1 |
tony |
319 |
{Used by IBIPC and implements System V IPC} |
2 |
tony |
209 |
|
3 |
tony |
319 |
uses IBMessages, ipc, Errors, baseunix; |
4 |
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5 |
tony |
209 |
const |
6 |
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IPCFileName: string = 'FB.SQL.MONITOR1_0'; |
7 |
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cNumberOfSemaphores = 10; |
8 |
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cMutexSemaphore = 0; |
9 |
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cMonitorCounter = 1; |
10 |
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cReadReadyEventSemaphore = 2; |
11 |
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cReadFinishedEventSemaphore = 4; |
12 |
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cDataAvailableEventSemaphore = 6; |
13 |
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cWriterBusyEventSemaphore = 8; |
14 |
tony |
320 |
cDefaultTimeout = 10; {seconds } |
15 |
tony |
209 |
|
16 |
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{$IF FPC_FULLVERSION = 30000 } |
17 |
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{Fix regression in FPC 3.0.0 ipc.pp unit. Expected to be fixed in fpc 3.0.2} |
18 |
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{$IF defined(darwin) } |
19 |
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SEM_GETNCNT = 3; { Return the value of sempid (READ) } |
20 |
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SEM_GETPID = 4; { Return the value of semval (READ) } |
21 |
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SEM_GETVAL = 5; { Return semvals into arg.array (READ) } |
22 |
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SEM_GETALL = 6; { Return the value of semzcnt (READ) } |
23 |
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SEM_GETZCNT = 7; { Set the value of semval to arg.val (ALTER) } |
24 |
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SEM_SETVAL = 8; { Set semvals from arg.array (ALTER) } |
25 |
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SEM_SETALL = 9; |
26 |
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{$ENDIF} |
27 |
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{$ENDIF} |
28 |
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29 |
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function GetLastErrno: cint; |
30 |
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begin |
31 |
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Result := fpgetErrno |
32 |
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end; |
33 |
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34 |
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type |
35 |
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{Interprocess Communication Objects. All platform dependent IPC is abstracted |
36 |
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into this set of objects } |
37 |
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38 |
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{ TIpcCommon } |
39 |
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|
40 |
tony |
319 |
TIpcCommon = class(TInterfacedObject) |
41 |
tony |
209 |
public |
42 |
tony |
319 |
function GetSa: PSecurityAttributes; |
43 |
tony |
209 |
property Sa : PSecurityAttributes read GetSa; |
44 |
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end; |
45 |
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46 |
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{ TSharedMemory } |
47 |
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48 |
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{ |
49 |
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The shared memory segment is used for interprocess communication and |
50 |
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holds both a message buffer and a number of shared variables. Shared |
51 |
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memory is allocated to each shared variable using the Allocate function. |
52 |
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An underlying assumption is that each process using the shared memory |
53 |
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calls "Allocate" in the same order and for the same memory sizes. |
54 |
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55 |
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Linux: |
56 |
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57 |
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The Linux implementation uses Linux shared memory. IPC_PRIVATE is used |
58 |
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to allocate the memory and the resulting memory id is written to a |
59 |
