc_fd *fd);
+void *grpc_pollset_get_polling_island(grpc_pollset *ps);
+bool grpc_are_polling_islands_equal(void *p, void *q);
+#endif /* defined(GPR_LINUX_EPOLL) */
+
+#endif /* GRPC_CORE_LIB_IOMGR_EV_EPOLL_LINUX_H */
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
index 4c360f13a3..a3c1e9db9a 100644
--- a/src/core/lib/iomgr/ev_posix.c
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -44,6 +44,7 @@
#include <grpc/support/string_util.h>
#include <grpc/support/useful.h>
+#include "src/core/lib/iomgr/ev_epoll_linux.h"
#include "src/core/lib/iomgr/ev_poll_and_epoll_posix.h"
#include "src/core/lib/iomgr/ev_poll_posix.h"
#include "src/core/lib/support/env.h"
@@ -53,6 +54,7 @@
grpc_poll_function_type grpc_poll_function = poll;
static const grpc_event_engine_vtable *g_event_engine;
+static const char *g_poll_strategy_name = NULL;
typedef const grpc_event_engine_vtable *(*event_engine_factory_fn)(void);
@@ -62,7 +64,9 @@ typedef struct {
} event_engine_factory;
static const event_engine_factory g_factories[] = {
- {"poll", grpc_init_poll_posix}, {"legacy", grpc_init_poll_and_epoll_posix},
+ {"epoll", grpc_init_epoll_linux},
+ {"poll", grpc_init_poll_posix},
+ {"legacy", grpc_init_poll_and_epoll_posix},
};
static void add(const char *beg, const char *end, char ***ss, size_t *ns) {
@@ -98,6 +102,7 @@ static void try_engine(const char *engine) {
for (size_t i = 0; i < GPR_ARRAY_SIZE(g_factories); i++) {
if (is(engine, g_factories[i].name)) {
if ((g_event_engine = g_factories[i].factory())) {
+ g_poll_strategy_name = g_factories[i].name;
gpr_log(GPR_DEBUG, "Using polling engine: %s", g_factories[i].name);
return;
}
@@ -105,6 +110,9 @@ static void try_engine(const char *engine) {
}
}
+/* Call this only after calling grpc_event_engine_init() */
+const char *grpc_get_poll_strategy_name() { return g_poll_strategy_name; }
+
void grpc_event_engine_init(void) {
char *s = gpr_getenv("GRPC_POLL_STRATEGY");
if (s == NULL) {
@@ -167,11 +175,6 @@ void grpc_fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
g_event_engine->fd_notify_on_write(exec_ctx, fd, closure);
}
-grpc_pollset *grpc_fd_get_read_notifier_pollset(grpc_exec_ctx *exec_ctx,
- grpc_fd *fd) {
- return g_event_engine->fd_get_read_notifier_pollset(exec_ctx, fd);
-}
-
size_t grpc_pollset_size(void) { return g_event_engine->pollset_size; }
void grpc_pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
diff --git a/src/core/lib/iomgr/ev_posix.h b/src/core/lib/iomgr/ev_posix.h
index 87e9bc4d46..579c84ef70 100644
--- a/src/core/lib/iomgr/ev_posix.h
+++ b/src/core/lib/iomgr/ev_posix.h
@@ -99,6 +99,9 @@ typedef struct grpc_event_engine_vtable {
void grpc_event_engine_init(void);
void grpc_event_engine_shutdown(void);
+/* Return the name of the poll strategy */
+const char *grpc_get_poll_strategy_name();
+
/* Create a wrapped file descriptor.
Requires fd is a non-blocking file descriptor.
This takes ownership of closing fd. */
diff --git a/src/core/lib/iomgr/network_status_tracker.c b/src/core/lib/iomgr/network_status_tracker.c
new file mode 100644
index 0000000000..38a1c9b7d4
--- /dev/null
+++ b/src/core/lib/iomgr/network_status_tracker.c
@@ -0,0 +1,121 @@
+/*
+ *
+ * Copyright 2015, 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/alloc.h>
+#include <grpc/support/log.h>
+#include "src/core/lib/iomgr/endpoint.h"
+
+typedef struct endpoint_ll_node {
+ grpc_endpoint *ep;
+ struct endpoint_ll_node *next;
+} endpoint_ll_node;
+
+static endpoint_ll_node *head = NULL;
+static gpr_mu g_endpoint_mutex;
+static bool g_init_done = false;
+
+void grpc_initialize_network_status_monitor() {
+ g_init_done = true;
+ gpr_mu_init(&g_endpoint_mutex);
+ // TODO(makarandd): Install callback with OS to monitor network status.
