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
|
/* -----------------------------------------------------------------------------
*
* (c) The GHC Team, 1998-2006
*
* The IO manager thread in THREADED_RTS.
* See also libraries/base/GHC/Conc.lhs.
*
* ---------------------------------------------------------------------------*/
#include "Rts.h"
#include "IOManager.h"
#include "Prelude.h"
#include <windows.h>
// Here's the Event that we use to wake up the IO manager thread
static HANDLE io_manager_event = INVALID_HANDLE_VALUE;
// must agree with values in GHC.Conc:
#define IO_MANAGER_WAKEUP 0xffffffff
#define IO_MANAGER_DIE 0xfffffffe
// spurios wakeups are returned as zero.
// console events are ((event<<1) | 1)
#if defined(THREADED_RTS)
#define EVENT_BUFSIZ 256
Mutex event_buf_mutex;
StgWord32 event_buf[EVENT_BUFSIZ];
nat next_event;
#endif
HANDLE
getIOManagerEvent (void)
{
// This function has to exist even in the non-THREADED_RTS,
// because code in GHC.Conc refers to it. It won't ever be called
// unless we're in the threaded RTS, however.
#ifdef THREADED_RTS
HANDLE hRes;
ACQUIRE_LOCK(&event_buf_mutex);
if (io_manager_event == INVALID_HANDLE_VALUE) {
hRes = CreateEvent ( NULL, // no security attrs
TRUE, // manual reset
FALSE, // initial state,
NULL ); // event name: NULL for private events
if (hRes == NULL) {
sysErrorBelch("getIOManagerEvent");
stg_exit(EXIT_FAILURE);
}
io_manager_event = hRes;
} else {
hRes = io_manager_event;
}
RELEASE_LOCK(&event_buf_mutex);
return hRes;
#else
return NULL;
#endif
}
HsWord32
readIOManagerEvent (void)
{
// This function must exist even in non-THREADED_RTS,
// see getIOManagerEvent() above.
#if defined(THREADED_RTS)
HsWord32 res;
ACQUIRE_LOCK(&event_buf_mutex);
if (io_manager_event != INVALID_HANDLE_VALUE) {
if (next_event == 0) {
res = 0; // no event to return
} else {
res = (HsWord32)(event_buf[--next_event]);
if (next_event == 0) {
if (!ResetEvent(io_manager_event)) {
sysErrorBelch("readIOManagerEvent");
stg_exit(EXIT_FAILURE);
}
}
}
} else {
res = 0;
}
RELEASE_LOCK(&event_buf_mutex);
// debugBelch("readIOManagerEvent: %d\n", res);
return res;
#else
return 0;
#endif
}
void
sendIOManagerEvent (HsWord32 event)
{
#if defined(THREADED_RTS)
ACQUIRE_LOCK(&event_buf_mutex);
// debugBelch("sendIOManagerEvent: %d\n", event);
if (io_manager_event != INVALID_HANDLE_VALUE) {
if (next_event == EVENT_BUFSIZ) {
errorBelch("event buffer overflowed; event dropped");
} else {
if (!SetEvent(io_manager_event)) {
sysErrorBelch("sendIOManagerEvent");
stg_exit(EXIT_FAILURE);
}
event_buf[next_event++] = (StgWord32)event;
}
}
RELEASE_LOCK(&event_buf_mutex);
#endif
}
void
ioManagerWakeup (void)
{
sendIOManagerEvent(IO_MANAGER_WAKEUP);
}
#if defined(THREADED_RTS)
void
ioManagerDie (void)
{
sendIOManagerEvent(IO_MANAGER_DIE);
// IO_MANAGER_DIE must be idempotent, as it is called
// repeatedly by shutdownCapability(). Try conc059(threaded1) to
// illustrate the problem.
ACQUIRE_LOCK(&event_buf_mutex);
io_manager_event = INVALID_HANDLE_VALUE;
RELEASE_LOCK(&event_buf_mutex);
// ToDo: wait for the IO manager to pick up the event, and
// then release the Event and Mutex objects we've allocated.
}
void
ioManagerStart (void)
{
initMutex(&event_buf_mutex);
next_event = 0;
// Make sure the IO manager thread is running
Capability *cap;
if (io_manager_event == INVALID_HANDLE_VALUE) {
cap = rts_lock();
rts_evalIO(&cap,ensureIOManagerIsRunning_closure,NULL);
rts_unlock(cap);
}
}
#endif
|