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well known file. By default this is in the current user's home directory, |
60 |
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but this can be over-ridden to specify a globally unique filename. |
61 |
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62 |
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Access to the shared memory is restricted to the current user/group. |
63 |
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Note that the Linux semaphore set is also created with the shared memory. |
64 |
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} |
65 |
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66 |
tony |
321 |
ISharedMemory = interface |
67 |
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['{db77bdd4-233a-4c9c-9212-dd7945e2e57c}'] |
68 |
tony |
320 |
function IsInitialiser: boolean; |
69 |
tony |
321 |
function Allocate(Size: integer): PByte; |
70 |
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function GetLastAllocationSize: integer; |
71 |
tony |
322 |
function sem_op(SemNum, op: integer; flags: cshort = 0): cint; |
72 |
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function sem_timedop(SemNum, op: integer; timeout_secs: integer; flags: cshort = 0): cint; |
73 |
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function GetSemValue(SemNum: integer): cint; |
74 |
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procedure SemInit(SemNum, AValue: cint); |
75 |
tony |
321 |
property LastAllocationSize: integer read GetLastAllocationSize; |
76 |
tony |
320 |
end; |
77 |
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|
78 |
tony |
319 |
TSharedMemory = class(TIpcCommon,ISharedMemory) |
79 |
tony |
209 |
private |
80 |
tony |
320 |
FSharedMemoryID: cint; |
81 |
tony |
322 |
FSemaphoreSetID: cint; |
82 |
tony |
319 |
FBuffer: PByte; |
83 |
tony |
209 |
FLastAllocationSize: integer; |
84 |
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FUnused: integer; |
85 |
tony |
319 |
FBufptr: PByte; |
86 |
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FIPCFileName: AnsiString; |
87 |
tony |
320 |
FInitialiser: boolean; |
88 |
tony |
209 |
procedure DropSharedMemory; |
89 |
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procedure GetSharedMemory(MemSize: integer); |
90 |
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public |
91 |
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constructor Create(MemSize: integer); |
92 |
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destructor Destroy; override; |
93 |
tony |
319 |
function Allocate(Size: integer): PByte; |
94 |
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function GetLastAllocationSize: integer; |
95 |
tony |
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function IsInitialiser: boolean; |
96 |
tony |
322 |
function sem_op(SemNum, op: integer; flags: cshort = 0): cint; |
97 |
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function sem_timedop(SemNum, op: integer; timeout_secs: integer; flags: cshort = 0): cint; |
98 |
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function GetSemValue(SemNum: integer): cint; |
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procedure SemInit(SemNum, AValue: cint); |
100 |
tony |
319 |
property LastAllocationSize: integer read GetLastAllocationSize; |
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tony |
209 |
end; |
102 |
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103 |
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{TMutex} |
104 |
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105 |
tony |
319 |
TMutex = class(TIpcCommon,IMutex) |
106 |
tony |
209 |
private |
107 |
tony |
322 |
FSharedMemory: ISharedMemory; |
108 |
tony |
209 |
FMutexSemaphore: cint; |
109 |
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FLockCount: integer; |
110 |
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public |
111 |
tony |
322 |
constructor Create(SemNumber: cint; sm: ISharedMemory); |
112 |
tony |
209 |
procedure Lock; |
113 |
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procedure Unlock; |
114 |
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end; |
115 |
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116 |
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{ TSingleLockGate } |
117 |
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118 |
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{ |
119 |
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A single lock gate is either open or closed. When open, any thread can pass |
120 |
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through it while, when closed, all threads are blocked as they try to pass |
121 |
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through the gate. When the gate is opened, all blocked threads are resumed. |