+}
+
+void grpc_destroy_network_status_monitor() {
+ for (endpoint_ll_node *curr = head; curr != NULL;) {
+ endpoint_ll_node *next = curr->next;
+ gpr_free(curr);
+ curr = next;
+ }
+ gpr_mu_destroy(&g_endpoint_mutex);
+}
+
+void grpc_network_status_register_endpoint(grpc_endpoint *ep) {
+ if (!g_init_done) {
+ grpc_initialize_network_status_monitor();
+ }
+ gpr_mu_lock(&g_endpoint_mutex);
+ if (head == NULL) {
+ head = (endpoint_ll_node *)gpr_malloc(sizeof(endpoint_ll_node));
+ head->ep = ep;
+ head->next = NULL;
+ } else {
+ endpoint_ll_node *prev_head = head;
+ head = (endpoint_ll_node *)gpr_malloc(sizeof(endpoint_ll_node));
+ head->ep = ep;
+ head->next = prev_head;
+ }
+ gpr_mu_unlock(&g_endpoint_mutex);
+}
+
+void grpc_network_status_unregister_endpoint(grpc_endpoint *ep) {
+ gpr_mu_lock(&g_endpoint_mutex);
+ GPR_ASSERT(head);
+ bool found = false;
+ endpoint_ll_node *prev = head;
+ // if we're unregistering the head, just move head to the next
+ if (ep == head->ep) {
+ head = head->next;
+ gpr_free(prev);
+ found = true;
+ } else {
+ for (endpoint_ll_node *curr = head->next; curr != NULL; curr = curr->next) {
+ if (ep == curr->ep) {
+ prev->next = curr->next;
+ gpr_free(curr);
+ found = true;
+ break;
+ }
+ prev = curr;
+ }
+ }
+ gpr_mu_unlock(&g_endpoint_mutex);
+ GPR_ASSERT(found);
+}
+
+// Walk the linked-list from head and execute shutdown. It is possible that
+// other threads might be in the process of shutdown as well, but that has
+// no side effect since endpoint shutdown is idempotent.
+void grpc_network_status_shutdown_all_endpoints() {
+ gpr_mu_lock(&g_endpoint_mutex);
+ if (head == NULL) {
+ gpr_mu_unlock(&g_endpoint_mutex);
+ return;
+ }
+ grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+ for (endpoint_ll_node *curr = head; curr != NULL; curr = curr->next) {
+ curr->ep->vtable->shutdown(&exec_ctx, curr->ep);
+ }
+ gpr_mu_unlock(&g_endpoint_mutex);
+ grpc_exec_ctx_finish(&exec_ctx);
+}
diff --git a/src/core/lib/iomgr/network_status_tracker.h b/src/core/lib/iomgr/network_status_tracker.h
new file mode 100644
index 0000000000..74a1aa8135
--- /dev/null
+++ b/src/core/lib/iomgr/network_status_tracker.h
@@ -0,0 +1,41 @@
+/*
+ *
+ * Copyright 2016, 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.
