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/* define macros for having usleep */
#define _BSD_SOURCE
#define _DEFAULT_SOURCE
#include "redismodule.h"
#include <string.h>
#include <assert.h>
#include <unistd.h>
#define UNUSED(V) ((void) V)
int child_pid = -1;
int exitted_with_code = -1;
void done_handler(int exitcode, int bysignal, void *user_data) {
child_pid = -1;
exitted_with_code = exitcode;
assert(user_data==(void*)0xdeadbeef);
UNUSED(bysignal);
}
int fork_create(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
{
long long code_to_exit_with;
long long usleep_us;
if (argc != 3) {
RedisModule_WrongArity(ctx);
return REDISMODULE_OK;
}
if(!RMAPI_FUNC_SUPPORTED(RedisModule_Fork)){
RedisModule_ReplyWithError(ctx, "Fork api is not supported in the current redis version");
return REDISMODULE_OK;
}
RedisModule_StringToLongLong(argv[1], &code_to_exit_with);
RedisModule_StringToLongLong(argv[2], &usleep_us);
exitted_with_code = -1;
int fork_child_pid = RedisModule_Fork(done_handler, (void*)0xdeadbeef);
if (fork_child_pid < 0) {
RedisModule_ReplyWithError(ctx, "Fork failed");
return REDISMODULE_OK;
} else if (fork_child_pid > 0) {
/* parent */
child_pid = fork_child_pid;
RedisModule_ReplyWithLongLong(ctx, child_pid);
return REDISMODULE_OK;
}
/* child */
RedisModule_Log(ctx, "notice", "fork child started");
usleep(usleep_us);
RedisModule_Log(ctx, "notice", "fork child exiting");
RedisModule_ExitFromChild(code_to_exit_with);
/* unreachable */
return 0;
}
int fork_exitcode(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
{
UNUSED(argv);
UNUSED(argc);
RedisModule_ReplyWithLongLong(ctx, exitted_with_code);
return REDISMODULE_OK;
}
int fork_kill(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
{
UNUSED(argv);
UNUSED(argc);
if (RedisModule_KillForkChild(child_pid) != REDISMODULE_OK)
RedisModule_ReplyWithError(ctx, "KillForkChild failed");
else
RedisModule_ReplyWithLongLong(ctx, 1);
child_pid = -1;
return REDISMODULE_OK;
}
int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
UNUSED(argv);
UNUSED(argc);
if (RedisModule_Init(ctx,"fork",1,REDISMODULE_APIVER_1)== REDISMODULE_ERR)
return REDISMODULE_ERR;
if (RedisModule_CreateCommand(ctx,"fork.create", fork_create,"",0,0,0) == REDISMODULE_ERR)
return REDISMODULE_ERR;
if (RedisModule_CreateCommand(ctx,"fork.exitcode", fork_exitcode,"",0,0,0) == REDISMODULE_ERR)
return REDISMODULE_ERR;
if (RedisModule_CreateCommand(ctx,"fork.kill", fork_kill,"",0,0,0) == REDISMODULE_ERR)
return REDISMODULE_ERR;
return REDISMODULE_OK;
}
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