122 |
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123 |
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There is an implementation assumption that only one writer thread at |
124 |
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a time (i.e. the thread which locks or unlocks the gate) can have access to |
125 |
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it at any one time. I.e. an external Mutex prevents race conditions. |
126 |
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127 |
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Linux: |
128 |
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129 |
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In the Linux implementation, the gate is implemented by a semaphore |
130 |
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and a share memory integer used as a bi-state variable. When the gate |
131 |
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is open, the bi-state variable is non-zero. It is set to zero when closed. |
132 |
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Another shared memory integer is used to count the number of waiting |
133 |
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threads, and a second semaphore is used to protect access to this. |
134 |
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135 |
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The event semaphore is initialised to zero. When a thread passes through the gate |
136 |
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it checks the state. If open, the thread continues. If closed then it |
137 |
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increments the count of waiting threads and then decrements the semaphore |
138 |
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and hence enters an indefinite wait state. |
139 |
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|
140 |
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When the gate is locked, the state is set to zero. When unlocked, the state |
141 |
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is set to one and the semaphore incremented by the number of waiting threads, |
142 |
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which itself is then zeroed. |
143 |
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144 |
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Always initialised to the Unlocked state |
145 |
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} |
146 |
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|
147 |
tony |
319 |
TSingleLockGate = class(TIpcCommon,ISingleLockGate) |
148 |
tony |
209 |
private |
149 |
tony |
321 |
FSharedMemory: ISharedMemory; |
150 |
tony |
209 |
FSemaphore: cint; |
151 |
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FMutex: cint; |
152 |
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FSignalledState: PInteger; |
153 |
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FWaitingThreads: PInteger; |
154 |
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function GetWaitingThreads: integer; |
155 |
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public |
156 |
tony |
321 |
constructor Create(SemNum: cint; sm: ISharedMemory); |
157 |
tony |
209 |
property WaitingThreads: integer read GetWaitingThreads; |
158 |
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public |
159 |
|
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procedure PassthroughGate; |
160 |
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procedure Unlock; |
161 |
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procedure Lock; |
162 |
|
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end; |
163 |
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164 |
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{ TMultilockGate } |
165 |
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|
166 |
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{ This type of Gate is used where several reader threads must pass |
167 |
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through the gate before it can be opened for a writer thread. |
168 |
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|
169 |
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The reader threads register their interest by each locking the gate. |
170 |
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The writer thread then waits on the locked gate until all the reader |
171 |
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threads have separately unlocked the gate. |
172 |
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|
173 |
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There is an underlying assumption of a single writer. A Mutex must |
174 |