+ *
+ */
+
+#ifndef GRPC_CORE_LIB_IOMGR_NETWORK_STATUS_TRACKER_H
+#define GRPC_CORE_LIB_IOMGR_NETWORK_STATUS_TRACKER_H
+#include "src/core/lib/iomgr/endpoint.h"
+
+void grpc_network_status_register_endpoint(grpc_endpoint *ep);
+void grpc_network_status_unregister_endpoint(grpc_endpoint *ep);
+void grpc_network_status_shutdown_all_endpoints();
+#endif /* GRPC_CORE_LIB_IOMGR_NETWORK_STATUS_TRACKER_H */
diff --git a/src/core/lib/iomgr/socket_utils_common_posix.c b/src/core/lib/iomgr/socket_utils_common_posix.c
index 3a1371617e..d2f6261e2a 100644
--- a/src/core/lib/iomgr/socket_utils_common_posix.c
+++ b/src/core/lib/iomgr/socket_utils_common_posix.c
@@ -169,6 +169,28 @@ grpc_error *grpc_set_socket_reuse_addr(int fd, int reuse) {
return GRPC_ERROR_NONE;
}
+/* set a socket to reuse old addresses */
+grpc_error *grpc_set_socket_reuse_port(int fd, int reuse) {
+#ifndef SO_REUSEPORT
+ return GRPC_ERROR_CREATE("SO_REUSEPORT unavailable on compiling system");
+#else
+ int val = (reuse != 0);
+ int newval;
+ socklen_t intlen = sizeof(newval);
+ if (0 != setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val))) {
+ return GRPC_OS_ERROR(errno, "setsockopt(SO_REUSEPORT)");
+ }
+ if (0 != getsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &newval, &intlen)) {
+ return GRPC_OS_ERROR(errno, "getsockopt(SO_REUSEPORT)");
+ }
+ if ((newval != 0) != val) {
+ return GRPC_ERROR_CREATE("Failed to set SO_REUSEPORT");
+ }
+
+ return GRPC_ERROR_NONE;
+#endif
+}
+
/* disable nagle */
grpc_error *grpc_set_socket_low_latency(int fd, int low_latency) {
int val = (low_latency != 0);
diff --git a/src/core/lib/iomgr/socket_utils_posix.h b/src/core/lib/iomgr/socket_utils_posix.h
index 30ff39dfa3..7bcc2219ae 100644
--- a/src/core/lib/iomgr/socket_utils_posix.h
+++ b/src/core/lib/iomgr/socket_utils_posix.h
@@ -55,6 +55,9 @@ grpc_error *grpc_set_socket_reuse_addr(int fd, int reuse);
/* disable nagle */
grpc_error *grpc_set_socket_low_latency(int fd, int low_latency);
+/* set SO_REUSEPORT */
+grpc_error *grpc_set_socket_reuse_port(int fd, int reuse);
+
/* Returns true if this system can create AF_INET6 sockets bound to ::1.
The value is probed once, and cached for the life of the process.
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index 017f52c367..2ab45e33ce 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -35,6 +35,7 @@
#ifdef GPR_POSIX_SOCKET
+#include "src/core/lib/iomgr/network_status_tracker.h"
#include "src/core/lib/iomgr/tcp_posix.h"
#include <errno.h>
@@ -152,6 +153,7 @@ static void tcp_ref(grpc_tcp *tcp) { gpr_ref(&tcp->refcount); }
#endif
static void tcp_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+ grpc_network_status_unregister_endpoint(ep);
grpc_tcp *tcp = (grpc_tcp *)ep;
TCP_UNREF(exec_ctx, tcp, "destroy");
}
@@ -160,7 +162,7 @@ static void call_read_cb(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp,
grpc_error *error) {
grpc_closure *cb = tcp->read_cb;
- if (false && grpc_tcp_trace) {
+ if (grpc_tcp_trace) {
size_t i;
const char *str = grpc_error_string(error);
gpr_log(GPR_DEBUG, "read: error=%s", str);
@@ -394,7 +396,7 @@ static void tcp_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
grpc_tcp *tcp = (grpc_tcp *)ep;
grpc_error *error = GRPC_ERROR_NONE;
- if (false && grpc_tcp_trace) {
+ if (grpc_tcp_trace) {
size_t i;
for (i = 0; i < buf->count; i++) {
@@ -474,6 +476,8 @@ grpc_endpoint *grpc_tcp_create(grpc_fd *em_fd, size_t slice_size,
