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/*
Minetest
Copyright (C) 2013 sapier, < sapier AT gmx DOT net >
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "jthread/jsemaphore.h"
JSemaphore::JSemaphore() {
m_hSemaphore = CreateSemaphore(
0,
0,
MAX_SEMAPHORE_COUNT,
0);
}
JSemaphore::~JSemaphore() {
CloseHandle(m_hSemaphore);
}
JSemaphore::JSemaphore(int initval) {
m_hSemaphore = CreateSemaphore(
0,
initval,
MAX_SEMAPHORE_COUNT,
0);
}
void JSemaphore::Post() {
ReleaseSemaphore(
m_hSemaphore,
1,
0);
}
void JSemaphore::Wait() {
WaitForSingleObject(
m_hSemaphore,
INFINITE);
}
bool JSemaphore::Wait(unsigned int time_ms) {
unsigned int retval = WaitForSingleObject(
m_hSemaphore,
time_ms);
if (retval == WAIT_OBJECT_0)
{
return true;
}
else {
assert(retval == WAIT_TIMEOUT);
return false;
}
}
typedef LONG (NTAPI *_NtQuerySemaphore)(
HANDLE SemaphoreHandle,
DWORD SemaphoreInformationClass,
PVOID SemaphoreInformation,
ULONG SemaphoreInformationLength,
PULONG ReturnLength OPTIONAL
);
typedef struct _SEMAPHORE_BASIC_INFORMATION {
ULONG CurrentCount;
ULONG MaximumCount;
} SEMAPHORE_BASIC_INFORMATION;
/* Note: this will only work as long as jthread is directly linked to application */
/* it's gonna fail if someone tries to build jthread as dll */
static _NtQuerySemaphore NtQuerySemaphore =
(_NtQuerySemaphore)
GetProcAddress
(GetModuleHandle ("ntdll.dll"), "NtQuerySemaphore");
int JSemaphore::GetValue() {
SEMAPHORE_BASIC_INFORMATION BasicInfo;
LONG retval;
assert(NtQuerySemaphore);
retval = NtQuerySemaphore (m_hSemaphore, 0,
&BasicInfo, sizeof (SEMAPHORE_BASIC_INFORMATION), NULL);
if (retval == ERROR_SUCCESS)
return BasicInfo.CurrentCount;
assert("unable to read semaphore count" == 0);
return 0;
}
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