1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/*
*
* Copyright 2015-2016, 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 "src/core/lib/iomgr/executor.h"
#include <string.h>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/sync.h>
#include <grpc/support/thd.h>
#include "src/core/lib/iomgr/exec_ctx.h"
typedef struct grpc_executor_data {
int busy; /**< is the thread currently running? */
int shutting_down; /**< has \a grpc_shutdown() been invoked? */
int pending_join; /**< has the thread finished but not been joined? */
grpc_closure_list closures; /**< collection of pending work */
gpr_thd_id tid; /**< thread id of the thread, only valid if \a busy or \a
pending_join are true */
gpr_thd_options options;
gpr_mu mu;
} grpc_executor;
static grpc_executor g_executor;
void grpc_executor_init() {
memset(&g_executor, 0, sizeof(grpc_executor));
gpr_mu_init(&g_executor.mu);
g_executor.options = gpr_thd_options_default();
gpr_thd_options_set_joinable(&g_executor.options);
}
/* thread body */
static void closure_exec_thread_func(void *ignored) {
grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
while (1) {
gpr_mu_lock(&g_executor.mu);
if (g_executor.shutting_down != 0) {
gpr_mu_unlock(&g_executor.mu);
break;
}
if (grpc_closure_list_empty(g_executor.closures)) {
/* no more work, time to die */
GPR_ASSERT(g_executor.busy == 1);
g_executor.busy = 0;
gpr_mu_unlock(&g_executor.mu);
break;
} else {
grpc_exec_ctx_enqueue_list(&exec_ctx, &g_executor.closures, NULL);
}
gpr_mu_unlock(&g_executor.mu);
grpc_exec_ctx_flush(&exec_ctx);
}
grpc_exec_ctx_finish(&exec_ctx);
}
/* Spawn the thread if new work has arrived a no thread is up */
static void maybe_spawn_locked() {
if (grpc_closure_list_empty(g_executor.closures) == 1) {
return;
}
if (g_executor.shutting_down == 1) {
return;
}
if (g_executor.busy != 0) {
/* Thread still working. New work will be picked up by already running
* thread. Not spawning anything. */
return;
} else if (g_executor.pending_join != 0) {
/* Pickup the remains of the previous incarnations of the thread. */
gpr_thd_join(g_executor.tid);
g_executor.pending_join = 0;
}
/* All previous instances of the thread should have been joined at this point.
* Spawn time! */
g_executor.busy = 1;
gpr_thd_new(&g_executor.tid, closure_exec_thread_func, NULL,
&g_executor.options);
g_executor.pending_join = 1;
}
void grpc_executor_enqueue(grpc_closure *closure, bool success) {
gpr_mu_lock(&g_executor.mu);
if (g_executor.shutting_down == 0) {
grpc_closure_list_add(&g_executor.closures, closure, success);
maybe_spawn_locked();
}
gpr_mu_unlock(&g_executor.mu);
}
void grpc_executor_shutdown() {
int pending_join;
grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
gpr_mu_lock(&g_executor.mu);
pending_join = g_executor.pending_join;
g_executor.shutting_down = 1;
gpr_mu_unlock(&g_executor.mu);
/* we can release the lock at this point despite the access to the closure
* list below because we aren't accepting new work */
/* Execute pending callbacks, some may be performing cleanups */
grpc_exec_ctx_enqueue_list(&exec_ctx, &g_executor.closures, NULL);
grpc_exec_ctx_finish(&exec_ctx);
GPR_ASSERT(grpc_closure_list_empty(g_executor.closures));
if (pending_join) {
gpr_thd_join(g_executor.tid);
}
gpr_mu_destroy(&g_executor.mu);
}
|