tcp->write_closure.cb = tcp_handle_write;
tcp->write_closure.cb_arg = tcp;
gpr_slice_buffer_init(&tcp->last_read_buffer);
+ /* Tell network status tracker about new endpoint */
+ grpc_network_status_register_endpoint(&tcp->base);
return &tcp->base;
}
diff --git a/src/core/lib/iomgr/tcp_server.h b/src/core/lib/iomgr/tcp_server.h
index 1d6e70dbe9..875a6ca14a 100644
--- a/src/core/lib/iomgr/tcp_server.h
+++ b/src/core/lib/iomgr/tcp_server.h
@@ -34,6 +34,8 @@
#ifndef GRPC_CORE_LIB_IOMGR_TCP_SERVER_H
#define GRPC_CORE_LIB_IOMGR_TCP_SERVER_H
+#include <grpc/grpc.h>
+
#include "src/core/lib/iomgr/closure.h"
#include "src/core/lib/iomgr/endpoint.h"
@@ -59,6 +61,7 @@ typedef void (*grpc_tcp_server_cb)(grpc_exec_ctx *exec_ctx, void *arg,
If shutdown_complete is not NULL, it will be used by
grpc_tcp_server_unref() when the ref count reaches zero. */
grpc_error *grpc_tcp_server_create(grpc_closure *shutdown_complete,
+ const grpc_channel_args *args,
grpc_tcp_server **server);
/* Start listening to bound ports */
diff --git a/src/core/lib/iomgr/tcp_server_posix.c b/src/core/lib/iomgr/tcp_server_posix.c
index 6fb547bb36..a1a463550a 100644
--- a/src/core/lib/iomgr/tcp_server_posix.c
+++ b/src/core/lib/iomgr/tcp_server_posix.c
@@ -112,8 +112,10 @@ struct grpc_tcp_server {
/* destroyed port count: how many ports are completely destroyed */
size_t destroyed_ports;
- /* is this server shutting down? (boolean) */
- int shutdown;
+ /* is this server shutting down? */
+ bool shutdown;
+ /* use SO_REUSEPORT */
+ bool so_reuseport;
/* linked list of server ports */
grpc_tcp_listener *head;
@@ -135,14 +137,42 @@ struct grpc_tcp_server {
size_t next_pollset_to_assign;
};
+static gpr_once check_init = GPR_ONCE_INIT;
+static bool has_so_reuseport;
+
+static void init(void) {
+ int s = socket(AF_INET, SOCK_STREAM, 0);
+ if (s >= 0) {
+ has_so_reuseport = GRPC_LOG_IF_ERROR("check for SO_REUSEPORT",
+ grpc_set_socket_reuse_port(s, 1));
+ close(s);
+ }
+}
+
grpc_error *grpc_tcp_server_create(grpc_closure *shutdown_complete,
+ const grpc_channel_args *args,
grpc_tcp_server **server) {
+ gpr_once_init(&check_init, init);
+
grpc_tcp_server *s = gpr_malloc(sizeof(grpc_tcp_server));
+ s->so_reuseport = has_so_reuseport;
+ for (size_t i = 0; i < (args == NULL ? 0 : args->num_args); i++) {
+ if (0 == strcmp(GRPC_ARG_ALLOW_REUSEPORT, args->args[i].key)) {
+ if (args->args[i].type == GRPC_ARG_INTEGER) {
+ s->so_reuseport =
+ has_so_reuseport && (args->args[i].value.integer != 0);
+ } else {
+ gpr_free(s);
+ return GRPC_ERROR_CREATE(GRPC_ARG_ALLOW_REUSEPORT
+ " must be an integer");
+ }
+ }
+ }
gpr_ref_init(&s->refs, 1);
gpr_mu_init(&s->mu);
s->active_ports = 0;
s->destroyed_ports = 0;
- s->shutdown = 0;
+ s->shutdown = false;
s->shutdown_starting.head = NULL;
s->shutdown_starting.tail = NULL;
s->shutdown_complete = shutdown_complete;
@@ -218,7 +248,7 @@ static void tcp_server_destroy(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s) {
gpr_mu_lock(&s->mu);
GPR_ASSERT(!s->shutdown);
- s->shutdown = 1;
+ s->shutdown = true;
/* shutdown all fd's */
if (s->active_ports) {
@@ -268,13 +298,19 @@ static int get_max_accept_queue_size(void) {
/* Prepare a recently-created socket for listening. */
static grpc_error *prepare_socket(int fd, const struct sockaddr *addr,
- size_t addr_len, int *port) {
+ size_t addr_len, bool so_reuseport,
