source: mainline/uspace/lib/c/include/fibril.h@ fb4a424

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since fb4a424 was c170438, checked in by Jakub Jermar <jakub@…>, 10 years ago

Do not create a new fibril for each IRQ notification

In the absence of fibril serialization, manager fibrils can
theoretically block in async IPC or on fibril synchronization
primitives. Consequently, it is safe to execute the IRQ handler directly
from the manager fibril. The manager fibril can block while processing
the notification, but most of the times it will not block and the
handler will execute atomically.

This changeset modifies the current behaviour so that we no longer spawn
a new notification fibril for each IRQ, but rather execute the handler
directly from the manager fibril and test if the execution blocked. If
it blocked, the manager fibril had assumed the role of a notification
fibril and we destroy it afterwards - merely to avoid fibril population
explosion. Otherwise, which is the usual behavior, we keep it so that
it resumes its job of a manager fibril.

  • Property mode set to 100644
File size: 3.3 KB
Line 
1/*
2 * Copyright (c) 2006 Ondrej Palkovsky
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup libc
30 * @{
31 */
32/** @file
33 */
34
35#ifndef LIBC_FIBRIL_H_
36#define LIBC_FIBRIL_H_
37
38#include <libarch/fibril.h>
39#include <adt/list.h>
40#include <libarch/tls.h>
41
42#define context_set_generic(c, _pc, stack, size, ptls) \
43 do { \
44 (c)->pc = (sysarg_t) (_pc); \
45 (c)->sp = ((sysarg_t) (stack)) + (size) - SP_DELTA; \
46 (c)->tls = (sysarg_t) (ptls); \
47 } while (0)
48
49#define FIBRIL_WRITER 1
50
51struct fibril;
52
53typedef struct {
54 struct fibril *owned_by;
55} fibril_owner_info_t;
56
57typedef enum {
58 FIBRIL_PREEMPT,
59 FIBRIL_TO_MANAGER,
60 FIBRIL_FROM_MANAGER,
61 FIBRIL_FROM_DEAD
62} fibril_switch_type_t;
63
64typedef sysarg_t fid_t;
65
66typedef struct fibril {
67 link_t link;
68 link_t all_link;
69 context_t ctx;
70 void *stack;
71 void *arg;
72 int (*func)(void *);
73 tcb_t *tcb;
74
75 struct fibril *clean_after_me;
76 int retval;
77 int flags;
78
79 fibril_owner_info_t *waits_for;
80
81 unsigned switches;
82} fibril_t;
83
84/** Fibril-local variable specifier */
85#define fibril_local __thread
86
87extern int context_save(context_t *ctx) __attribute__((returns_twice));
88extern void context_restore(context_t *ctx) __attribute__((noreturn));
89
90#define FIBRIL_DFLT_STK_SIZE 0
91
92#define fibril_create(func, arg) \
93 fibril_create_generic((func), (arg), FIBRIL_DFLT_STK_SIZE)
94extern fid_t fibril_create_generic(int (*func)(void *), void *arg, size_t);
95extern void fibril_destroy(fid_t fid);
96extern fibril_t *fibril_setup(void);
97extern void fibril_teardown(fibril_t *f, bool locked);
98extern int fibril_switch(fibril_switch_type_t stype);
99extern void fibril_add_ready(fid_t fid);
100extern void fibril_add_manager(fid_t fid);
101extern void fibril_remove_manager(void);
102extern fid_t fibril_get_id(void);
103extern void fibril_inc_sercount(void);
104extern void fibril_dec_sercount(void);
105extern int fibril_get_sercount(void);
106
107static inline int fibril_yield(void)
108{
109 return fibril_switch(FIBRIL_PREEMPT);
110}
111
112#endif
113
114/** @}
115 */
Note: See TracBrowser for help on using the repository browser.