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be used to control access to the gate from the writer side if this |
175 |
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assumption is invalid. |
176 |
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177 |
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Linux: |
178 |
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|
179 |
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The Linux implementation uses a single semaphore to implement the gate, |
180 |
|
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which is initialised to 1 (unlocked), and a count of the number of |
181 |
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threads that have locked the gate (LockCount). A mutex semaphore |
182 |
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protects access to the LockCount. When the gate is locked, the lockcount |
183 |
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is incremented and, if the LockCount was originally zero, the semaphore is |
184 |
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set to zero (Gate Closed). |
185 |
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|
186 |
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Unlocking the gate, is the reverse. The LockCount is decremented and, if it |
187 |
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reaches zero, the semaphore is set to one (Gate Opened). |
188 |
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|
189 |
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When a writer passes through the gate, it checks the LockCount, if zero it |
190 |
|
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proceeds to pass through the gate. Otherwise it decrements and waits on the |
191 |
|
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semaphore. When the writer resumes, it increments the semaphore in order |
192 |
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to return it to its unlocked state. The wait is a timed wait, as there is |
193 |
|
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a risk that a reader thread may terminate while the gate is locked. If the |
194 |
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LockCount is non-zero, it is decremented and the writer returns to wait on |
195 |
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the gate. |
196 |
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|
197 |
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Always initialised to the Unlocked state |
198 |
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} |
199 |
|
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|
200 |
tony |
319 |
TMultilockGate = class(TIpcCommon,IMultiLockGate) |
201 |
tony |
209 |
private |
202 |
tony |
321 |
FSharedMemory: ISharedMemory; |
203 |
tony |
209 |
FOnGateTimeout: TNotifyEvent; |
204 |
|
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FSemaphore: cint; |
205 |
|
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FMutex: cint; |
206 |
|
|
FLockCount: PInteger; |
207 |
|
|
function GetLockCount: integer; |
208 |
|
|
public |
209 |
tony |
321 |
constructor Create(SemNum: cint; sm: ISharedMemory); |
210 |
tony |
209 |
procedure Lock; |
211 |
|
|
procedure Unlock; |
212 |
|
|
procedure PassthroughGate; |
213 |
tony |
319 |
function GetOnGateTimeout: TNotifyEvent; |
214 |
|
|
procedure SetOnGateTimeout(AValue: TNotifyEvent); |
215 |
tony |
209 |
property LockCount: integer read GetLockCount; |
216 |
tony |
319 |
property OnGateTimeout: TNotifyEvent read GetOnGateTimeout write SetOnGateTimeout; |
217 |
tony |
209 |
end; |
218 |
|
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|
219 |
tony |
319 |
{ TIPCInterface } |
220 |
tony |
209 |
|
221 |
tony |
319 |
TIPCInterface = class(TIpcCommon,IIPCInterface) |
222 |
tony |
209 |
private |
223 |
|
|
FMaxBufferSize: integer; |
224 |
tony |
321 |
FSharedMemory: ISharedMemory; |
225 |
tony |
319 |
FWriteLock: IMutex; |
226 |
|
|
FBuffer: PByte; |
227 |
tony |
209 |
FTraceDataType, |
228 |
|
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FBufferSize: PInteger; |
229 |
|
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FTimeStamp: PDateTime; |
230 |
tony |
319 |
FMsgNumber: PInteger; |
231 |
|
|
FReadReadyEvent: IMultiLockGate; |
232 |
|
|
FReadFinishedEvent: IMultiLockGate; |
233 |
|
|
FDataAvailableEvent: ISingleLockGate; |
234 |
|
|
FWriterBusyEvent: ISingleLockGate; |
235 |
tony |
209 |
public |
236 |
|
|
constructor Create; |
237 |
|
|
procedure IncMonitorCount; |
238 |
|
|
procedure DecMonitorCount; |
239 |
|
|
procedure SendTrace(TraceObject: TTraceObject); |
240 |
|
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procedure ReceiveTrace(TraceObject: TTraceObject); |
241 |
tony |
319 |
