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
|
/*
*
* 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_EXEC_CTX_H
#define GRPC_CORE_LIB_IOMGR_EXEC_CTX_H
#include "src/core/lib/iomgr/closure.h"
/* #define GRPC_EXECUTION_CONTEXT_SANITIZER 1 */
/** A workqueue represents a list of work to be executed asynchronously.
Forward declared here to avoid a circular dependency with workqueue.h. */
typedef struct grpc_workqueue grpc_workqueue;
typedef struct grpc_combiner grpc_combiner;
/* This exec_ctx is ready to return: either pre-populated, or cached as soon as
the finish_check returns true */
#define GRPC_EXEC_CTX_FLAG_IS_FINISHED 1
/* The exec_ctx's thread is (potentially) owned by a call or channel: care
should be given to not delete said call/channel from this exec_ctx */
#define GRPC_EXEC_CTX_FLAG_THREAD_RESOURCE_LOOP 2
/** Execution context.
* A bag of data that collects information along a callstack.
* Generally created at public API entry points, and passed down as
* pointer to child functions that manipulate it.
*
* Specific responsibilities (this may grow in the future):
* - track a list of work that needs to be delayed until the top of the
* call stack (this provides a convenient mechanism to run callbacks
* without worrying about locking issues)
* - provide a decision maker (via grpc_exec_ctx_ready_to_finish) that provides
* signal as to whether a borrowed thread should continue to do work or
* should actively try to finish up and get this thread back to its owner
*
* CONVENTIONS:
* - Instance of this must ALWAYS be constructed on the stack, never
* heap allocated.
* - Instances and pointers to them must always be called exec_ctx.
* - Instances are always passed as the first argument to a function that
* takes it, and always as a pointer (grpc_exec_ctx is never copied).
*/
struct grpc_exec_ctx {
grpc_closure_list closure_list;
/** currently active combiner: updated only via combiner.c */
grpc_combiner *active_combiner;
/** last active combiner in the active combiner list */
grpc_combiner *last_combiner;
uintptr_t flags;
void *check_ready_to_finish_arg;
bool (*check_ready_to_finish)(grpc_exec_ctx *exec_ctx, void *arg);
};
/* initializer for grpc_exec_ctx:
prefer to use GRPC_EXEC_CTX_INIT whenever possible */
#define GRPC_EXEC_CTX_INITIALIZER(flags, finish_check, finish_check_arg) \
{ GRPC_CLOSURE_LIST_INIT, NULL, NULL, flags, finish_check_arg, finish_check }
/* initialize an execution context at the top level of an API call into grpc
(this is safe to use elsewhere, though possibly not as efficient) */
#define GRPC_EXEC_CTX_INIT \
GRPC_EXEC_CTX_INITIALIZER(GRPC_EXEC_CTX_FLAG_IS_FINISHED, NULL, NULL)
extern grpc_closure_scheduler *grpc_schedule_on_exec_ctx;
/** Flush any work that has been enqueued onto this grpc_exec_ctx.
* Caller must guarantee that no interfering locks are held.
* Returns true if work was performed, false otherwise. */
bool grpc_exec_ctx_flush(grpc_exec_ctx *exec_ctx);
/** Finish any pending work for a grpc_exec_ctx. Must be called before
* the instance is destroyed, or work may be lost. */
void grpc_exec_ctx_finish(grpc_exec_ctx *exec_ctx);
/** Returns true if we'd like to leave this execution context as soon as
possible: useful for deciding whether to do something more or not depending
on outside context */
bool grpc_exec_ctx_ready_to_finish(grpc_exec_ctx *exec_ctx);
/** A finish check that is never ready to finish */
bool grpc_never_ready_to_finish(grpc_exec_ctx *exec_ctx, void *arg_ignored);
/** A finish check that is always ready to finish */
bool grpc_always_ready_to_finish(grpc_exec_ctx *exec_ctx, void *arg_ignored);
void grpc_exec_ctx_global_init(void);
void grpc_exec_ctx_global_init(void);
void grpc_exec_ctx_global_shutdown(void);
#endif /* GRPC_CORE_LIB_IOMGR_EXEC_CTX_H */
|
