Bug Summary

File:pr/Linux4.19_x86_64_gcc_glibc_PTH_64_DBG.OBJ/pr/tests/../../../pr/tests/lockfile.c
Warning:line 130, column 5
Value stored to 'status' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name lockfile.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/var/lib/jenkins/workspace/nss-scan-build/nspr/Linux4.19_x86_64_gcc_glibc_PTH_64_DBG.OBJ/pr/tests -fcoverage-compilation-dir=/var/lib/jenkins/workspace/nss-scan-build/nspr/Linux4.19_x86_64_gcc_glibc_PTH_64_DBG.OBJ/pr/tests -resource-dir /usr/lib/llvm-18/lib/clang/18 -U NDEBUG -D DEBUG_jenkins -D PACKAGE_NAME="" -D PACKAGE_TARNAME="" -D PACKAGE_VERSION="" -D PACKAGE_STRING="" -D PACKAGE_BUGREPORT="" -D PACKAGE_URL="" -D DEBUG=1 -D HAVE_VISIBILITY_HIDDEN_ATTRIBUTE=1 -D HAVE_VISIBILITY_PRAGMA=1 -D XP_UNIX=1 -D _GNU_SOURCE=1 -D HAVE_FCNTL_FILE_LOCKING=1 -D HAVE_POINTER_LOCALTIME_R=1 -D LINUX=1 -D HAVE_DLADDR=1 -D HAVE_GETTID=1 -D HAVE_LCHOWN=1 -D HAVE_SETPRIORITY=1 -D HAVE_STRERROR=1 -D HAVE_SYSCALL=1 -D HAVE_SECURE_GETENV=1 -D _REENTRANT=1 -D FORCE_PR_LOG -D _PR_PTHREADS -U HAVE_CVAR_BUILT_ON_SEM -I /var/lib/jenkins/workspace/nss-scan-build/nss/../dist/Linux4.19_x86_64_gcc_glibc_PTH_64_DBG.OBJ/include -I ../../../pr/include -I ../../../pr/include/private -internal-isystem /usr/lib/llvm-18/lib/clang/18/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -ferror-limit 19 -fvisibility=hidden -fgnuc-version=4.2.1 -fno-inline -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2024-05-18-082241-28900-1 -x c ../../../pr/tests/lockfile.c
1/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6/*
7** File: lockfile.c
8** Purpose: test basic locking functions
9** Just because this times stuff, don't think its a perforamnce
10** test!!!
11**
12** Modification History:
13** 19-May-97 AGarcia- Converted the test to accomodate the debug_mode flag.
14** The debug mode will print all of the printfs associated with this test.
15** The regress mode will be the default mode. Since the regress tool limits
16** the output to a one line status:PASS or FAIL,all of the printf statements
17** have been handled with an if (debug_mode) statement.
18** 04-June-97 AGarcia removed the Test_Result function. Regress tool has been updated to
19** recognize the return code from tha main program.
20***********************************************************************/
21/***********************************************************************
22** Includes
23***********************************************************************/
24/* Used to get the command line option */
25#include "plgetopt.h"
26
27#include "prcmon.h"
28#include "prerror.h"
29#include "prinit.h"
30#include "prinrval.h"
31#include "prlock.h"
32#include "prlog.h"
33#include "prmon.h"
34#include "prthread.h"
35#include "prtypes.h"
36
37#include "private/pprio.h"
38
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42
43PRIntn failed_already=0;
44PRIntn debug_mode;
45
46const static PRIntervalTime contention_interval = 50;
47
48typedef struct LockContentious_s {
49 PRLock *ml;
50 PRInt32 loops;
51 PRIntervalTime overhead;
52 PRIntervalTime interval;
53} LockContentious_t;
54
55#define LOCKFILE"prlock.fil" "prlock.fil"
56
57
58
59static PRIntervalTime NonContentiousLock(PRInt32 loops)
60{
61 PRFileDesc *_lockfile;
62 while (loops-- > 0)
63 {
64 _lockfile = PR_Open(LOCKFILE"prlock.fil", PR_CREATE_FILE0x08|PR_RDWR0x04, 0666);
65 if (!_lockfile) {
66 if (debug_mode) printf(
67 "could not create lockfile: %d [%d]\n",
68 PR_GetError(), PR_GetOSError());
69 return PR_INTERVAL_NO_TIMEOUT0xffffffffUL;
70 }
71 PR_LockFile(_lockfile);
72 PR_UnlockFile(_lockfile);
73 PR_Close(_lockfile);
74 }
75 return 0;
76} /* NonContentiousLock */
77
78static void PR_CALLBACK LockContender(void *arg)
79{
80 LockContentious_t *contention = (LockContentious_t*)arg;
81 PRFileDesc *_lockfile;
82 while (contention->loops-- > 0)
83 {
84 _lockfile = PR_Open(LOCKFILE"prlock.fil", PR_CREATE_FILE0x08|PR_RDWR0x04, 0666);
85 if (!_lockfile) {
86 if (debug_mode) printf(
87 "could not create lockfile: %d [%d]\n",
88 PR_GetError(), PR_GetOSError());
89 break;
90 }
91 PR_LockFile(_lockfile);
92 PR_Sleep(contention->interval);
93 PR_UnlockFile(_lockfile);
94 PR_Close(_lockfile);
95 }
96
97} /* LockContender */
98
99/*