function GetDataAvailableEvent: ISingleLockGate; |
242 |
|
|
function GetWriterBusyEvent: ISingleLockGate; |
243 |
|
|
function GetReadReadyEvent: IMultiLockGate; |
244 |
|
|
function GetReadFinishedEvent: IMultiLockGate; |
245 |
|
|
function GetWriteLock: IMutex; |
246 |
|
|
function GetMonitorCount: integer; |
247 |
|
|
function GetMaxBufferSize: integer; |
248 |
|
|
property DataAvailableEvent: ISingleLockGate read GetDataAvailableEvent; |
249 |
|
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property WriterBusyEvent: ISingleLockGate read GetWriterBusyEvent; |
250 |
|
|
property ReadReadyEvent: IMultiLockGate read GetReadReadyEvent; |
251 |
|
|
property ReadFinishedEvent: IMultiLockGate read GetReadFinishedEvent; |
252 |
|
|
property WriteLock: IMutex read GetWriteLock; |
253 |
tony |
209 |
property MonitorCount: integer read GetMonitorCount; |
254 |
tony |
319 |
property MaxBufferSize: integer read GetMaxBufferSize; |
255 |
tony |
209 |
end; |
256 |
|
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|
257 |
|
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{ TSharedMemory } |
258 |
|
|
|
259 |
|
|
procedure TSharedMemory.GetSharedMemory(MemSize: integer); |
260 |
|
|
var F: cint; |
261 |
|
|
begin |
262 |
tony |
319 |
if GetEnvironmentVariable('FBSQL_IPCFILENAME') <> '' then |
263 |
|
|
FIPCFileName := GetEnvironmentVariable('FBSQL_IPCFILENAME') |
264 |
|
|
else |
265 |
|
|
FIPCFileName := GetTempDir(true) + IPCFileName + '.' + GetEnvironmentVariable('USER'); |
266 |
|
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|
267 |
tony |
209 |
{Get the Shared Memory and Semaphore IDs from the Global File if it exists |
268 |
|
|
or create them and the file otherwise } |
269 |
|
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|
270 |
|
|
repeat |
271 |
tony |
319 |
F := fpOpen(FIPCFileName, O_WrOnly or O_Creat or O_Excl); |
272 |
tony |
209 |
if F < 0 then |
273 |
|
|
begin |
274 |
|
|
if fpgetErrno = ESysEEXIST {EEXIST} then |
275 |
|
|
begin |
276 |
|
|
{ looks like it already exists} |
277 |
|
|
Sleep(100); |
278 |
tony |
319 |
F := fpOpen(FIPCFileName,O_RdOnly); |
279 |
tony |
209 |
if (F < 0) and (fpgetErrno = ESysENOENT {ENOENT}) then |
280 |
|
|
{probably just got deleted } |
281 |
|
|
else |
282 |
|
|
if F < 0 then |
283 |
|
|
IBError(ibxeCannotCreateSharedResource,['Error accessing IPC File - ' + |
284 |
|
|
StrError(fpgetErrno)]); |
285 |
|
|
end |
286 |
|
|
else |
287 |
|
|
IBError(ibxeCannotCreateSharedResource,['Error creating IPC File - ' + |
288 |
|
|
StrError(fpgetErrno)]); |
289 |
|
|
end |
290 |
|
|
else |
291 |
|
|
FInitialiser := true |
292 |
|
|
until F >= 0; |
293 |
|
|
|
294 |
|
|
if FInitialiser then |
295 |
|
|
begin |
296 |
|
|
FSharedMemoryID := shmget(IPC_PRIVATE,MemSize, IPC_CREAT or |
297 |
|
|
S_IRUSR or S_IWUSR or S_IRGRP or S_IWGRP); |
298 |
|
|
if FSharedMemoryID < 0 then |
299 |
|
|
IBError(ibxeCannotCreateSharedResource,['Cannot create shared memory segment - ' + |
300 |
|
|
StrError(fpgetErrno)]); |
301 |
|
|
|
302 |
|
|
FSemaphoreSetID := semget(IPC_PRIVATE, cNumberOfSemaphores,IPC_CREAT or |
303 |
|
|
S_IRUSR or S_IWUSR or S_IRGRP or S_IWGRP); |
304 |
|
|
if FSemaphoreSetID < 0 then |
305 |
|
|
IBError(ibxeCannotCreateSharedResource,['Cannot create shared semaphore set - ' + |
306 |
|
|
StrError(fpgetErrno)]); |
307 |
|
|
|
308 |
|
|
fpWrite(F,FSharedMemoryID,sizeof(FSharedMemoryID)); |
309 |
|
|
fpWrite(F,FSemaphoreSetID,sizeof(FSemaphoreSetID)); |
310 |
|
|
end |
311 |
|
|
else |
312 |
|
|
begin |
313 |
|
|
fpRead(F,FSharedMemoryID,sizeof(FSharedMemoryID)); |
314 |
|
|
fpRead(F,FSemaphoreSetID,sizeof(FSemaphoreSetID)); |
315 |
|
|
if GetSemValue(cMonitorCounter) = 0 then |
316 |
|
|
begin |
317 |
|
|
FInitialiser := true; |
318 |
|
|
//writeln('Opened file and is initialiser'); |
319 |
|
|
end |
320 |
|
|
end; |
321 |
|
|
fpClose(F); |
322 |
|
|
end; |
323 |
|
|
|
324 |
|
|
procedure TSharedMemory.DropSharedMemory; |
325 |
|
|
var ds: TShmid_ds; |
326 |
|
|
arg: tsemun; |
327 |
|
|
begin |
328 |
|
|
if shmctl(FSharedMemoryID,IPC_STAT,@ds) < 0 then |
329 |
|
|
IBError(ibxeSV5APIError,['Error getting shared memory info' + strError(fpgetErrno)]); |
330 |
|
|
if ds.shm_nattch = 0 then { we are the last one out - so, turn off the lights } |
331 |
|
|
begin |
332 |
|
|
shmctl(FSharedMemoryID,IPC_RMID,nil); |
333 |
|
|
semctl(FSemaphoreSetID,0,IPC_RMID,arg); |
334 |
tony |
319 |
DeleteFile(FIPCFileName); |
335 |
tony |
209 |
end; |
336 |
|
|
end; |
337 |
|
|
|
338 |
|
|
constructor TSharedMemory.Create(MemSize: integer); |
339 |
|
|
begin |
340 |
|
|
inherited Create; |
341 |
|
|
FInitialiser := false; |
342 |
|
|
GetSharedMemory(MemSize); |
343 |
|
|
FBuffer := shmat(FSharedMemoryID,nil,0); |
344 |
|
|
if PtrInt(FBuffer) = -1 then |
345 |
|
|
IBError(ibxeCannotCreateSharedResource,[StrError(Errno)]); |
