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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
*
* 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_INTERNAL_CORE_CHANNEL_CHANNEL_STACK_H
#define GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_STACK_H
/* A channel filter defines how operations on a channel are implemented.
Channel filters are chained together to create full channels, and if those
chains are linear, then channel stacks provide a mechanism to minimize
allocations for that chain.
Call stacks are created by channel stacks and represent the per-call data
for that stack. */
#include <stddef.h>
#include <grpc/grpc.h>
#include <grpc/support/log.h>
#include "src/core/debug/trace.h"
#include "src/core/transport/transport.h"
typedef struct grpc_channel_element grpc_channel_element;
typedef struct grpc_call_element grpc_call_element;
/* Channel filters specify:
1. the amount of memory needed in the channel & call (via the sizeof_XXX
members)
2. functions to initialize and destroy channel & call data
(init_XXX, destroy_XXX)
3. functions to implement call operations and channel operations (call_op,
channel_op)
4. a name, which is useful when debugging
Members are laid out in approximate frequency of use order. */
typedef struct {
/* Called to eg. send/receive data on a call.
See grpc_call_next_op on how to call the next element in the stack */
void (*start_transport_stream_op)(grpc_call_element *elem,
grpc_transport_stream_op *op);
/* Called to handle channel level operations - e.g. new calls, or transport
closure.
See grpc_channel_next_op on how to call the next element in the stack */
void (*start_transport_op)(grpc_channel_element *elem, grpc_transport_op *op);
/* sizeof(per call data) */
size_t sizeof_call_data;
/* Initialize per call data.
elem is initialized at the start of the call, and elem->call_data is what
needs initializing.
The filter does not need to do any chaining.
server_transport_data is an opaque pointer. If it is NULL, this call is
on a client; if it is non-NULL, then it points to memory owned by the
transport and is on the server. Most filters want to ignore this
argument.*/
void (*init_call_elem)(grpc_call_element *elem,
const void *server_transport_data,
grpc_transport_stream_op *initial_op);
/* Destroy per call data.
The filter does not need to do any chaining */
void (*destroy_call_elem)(grpc_call_element *elem);
/* sizeof(per channel data) */
size_t sizeof_channel_data;
/* Initialize per-channel data.
elem is initialized at the start of the call, and elem->channel_data is
what needs initializing.
is_first, is_last designate this elements position in the stack, and are
useful for asserting correct configuration by upper layer code.
The filter does not need to do any chaining */
void (*init_channel_elem)(grpc_channel_element *elem, grpc_channel *master,
const grpc_channel_args *args,
grpc_mdctx *metadata_context, int is_first,
int is_last);
/* Destroy per channel data.
The filter does not need to do any chaining */
void (*destroy_channel_elem)(grpc_channel_element *elem);
/* The name of this filter */
const char *name;
} grpc_channel_filter;
/* A channel_element tracks its filter and the filter requested memory within
a channel allocation */
struct grpc_channel_element {
const grpc_channel_filter *filter;
void *channel_data;
};
/* A call_element tracks its filter, the filter requested memory within
a channel allocation, and the filter requested memory within a call
allocation */
struct grpc_call_element {
const grpc_channel_filter *filter;
void *channel_data;
void *call_data;
};
/* A channel stack tracks a set of related filters for one channel, and
guarantees they live within a single malloc() allocation */
typedef struct {
size_t count;
/* Memory required for a call stack (computed at channel stack
initialization) */
size_t call_stack_size;
} grpc_channel_stack;
/* A call stack tracks a set of related filters for one call, and guarantees
they live within a single malloc() allocation */
typedef struct { size_t count; } grpc_call_stack;
/* Get a channel element given a channel stack and its index */
grpc_channel_element *grpc_channel_stack_element(grpc_channel_stack *stack,
size_t i);
/* Get the last channel element in a channel stack */
grpc_channel_element *grpc_channel_stack_last_element(
grpc_channel_stack *stack);
/* Get a call stack element given a call stack and an index */
grpc_call_element *grpc_call_stack_element(grpc_call_stack *stack, size_t i);
/* Determine memory required for a channel stack containing a set of filters */
size_t grpc_channel_stack_size(const grpc_channel_filter **filters,
size_t filter_count);
/* Initialize a channel stack given some filters */
void grpc_channel_stack_init(const grpc_channel_filter **filters,
size_t filter_count, grpc_channel *master,
const grpc_channel_args *args,
grpc_mdctx *metadata_context,
grpc_channel_stack *stack);
/* Destroy a channel stack */
void grpc_channel_stack_destroy(grpc_channel_stack *stack);
/* Initialize a call stack given a channel stack. transport_server_data is
expected to be NULL on a client, or an opaque transport owned pointer on the
server. */
void grpc_call_stack_init(grpc_channel_stack *channel_stack,
const void *transport_server_data,
grpc_transport_stream_op *initial_op,
grpc_call_stack *call_stack);
/* Destroy a call stack */
void grpc_call_stack_destroy(grpc_call_stack *stack);
/* Call the next operation in a call stack */
void grpc_call_next_op(grpc_call_element *elem, grpc_transport_stream_op *op);
/* Call the next operation (depending on call directionality) in a channel
stack */
void grpc_channel_next_op(grpc_channel_element *elem, grpc_transport_op *op);
/* Given the top element of a channel stack, get the channel stack itself */
grpc_channel_stack *grpc_channel_stack_from_top_element(
grpc_channel_element *elem);
/* Given the top element of a call stack, get the call stack itself */
grpc_call_stack *grpc_call_stack_from_top_element(grpc_call_element *elem);
void grpc_call_log_op(char *file, int line, gpr_log_severity severity,
grpc_call_element *elem, grpc_transport_stream_op *op);
void grpc_call_element_send_cancel(grpc_call_element *cur_elem);
extern int grpc_trace_channel;
#define GRPC_CALL_LOG_OP(sev, elem, op) \
if (grpc_trace_channel) grpc_call_log_op(sev, elem, op)
#endif /* GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_STACK_H */
|
