source: libcfa/src/concurrency/ready_subqueue.hfa @ 16fd826

arm-ehenumforall-pointer-decayjacob/cs343-translationnew-ast-unique-exprpthread-emulationqualifiedEnum
Last change on this file since 16fd826 was 16fd826, checked in by Thierry Delisle <tdelisle@…>, 19 months ago

Added count to the ready sub_queues

  • Property mode set to 100644
File size: 4.1 KB
Line 
1#pragma once
2
3#define __CFA_NO_SCHED_STATS__
4
5#include "containers/queueLockFree.hfa"
6
7// Intrusives lanes which are used by the relaxed ready queue
8struct __attribute__((aligned(128))) __intrusive_lane_t {
9        struct $thread * prev;
10
11        // spin lock protecting the queue
12        volatile bool lock;
13
14        #if !defined(__CFA_NO_STATISTICS__)
15                unsigned cnt;
16        #endif
17
18        __thread_desc_link anchor;
19};
20
21// Get the head pointer (one before the first element) from the anchor
22static inline $thread * mock_head(const __intrusive_lane_t & this) {
23        $thread * rhead = ($thread *)(
24                (uintptr_t)( &this.anchor ) - __builtin_offsetof( $thread, link )
25        );
26        return rhead;
27}
28
29// Ctor
30void ?{}( __intrusive_lane_t & this ) {
31        this.lock = false;
32        this.prev = mock_head(this);
33        this.anchor.next = 0p;
34        this.anchor.ts   = 0;
35        #if !defined(__CFA_NO_STATISTICS__)
36                this.cnt  = 0;
37        #endif
38
39        // We add a boat-load of assertions here because the anchor code is very fragile
40        /* paranoid */ _Static_assert( offsetof( $thread, link ) == offsetof(__intrusive_lane_t, anchor) );
41        /* paranoid */ verify( offsetof( $thread, link ) == offsetof(__intrusive_lane_t, anchor) );
42        /* paranoid */ verify( ((uintptr_t)( mock_head(this) ) + offsetof( $thread, link )) == (uintptr_t)(&this.anchor) );
43        /* paranoid */ verify( &mock_head(this)->link.next == &this.anchor.next );
44        /* paranoid */ verify( &mock_head(this)->link.ts   == &this.anchor.ts   );
45        /* paranoid */ verify( mock_head(this)->link.next == 0p );
46        /* paranoid */ verify( mock_head(this)->link.ts   == 0  );
47        /* paranoid */ verify( mock_head(this) == this.prev );
48        /* paranoid */ verify( __alignof__(__intrusive_lane_t) == 128 );
49        /* paranoid */ verify( __alignof__(this) == 128 );
50        /* paranoid */ verifyf( ((intptr_t)(&this) % 128) == 0, "Expected address to be aligned %p %% 128 == %zd", &this, ((intptr_t)(&this) % 128) );
51}
52
53// Dtor is trivial
54void ^?{}( __intrusive_lane_t & this ) {
55        // Make sure the list is empty
56        /* paranoid */ verify( this.anchor.next == 0p );
57        /* paranoid */ verify( this.anchor.ts   == 0  );
58        /* paranoid */ verify( mock_head(this)  == this.prev );
59}
60
61// Push a thread onto this lane
62// returns true of lane was empty before push, false otherwise
63static inline void push( __intrusive_lane_t & this, $thread * node ) {
64        /* paranoid */ verify( this.lock );
65        /* paranoid */ verify( node->link.next == 0p );
66        /* paranoid */ verify( node->link.ts   == 0  );
67        /* paranoid */ verify( this.prev->link.next == 0p );
68        /* paranoid */ verify( this.prev->link.ts   == 0  );
69        if( this.anchor.next == 0p ) {
70                /* paranoid */ verify( this.anchor.next == 0p );
71                /* paranoid */ verify( this.anchor.ts   == 0  );
72                /* paranoid */ verify( this.prev == mock_head( this ) );
73        } else {
74                /* paranoid */ verify( this.anchor.next != 0p );
75                /* paranoid */ verify( this.anchor.ts   != 0  );
76                /* paranoid */ verify( this.prev != mock_head( this ) );
77        }
78
79        // Get the relevant nodes locally
80        this.prev->link.next = node;
81        this.prev->link.ts   = rdtscl();
82        this.prev = node;
83        #if !defined(__CFA_NO_STATISTICS__)
84                this.cnt++;
85        #endif
86}
87
88// Pop a thread from this lane (must be non-empty)
89// returns popped
90// returns true of lane was empty before push, false otherwise
91static inline [* $thread, unsigned long long] pop( __intrusive_lane_t & this ) {
92        /* paranoid */ verify( this.lock );
93        /* paranoid */ verify( this.anchor.next != 0p );
94        /* paranoid */ verify( this.anchor.ts   != 0  );
95
96        // Get the relevant nodes locally
97        unsigned long long ts = this.anchor.ts;
98        $thread * node = this.anchor.next;
99        this.anchor.next = node->link.next;
100        this.anchor.ts   = node->link.ts;
101        bool is_empty = this.anchor.ts == 0;
102        node->link.next = 0p;
103        node->link.ts   = 0;
104        #if !defined(__CFA_NO_STATISTICS__)
105                this.cnt--;
106        #endif
107
108        // Update head time stamp
109        if(is_empty) this.prev = mock_head( this );
110
111        /* paranoid */ verify( node->link.next == 0p );
112        /* paranoid */ verify( node->link.ts   == 0  );
113        return [node, ts];
114}
115
116// Check whether or not list is empty
117static inline bool is_empty(__intrusive_lane_t & this) {
118        return this.anchor.ts == 0;
119}
120
121// Return the timestamp
122static inline unsigned long long ts(__intrusive_lane_t & this) {
123        // Cannot verify here since it may not be locked
124        return this.anchor.ts;
125}
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