346 |
|
|
FBufPtr := FBuffer; |
347 |
|
|
FUnused := MemSize |
348 |
|
|
end; |
349 |
|
|
|
350 |
|
|
destructor TSharedMemory.Destroy; |
351 |
|
|
begin |
352 |
|
|
shmdt(FBuffer); |
353 |
|
|
DropSharedMemory; |
354 |
|
|
inherited Destroy; |
355 |
|
|
end; |
356 |
|
|
|
357 |
tony |
319 |
function TSharedMemory.Allocate(Size: integer): PByte; |
358 |
tony |
209 |
begin |
359 |
|
|
if Size > FUnused then |
360 |
|
|
IBError(ibxeCannotCreateSharedResource, ['Not enough shared memory']); |
361 |
|
|
Result := FBufPtr; |
362 |
|
|
|
363 |
|
|
if Size = 0 then |
364 |
|
|
begin |
365 |
|
|
FLastAllocationSize := FUnused; |
366 |
|
|
FUnused := 0 |
367 |
|
|
end |
368 |
|
|
else |
369 |
|
|
begin |
370 |
|
|
FLastAllocationSize := Size; |
371 |
|
|
Dec(FUnused,Size); |
372 |
|
|
end; |
373 |
|
|
Inc(FBufPtr,Size) |
374 |
|
|
end; |
375 |
|
|
|
376 |
tony |
319 |
function TSharedMemory.GetLastAllocationSize: integer; |
377 |
|
|
begin |
378 |
|
|
Result := FLastAllocationSize; |
379 |
|
|
end; |
380 |
|
|
|
381 |
tony |
320 |
function TSharedMemory.IsInitialiser: boolean; |
382 |
|
|
begin |
383 |
|
|
Result := FInitialiser; |
384 |
|
|
end; |
385 |
|
|
|
386 |
tony |
322 |
function TSharedMemory.sem_op(SemNum, op: integer; flags: cshort): cint; |
387 |
tony |
209 |
var sembuf: TSEMbuf; |
388 |
|
|
begin |
389 |
|
|
sembuf.sem_num := SemNum; |
390 |
|
|
sembuf.sem_op:= op; |
391 |
|
|
sembuf.sem_flg := flags or SEM_UNDO; |
392 |
|
|
Result := semop(FSemaphoreSetID,@sembuf,1); |
393 |
|
|
end; |
394 |
|
|
|
395 |
tony |
322 |
function TSharedMemory.sem_timedop(SemNum, op: integer; timeout_secs: integer; |
396 |
tony |
209 |
flags: cshort): cint; |
397 |
|
|
var sembuf: TSEMbuf; |
398 |
|
|
timeout: TimeSpec; |
399 |
|
|
begin |
400 |
|
|
sembuf.sem_num := SemNum; |
401 |
|
|
sembuf.sem_op:= op; |
402 |
|
|
sembuf.sem_flg := flags or SEM_UNDO; |
403 |
|
|
timeout.tv_sec := timeout_secs; |
404 |
|
|
timeout.tv_nsec := 0; |
405 |
tony |
319 |
{$IF declared(semtimedop)} |
406 |
tony |
209 |
Result := semtimedop(FSemaphoreSetID,@sembuf,1,@timeout); |
407 |
|
|
{$ELSE} |
408 |
|
|
Result := semop(FSemaphoreSetID,@sembuf,1); {May hang on race condition} |
409 |
tony |
319 |
{$IFEND} |
410 |
tony |
209 |
end; |
411 |
|
|
|
412 |
tony |
322 |
function TSharedMemory.GetSemValue(SemNum: integer): cint; |
413 |
tony |
209 |
var args :TSEMun; |
414 |
|
|
begin |
415 |
|
|
Result := semctl(FSemaphoreSetID,SemNum,SEM_GETVAL,args); |
416 |
|
|
if Result < 0 then |
417 |
|
|
IBError(ibxeSV5APIError,['GetSemValue: '+strError(GetLastErrno)]); |
418 |
|
|
end; |
419 |
|
|
|
420 |
tony |
322 |
procedure TSharedMemory.SemInit(SemNum, AValue: cint); |
421 |
tony |
209 |
var args :TSEMun; |
422 |
|
|
begin |
423 |
|
|
//writeln('Initialising ',SemNum,' to ',AValue); |
424 |
|
|
args.val := AValue; |
425 |
|
|
if semctl(FSemaphoreSetID,SemNum,SEM_SETVAL,args) < 0 then |
426 |
|
|
IBError(ibxeCannotCreateSharedResource,['Unable to initialise Semaphone ' + |
427 |
|
|
IntToStr(SemNum) + '- ' + StrError(GetLastErrno)]); |
428 |
|
|
|
429 |
|
|
end; |
430 |
|
|
|
431 |
tony |
322 |
{ TIpcCommon } |
432 |
|
|
|
433 |
|
|
function TIpcCommon.GetSa: PSecurityAttributes; |
434 |
|
|
begin |
435 |
|
|
Result := nil |
436 |
|
|
end; |
437 |
|
|
|
438 |
tony |
209 |
{ TMutex } |
439 |
|
|
|
440 |
tony |
322 |
constructor TMutex.Create(SemNumber: cint; sm: ISharedMemory); |
441 |
tony |
209 |
begin |
442 |
|
|
inherited Create; |
443 |
tony |
322 |
FSharedMemory := sm; |
444 |
tony |
209 |
FMutexSemaphore := SemNumber; |
445 |
tony |
322 |
if FSharedMemory.IsInitialiser then |
446 |
|
|
FSharedMemory.SemInit(FMutexSemaphore,1) |
447 |
tony |
209 |
end; |
448 |
|
|
|
449 |
|
|
{ Obtain ownership of the Mutex and prevent other threads from accessing protected resource } |
450 |
|
|
|
451 |
|
|
procedure TMutex.Lock; |
452 |
|
|
begin |
453 |
|
|
//writeln('Lock: Entering Mutex ',FMutexSemaphore,' LockCount=',FLockCount,' State = ',GetSemValue(FMutexSemaphore)); |
454 |
|
|
if FLockCount = 0 then |
455 |
tony |
322 |
FSharedMemory.sem_op(FMutexSemaphore,-1); |
456 |
tony |
209 |
Inc(FLockCount); |
457 |
|
|
//writeln('Lock: Mutex Exit'); |
458 |
|
|
end; |
459 |
|
|
|
460 |
|
|
{Give up ownership of the Mutex and allow other threads access } |
461 |
|
|
|
462 |
|
|
procedure TMutex.Unlock; |
463 |
|
|
begin |
464 |
|
|
//writeln('UnLock: Entering Mutex, LockCount=',FLockCount); |
465 |
|
|
if FLockCount = 0 then Exit; |
466 |
|
|
Dec(FLockCount); |
467 |
|
|
if FLockCount = 0 then |
468 |
tony |
322 |
FSharedMemory.sem_op(FMutexSemaphore,1); |
469 |
tony |
209 |
//writeln('UnLock: Mutex Exit',' State = ',GetSemValue(FMutexSemaphore)); |
470 |
|
|
end; |
471 |
|
|
|
472 |
|
|
{ TSingleLockGate } |
473 |
|
|
|
474 |
|
|
function TSingleLockGate.GetWaitingThreads: integer; |