100** Win16 requires things passed to Threads not be on the stack
101*/
102static LockContentious_t contention;
103
104static PRIntervalTime ContentiousLock(PRInt32 loops)
105{
106 PRStatus status;
107 PRThread *thread = NULL((void*)0);
108 PRIntervalTime overhead, timein = PR_IntervalNow();
109
110 contention.loops = loops;
111 contention.overhead = 0;
112 contention.ml = PR_NewLock();
113 contention.interval = contention_interval;
114 thread = PR_CreateThread(
115 PR_USER_THREAD, LockContender, &contention,
116 PR_PRIORITY_LOW, PR_LOCAL_THREAD, PR_JOINABLE_THREAD, 0);
117 PR_ASSERT(thread != NULL)((thread != ((void*)0))?((void)0):PR_Assert("thread != NULL",
"../../../pr/tests/lockfile.c",117));
118
119 overhead = PR_IntervalNow() - timein;
120
121 while (contention.loops > 0)
122 {
123 PR_Lock(contention.ml);
124 contention.overhead += contention.interval;
125 PR_Sleep(contention.interval);
126 PR_Unlock(contention.ml);
127 }
128
129 timein = PR_IntervalNow();
130 status = PR_JoinThread(thread);
Value stored to 'status' is never read
131 PR_DestroyLock(contention.ml);
132 overhead += (PR_IntervalNow() - timein);
133 return overhead + contention.overhead;
134} /* ContentiousLock */
135
136static PRIntervalTime Test(
137 const char* msg, PRIntervalTime (*test)(PRInt32 loops),
138 PRInt32 loops, PRIntervalTime overhead)
139{
140 /*
141 * overhead - overhead not measured by the test.
142 * duration - wall clock time it took to perform test.
143 * predicted - extra time test says should not be counted
144 *
145 * Time accountable to the test is duration - overhead - predicted
146 * All times are Intervals and accumulated for all iterations.
147 */
148 PRFloat64 elapsed;
149 PRIntervalTime accountable, duration;
150 PRUintn spaces = strlen(msg);
151 PRIntervalTime timeout, timein = PR_IntervalNow();
152 PRIntervalTime predicted = test(loops);
153 timeout = PR_IntervalNow();
154 duration = timeout - timein;
155 accountable = duration - predicted;
156 accountable -= overhead;
157 elapsed = (PRFloat64)PR_IntervalToMicroseconds(accountable);
158 if (debug_mode) {
159 printf("%s:", msg);
160 }
161 while (spaces++ < 50) if (debug_mode) {
162 printf(" ");
163 }
164 if ((PRInt32)accountable < 0) {
165 if (debug_mode) {
166 printf("*****.** usecs/iteration\n");
167 }
168 } else {
169 if (debug_mode) {
170 printf("%8.2f usecs/iteration\n", elapsed/loops);
171 }
172 }
173 return duration;
174} /* Test */
175
176int main(int argc, char **argv)
177{
178 PRIntervalTime duration;
179 PRUint32 cpu, cpus = 2;
180 PRInt32 loops = 100;
181
182
183 /* The command line argument: -d is used to determine if the test is being run
184 in debug mode. The regress tool requires only one line output:PASS or FAIL.
185 All of the printfs associated with this test has been handled with a if (debug_mode)
186 test.
187 Usage: test_name -d
188 */
189 PLOptStatus os;
190 PLOptState *opt = PL_CreateOptState(argc, argv, "d:");
191 while (PL_OPT_EOL != (os = PL_GetNextOpt(opt)))
192 {
193 if (PL_OPT_BAD == os) {
194 continue;
195 }
196 switch (opt->option)
197 {
198 case 'd': /* debug mode */
199 debug_mode = 1;
200 break;
201 default:
202 break;
203 }
204 }
205 PL_DestroyOptState(opt);
206
207 /* main test */
208
209 PR_Init(PR_USER_THREAD, PR_PRIORITY_NORMAL, 0);
210 PR_STDIO_INIT();
211
212 if (argc > 1) {
213 loops = atoi(argv[1]);
214 }
215 if (loops == 0) {
216 loops = 100;
217 }
218 if (debug_mode) {
219 printf("Lock: Using %d loops\n", loops);
220 }
221
222 cpus = (argc < 3) ? 2 : atoi(argv[2]);
223 if (cpus == 0) {
224 cpus = 2;
225 }
226 if (debug_mode) {
227 printf("Lock: Using %d cpu(s)\n", cpus);
228 }
229
230
231 for (cpu = 1; cpu <= cpus; ++cpu)
232 {
233 if (debug_mode) {
234 printf("\nLockFile: Using %d CPU(s)\n", cpu);
235 }
236 PR_SetConcurrency(cpu);
237
238 duration = Test("LockFile non-contentious locking/unlocking", NonContentiousLock, loops, 0);
239 (void)Test("LockFile contentious locking/unlocking", ContentiousLock, loops, duration);
240 }
241
242 PR_Delete(LOCKFILE"prlock.fil"); /* try to get rid of evidence */
243
244 if (debug_mode) {
245 printf("%s: test %s\n", "Lock(mutex) test", ((failed_already) ? "failed" : "passed"));
246 }
247 if(failed_already) {
248 return 1;
249 }
250 else {
251 return 0;
252 }
253} /* main */
254
255/* testlock.c */