+ int *port) {
struct sockaddr_storage sockname_temp;
socklen_t sockname_len;
grpc_error *err = GRPC_ERROR_NONE;
GPR_ASSERT(fd >= 0);
+ if (so_reuseport) {
+ err = grpc_set_socket_reuse_port(fd, 1);
+ if (err != GRPC_ERROR_NONE) goto error;
+ }
+
err = grpc_set_socket_nonblocking(fd, 1);
if (err != GRPC_ERROR_NONE) goto error;
err = grpc_set_socket_cloexec(fd, 1);
@@ -407,7 +443,7 @@ static grpc_error *add_socket_to_server(grpc_tcp_server *s, int fd,
char *addr_str;
char *name;
- grpc_error *err = prepare_socket(fd, addr, addr_len, &port);
+ grpc_error *err = prepare_socket(fd, addr, addr_len, s->so_reuseport, &port);
if (err == GRPC_ERROR_NONE) {
GPR_ASSERT(port > 0);
grpc_sockaddr_to_string(&addr_str, (struct sockaddr *)&addr, 1);
@@ -443,6 +479,52 @@ static grpc_error *add_socket_to_server(grpc_tcp_server *s, int fd,
return err;
}
+static grpc_error *clone_port(grpc_tcp_listener *listener, unsigned count) {
+ grpc_tcp_listener *sp = NULL;
+ char *addr_str;
+ char *name;
+ grpc_error *err;
+
+ for (grpc_tcp_listener *l = listener->next; l && l->is_sibling; l = l->next) {
+ l->fd_index += count;
+ }
+
+ for (unsigned i = 0; i < count; i++) {
+ int fd, port;
+ grpc_dualstack_mode dsmode;
+ err = grpc_create_dualstack_socket(&listener->addr.sockaddr, SOCK_STREAM, 0,
+ &dsmode, &fd);
+ if (err != GRPC_ERROR_NONE) return err;
+ err = prepare_socket(fd, &listener->addr.sockaddr, listener->addr_len, true,
+ &port);
+ if (err != GRPC_ERROR_NONE) return err;
+ listener->server->nports++;
+ grpc_sockaddr_to_string(&addr_str, &listener->addr.sockaddr, 1);
+ gpr_asprintf(&name, "tcp-server-listener:%s/clone-%d", addr_str, i);
+ sp = gpr_malloc(sizeof(grpc_tcp_listener));
+ sp->next = listener->next;
+ listener->next = sp;
+ sp->server = listener->server;
+ sp->fd = fd;
+ sp->emfd = grpc_fd_create(fd, name);
+ memcpy(sp->addr.untyped, listener->addr.untyped, listener->addr_len);
+ sp->addr_len = listener->addr_len;
+ sp->port = port;
+ sp->port_index = listener->port_index;
+ sp->fd_index = listener->fd_index + count - i;
+ sp->is_sibling = 1;
+ sp->sibling = listener->is_sibling ? listener->sibling : listener;
+ GPR_ASSERT(sp->emfd);
+ while (listener->server->tail->next != NULL) {
+ listener->server->tail = listener->server->tail->next;
+ }
+ gpr_free(addr_str);
+ gpr_free(name);
+ }
+
+ return GRPC_ERROR_NONE;
+}
+
grpc_error *grpc_tcp_server_add_port(grpc_tcp_server *s, const void *addr,
size_t addr_len, int *out_port) {
grpc_tcp_listener *sp;
@@ -599,14 +681,29 @@ void grpc_tcp_server_start(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s,
s->on_accept_cb_arg = on_accept_cb_arg;
s->pollsets = pollsets;
s->pollset_count = pollset_count;
- for (sp = s->head; sp; sp = sp->next) {
- for (i = 0; i < pollset_count; i++) {
- grpc_pollset_add_fd(exec_ctx, pollsets[i], sp->emfd);
+ sp = s->head;
+ while (sp != NULL) {
+ if (s->so_reuseport && pollset_count > 1) {
+ GPR_ASSERT(GRPC_LOG_IF_ERROR(
+ "clone_port", clone_port(sp, (unsigned)(pollset_count - 1))));
+ for (i = 0; i < pollset_count; i++) {
+ grpc_pollset_add_fd(exec_ctx, pollsets[i], sp->emfd);
+ sp->read_closure.cb = on_read;
+ sp->read_closure.cb_arg = sp;
+ grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
+ s->active_ports++;
+ sp = sp->next;
+ }
+ } else {
+ for (i = 0; i < pollset_count; i++) {
+ grpc_pollset_add_fd(exec_ctx, pollsets[i], sp->emfd);
+ }