475 |
|
|
begin |
476 |
|
|
Result := FWaitingThreads^ |
477 |
|
|
end; |
478 |
|
|
|
479 |
tony |
321 |
constructor TSingleLockGate.Create(SemNum: cint; sm: ISharedMemory); |
480 |
tony |
209 |
begin |
481 |
|
|
inherited Create; |
482 |
tony |
319 |
FSharedMemory := sm; |
483 |
|
|
FSignalledState := PInteger(FSharedMemory.Allocate(sizeof(FSignalledState))); |
484 |
|
|
FWaitingThreads := PInteger(FSharedMemory.Allocate(sizeof(FWaitingThreads))); |
485 |
tony |
209 |
FSemaphore := SemNum; |
486 |
|
|
FMutex := SemNum + 1; |
487 |
tony |
320 |
if FSharedMemory.IsInitialiser then |
488 |
tony |
209 |
begin |
489 |
|
|
FSignalledState^ := 1; |
490 |
|
|
FWaitingThreads^ := 0; |
491 |
tony |
322 |
FSharedMemory.SemInit(FSemaphore,0); |
492 |
|
|
FSharedMemory.SemInit(FMutex,1); |
493 |
tony |
209 |
end; |
494 |
|
|
end; |
495 |
|
|
|
496 |
|
|
procedure TSingleLockGate.PassthroughGate; |
497 |
|
|
begin |
498 |
|
|
if FSignalledState^ = 0 then |
499 |
|
|
begin |
500 |
tony |
322 |
FSharedMemory.sem_op(FMutex,-1,0); //Acquire Mutex |
501 |
tony |
209 |
Inc(FWaitingThreads^); |
502 |
tony |
322 |
FSharedMemory.sem_op(FMutex,1,0); //Release Mutex |
503 |
tony |
209 |
//writeln(ClassName + ': Wait State Entered ',FSemaphore,' = ',GetSemValue(FSemaphore)); |
504 |
tony |
322 |
FSharedMemory.sem_op(FSemaphore,-1,0); //Enter Wait |
505 |
tony |
209 |
//writeln(ClassName + ': Wait State Ends ',FSemaphore); |
506 |
|
|
end; |
507 |
|
|
end; |
508 |
|
|
|
509 |
|
|
procedure TSingleLockGate.Unlock; |
510 |
|
|
begin |
511 |
|
|
if FSignalledState^ = 0 then |
512 |
|
|
begin |
513 |
|
|
FSignalledState^ := 1; |
514 |
tony |
322 |
FSharedMemory.sem_op(FMutex,-1,0); //Acquire Mutex |
515 |
tony |
319 |
{$IFDEF DEBUG}writeln(ClassName + ': Unlocking' ,FSemaphore);{$ENDIF} |
516 |
tony |
322 |
FSharedMemory.sem_op(FSemaphore,FWaitingThreads^,0); |
517 |
tony |
209 |
FWaitingThreads^ := 0; |
518 |
tony |
322 |
FSharedMemory.sem_op(FMutex,1,0); //Release Mutex |
519 |
tony |
209 |
end; |
520 |
|
|
end; |
521 |
|
|
|
522 |
|
|
procedure TSingleLockGate.Lock; |
523 |
|
|
begin |
524 |
|
|
if FSignalledState^ = 1 then |
525 |
|
|
begin |
526 |
tony |
319 |
{$IFDEF DEBUG}writeln(ClassName + ': Locking Gate ',FSemaphore);{$ENDIF} |
527 |
tony |
322 |
FSharedMemory.SemInit(FSemaphore,0); |
528 |
tony |
209 |
FSignalledState^ := 0; |
529 |
|
|
end; |
530 |
|
|
end; |
531 |
|
|
|
532 |
|
|
{ TMultilockGate } |
533 |
|
|
|
534 |
tony |
321 |
constructor TMultilockGate.Create(SemNum: cint; sm: ISharedMemory); |
535 |
tony |
209 |
begin |
536 |
|
|
inherited Create; |
537 |
|
|
FSemaphore := SemNum; |
538 |
|
|
FMutex := SemNum + 1; |
539 |
tony |
319 |
FSharedMemory := sm; |
540 |
|
|
FLockCount := PInteger(FSharedMemory.Allocate(sizeof(FLockCount))); |
541 |
tony |
320 |
if FSharedMemory.IsInitialiser then |
542 |
tony |
209 |
begin |
543 |
|
|
FLockCount^ := 0; |
544 |
tony |
322 |
FSharedMemory.SemInit(FSemaphore,1); |
545 |
|
|
FSharedMemory.SemInit(FMutex,1); |
546 |
tony |
209 |
end; |
547 |
|
|
end; |
548 |
|
|
|
549 |
|
|
function TMultilockGate.GetLockCount: integer; |
550 |
|
|
begin |
551 |
|
|
Result := FLockCount^ |
552 |
|
|
end; |
553 |
|
|
|
554 |
tony |
319 |
function TMultilockGate.GetOnGateTimeout: TNotifyEvent; |
555 |
|
|
begin |
556 |
|
|
Result := FOnGateTimeout; |
557 |
|
|
end; |
558 |
|
|
|
559 |
|
|
procedure TMultilockGate.SetOnGateTimeout(AValue: TNotifyEvent); |
560 |
|
|
begin |
561 |
|
|
FOnGateTimeout := AValue; |
562 |
|
|
end; |
563 |
|
|
|
564 |
tony |
209 |
procedure TMultilockGate.Lock; |
565 |
|
|
begin |
566 |
tony |
322 |
FSharedMemory.sem_op(FMutex,-1,0); //Acquire Mutex |
567 |
tony |
209 |
if FLockCount^ = 0 then |
568 |
|
|
begin |
569 |
tony |
319 |
{$IFDEF DEBUG}writeln(ClassName,': Locking ',FSemaphore);{$ENDIF} |
570 |
tony |
322 |
FSharedMemory.SemInit(FSemaphore,0); |
571 |
tony |
209 |
end; |
572 |
|
|
Inc(FLockCount^); |
573 |
tony |
322 |
FSharedMemory.sem_op(FMutex,1,0); //Release Mutex |
574 |
tony |
209 |
end; |
575 |
|
|
|
576 |
|
|
procedure TMultilockGate.Unlock; |
577 |
|
|
begin |
578 |
tony |
322 |
FSharedMemory.sem_op(FMutex,-1,0); //Acquire Mutex |
579 |
tony |
209 |
Dec(FLockCount^); |
580 |
|
|
if FLockCount^ <= 0 then |
581 |
|
|
begin |
582 |
tony |
319 |
{$IFDEF DEBUG}writeln(ClassName,': UnLocking ',FSemaphore);{$ENDIF} |
583 |
tony |
322 |
FSharedMemory.SemInit(FSemaphore,1); |
584 |
tony |
209 |
FLockCount^ := 0 |
585 |
|
|
end; |
586 |
tony |
322 |
FSharedMemory.sem_op(FMutex,1,0); //Release Mutex |
587 |
tony |
209 |
end; |
588 |
|
|
|
589 |
|
|
procedure TMultilockGate.PassthroughGate; |
590 |
|
|
begin |
591 |
|
|
if FLockCount^ = 0 then |
592 |
|
|
Exit; |
593 |
tony |
319 |
{$IFDEF DEBUG}writeln(ClassName,': Waiting on ',FSemaphore);{$ENDIF} |
594 |
tony |
322 |
