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Commit | Line | Data |
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a14849de ER |
1 | https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=146549 |
2 | ||
3 | --- rpm-4.4.2/rpmio/rpmsq.c.deadlock 2005-07-13 12:47:03.000000000 +0200 | |
4 | +++ rpm-4.4.2/rpmio/rpmsq.c 2005-08-19 14:47:53.000000000 +0200 | |
5 | @@ -218,7 +218,6 @@ | |
6 | ||
7 | sq->id = ME(); | |
8 | ret = pthread_mutex_init(&sq->mutex, NULL); | |
9 | - ret = pthread_cond_init(&sq->cond, NULL); | |
10 | insque(elem, (prev != NULL ? prev : rpmsqQueue)); | |
11 | ret = sigrelse(SIGCHLD); | |
12 | } | |
13 | @@ -240,8 +239,11 @@ | |
14 | ret = sighold (SIGCHLD); | |
15 | if (ret == 0) { | |
16 | remque(elem); | |
17 | - ret = pthread_cond_destroy(&sq->cond); | |
18 | - ret = pthread_mutex_destroy(&sq->mutex); | |
19 | + | |
20 | + /* Unlock the mutex and then destroy it */ | |
21 | + if((ret = pthread_mutex_unlock(&sq->mutex)) == 0) | |
22 | + ret = pthread_mutex_destroy(&sq->mutex); | |
23 | + | |
24 | sq->id = NULL; | |
25 | /*@-bounds@*/ | |
26 | if (sq->pipes[1]) ret = close(sq->pipes[1]); | |
27 | @@ -315,11 +317,20 @@ | |
28 | sq != NULL && sq != rpmsqQueue; | |
29 | sq = sq->q_forw) | |
30 | { | |
31 | + int ret; | |
32 | + | |
33 | if (sq->child != reaped) | |
34 | /*@innercontinue@*/ continue; | |
35 | sq->reaped = reaped; | |
36 | sq->status = status; | |
37 | - (void) pthread_cond_signal(&sq->cond); | |
38 | + | |
39 | + /* Unlock the mutex. The waiter will then be able to | |
40 | + * aquire the lock. | |
41 | + * | |
42 | + * XXX: jbj, wtd, if this fails? | |
43 | + */ | |
44 | + ret = pthread_mutex_unlock(&sq->mutex); | |
45 | + | |
46 | /*@innerbreak@*/ break; | |
47 | } | |
48 | } | |
49 | @@ -391,6 +402,7 @@ | |
50 | { | |
51 | pid_t pid; | |
52 | int xx; | |
53 | + int nothreads = 0; /* XXX: Shouldn't this be a global? */ | |
54 | ||
55 | if (sq->reaper) { | |
56 | xx = rpmsqInsert(sq, NULL); | |
57 | @@ -405,6 +417,24 @@ | |
58 | ||
59 | xx = sighold(SIGCHLD); | |
60 | ||
61 | + /* | |
62 | + * Initialize the cond var mutex. We have to aquire the lock we | |
63 | + * use for the condition before we fork. Otherwise it is possible for | |
64 | + * the child to exit, we get sigchild and the sig handler to send | |
65 | + * the condition signal before we are waiting on the condition. | |
66 | + */ | |
67 | + if (!nothreads) { | |
68 | + if(pthread_mutex_lock(&sq->mutex)) { | |
69 | + /* Yack we did not get the lock, lets just give up */ | |
70 | +/*@-bounds@*/ | |
71 | + xx = close(sq->pipes[0]); | |
72 | + xx = close(sq->pipes[1]); | |
73 | + sq->pipes[0] = sq->pipes[1] = -1; | |
74 | +/*@=bounds@*/ | |
75 | + goto out; | |
76 | + } | |
77 | + } | |
78 | + | |
79 | pid = fork(); | |
80 | if (pid < (pid_t) 0) { /* fork failed. */ | |
81 | /*@-bounds@*/ | |
82 | @@ -462,10 +492,6 @@ | |
83 | /* Protect sq->reaped from handler changes. */ | |
84 | ret = sighold(SIGCHLD); | |
85 | ||
86 | - /* Initialize the cond var mutex. */ | |
87 | - if (!nothreads) | |
88 | - ret = pthread_mutex_lock(&sq->mutex); | |
89 | - | |
90 | /* Start the child, linux often runs child before parent. */ | |
91 | /*@-bounds@*/ | |
92 | if (sq->pipes[0] >= 0) | |
93 | @@ -486,7 +512,13 @@ | |
94 | ret = sigpause(SIGCHLD); | |
95 | else { | |
96 | xx = sigrelse(SIGCHLD); | |
97 | - ret = pthread_cond_wait(&sq->cond, &sq->mutex); | |
98 | + | |
99 | + /* | |
100 | + * We start before the fork with this mutex locked; | |
101 | + * The only one that unlocks this the signal handler. | |
102 | + * So if we get the lock the child has been reaped. | |
103 | + */ | |
104 | + ret = pthread_mutex_lock(&sq->mutex); | |
105 | xx = sighold(SIGCHLD); | |
106 | } | |
107 | } | |
108 | @@ -495,9 +527,6 @@ | |
109 | /* Accumulate stopwatch time spent waiting, potential performance gain. */ | |
110 | sq->ms_scriptlets += rpmswExit(&sq->op, -1)/1000; | |
111 | ||
112 | - /* Tear down cond var mutex, our child has been reaped. */ | |
113 | - if (!nothreads) | |
114 | - xx = pthread_mutex_unlock(&sq->mutex); | |
115 | xx = sigrelse(SIGCHLD); | |
116 | ||
117 | #ifdef _RPMSQ_DEBUG |