+ sp->read_closure.cb = on_read;
+ sp->read_closure.cb_arg = sp;
+ grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
+ s->active_ports++;
+ sp = sp->next;
}
- sp->read_closure.cb = on_read;
- sp->read_closure.cb_arg = sp;
- grpc_fd_notify_on_read(exec_ctx, sp->emfd, &sp->read_closure);
- s->active_ports++;
}
gpr_mu_unlock(&s->mu);
}
diff --git a/src/core/lib/iomgr/tcp_server_windows.c b/src/core/lib/iomgr/tcp_server_windows.c
index 2a51671ec7..7b0966704c 100644
--- a/src/core/lib/iomgr/tcp_server_windows.c
+++ b/src/core/lib/iomgr/tcp_server_windows.c
@@ -103,6 +103,7 @@ struct grpc_tcp_server {
/* Public function. Allocates the proper data structures to hold a
grpc_tcp_server. */
grpc_error *grpc_tcp_server_create(grpc_closure *shutdown_complete,
+ const grpc_channel_args *args,
grpc_tcp_server **server) {
grpc_tcp_server *s = gpr_malloc(sizeof(grpc_tcp_server));
gpr_ref_init(&s->refs, 1);
@@ -396,7 +397,7 @@ static grpc_error *add_socket_to_server(grpc_tcp_server *s, SOCKET sock,
size_t addr_len, unsigned port_index,
grpc_tcp_listener **listener) {
grpc_tcp_listener *sp = NULL;
- int port;
+ int port = -1;
int status;
GUID guid = WSAID_ACCEPTEX;
DWORD ioctl_num_bytes;
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index b2af8030aa..37ab59021e 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -37,6 +37,7 @@
#include <limits.h>
+#include "src/core/lib/iomgr/network_status_tracker.h"
#include "src/core/lib/iomgr/sockaddr_windows.h"
#include <grpc/support/alloc.h>
@@ -378,6 +379,7 @@ static void win_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
}
static void win_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+ grpc_network_status_unregister_endpoint(ep);
grpc_tcp *tcp = (grpc_tcp *)ep;
TCP_UNREF(tcp, "destroy");
}
@@ -401,6 +403,9 @@ grpc_endpoint *grpc_tcp_create(grpc_winsocket *socket, char *peer_string) {
grpc_closure_init(&tcp->on_read, on_read, tcp);
grpc_closure_init(&tcp->on_write, on_write, tcp);
tcp->peer_string = gpr_strdup(peer_string);
+ /* Tell network status tracking code about the new endpoint */
+ grpc_network_status_register_endpoint(&tcp->base);
+
return &tcp->base;
}
diff --git a/src/core/lib/iomgr/udp_server.c b/src/core/lib/iomgr/udp_server.c
index 16150687d3..1ebccf2ee2 100644
--- a/src/core/lib/iomgr/udp_server.c
+++ b/src/core/lib/iomgr/udp_server.c
@@ -243,13 +243,13 @@ static int prepare_socket(int fd, const struct sockaddr *addr,
if (!grpc_set_socket_sndbuf(fd, buffer_size_bytes)) {
gpr_log(GPR_ERROR, "Failed to set send buffer size to %d bytes",
- buf_size_bytes);
+ buffer_size_bytes);
goto error;
}
if (!grpc_set_socket_rcvbuf(fd, buffer_size_bytes)) {
gpr_log(GPR_ERROR, "Failed to set receive buffer size to %d bytes",
- buf_size_bytes);
+ buffer_size_bytes);
goto error;
}
diff --git a/src/core/lib/iomgr/wakeup_fd_eventfd.c b/src/core/lib/iomgr/wakeup_fd_eventfd.c
index 667b4a5f90..95f6102330 100644
--- a/src/core/lib/iomgr/wakeup_fd_eventfd.c
+++ b/src/core/lib/iomgr/wakeup_fd_eventfd.c
@@ -84,8 +84,10 @@ static void eventfd_destroy(grpc_wakeup_fd* fd_info) {
}
static int eventfd_check_availability(void) {
- /* TODO(klempner): Actually check if eventfd is available */
- return 1;
+ const int efd = eventfd(0, 0);
+ const int is_available = efd >= 0;
+ if (is_available) close(efd);
+ return is_available;
}
const grpc_wakeup_fd_vtable grpc_specialized_wakeup_fd_vtable = {