while FSharedMemory.sem_timedop(FSemaphore,-1,cDefaultTimeout) < 0 do |
595 |
tony |
209 |
{looks like we lost a reader} |
596 |
|
|
begin |
597 |
tony |
319 |
{$IFDEF DEBUG}writeln(ClassName,': reader lost timeout');{$ENDIF} |
598 |
tony |
209 |
if FLockCount^ > 0 then |
599 |
|
|
begin |
600 |
|
|
UnLock; |
601 |
|
|
if assigned(FOnGateTimeout) then |
602 |
|
|
OnGateTimeout(self) |
603 |
|
|
end |
604 |
|
|
end; |
605 |
tony |
322 |
FSharedMemory.sem_op(FSemaphore,1); |
606 |
tony |
319 |
{$IFDEF DEBUG}writeln(ClassName,': Wait done on ',FSemaphore);{$ENDIF} |
607 |
tony |
209 |
end; |
608 |
|
|
|
609 |
|
|
|
610 |
tony |
319 |
{ TIPCInterface } |
611 |
tony |
209 |
|
612 |
tony |
319 |
function TIPCInterface.GetMonitorCount: integer; |
613 |
tony |
209 |
begin |
614 |
tony |
322 |
Result := FSharedMemory.GetSemValue(cMonitorCounter) |
615 |
tony |
209 |
end; |
616 |
|
|
|
617 |
tony |
319 |
function TIPCInterface.GetMaxBufferSize: integer; |
618 |
|
|
begin |
619 |
|
|
Result := FMaxBufferSize; |
620 |
|
|
end; |
621 |
|
|
|
622 |
|
|
constructor TIPCInterface.Create; |
623 |
|
|
begin |
624 |
tony |
209 |
inherited Create; |
625 |
|
|
FSharedMemory := TSharedMemory.Create(cMonitorHookSize); |
626 |
|
|
|
627 |
tony |
322 |
FWriteLock := TMutex.Create(cMutexSemaphore,FSharedMemory); |
628 |
tony |
209 |
|
629 |
tony |
319 |
FDataAvailableEvent := TSingleLockGate.Create(cDataAvailableEventSemaphore,FSharedMemory); |
630 |
|
|
FWriterBusyEvent := TSingleLockGate.Create(cWriterBusyEventSemaphore,FSharedMemory); |
631 |
|
|
FReadReadyEvent := TMultiLockGate.Create(cReadReadyEventSemaphore,FSharedMemory); |
632 |
|
|
FReadFinishedEvent := TMultiLockGate.Create(cReadFinishedEventSemaphore,FSharedMemory); |
633 |
tony |
209 |
|
634 |
tony |
320 |
if FSharedMemory.IsInitialiser then |
635 |
tony |
322 |
FSharedMemory.SemInit(cMonitorCounter,0); |
636 |
tony |
209 |
FTraceDataType := PInteger(FSharedMemory.Allocate(sizeof(Integer))); |
637 |
|
|
FTimeStamp := PDateTime(FSharedMemory.Allocate(sizeof(TDateTime))); |
638 |
|
|
FBufferSize := PInteger(FSharedMemory.Allocate(sizeof(Integer))); |
639 |
tony |
319 |
FMsgNumber := PInteger(FSharedMemory.Allocate(sizeof(Integer))); |
640 |
tony |
209 |
FBuffer := FSharedMemory.Allocate(0); //All remaining |
641 |
|
|
FMaxBufferSize := FSharedMemory.LastAllocationSize; |
642 |
|
|
|
643 |
tony |
320 |
if FSharedMemory.IsInitialiser then |
644 |
tony |
209 |
begin |
645 |
|
|
FBufferSize^ := 0; |
646 |
tony |
319 |
FDataAvailableEvent.Lock; |
647 |
|
|
FMsgNumber^ := 0; |
648 |
tony |
209 |
end; |
649 |
|
|
end; |
650 |
|
|
|
651 |
tony |
319 |
procedure TIPCInterface.IncMonitorCount; |
652 |
tony |
209 |
begin |
653 |
tony |
322 |
FSharedMemory.sem_op(cMonitorCounter,1); |
654 |
tony |
209 |
end; |
655 |
|
|
|
656 |
tony |
319 |
procedure TIPCInterface.DecMonitorCount; |
657 |
tony |
209 |
begin |
658 |
tony |
322 |
FSharedMemory.sem_op(cMonitorCounter,-1,IPC_NOWAIT); |
659 |
tony |
209 |
end; |
660 |
|
|
|
661 |
tony |
319 |
procedure TIPCInterface.SendTrace(TraceObject: TTraceObject); |
662 |
tony |
209 |
begin |
663 |
|
|
FTraceDataType^ := Integer(TraceObject.FDataType); |
664 |
|
|
FTimeStamp^ := TraceObject.FTimeStamp; |
665 |
tony |
319 |
if Length(TraceObject.FMsg) > MaxBufferSize then |
666 |
|
|
FBufferSize^ := MaxBufferSize |
667 |
|
|
else |
668 |
|
|
FBufferSize^ := Length(TraceObject.FMsg); |
669 |
|
|
FMsgNumber^ := TraceObject.FMsgNumber; |
670 |
tony |
209 |
Move(TraceObject.FMsg[1], FBuffer^, FBufferSize^); |
671 |
|
|
end; |
672 |
|
|
|
673 |
tony |
319 |
procedure TIPCInterface.ReceiveTrace(TraceObject: TTraceObject); |
674 |
tony |
209 |
begin |
675 |
tony |
319 |
SetString(TraceObject.FMsg, PAnsiChar(FBuffer), FBufferSize^); |
676 |
tony |
209 |
TraceObject.FDataType := TTraceFlag(FTraceDataType^); |
677 |
|
|
TraceObject.FTimeStamp := TDateTime(FTimeStamp^); |
678 |
tony |
319 |
TraceObject.FMsgNumber := FMsgNumber^; |
679 |
tony |
209 |
end; |
680 |
|
|
|
681 |
tony |
319 |
function TIPCInterface.GetDataAvailableEvent: ISingleLockGate; |
682 |
|
|
begin |
683 |
|
|
Result := FDataAvailableEvent; |
684 |
|
|
end; |
685 |
tony |
209 |
|
686 |
tony |
319 |
function TIPCInterface.GetWriterBusyEvent: ISingleLockGate; |
687 |
|
|
begin |
688 |
|
|
Result := FWriterBusyEvent; |
689 |
|
|
end; |
690 |
tony |
209 |
|
691 |
tony |
319 |
function TIPCInterface.GetReadReadyEvent: IMultiLockGate; |
692 |
|
|
begin |
693 |
|
|
Result := FReadReadyEvent; |
694 |
|
|
end; |
695 |
|
|
|
696 |
|
|
function TIPCInterface.GetReadFinishedEvent: IMultiLockGate; |
697 |
|
|
begin |
698 |
|
|
Result := FReadFinishedEvent; |
699 |
|
|
end; |
700 |
|
|
|
701 |
|
|
function TIPCInterface.GetWriteLock: IMutex; |
702 |
|
|
begin |
703 |
|
|
Result := FWriteLock; |
704 |
|
|
end; |
705 |
|
|
|
706 |
|
|
|
707 |
|
|
|