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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/*
*
* 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_EXT_CLIENT_CONFIG_LB_POLICY_H
#define GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H
#include "src/core/ext/client_config/subchannel.h"
#include "src/core/lib/iomgr/polling_entity.h"
#include "src/core/lib/transport/connectivity_state.h"
/** A load balancing policy: specified by a vtable and a struct (which
is expected to be extended to contain some parameters) */
typedef struct grpc_lb_policy grpc_lb_policy;
typedef struct grpc_lb_policy_vtable grpc_lb_policy_vtable;
typedef void (*grpc_lb_completion)(void *cb_arg, grpc_subchannel *subchannel,
grpc_status_code status, const char *errmsg);
struct grpc_lb_policy {
const grpc_lb_policy_vtable *vtable;
gpr_atm ref_pair;
/* owned pointer to interested parties in load balancing decisions */
grpc_pollset_set *interested_parties;
};
struct grpc_lb_policy_vtable {
void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
/** implement grpc_lb_policy_pick */
int (*pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
grpc_polling_entity *pollent,
grpc_metadata_batch *initial_metadata,
uint32_t initial_metadata_flags,
grpc_connected_subchannel **target, grpc_closure *on_complete);
void (*cancel_pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
grpc_connected_subchannel **target);
void (*cancel_picks)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
uint32_t initial_metadata_flags_mask,
uint32_t initial_metadata_flags_eq);
void (*ping_one)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
grpc_closure *closure);
/** try to enter a READY connectivity state */
void (*exit_idle)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
/** check the current connectivity of the lb_policy */
grpc_connectivity_state (*check_connectivity)(
grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
grpc_error **connectivity_error);
/** call notify when the connectivity state of a channel changes from *state.
Updates *state with the new state of the policy */
void (*notify_on_state_change)(grpc_exec_ctx *exec_ctx,
grpc_lb_policy *policy,
grpc_connectivity_state *state,
grpc_closure *closure);
};
/*#define GRPC_LB_POLICY_REFCOUNT_DEBUG*/
#ifdef GRPC_LB_POLICY_REFCOUNT_DEBUG
#define GRPC_LB_POLICY_REF(p, r) \
grpc_lb_policy_ref((p), __FILE__, __LINE__, (r))
#define GRPC_LB_POLICY_UNREF(exec_ctx, p, r) \
grpc_lb_policy_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
#define GRPC_LB_POLICY_WEAK_REF(p, r) \
grpc_lb_policy_weak_ref((p), __FILE__, __LINE__, (r))
#define GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, p, r) \
grpc_lb_policy_weak_unref((exec_ctx), (p), __FILE__, __LINE__, (r))
void grpc_lb_policy_ref(grpc_lb_policy *policy, const char *file, int line,
const char *reason);
void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
const char *file, int line, const char *reason);
void grpc_lb_policy_weak_ref(grpc_lb_policy *policy, const char *file, int line,
const char *reason);
void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
const char *file, int line, const char *reason);
#else
#define GRPC_LB_POLICY_REF(p, r) grpc_lb_policy_ref((p))
#define GRPC_LB_POLICY_UNREF(cl, p, r) grpc_lb_policy_unref((cl), (p))
#define GRPC_LB_POLICY_WEAK_REF(p, r) grpc_lb_policy_weak_ref((p))
#define GRPC_LB_POLICY_WEAK_UNREF(cl, p, r) grpc_lb_policy_weak_unref((cl), (p))
void grpc_lb_policy_ref(grpc_lb_policy *policy);
void grpc_lb_policy_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
void grpc_lb_policy_weak_ref(grpc_lb_policy *policy);
void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
#endif
/** called by concrete implementations to initialize the base struct */
void grpc_lb_policy_init(grpc_lb_policy *policy,
const grpc_lb_policy_vtable *vtable);
/** Given initial metadata in \a initial_metadata, find an appropriate
target for this rpc, and 'return' it by calling \a on_complete after setting
\a target.
Picking can be asynchronous. Any IO should be done under \a pollset. */
int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
grpc_polling_entity *pollent,
grpc_metadata_batch *initial_metadata,
uint32_t initial_metadata_flags,
grpc_connected_subchannel **target,
grpc_closure *on_complete);
void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
grpc_closure *closure);
void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
grpc_connected_subchannel **target);
/** Cancel all pending picks which have:
(initial_metadata_flags & initial_metadata_flags_mask) ==
initial_metadata_flags_eq */
void grpc_lb_policy_cancel_picks(grpc_exec_ctx *exec_ctx,
grpc_lb_policy *policy,
uint32_t initial_metadata_flags_mask,
uint32_t initial_metadata_flags_eq);
void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy);
void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx,
grpc_lb_policy *policy,
grpc_connectivity_state *state,
grpc_closure *closure);
grpc_connectivity_state grpc_lb_policy_check_connectivity(
grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy,
grpc_error **connectivity_error);
#endif /* GRPC_CORE_EXT_CLIENT_CONFIG_LB_POLICY_H */
|
